sB 32} ·P:tbt PROCEEDINGS OF ~ /'-- , ' ( / (_ t" " ....... U ,1 r t 2 1 úL THIRD MULTJDISCIPLINARY WORKSHOP ON BEAN RESEARCH IN EASTERN AFRICA <-, ~ '" ~ " ' ~ " ~ Ed1ted by J 8 Sm1thson THIKA, KENY A 19-22 Apnl 1993 CIA T Afncan W orkshop Senes No 28 Workshop orgamzers R' A Kukby CIAT S T Kanyag1a, KARI Correct CJtatJon J B Smlthson (Ed) Proceedmgs of Tiurd Mulhd!sclphnary Workshop on Bean Research m Eastem Afnca, Th1ka, Kenya, 19 22 Apnl 1993 Network on Bean Researth m Afnca Workshop Senes No 28 CIAT Kampala, Uganda PREFACE Tlus volume ts the proceedmgs of the thtrd workshop lo report revtew and plan rcscarch on bcans m eastem Afnca camed out by nattonal programmes that are members of the Eastem Afnca Bean Researeh Network (EABRN) estabhshed m assoctalton wtth the CIA T Regmnal Programme on Beans m Eastem Afnca The evolutton of the EABRN ts reflected m the changes that have occurred m the nature and stze of the workshops The first (held m Mukono m Uganda m June 1986) revtewed the pnnctpal constramts lobean produclton m eastem Afnca and the research accomphshed lo solve these problems and attempted to tdenttfy the mam future researeh needs of the regton Thtrty five parttctpants (more than half of them from Uganda whtch supports probably the oldest estabhshcd bean researeh programme m Afnca) from four countnes m the regmn presented 24 papers In the second workshop m the senes (m Natrobt m Mareh 1990) emphasts was on presentalton of thc research that had been camed out durmg the mtervenmg four years and notably on revtewmg work on the sub projecls recetvmg funds from the regtonal programme A total of 53 parttctpants from seven countnes m the regton presented 47 papers etght of whtch concemed regtonal collaborattve sub projects In the curren! workshop three years on 62 parttctpants (see Parttctpants Ltst on pages 365 367) presented 44 researeh papers They agam mclude progress reports on the much mcreased number of regtonal sub projects supported by the EABRN dunng the past three years Other papers were selected compettbvely on the basts of abstracts otherwtse the contnbutmns would have been too many lo dtscuss m the lime avatlable Dtscusstons of papers were held al the end of each sesston and finally problem focused workmg groups brought together mulb-dtsctphnary groups of more expenenced researehers and development staff lo tdenttfy pnonttes for future researeh An essenbal feature of these workshops has been the parttctpabon of nattonal staff from the Great Lakes and SADC Regmnal ProJecls and personnel of assoctated mtemattonal organwtltons because ti ts obvtous that researeh m one regton wtll be relevan! to ecologtcally stmtlar envtronments m all three regtons Exchange of mformatton wtll help to reduce duphcabon and enable more effictent use of researeh resoun:es factltlated by parbctpabon of EABRN staff also m rcgmnal and spectaltst workshops m the other regtons Dunng the past mne years nearly 30 workshops regtonal and spectaltst have been orgamzed m the three Afncan regtonal proJects and thetr proceedmgs pubhshed (see Lts' of Pubhcattons pages 368 371 of thts volume) In addtlton there are the Occasmnal Pubhcattons Senes whtch mcludes mtemal reports on toptcs of general mterest and the Repnnt Senes whtch compnses repnnts from sctenltfic JOumals of papers wnUen by network staff Together these senes represen! a constderable body of mformatton on the constramts to bean productton m Afnca and the researeh conducted to seek pracbcal soluttons to them Fundmg for the researeh descnbed here ts provtded by the Umted States Agency for lntemattonal Development the Canadtan lntematmnal Development Agency (CIDA) the Swtss Agency for Development and Cooperatton and governments of all concemed natmnal programmes lnformatton on the networks and captes of all pubhcattons m ay be obtatned from Pan Afncan Coordmator CIAT Kawanda Agncultural Researeh lnstttute PO Box 624 7 Kampala Uganda Regmnal Coordmator SADC/CIA T Regtonal Programme on Beans for Southem Afnca Sehan Agncultural Researeh Centre PO Box 2704 Arusha Tanzanta ACKNOWLEDGEMENTS Acknowledgements are due to Dr Cyrus Ndmtu the Dtrcctor of thc Kenya Agncultural Rcscarch lnstttute (KARl) for authonsmg the holdmg ofthe workshop m Kcnya Mrs Mary Wabulc Asststant Dtrector (Horttculturc) KARl for gractously opemng the workshop Mr DO Mtchteka Dtrcctor Nattonal Horttcultural Research Stalton Thtka and Mr S T Kanyagta Nattonal Bean Programmc Coordmator and staff for hosltng the workshop organmng a ficld vtstt and asststmg wtth local arrangements Grateful thanks are due to Mrs Ruth Mahona and Ms Eva Ngalo for logtsltcal asstslance to parttctpants and for typmg thc proceedmgs Thts repnnt was made posstble through support provtded by the Officc of Agnculturc Burcau for Research and Development Untted States Agency for lntcmaltonal Development (under Grant No LAG-4111 G 00 2025 O) by the Canadtan lntcmaltonal Devclopmcnt Agency and by thc Swtss Agency for Develpment and Cooperalton The optmons exprcssed herem are those of the authors and do not necessanlly reflect the vtews of these contnbutmg donor organt7.altons 11 CONTENTS SESSION 1 OPENING SESSION WELCOME ADDRESS Teshome G1rma EVOLUTION OF THE EASTERN AFRICA BEAN RESEARCH NETWORK AND OBJECTIVES OF THE WORKSHOP R A K1rkby SESSION 11 GENETIC IMPROVEMENT BEAN BREEDING STRATEGY IN ETHIOPIA Teshome G1rma and DereJe Negatu SCREENING BEANS (Phaseo/us vulgans L ) FOR ADAPTA TION TO THE COOL SEMI ARID HIGHLANDS OF EASTERN AFRICA WK Rono SNAP BEAN BREEDING IN KENY A J K Kamau S G S M01gru and S M Wachmn HETEROSIS AND COMBINING ABILITY FOR YIELD AND OTHER QUANTITATIVE CHARACTERS IN HARICOT BEAN Phaseolus vulgam L Meiaku Ayeie HARD TO COOK DEFECTS IN BEANS (Phaseoluv vulgam) INFLUENCE OF LOCATIONS AND VARIETIES Senay1t Y etneberk. REGIONAL SUPPORT FOR VARIETY DEVELOPMENT BREEDING FOR RESISTANCE TO NECROSIS INDUCING STRAINS OF BCMV HE Gndiey PROCEDURES FOR HANDLING BEAN GERMPLASM WITH EMPHASIS ON SILICA GEL SEED DRYING M F1schier DISCUSSION SESSION 11 SESSION 111 BREEDINGli'OR DISEASE AND INSECT RESISTANCE INVESTIGATIONS OF COMMON MOSAIC VIRUS IN EASTERN AFRICA T Sengooba, D G Walkey D J Allen and A Fem• Lana. PROGRESS OF STUDIES OF PHOMA BLIGHT OF BEANS IN EASTERN AFRICA B S MaJe Kay1wa 111 Page 2 8 I3 20 27 34 43 50 59 6I 68 SCREENING DRY BEAN (Phaseo/us vulgam) GENOTYPES FOR RESISTANCE TO Macrophomma phaseolma THE CHARCOAL ROT PATHOGEN Page W A Songa 72 MANAGEMENT OF BEAN ANTHRACNOSE IN ETHIOPIA Tesfaye Beshrr PERFORMANCE OF ADVANCED GENERATION BEAN LINES SELECTED FOR MULTIPLE DISEASE RESISTANCE P M Ktmam A W Mwangombe and J W KtmenJu DISCUSSION SESSION 111 SESSION IV INTEGRATED MANAGEMENT OF DISEASES AND PESTS BEAN RUST IN EASTERN AFRICA RESEARCH RESULT HIGHLIGHTS 1990 1992 Habtu Assefa STUDY OF BEAN RUST IN MADAGASCAR DISEASE SURVEY AND VARIETY RESISTANCE TRIAL A Rabakoanhanta and G Rakotomalala COLLABORATIVE RESEARCH PROJECT ON COMMON BACTERIAL BLIGHT OF BEANS A F Opto and M S Musaana EFFECTS OF CULTURAL AND VARIETAL COMPONENTS IN INTEGRATED MANAGEMENT OF ROOT ROTS OF BEANS IN RWANDA R A Buruchara U C Schetdegger and L S Sperhng STUDIES OF THE CONTROL OF THE BEAN BRUCHIDS Acanthosceildes obtectus (Say) AND labro/es subfasClalus (Boheman) BRUCHIDAE COLEOPTERA IN EASTERN AFRICA M Nahdy Sthm SURVEY OF THE PESTS AND CURRENT CONTROL MEASURES OF MAJOR PESTS OF FRENCH BEANS J H Ndentu and J J Anyango DISEASE AND PEST CONTROL BY SMALL SCALE FRENCH BEAN FARMERS IN KENYA Merey W W BnJtru. HOST PLANT RESISTANCE AGAINST BEAN STEM MAGGOTS A PROGRESS REPORT Tsedeke Abate Amanuel Grrma and Gashawbeza Ayalew IV 78 85 93 98 103 108 113 118 124 133 140 TOWARO AN INTEGRATEO STRATEGY FOR MANAGEMENT OF SEAN STEM MAGGOTS (OphwmJIIa spp) Page J K Ampofo 149 DISCUSSION SESSION IV 156 SESSION V GENETIC TOLERANCE OF SOIL CONSTRAINTS EVALUATION OF SEAN GENOTYPES ANO RHIZOBIA STRAINS FOR NITROGEN FIXATION POTENTIAL ON TWO SOIL TYPES IN ETHIOPIA M11Iku Hade ENHANCING COMMON SEAN YIELOS THROUGH BIOLOGICAL NITROGEN FIXATION ANO IMPROVEO N USE EFFICIENCY I SCREENING RHIZOBIAL STRAINS FOR N FIXA TION POTENTIAL Patnck K JJemba SCREENING BEANS FOR MANGANESE TOXICITY TOLERANCE IN UGANOA V1ctor A Ochwoh SCREENING FOOO SEAN (PHASEOLUS VULGAR/S L) GENOTYPES FOR TOLERANCE TO LOW PHOSPHORUS G O Racluer R M Otsyula and N Amb1ts1 DISCUSSION SESSION V SESSION VI INTEGRATED CROP AND SOIL MANAGEMENT MINIMUM TILLAGE IN MAIZE SEAN PROOUCTION SYSTEMS IN KENY A John G N Mutham1a EFFECT OF WATER HARVESTING SYSTEMS ON SEAN MAIZE INTERCROPPING IN ARIO ANO SEMI ARIO LANOS OF KENY A O O M1clueka, A M Ndegwa and G W Mbugua THE EFFECTS OF SELECTEO SOIL AMENOMENTS ON ORY SEAN YIELOS IN MAURITIUS 161 168 177 I88 I92 I96 202 N Govmden B Gowrea and F Ismael 208 THE EFFECTS OF SEASON ON GRAIN YIELOS ANO SOIL NITROGEN CONTRIBUTIONS OF FOUR CUL TIV ARS OF SEAN S (Phaseolus vulgam L) R T Jasdanwala and A G Chege 2 I 5 FARMER PARTICIPATORY RESEARCH IN MATUGGA VILLAGE (UGANOA) AN ALTERNATIVE APPROACH TO TECHNOLOGY OEVELOPMENT ANO TRANSFER ANO RESEARCH IMPLEMENTATION BY FARMERS M A Ugen and P K Jjemba V 227 MANAGEMENT OF ACID SOILS A DIAGNOSTIC SURVEY IN AMBOHIBARY ANO ANTANIFOTSY Pagc B Rabary 233 HARICOT BEAN OOUBLE CROPPING WITH MAIZE WHEA T TEF ANO IRISH POTATO UNOER RAINFEO CONDITIONS IN THE SOUTHERN RIFT VALLEY OF ETHIOPIA Tenaw Workayehu and Waga Mazeng1a HIGHLIGHTS OF AGRONOMIC RESEARCH IN SUPPORT OF THE REGIONAL BEAN NETWORK Charles S Wortm ann DISCUSSION SESSION VI SESSION VII TECHNOLOGY TESTING AND TRANSFER AND SOCIO ECONOMIC ISSUES COMPARATIVE PROFITABILITY OF HARICOT BEAN PROOUCTION IN ETHIOPIA Sen81t Regassa HARICOT BEAN MARKETING IN ETHIOPIA SOME POLICY IMPLICATIONS Alehgne Kefyalew EXPERIENCES IN ON FARM RESEARCH WITH BEAN (Phaseolus vulgans) CULTIVARS Isaac Mulagolt RETAIL MARKET SURVEY OF ORY BEAN CULTIVARS SOLO IN KENYA Susan M W Munene DISSEMINATION STRATEGIES FOR IMPROVEO BEAN CULTIVARS ANO MANAGEMENT PRACTICES IN THE CENTRAL RIFT VALLEY OF ETHIOPIA Aberra Oeressa TECHNOLOGY TRANSFER HARICOT BEAN EXPERIENCE IN THE SOUTHERN ZONE OF ETHIOPIA Getachew Kassaye PROOUCTION ANO DISTRIBUTION OF SNAP BEAN SEEO IN KENY A Merey W W&nJlru ANALYSIS OF BEAN SEEO CHANNELS IN THE GREAT LAKES REGION Lomse Sperhng DISCUSSION SESSION VII VI 239 245 251 256 264 272 283 294 302 308 315 324 SESSION VIII REVIEW OF REGIONAL PRIORITIES RESEARCH FOR IMPROVING BEAN PROOUCTION SYSTEMS IN AFRICA APPLICATION OF INFORMATION ANO AOAPTIVE RESEARCH Charles S Wortm ann SAOCC/CIAT BEAN RESEARCH NETWORK IN SOUTHERN AFRICA C S Mush1 M E T Mm baga and 1 K Kullaya REGIONAL BEAN RESEARCH IN THE GREA T LAKES U C Sche1degger DISCUSSION SESSION VIII WORKING GROUPS ON PRIORITIES FOR SUB PROJECT RESEARCH ANO SUPPORTING ACTIVITIES IN EASTERN AFRICA CLOSING AOORESS PARTICIPANTS LIST PUBLICATIONS OF THE NETWORK ON BEAN RESEARCH IN AFRICA VIl Page 328 334 342 356 357 364 365 368 SESSION L OPENING SESSION WELCOME ADDRESS Tesbome Gmna Cbmrman, Steenng Comm1ttee, Reg10nal Programme on Beans m Eastern Afnca Mrs Mary Wabule Ass•stant Drrector (Horllculture) representiRg the Drrector KARI Dr Cyrus G Ndmtu CIA T Pan Afncan CoordiRator Dr Roger A K1rkby Orgaruzers 0JstiRguished Guests Parllcipants Colleagues It IS a great pleasure to welcome you to Tluka, Kenya for this Multi-disciphnary Workshop on Bean Research IR Eastem Afnca The workshop IS the tlurd of Its kiRd As you m ay remember the first regional workshop was held IR Mukono Uganda IR 1986 concentraiiRg on regiOnal sub project proposals on the diseases and pests considered to be maJor biotic production constramts to common bean IR eastem Afnca The second regional workshop was held IR N811'0bi Kenya IR 1990 when emphasis was slufted to agronomic and economic constraiRts More recently attenllon has centred on bean dissemiRIÚIOn problems The Eastem Afnca Bean Network has also orgaruzed tours workiRg group meetiRgs and workshops IR respective discipiiRes The regional steermg committee approved the hostiRg of this workshop as an appropnate forum to exchange expenences and Ideas among bean researchers of dlfferent chsciphnes Withm and outside the reg10n with a view to enhanciRg the development of tlus Importan! commodity and to benefit small bean farmers who are confronted with numerous productiOn problems Ulllmately the workshop IS expected to produce recommendallons wh1ch wiii signúicantly contnbute to the drrecllon of and pnonbes for future bean research activiiies IR the region We are grateful to the Govemment of Kenya and KARI for allowiRg the Workshop to be held at this venue and to the CIA T regional bean network for fmancial and techrucél support Fmally It IS m.y great pleasun: to request the Director of KARI Dr Cyrus Ndmtu to address Parllcipants and officially open the Workshop Thank you very much 1 ,' 7 nr- EVOLUTION OF THE EASTERN AFRICA BEAN RESEARCH NETWORK AND OBJECTIVES OF THE WORKSHOP ~~ o > RA"Ktrkby CIAT, Dar es Salaam, Tanza01a THE NETWORK The pnnctpal bean produciDg countnes of thts reg10n are Kcnya (Afnca s largest producer) Uganda and Etluopta Stgmficant amounls of beans are also produced ID Madagascar and Sudan and the crop ts unportant to consumers ID Somalta and Mauntms the latter country currenlly makiDg efTorts through research to become self suffictenl Maunllus and Tanzama are JOIDIDg the Network thts year Tanzama wtshes to take advantage of the agroecologtcal stmtlanttes of tls northem producmg arcas wtth adjacenl EABRN countnes whtle conlmumg tls mem berslup of our stsler network ID the SADe regton Maunttus has expenences to ofTer ID cane bean 1Dtercropp1Dg Although Somalta has ceased to be acllve m bean research the other countnes menlloned here logether wtth eiAT make up the memberslup of the Eastem Afnca Bean Research Network (EABRN) The base locatton for much of eiAT s sctenttfic acllvtlles contiDues to be Kawanda m Uganda bul support to the regton ID the fields of entomology pathology and soctal sctence ts drawn from eJA T s team s located m Arusha m T artzanta and Rubo na m R wanda The regtonal coordmator who acls also as eiA T s pan Afncan coordmator ts currently based m Dar es Salaam m Tartzanta We are grateful lo the two donors to EABRN acllvtltes for thetr support the eanadtan lntemallonal Development Agency (eiDA) and the Umted States Agency for lnlemallonal Development (USAID) EABRN'S PLANNING FRAMEWORK ActlVlttes are plarmed by the Network s Steenng eommtttee (SC) Lpst year the Se developed a plarmmg framework for EABRN whtch ts now bemg apphed m selectmg actiVIIles for the annual work plan and budget The Network s goal was expressed as lo tmprove food secunty and avadabthty for small farmers to tmprove farmers mcomes and to mercase protem avwlabthty for low mcome groups m member countnes by bwldmg on prevtous achtevemenls to tmprove bean producllvtty and develop sustwnable teehnology that ts adopled by produecrs Objecbves and strategtes (Table 1) are each addressed by mtended actlVlttes whtch can be found m the se S 1992 Mmutes avwlable from natiOnal coordmators and ID research hbranes By the bme of our last multtdtsctplmary workshop m 1990 the number of sub proJecls had mcreased to mne stx on pest and dtsease problems and three on agronomtc constrwnls However the focus was sllll on genehc soluttons mcludmg drought toleranec and btologtcal mtrogen fixabon For EABRN s curren! financtal year (1992/93) the se approved 26 sub projecls selected from among 19 projecls that had submttted proposals for conlmuatton as well as 20 new proposals Wtth no mercase m funds tlus has meant not only more compeblton bul also leaner and meaner projecls thal should gtve greater value for the funds entrosted lo the Network by our donors Fundmg levels lo sub proJecls acbve for four or five years were reduced and relabvely small sums (aboul US$1 000 each) were approved for a tnal one year penod for severa! new sub proJecls The average fundmg level ts now US$2,340 per armum 2 Table 1 EABRN s plannmg framework objecllves and strateg1cs ObjectJve 1 Strengthen and sustam natJonal research programmes 2 1m pro ve the sustamab1hty of the Network 3 Reduce bmt1c constramts to bean productmn 4 lm pro ve croppmg systems that mclude beans 5 lncrease market potent1al of beans 6 lmprove transfer of technology Strategy lnstJtutmnal•se and refine natlonal research plannmg Ass1st NARS to sustam or mercase resource allocahon to bean rcsearch lncrease effectJveness of nahonal research lncrease the role of NARS m network management Encourage natmnal government and donor financ1al support to NARS and the Network lncrease effectiVe collaboratmn w1thm the Network Extend collaborahon among bean networks Develop h1gh y1eldmg res1stant vanehcs Mamtam and enhance germplasm d1vers1ty on farms and m NARS Dev1se other solut1ons to bmt•c constramts lncrease produchv1ty of croppmg systems m relahvcly h1gh potcnhal arcas Contnbute to sustam croppmg systems produchv1ty m frag1le envuonmcnts Address consumer preferences for beans Reduce post harvest losses lmprove export opportumhes lncrease farmers part1c1patmn m research lmprove nahonal hnks between extensmn serv1ces and research mshtuhons Accelerate technology transfer through 1mproved seed systems Encourage mter and mtra network technology transfer Top1cs have d1vers1fied m lme w1th reg1onal pnonhes The Network s portfoho now mcludes sub projCCts on vanetal tolerance to severa! s01l constramts mtegrated pest management (IPM) m1mmum ullage farmer parllc1patory research on sod management and non formal seed d1ssemmahon channels (fable 2) 3 Table 2 EABRN sub pro¡ect research m 1992/93 Area of research V anety development and d1sease res1stance lntegrated pest and d1sease management Genellc tolerance lo sod constramts Integrated crop and s01l management Soc1al sc•ence 1ssues Total A PAN AFRICAN PERSPECTIVE Number of sub pro¡ects 9 4 6 4 3 26 Percentage of budget 39 21 18 12 10 100 Our s1ster network m the Great Lakes Reg1on (GLR) of Central Afnca known as RESAPAC from 11s French acronym contmues to be of considerable ass1stance lo EABRN Rwanda has been a useful source of vanelles for ne1ghbours that share 1ts envrronment th•s enabled Uganda to make qwck releases al a tune when 11s own nat1onal programme was sllll m a rebwldmg phase More strateg•cally analyses of bean producllon problems and research opportumlles m the GLR charactensed by the lughest average land pressure and per cap1ta consumpt1on of beans m Afnca offer Eastem Afnca some pomters lo our own future To a cons1derable extent what they face today we should be ready lo confront tomorrow and at least some of the of the potenllal technolog•es w1th wh1ch to do tlus are hkely to be sun1lar The mtroduct•on of clunbmg beans to double y1eld potenllal m !hose lughland areas w1th adequate ramfall 1s currently the most notable example of tlus technology borrowmg The five new vanelles of clunbers that proved most successful m Rwanda are currently the sub¡ect of farmer testmg m Uganda There 1s untapped potenllal for GLR nursenes of bush beans to be evaluated m south west Uganda and north west T anzama Bean product1on problems assoc1ated w1th dechrung s01l fert1hty are hkely to become ever more unportant m our reg1on and the SC s planrung framework recogruses the need for more attenllon to crop/sod management research m EABRN SURVEY OF NETWORK MEMBER SCIENTISTS Late m 1992 the 95 bean sc•enllsls m EABRN member countnes who appeared on the Network s madmg hst were sent a quest10nnaue The survey had three purposes The first two were to sohc1t feedback from members on aspecls of the Network that they had found part1cularly useful and those lo wluch more attenllon should be g1ven A tlurd purpose was lo obtam basehne mformat10n on sc•enllsts pubhcat1ons records that could be useful m future evaluat10n of Network performance m sllmulatmg sc•enllfic acluevements PartJapaUoo ID tbe Network Rephes were rece1ved from 45 sc•ent1sls (4 7%) about half of them bemg very acllve m the network through a reg•onal sub pro¡ect oras a member ofthe SC Network act•v•lles menlloned as havmg been parllcularly useful were spread across the curren! range of acllvllles (Table 3) Those most frequently hsted were collaborallve research and sub pro¡ecls trrurung workshops mformat10n and pubhcat1ons 4 Access to gemplasm adv1ce from CIAT sclcnllsts and momtonng tours wcrc also 1mportant lo many sc1enllsts Table 3 Bencfits of EABRN part1c1pallon that havc bcen most valued by natwnal sc1cnllsts Nature of Numbcr of collaborat1on rcspondcnts Access to bean gcrmplasm 9 Research collaborat10n 15 Workshops 16 Momtonng tours 7 lnformatwn/publlcallons 16 Trwmng 18 Techmcal adv1ce 7 Research fundmg 13 Fundmg for equrpment 2 Other 2 None 6 Sorne of the s1x respondents who md1cated no actlvlty from wh1ch thcy felt thcy had dcnvcd s1gruficant benefit no longer work acllvely on beans Howevcr two bean sc1enllsts cla1mcd to havc httle knowledge of the Network m at least one case duc to be1ng locatcd al a stallon 1solated from the nallonal coordmatmg centre Part1c1pants' suggest1ons for future d1recllons Many construcllve suggesllons were madc Several respondcnts wantcd to sce mcreascd attcnllon bcmg g1ven to research on SOC1o-econom1c 1ssues (on farm rcscarch cxtenswn lmks adopt10n stud1es bean ullhsat1on and new research on bean marketmg) and to IPM (mcludmg d1scases) Contmuallon ofpost graduate trwnmg rece1ved w1de support and part1c1pat10n of research ass1stants m reg1onal VISIIS was suggested More adv1ce followup and feedback from CIAT on research and cspec1ally sub projccts would be apprec1ated and more use m1ght be made of local resource persons for these purposes Effic1ency could be enhanced by mcreasmg the number of sub projecls Rather fewer suggesllons were made concemmg techmcal arcas that could recc1ve less emphas1s but these tended lo be too general and w1dely scattered among essent1al d1sc1phnes lo be vcry uscful m pnonty setllng A v1ew was expressed that nallonal coordmatmg centres should start to recc1vc less network support than outlymg stallons PubhcatJons by Network memben The total number of bean related pubhcatwns reported from the start of these sc1enllsts careers was 213 (Table 4) However the average of 4 7 pubhcatwns per sCICDh&t masks a w1de range m md1v1dual performance (O 24 pubhcallons) w1th 66% of respondents reportmg from 1 to 6 pubhcallons each lf we d1scount reports of an annual or natJonal projecl nature and unpubhshed theses (thc cons1stency wtth wluch these "requrred reports were mcluded m respondents returns 1s open lo doubt) the average drops from 4 7 lo 2 7 pubhcallons per sc1ent1Sl 5 Table 4 Bean research pubhcallons by Network member sctenllsts Kmd of pubhcatton Intemallonal JOumalslbook chapters Local or regtonal Jomals mcludmg BlC CIAT/Network workshop proceedmgs Other workshop proceedmgs Postgraduate theses N allonal and other reports Total Number of pubhcallons 7 34 49 32 7 84 213 Almost half (45%) of repondents etther had not yet started the1r research careers or were workmg on another crop pnor to 1986 when the acttvtlles of the Reg10nal Bean Programme began As would be expected those workmg on beans longest have a htgher average of 6 O pubhcattons Interestmgly however by thts measure the rate of output of the group that JOmed bean research after 1986 ts greater than that of the group that was already workmg on beans at that tune (O 84 and O 71 pubhcallons per annum) Almost one quarter of all pubhcallons appeared m proceedmgs of workshops organtsed and pubhshed by EABRN/CIA T Tlus network actlVlty appears to be meetmg a need and to have stunulated pubhcatton EABRN also pays subscnpllon charges to the Bean lmprovement Cooperallve (BIC) for the regton s pnnctpal research stallons wluch m ay have contnbuted to the mcreasmg number of pubhcallons reported for thts outlet The shortage of mtemat10nally pubhshed work ts both a concem and a potenttally cnttcal basehne stallsllc for NARS and for the Network A smgle sctenllst accounted for four of the 7 pubhcatlons m thts categoryl Severa! respondents suggested the Network offer asststance m tlus area and 1 am pleased that the se recently set astde funds to meet sctenttsts page charges for bean papers pubhshed bv mtemattonal JOumals SUSTAINING THE NETWORK CIA T auns to complete the tnstttullonallSallon of thts and other reg10nal bean networks by the mtd 1990s so as to leave sctentúic coordmatJon and fmanctal management wtth mslltuttons of the regtons Tlus objecllve ts one of the reasons for the emphasts bemg gtven to the establishment of effecllve management systems and to the encouragement of local leaderslup In the early years of the Network CIA T staff organtsed and facthtated tts acttvtlles but spent constderably less tune m support through research Wlule much of tlus work ts sttll necessary the more expenenced sub proJect leaders are startJng to take on regtonal roles orgarusmg travelhng workshops and tr8llllll8 and advtsmg weaker nahonal programmes Among those that have recetved peer recogruhon as regtonal sctentúic leaders spectal mentton mtght be made of the Ethtoptan rust sub project leader s travel to Madagascar where he asststed local sctenttsts m the destgn of rust research there 6 Thts aspecl of reg10nal collaborauon 1s of part1cular mleresl lo NARS d1reclors of research A newly msUtuled EABRN D1rec1ors eomm1ttee mel lasl year for the fJrsl tJme and agreed m pnnc1ple thal EABRN should recrwl a coordmator from the reg1on lo lake over network respons1b1h11es from e !A T Exaclly how and when tlus w11l happen has nol been dec1ded yel and the d1rec1ors wdl be followmg the expenence of RESAPAe whose dJreclors are currenlly seekmg appropnale mslltullonal arrangements OBJECTIVES OF TRIS WORKSHOP Thts workshop 1s the thml multJ-dlsc1phnary workshop lo be held by th1s reg1onal Network followmg those of 1987 and 1990 In lme w1th the currenl emphas1s of the se upon sub proJecls as the Network s core the pnnc1pal obJecUves are lo share mformallon on theu lechrucal progress and lo obtam comments from a peer group eonsequenlly the Se expects each sub proJecl leader lo make a presentat10n here 7 t. 7 OCl SESSION D. GENETIC IMPROVEMENT BEAN BREEDING STRATEGY IN ETHIOPIA Tesbome G1rma and DereJe Negatu InstJtute of Agnc:nltural Researc:b, Nazretb, Etb1op1a ABSTRACT Etlnop1a s bean producmg areas can be broadly class1fied mto four agroecolog•cal zones dúfenng m altltude ramfall and soJI The zones also dúfer m producbon systems and constramts and purpose of growmg beans In the past vanetal 1mprovement was centrally coordmated from Nazreth Research Center (NRC) at Melkassa and the spec1fic needs of zonal centers rece1ved httle attentlon A decentrahzed evaluabon system of vanety tnals for germplasm advancement has been estabhshed to 1dent1fy new vanet1es and reqwres an effic1ent zonal programme Conboued release of unproved !mes 1s dependen\ on the establishment of strong crossmg programmes at NRC and zonal centres INTRODUCTION In the past m developmg 1mproved bean vanettes the Nat1onal Bean Program tesled advanced hnes across several envii'Onments diVerse m altttude ramfall sod and produc11on syslem w1th the behef that combmed res1stance lo productton lun•ttng faclors can mercase the adapt1ve range and general performance of culttvars m dúferenl growmg conch11ons (Amare Abebe and Hade Kefene 1989) Several 1mproved vanettes were released bul the strategy 1gnored the specúic needs of each zone and m ay have rejected culttvars appropnate lo specúic productton syslems Because of large dúferences m consumer preference and specúictty of adaptatton lo chmaltc conchttons and croppmg systems a smgle genotype wdl nol be swled lo all bean growmg envii'Onments (Smgh 1991) Thus m a Nattonal Strategy Plannmg Workshop held m 1990 ti was dectded lo adopl a decentraltzed breedmg approach for bean tmprovemenl lo gtve more raptd genettc progress through mcreased local seleclton pressure the use of two seasons per year (m e astero and southern parts of the country) for testtng and populatlon advancemenl and unproved profess10nal mcenttves Thts paper descnbes the classúicatton of bean growmg areas of Ethtopta mio broad agroecologtcal zones and Iughltghts the strategtes followed for vanetal 1mprovemen1 AGROECOLOGICAL ZONATION Ethtopta s bean producmg areas can be broadly classtfied mio four major agroecologtcal zones These are the central eastem southern and westem zones grouped accordmg lo altttude ramfall sod produetton system and geograpluc locatlon (Table 1) Mosl productton constramts are specúic though some such as local vanettes Wlth low potenttal yteld and suscepttbdtty lo pests and dtseases and brucluds m stored beans are common to all zones 8 Table 1 A broad classúicatJon of bean produciDg zones of Etluop1a ---- --- - Zone Alutude RaiDfall So JI Product1on Purpose (masl) system ------ Central 1500 low/ low monocrop 1900 med1um NP siDgle season cash (med1um) labour scarce Eastem 1700 low/ eros10n 1Dtercropp1Dg of food 2200 med1um lowNP sorghum/mwze & (lugh) two seasons cash land scarce Southem 1500 med1um/ low two seasons 1900 lugh N,P land scarce food (med1um) Westem 1000 lughl heavy bush and food 1700 very lugh chmbers mmze (low) 1Diercropp1Dg potenllal labour and draft power constraJDts --- ----- (Source NatJonal Strategy Plannmg Workshop 1990) Central Zoae The maJD bean produciDg area 1s ID the 10ft V alley where fanners grow mostly wlute pea bean types as cash crops Coloured beans are also grown for local consumpllon Beans are grown as monocrops and have a short growmg season so aclueve rap1d growth compete well WJth weeds and av01d c:ompellllon WJth other crops for labour Producllon 1s IDcreasiDg ID the 10ft V alley because current rwnfall pattems swt beans and the area under the crop c:ons1derably IDcreases when the onset of rmns 1s delayed The crop plays an unportant part ID fanners nsk avers1on strategy (Alehgne Kefyalew 1990) Eutera Zoae The Eastem Zone c:ompnses a sec:ond m111or bean produciDg reg10n of Etluop1a Beans are IDtercropped WJth sorghum and mwze (about 95% of all sorghum m the eastem lughlands 1s IDtercropped WJth beans) so shade tolerance and early matunty are 1mportant Beans are grown because of therr low mo1sture reqwrement and therr potenllal as a catch crop ID case of fadure of maJOr cereal crops (Siumehs M/Hawanat el al 1990) The culttvars and mixtures planted for food and cash dlffer but wlute and red beans are preferred Bush types are preferred to clunbmg types to facd1tate leaf stnpp1Dg ID mtercropped sorghum and also for therr earliDess 9 Southem Zone The Southem Zone mcludes S1damo Gamo Goffa and part of Bale There are two raiDy seasons In the flfSt season (March Apnl) fanners grow beans mtercropped w1th m8lze and m the second season (July/August) beans are grown m monocrop Red and wlute beans are preferred and mostly used for home consumpt1on (Getahun Degu and Yesh• Cluche 1989) In some areas double cropp1Dg w1th bean has developed ID response to land scarc1ty Bean stem maggots and weeds are the m8ln bean producllon constr8lnts ID the zone Westem Zone The Westem Zone mcludes the Welega, Illubabor and Gojam admiDlslrallve reg10ns Small fanners grow beariS of vanous growth hab1ts (chmbiDg or bush) gr8ln s1zes (small or large) and gr8ln colours (red whlle black or m1xed) Chmbmg beans are grown along fences and also IDtercropped w1th m8lze on small plots around homesteads bush types are grown as monocrops In the Bako area, beans are rarely mtercropped w1th m8lze as th1s pracllce creates IDConveruence m m8lze weedmg However such problems can be resolved by broadcastmg bean seed al the lime of ox culllvat1on (Gemechu Gedeno 1990) In the Illubabor area most fanners pract1ce IDiercroppmg of beans w1th m8lze rather than sole cropp1Dg (Kassahun Seyoum el al 1989) Most produce 1s for home consumpt1on Small quanllt•es of fresh and dry beans are sold m local markets Gojam espec1ally Pawe settlement area •s a lowland envuonment wluch has a long UD!modal r8lny season of about five months Beans are IDtercropped w1th m8lze ID a hm1ted area by local fanners ID Pawe mostly for home consumpllon In the Westem Zone lack of 1mproved bean culllvars angular leaf spot web bhght and bean stem maggots are the maJor producllon constr8lnls STRATEGIES FOR VARIETAL IMPROVEMENT Beans are grown under vaned env•ronmental cond•llons and producllon systems varyiDg ID growth hab1t seed s1ze and matunty Seed s1ze growth hab1t and matunty are mtnns1c charactensllcs and are largely respons1ble for dlfferences ID y1eld potent1al of bean culllvars Such y1eld dlfferences were observed ID our vanety tnals at severa! research s1tes ID dlfferent zonc:s (Tables 2 and 3) Therefore 11 would be erroneous to thiDk of the same y1eld potenllal for all bean types or the same y1eld target for spectfic bean types across all growmg envuonments (SIDgh 1991) Table 2 Mean seed y1elds (kglha) ID Nallonal Vanety Tnals 1990 Type of tnal Alemaya Awassa Bako Junma Melkassa Wh1te pea bean 1991 I078 1993 3527 2024 Drfferent color 2466 931 2145 3539 1803 Large seed bean 2299 Il87 1224 2779 2294 (Source lAR 1990) The pnncrple of orgaruziDg vanetal 1mprovement on a zonal bas1s was accepted first w1th food bean types to be followed at a later date w1th the wh1te pea bean types for cons•deratwns of cost effect1veness as well as the need for produciDg standard wh1te pea beans for export Th1s suggests the need for a temporary nat10nal approach to wlute pea bean unprovement wluch should be m81nl81ned untll the zonal approach 1s firmly m place w1th food bean types 10 Tab1e 3 Seed y•e1ds (kg/ha) of random1y se1ecled vanehes from Pre Na11onal Vanety Tnals m 1990 Vanety A1emaya Awassa Bako J1mma Me1kassa Mex1can 142 2156 1057 763 1816 2061 PAC 19 1688 1127 1408 2070 2388 PAN 175 1542 1060 1493 2305 2058 G 11233 1180 1582 1992 3066 1963 TY 3396 1 2652 1060 2008 3633 2316 A 182 1748 1235 1544 2891 1676 ICA Lmea 64 2486 1149 1230 3203 2682 Brown Speckled 1794 536 978 2246 1863 Red Wo1wla 981 722 1312 2480 1760 (Source lAR 1990) In consultahon w1th zonal breeders the coordmalor/breeder al the coordmalmg cenler lakes the necessary whallve lo mtroduce new germplasm and 1den11fy genotypes appropnale lo each zone Th1s helps lo av01d duphcahon m mtroduchons and lo follow quaranlme regulal10ns wh1ch reqwre laboratory and field mspechon before d1stnbu11on After quaranlme mspec110n and seed mul11phcahon mtroduced malenals are senl s•mu11aneously lo each of the four rones m the form of Nursery I and each zone •den11fies 11s own entnes for subsequenl stages of evalua11on m zonal tnals as shown m F1gure 1 F1gure 1 Evaluahon scheme for vanelal 1mprovemenl on zonal bas1s CENTRAL EASTERN SOUTHERN WESTERN (Melkassa) (A1emaya) (Awassa! Areka) (Pawe/Bako/ J1mma) Nursery I NI NI NI Zonal Nursery 11 ZNII ZN 11 ZN 11 Zonal V anety Tnal ZVT ZVT ZVT < N ahonal V anety T nals > On Farm Tnal OFT OFT OFT (Source Natlonal Planmng Workshop 1990) The decentrahzed approach does nol 1mply thal zonal centres cannol requesl tnals/hnes from other rones Ü they feel the need for the1r zone A Nahonal Vanety Tnal can be formulaled by the contnbuhon of ehle advanced culhvars from all rones for companson across env1ronmen1s 11 • Advantage should be taken of the comparabve strengths and pnonues of several centres The effictency of each centre m every zone ts enhanced by sharmg dats and tnals holdmg annual meebngs and character unprovement acltvtlles such as pest and dtsease reststance and tolerance to low sod femhty Though mtroducllon of estabhshed lmes from other sources (CIA T and other nallonal programmes) wtll conbnue segregabng populauons from crosses made locally and abroad wdl assume a greater role m vanetal unprovement by strengthenmg the CXIsúng crossmg programme al NRC and estabhshmg new programmes at zonal centres Pawe (Westem Zone) and Awassa (Southem Zone) Research Centers started to formulate theu own zonal vanety tnals from mtroduced matenals from the NRC several years ago The Nallonal Program 1s trymg to strengthen theu capabdtly further and the remammg centers are gradually movmg towards the same goal lt tS hoped that tlus approach wtll promote the better use of genellc matenals and the subsequent release of more culllvars m respecllve zones REFERENCES Alehgne Kefyalew (1990) Farm surveys and on farm research m hancot bean m the mtddle Rtft Valley of Etluopta In Proceedmgs of Workshop on Research on Hancot Bean m Etluopta an Assessment of Status Progress Pnonlles and Strategtes pp 3 7 Amare Abebe and Hade Kefene (1989) Country Report Etluopta In J B Smtthson (Ed) Proceedmgs of Workshop on Bean Vanetal lmprovement m Afnca, Maseru Lesotho 30 January 2 February 1989 CIAT Afncan Workshop Senes No 4 pp 110 120 Getahun Degu and Yeslu Chtche (1989) Evaluatton of farmers preferences for hancot bean vanettes Shebedmo Farmmg Systems Zone Stdamo Regton lnslltute of Agncullliral Research Workmg Paper No 6 17 p Gemechu Gedeno (1990) Hancot bean (Phaseolus vu/gans) agronomtc research al Bako In Proceedmgs of Workshop on Research on Hancot Bean m Etluopta an Assessment of Status Progress Pnonlles and Strategtes pp 68 71 lAR (1990) Progress Report 1990 Na=th Research Center lnstttute of Agncullliral Research Addts Ababa (m preparaban) Kassahun Seyoum Hade Tafesse Tesfa Bogale Tdahun Tadtous and Franze1 S (1989) lntllal Results of an Informal Survey Asendabo Sokoru Cereal Producmg Area of Kefa Reg10n Workmg Paper No 7 lnslltute of Agncullliral Research Addts Ababa Slumehs W/Hawanat Mtúku Hade and Wogayehu Beke1e (1990) Hancot bean producllon system m the Hararghe Htghlands In Proceedmgs of Workshop on Research on Hancot Bean m Etluopta an Assessment of Status Progress Pnonlles and Strategtes 114 pp Smgh S P (1991) Breedmg for seed yteld In A van Schoonhoven and O Voysest (Eds) Common Bean Research for Crop lmprovement CAB lntemabonal Wallmgford Oxon UK pp 3 8 3 443 12 J ., ., ' 1 úC r .~sa SCREENING BEANS (Phaseolus vulgaru L) FOR ADAPTATION TO THE COOL SEMI ARID HIGHLANDS OF EASTERN AFRICA W K Rono Kenya Agncultural Researcb lnst1tute, Nabonal Drylaud Famung Researcb Centre KatumaUJ, Mac:bakos, Kenya ABSTRACT Two bean nursenes were evaluated for adaptahon to cool semi and highland cond1hons at Matanya m Nanyulu (1800 masl) dunng the first (March May) and second (Octoher January) croppmg seasons of 1992 The locatoon receoves 250 350 mm raJnfall per season and has a mean daoly temperature of 18 6"C Mean mmomurn temperatures vary hetween 9 5 and 14 C The ObJecllve os lo odenllfy hean hnes whoch are early m matunty hogh yoeldmg and adapted to cool serm and condthons In the wann medtum clunate (WMC) nursery 40 mtroduchons were screened m the first season and 16 m the second season The maJonty of the mtroducllons flowered and matured later than the local checks MweLI MoJa (Kat mm) GLP 2 and 3334 However AFR 393 AFR 390 AFR 404 AND 737 RWR 159 AFR 398 CAL 103 and DRK 24 were early Matunty penods were generally earher durmg the firsl season Of the 20 mtroducllons m the cool medourn chmate (CMC) nursery only 1 AS 245 flowered and matured early and yoelded consoslently (1201 and 1461 kglha durmg the lwo seasons respecllvely) In both nursenes days lo flower and days lo malunly were negallvely correlaled wtth yoeld wlule days lo maluroty was posollvely correlated woth seed weoghl and pods per plan! woth yoeld INTRODUCTION Dty beans (Phaseolus vulgans L) are known lo have WJde adaplal1on lo chmale Although they are preferably adapted to lugh allttudes ID the trop1cs and lo lemperale zoues they are also cul11vated ID hum1d and sem1 and trop1cs and ID cold chmate reg10ns (CIAT 1991) These reg1ons have h1gh rauúall or the crop 1s culltvated under 1mga1ton The maJonty of farmers ID easlem Afnca culllvale theu crops under rauúed condotJons W1th the rap1d expans1on of populat1on ID hoghland med1um potenltal reg1ons there 1s a tremendous mercase m pressure Tlus has led lo an IDflux of young" or starltng fanners IDto both low and h1gh allltude sem1 and reg10ns of\en bnngiDg bean vanelles thal are unadapted to these cond11J0ns V anous methods have been used or recommended by bean workers for sereenmg for cold lolerance (D1ckson and Boellger 1984 HolluboWJcz, 1986) bul field screeniDg JS probably sltll an effecllve method for 1den1Jfy1Dg smlable liDes Although sorne vanelles have been developed for hol low albtude sem1 and areas (Mu1gBJ and Rono 1990) hm11ed atteniJOn has been g~ven to the cool sem1 and lughlands of eastem Afnca Tbe mam objecllve of the study was lo 1den1tfy beans suotable for cult1vat1on ID the cool sem1 and areas of eastem Afnca These culltvars should be early ID matunly h1gh y1eld1Dg and of appropnate secd s1zes and colours 13 MATERIALS ANO METHOOS Two types of nursery warm me(bum clunate (WMC) and cool med1um chmate (CMC) were sown m rephcated plots at Matanya, Nanyul" (1800 mas!) dunng the fust (March May) and second (October November) croppmg seasons of 1992 at a spacmg of 45 x 20 cm In the WMC Nursery 40 mtroducbons and three local checks (MweZI MoJa (Kat mm) GLP 2 and 3334) were sown m the first season and 36 !mes w1th two checks m the second season In the CMC Nursery 20 mtroduct1ons and the same three checks were sown m the fust season and 16 !mes m the second season The followmg agronom1c charactensllcs were est1mated from net plots of 368m2 m the first season and 1 28m 2 m the second season a) days to emergence from plantmg b) days to flowenng (50%) e) days to matunty (50%) d) number of pods per plant e) num ber of seeds per pod 1) we1ght of 100 seeds (g) and g) seed y1eld (kg/ha) Statlst1cal analyses were peñormed usmg MST A TC RESULTS ANO OISCUSSION Warm Me(bum Chmate (WMC) Nursery The limes to emergence were greater (between 12 and 14 days) dunng the first season (Table 1) than dunng the second season (7 10 days) (Table 2) probably due to cooler sml temperatures m March Days to flowenng were s1m1lar between seasons In the first season e1ght mtroducllons (AFR 393 AFR 390 AFR 404 ANO 737 RWR 159 AFR 398 CAL 104 and DRK 24) were s1m1lar m flowermg tune to the checks but the other mtroduct10ns were much later Durmg the second season AFR 393 CAL 104 and DRK 24 were later flowenng but severa! of the the remammg mtroduct1ons were early Matunty penods vaned between 74 and 89 days m the first season and 89 and 1 15 days m the second DRK 24 matured later among the early flowenng Imes LRK 21 was early m matunty dunng the fust season and RWR 352 dunng the second season although both flowered late In both seasons there was cons1derable vanat10n among entnes m pods per plant (2 O 16 3 and 7 3 19 O) seeds per pod (2 O 52 and 2 2 5O) and we1ght of 100 seeds (28 O 55 O and 48 O 83 3 g) Pods per plan! and seed we1ght vaned between seasons but seeds per pod were unaffected Except for LRK 21 the early to flower and mature !mes y1elded s1m1lar to or better than the checks (897 1992 kg/ha) m the fust season R WR 159 was the earhest mtroduct10n and best y1elder Dunng the second season the earher matunng !mes peñormed sun1larly to the later matunng lmes AFR 377 was the heav1est y1elder (3987 kg/ha) The better average y1elds dunng the season were attnbuted to the prolonged ramy penod 14 Table 1 Phenologtcal and agronomtc characlensltcs of WMC beans Nanyukt long rwns 1992 Days lo Days lo Oays lo Pods/ Seeds/ Wl /100 Ytelds Entnes emerge flower mature planl pod seeds (g) (kg/ha) --- --- MweZl MoJa 12 41 76 43 3 1 40 o 421 AFR 445 12 50 86 75 26 43 o 410 AFR 368 12 53 86 42 33 31 o 481 AFR 393 12 41 74 86 36 42 o 897 AFR 451 12 50 86 87 29 36 o 576 AFR 760 12 56 86 68 42 41 o 688 AFR 761 12 57 81 70 30 38 o 563 LRK 21 12 54 75 43 43 35 o 446 AFR 371 12 78 86 94 3 7 28 o 655 AND 774 12 50 88 49 43 31 o 628 AND 182 13 50 86 10 o 3 8 38 o 769 RWR 352 13 47 80 10 7 36 40 o 1122 AFR 723 14 47 78 20 35 30 o 465 AND 765 14 49 84 58 3 5 41 o 772 AND 766 12 47 84 80 28 41 o 777 AFR 461 13 47 81 78 42 38 o 940 AFR 463 13 49 84 97 20 40 o 1025 AND 715 13 52 89 88 34 35 o 1258 AND 733 14 47 86 99 36 37 5 889 AND 739 14 50 85 83 3 7 38 o 919 ANO 740 13 47 84 92 44 31 o 769 AND 749 12 55 83 76 36 38 o 701 AND 759 13 50 83 97 43 40 5 989 AND 770 14 47 83 1 o 1 42 42 o 1565 CAL 85 12 50 84 76 36 35 o 978 AFR 346 12 54 88 10 5 34 43 o 1253 AFR 373 14 50 86 10 6 52 43 o 1663 AND 735 14 50 81 11 2 30 38 o 630 AND 736 14 50 81 15 8 30 40 o 1546 ANO 763 12 53 85 66 30 35 o 1158 CAL 103 12 50 76 10 8 36 41 o 1090 AFR 377 13 49 83 16 3 36 42 o 1764 AFR 390 13 44 81 92 3 5 41 o 1380 AFR 404 12 44 80 11 8 39 40 o 1650 AND 737 13 44 81 95 35 45 o 1025 AND 750 13 50 83 90 36 43 o 1245 CAL 89 13 47 81 14 6 32 40 o 1780 RWR 159 12 41 81 14 2 34 47 o 1992 AFR 398 12 46 76 JO 3 3 1 49 o 1557 CAL 104 12 44 76 12 8 42 41 o 1842 ORK 24 12 44 78 14 8 3 1 55 o 1435 3334 12 46 76 10 4 3 5 43 o 1372 GLP 2 12 44 75 10 2 30 48 o 11 o 1 Means 12 7 49 2 82 o ·~ ~Aí.:'-¿:..~ 1050 l~((SlJ~§ UN,DtiD D 1NrJ'h-mall seeded hnes exhtbtted the heav1est yteld and therr adoptlon could stgntficantly contnbute to mcrcased produchon Genotype x envtronment mteracllons for seed yteld were frequent m the multtsttc ytcld tnals A breakdown of these mteracttons suggested that cross over or quahtahvc mterachons predommated and mdtcated means lo refine yteld teshng strateg1es INTRODUCTION Bean common mosruc vtrus (BCMV) IS a seed transm11ted d1sease and the most 1mportant v1rus d1sease of beans IR Afnca Although oflen sporad1c 1ts prevalence dependiRg on the presence of the aph1d vector 11 can cause severe crop loss rangmg from 35 to 98% (Galve~ 1980) Ten pathogemc1ty strruns have been 1dentdied w1th res1stance cond11loned by a dom IRant necroSIS 1 gene a non specdic recess1ve gene (be u) and three strrun spec1fic recess1ve genes (bcl bc2 and bc3) (DnJfhout 1978) The domiRant 1 gene prevents the establishment of a chromc system1c IRfecllon (mosruc) by any of the known strruns of BCMV and has been routiRely mcorporated mto many breediRg IIRes al CIAT However mfechon of plants carryiRg the 1 gene w1th the temperature msens1bve BCMV strruns NL3 NLS and NL8 result m a hypersens1hve reacllon resultmg IR system1c necrosts or the so called 'black root symptom leadiRg to early death Recen! surveys show thal the necrobc stram NL3 predomiRales IR eastem central and southem Afnca thus hrn1I1Rg the usefulness IR Afnca of the many breedmg hnes from CIA T carrymg the 1 gene Of the recess1ve genes bc3 alone confers 1mmumty lo all strruns of BCMV and has been mcorporated al CIA T IRio a range of breediRg hnes mrunly targeted for consumers m LatiR A menea In 1990 a breedmg programme was 1Rl11ated IR Uganda to develop a range of hnes carryiRg th1s gene w•th seed charactenst•cs acceptable to consumers IR Afnca uhhzmg homozygous breedmg hnes and segregatmg populal1ons from CIA T 43 MATERIALS AND METHODS After screemng and yteld evaluatton of 122 mtroducttons from CIA T tn second season 1990 (90a) supenor !mes were passed to the nattonal breedtng programme for nattonal testtng and three of these !mes were selected for pre release tn 1993 Seventy four small seeded mdetenntnate ltnes from a "econd mtroductton tn the first season 1992 (92a) were yteld tested tn two prehmmary (tntemattonal) yteld tnals (PIBR 1 and 2) tn 92b at three sttes the term BR refemng to tnals testtng black root reststant !mes Ftgure 1 outhnes the selectton scheme apphed to segregattng populattons tn Uganda between 90a and 93a to develop well adapted BCMV black root reststant !mes Selectton of symptomless (no mosatc or black root) smgle plants commences m early generattons usually the F2 wtth the populattons grown wtth tnfector rows ata hot spot for NL3 After suntlar screentng symptomless F, (smgle plant) progemes are bulked wtth the resultmg !mes undergomg a further generatton of screentng before potenttally reststant ltnes are tested tn multtstte yteld tnals Arttfictal screentng ts used to help ehmtnate suscepttble smgle plants/progemes and lmes Ftgure 1 Selectton for BCMV black root reststance tn segregatmg populattons tn Uganda from 1990a to l993a - ------ Season PHASE 1 90a 1 F, SP 3 F, SP 19 F, SP 1 1 1 90b 153 F, SPP 494 F, SPP 1234 F, SPP PHASE 2 1 1 1 9la 18 F, 310 F, 399 F, 43 F, SP 1 1 1 1 PBR 1 1 9lb 16 F, 1 166 F, 237 F, 2835 F, SPP 1 1 1 PHASE 3 IBR -PBR- 1 92a 6 F, 1 103 F, 182 F, 2399 F, 38 F, SP 1 1 1 ABR --IBR- -PBR- 1 92b 6 F, 1 39 F, 40 F7 405 F, 551 F, 1 1 1 1 1 -ABR- -IBR- 1 93a Dtstnbutton to 21 F, 103 F, 2325 F, nattonal programmes tn pp Uganda Rwanda PBR Malawt Tanzanta (POP BULK)1 -- ----- SP = segregatmg populatton SPP = smgle plant progeny genotypes m succeedtng generattons referred to as !mes PBR IBR ABR = prehmmary mtermedtate and advanced BCMV reststance tnals 1 PBR of F5 ltnes and F3 SPPs bulked wtthtn populattons 44 Three phases have been IDII1ated In the first phase followmg select1on and testmg 45 F, and F, large seeded (LS) and 40 F, small seeded (SS) bush lmes were tested m 92b m advanced (ABR) and mtermed1ate (IBR) y1eld tnals respecllvely at five Sltes m 92b Supenor y1eldmg lmes from the IBR of 92a are bemg tested by the Ugandan nallonal programme and lmes m the ABR of 92b have been d1stnbuted lo nat10nal programmes ID Rwanda Tanzama and Malaw1 In the second phase 405 F, liDes were y1eld tested w1th a further 55 I F, liDes sbll bemg screened wlulst ID the thlrd 2325 F3 progemes have undergone only a f¡rst screeniDg A sample of seed from each of the latter F, !mes and F, progemes have been bulked w1th1D populallons for y1eld testmg to 1den11fy supenor populallons m wluch to concentrate future selecllon and testmg AII tnals were Simple latt1ces w1th plot s1zes of three rows of 3 m or four rows of 4 m and between and w1thm row spacmgs of O 5 m and O 1 m respecllvely of test lmes plus the followmg controls K20 a w1dely grown large seeded (LS) bush culllvar released ID 1968 CAL 96 a large seeded (LS) bush cultivar released m 1991 w1th a y1eld potenllal around 30% greater than K20 MCM 5001 a small seeded (SS) bush culllvar released ID 1991 w1th a y1eld potenllal around 80% greater than K20 Across s1te anovas were undertaken for s1tes common to tnals grown m 92a and 92b usmg actual and transformed (we1ghted by the rec1procal of the error mean square) plot data, accordmg to Johnson Robmson and Comstock (1955) S1mple (rp) and rank (rs) correiallons over s1tes were denved from the appropnate vanance and covanance terms The term s1gmficant apphes lo a probab1hty leve! equal to or less than O 05 RESULTS ANO DISCUSSION Y 1eld 1mprovement Genotypes d1ffered Slgmficantly for seed y1eld m all tnals al all s1tes except two for the ABR where coeffic1ents of vanat1on were m excess of 40% data from these s1tes were excluded from the mean y1eld over s1tes The y1elds of 75 51 and 11% of the 159 !mes ID the PIBR 1 and 2 IBR and ABR of 92b respecllvely exceeded the mean y1eld over s1tes ofthe control culllvars K20 CAL 96 and MCM 5001 (Table 1) The SS hnes m the PIBRs and the IBR had the larger mercases over the LS controls K20 and CAL 96 w1th 43 and 26 lmes respect1vely outy1eldmg these by 50% or more s1x lmes recorded double the y1eld of K20 In contras! no y1eld mercase of the 39 and 9 LS lmes over these controls exceeded 50% although such lmes are normally cons1dered the more readJiy adopted However due to 1ts y1eld potenllal the SS cult1var MCM 500I has proved acceptable to farmers and expans10n of the area sown to SS types could s1gnmcantly mercase bean product1on 45 Table 1 Mean y1elds (% of control culllvars) over s1tes of BCMV black root reSIStan! hnes m prehmm31) (PIBR) mtermed1ate (IBR) and advanced (ABR) tnals conducted m Uganda m the second season of 1992 Number of lmes PIBR 1/21 ABR IBR All tnals K20 CAL MCM K20 CAL MCM K20 CAL MCM K20 CAL MCM Y1eld2 96 5001 96 5001 96 5001 96 5001 200 3 3 4 No hnes/ tnal 74 45 40 159 1 number of s1tes PIBR 1/2 and ABR three IBR five 2 y1eld of control cult1var 100% The potenllal for releasmg heav1er y1eldmg BCMV reSIStan! SS culllvars 1s ev1dent w1th 15 lmes m the PIBRs and the IBR outy1eldmg MCM 5001 by up to 25% and the best two recordmg mercases of 27 and 31% Moreover w1th the F, SS lmes m the IBR denved from F2 smgle plants (F1gure 1) explmtat1on of genellc vanat•on through selecllon m supenor y1eldmg Imes m ay ach•eve further y1eld mcreases The y1eld advances were ach1eved m sp1te of a severe reducllon m genellc vanat10n m the source populat10ns dueto only res1stant progemes and )mes bemg promoted To counter thts a d1verse range of populahons was screened and the number of genotypes handled max1m1zed w1thm avadable resources between 90a and 92b 7041 smgle plant progemes were screened of wh1ch 769 denved lmes entered prelunmary y1eld tnals (F1gure 1) Crosses have been IDihated between heavy y•eldmg lmes of d1verse ongm to generate arrays of well adapted populallons to seek further y1eld advances Y1eld performance over s1tes Across s1te analys•s w1th the actual and transformed data for s1tes common to tnals m 92a and 92b detected mteract1ons for the same nme tnals whdst the PBR 5 of92a showed an addlllonalmterachon w1th the transformed data (Tables 2 and 3) A 'breakdown of these 1 O three way s•te mteract•ons mto the1r (three) two way s1te com bmat1ons showed that wh1lst the maJonty of s1mple correlallons between lme y1elds were s•gmficant except m one case there was no similar concordance m rankmgs suggestmg that cross-over or qual1tat•ve mteracllons (Baker 1988a) predommated For e1ght of the 1 O tnals no s1gmficant mteracllon occurred for one of the three two way combmallons wh1ch was cons•stently Kawandallkulwe for the 92a PBRs and Kawanda/Namulonge (on three out of four occas1ons) for the 92b tnals suggestmg poss1ble redundancy m testmg lmes al both s1tes for these two com bmallons 46 Table 2 Genotype x envii'Onment parameters for seed yield from breedmg tnals testmg BCMV black root resistan! !mes m U ganda m the first season of 1992 Two way site combmations (2 3 4 5) All si tes (2 3) Numbers of LSI No ofhnes Correlation common to 1 O LSI heaviest yieldmg Tnal Sites Lmes Actual Trsf Sites Actual rp rs over Sites at IBR 1 3 49 IBR 2 3 36 IBR 3 3 36 PBR 1 3 49 PBR 2 3 49 PBR 3 3 49 PBR 4 3 36 PBR 53 25 O 001 O 001 KAIBK •• ns ns ns ns o 01 o 01 KA/NG ••• •• ns ••• ns ns ns ••• ns ns • ns ns •• ns KA BK NG 5 3 8 7 5 9 7 5 6 BKING ••• KAIBK KA/NG BKING KAIBK ns KA/NG •• BKING •• ns ns (Total /9 /3 23) ns ns KAIBK KAIIK BKIIK O 01 O 001 KAIBK ••• KAIIK ns BKIIK • O 001 O 001 KAIBK ••• KAIIK ns BKIIK •• O 01 O 001 KAIBK ••• KA/IK ns BKIIK •• ns O 001 KAIBK ••• KA/IK ns BKIIK •• ••• ns ••• ns ••• ns ••• • ••• ns •••••• ••• ns •• ns •• ns • ns •• ns ns ns ••• ns ••• ns ••• os KA BK IK 9 7 6 7 5 6 8 6 6 8 4 5 JO 8 8 (Total 42 30 31) LSI = signúicance leve! of Jme x SIIe mteraction Trsf = transformed data KA = Kawanda, BK = Bukalasa, NG = Nakabango JK = Ikulwe rp/rs = simple and rank correlations for seed yield ns • •• ••• non sigruficant and sigruficant at Peld data from the first y1eld loss tnal are shown ID Table 1 S1gmficant y1eld reduct>ons due 10 treatmenls were detected only ID Season 91B In Seasons 90B and 91A d1sease express1on d1d not dúTer among treatments and y>eld Iosses were not s1gmficant There were s•gmficant d11Terences among vanety y•elds ID each season and overall and there was a s>gmficant S x V IDieracllon The heav.esl y1elds and largest phoma bhght scores were observed ID the season w1th the h1ghest r81Dfall 69 The y1elds of the md1v1dual vanehes when protected and the percent reduchons m natural and severe mfechon by phoma bhght are shown m Table 2 The y1eld reduct10n 1s also affected by other d1seases such as anthracnose and angular leaf spot whose seventy changed under the dlfferent treatments Table 1 Mean squares from analys1s of vanance of seed y1elds from d1sease loss tnal m Seasons 908 91A and 918 Source of vanahon df 908 91A 918 Combmed -- - Treatments (T) 2 ns ns 626853** 4612361** V anet1es (V) 8 888120** 194522** 2333673** 826368** TxV 16 ns ns ns ns Seasons (S) 2 4746325** SxT 4 ns SxV 16 512561 .. SxTxV 32 ns •• s1gruficant at P 96 days) matunng lmes wtth ytelda of over 2 t gtam ha 1 and supenor to local commerctal culttvars were finally selected These hnes combmed reststance to three or more dtseases wtth preferred seed charactensttcs INTRODUCTION Most bean culttvars currently grown m eastem Afnca are suscepttble to one or more d1seases (Kunam el al 1990) When such culhvars are grown m areas where the dtseases are endem1c thetr ytelds are dramaltcally reduced (Gndley 1990) Dtsease mctdence and seventy tend to vary among locattons and seasons Because of the Wlde range of chmatJc condtttons 11 1s dlflícult to breed culhvars su1ted to every regton Culttvars Wlth Wlde adaptabl11ty and wtth res1stance to the m&Jor d1seases can stabthze y1elds m a Wlde range of env1ronments Relat1vely hUle work has been done m the reg10n to develop bean culltvars Wlth multtple reSJStance In recen! years natJOnal programs have started development of bean populaltons Wlth reSJStance to spectfic maJor dtseases such as common bactenal bhght (Musaana and Opto 1990) rust (Assefa 1990) phoma bhght (Sengooba and MaJe Kay1wa, 1990) and bean common mosmc vtrus (Owera, 1990) for utthzatton m the whole regton CIAT has made constderable efforts to 1denhfy and mcorporate reststance mto breedmg lmes wh1ch have been dtstnbuted m dtsease nursenes for evalualton by nahonal programmes for res1stance to prevalen! pathogens (Gndley 1990) Lmes w1th reststance to common bactena bhght halo bhght and rust from such nursenes have been tdenttfied m test s•tes m Uganda Confmned sources of res1stance are mtended for uhhzalton m developmg mult1ple reststant cult1vars ICJman• el al (1990) selected several F, and F, lmes combmmg reststance to three or more d1seases acceptable seed charactenshcs and yteld potenhal from populattons created from a seven paren! dtallel cross The purpose of thts paper ts to descnbe the performance of advanced generatton !mes from these selechons w1th respect to dtsease reachon yteld and related trmts 85 MATERIALS AND METHODS Over two hundred F, and F, !mes selected from nme populat10ns were grown m nme envrronments between 1988 and 1992 m Kenya These !mes were denved from crosses among four commerc1al cult1vars GLP 2 (Rosecoco) GLP 288 (Rosecoco) GLP 24 (Canad•an Wonder) GLP X 92 (Mw1temarua) one lme developed through mutation breedmg (M 535) one recently mtroduced wlute seeded breedmg lme (L 226 10) and a local black seeded landrace (NB 123) In add•tion 30 advanced !mes (M9 and MIO) denved from urad1ated seeds of Canad1an Wonder were mcluded (Kunaru 1988) D1sease and y•eld charactenstics of the parental !mes and the1r F 1 to F, generations have been prev10usly descnbed (K1maru el al1990) Popular local cultivars (GLP 2 GLP 24 and GLP X 92) were used as checks The !mes were grown at Kabete dunng the 1988 short ram season and the 1989 and 1990 long rwn seasons In 1991 they were grown at Kabete (Nwrob• d1stnct) Tluka (Muranga d1stnct) Manmant• (Meru d1stnct) and Rongw (Nakuru d1stnct) durmg the long rwn season and at Kabete and T1gom (Klambu d•stnct) dunng the short rwn season They were also grown at Kabete durmg the 1992 long rwn season The tnals were arranged m a random•zed complete block des•gn With four repbcates Each plot cons1sted of four rows 5 m long Spacmg was 50 cm between rows and 1 O cm w1thm rows 100 kg ha 1 d1ammomum phosphate (18% N and 45% P,O,) was appbed at planbng Plots were kept weed free by hand cultivattOn Seeds harvested each season were used for sowmg m the next season Plots were rated for react10ns to rust BCMV angular leaf spot anthracnose and halo bbght pathogens From 1988 to 1990 d1sease assessment was based on natural ep1phytotics In 1991 and 1992 the tnals were also artlfícially moculated w1th all the five pathogens To ensure that the matenals were subjected to a w1de vanety of ex1stmg pathotypes 1solates were gathered from dlfTerent bean growmg areas m Kenya The •solates were multipbed separately and m1xed before moculabon Procedures for pathogen Jsolation multipbcation and moculation were descnbed prev1ously (KIDlaru el al 1990) CBB) was rated only m 1989 1991 and 1992 A 1 9 d1sease seventy scale was used wluch corresponds to the 1 5 scale descnbed prev10usly ( 1 2 3 4 and 5 corresponds to 1 3 5 7 and 9 respectively) (KIDlani el al 1990) D1seases were assessed about 21 days after moculabon (R6) and at m1d pod filbng (R8) The larger of the two rabngs was taken as the fmal score Ten randomly selected plants m each plot were tagged and assessed for d1sease seventy on leaves (R6 stage) and on pods (R8 stage) Susceptible plants and/or !mes and those With other undemable characters were d1scarded Grwn y•elds and times to flowenng and matunty was recorded on the mner two rows of each plot A random sample of 100 seeds from each plot was used to determme seed s•ze Data was analyzed on md1v1dual s•te bas•s to determme 1f they were any s1gmficant genotyp•c dlfTerences A combmed analys1s was performed accordmg to procedures outlmed by Gomez and Gomez (1984) each locat•on m a particular year and season bemg cons1dered an envrronment Genotypes were cons1dered fixed and env1ronments random Protected least s1gmficant dlfferences (PLSDs) were used for means separation Matunty groups were analysed separately RESUL TS AND DISCUSSION AnalySIS of vanance showed that there were s•gmficant d•fferences m matunty d1sease rabng seed charactenstics and y1elds among !mes and env1ronments (Table 1 2 and 3) Of the two hundred !mes evaluated for mne seasons 50 were finally selected for comb1nmg desrrable seed charactenstics d1sease res•stance and y•eld Segregation for vanous characters decreased cons•stently as the matenals were advanced from F, generation and had v•rtually ceased by the F 9 and F 10 generabons The selected !mes ongmated from 14 of the 36 F 2 populations 86 Table 1 Oays to flowenng and matunty seed types and s1zes d1sease ratmgs and gram y1elds of ten early matunng bean lmes and culllvars grown m mne envrronments m 1988 92 We1ght 01sease ratmgs (means 4 worst seasons) Gram Lmes/ Seed of 100 y1elds culllvars OFF OM type seeds (g)BCMV HB CBB Anth Rust ALS (kg/ha) K1/6A 42 81 RC 518 o 1 5 1 1 35 1 6 54 2158 K1/9A 40 83 RC 55 6 o 20 1 o 1 9 33 44 2172 K1/12A/2 45 83 RC 60 4 o 1 5 1 1 2 1 30 45 2484 K1/13A 111 43 84 RC 521 o 30 1 o 20 21 55 2210 K1/26B 43 81 RC 60 8 o 20 1 o 36 26 5 1 2721 K1121A/1 42 83 RC 513 o 1 5 1 o 1 1 1 5 51 2260 KI5/IAI 42 83 RC 515 o 25 1 o 3 5 40 3 1 2228 KI5/2A/I 42 83 RC 51 9 o 25 1 1 31 45 48 2310 KI5/6C 1 44 83 RC 515 o 25 1 1 45 3 8 48 2172 KI5/7A 42 83 RC 58 5 o 25 1 1 4 1 55 53 2232 GLP 2 45 81 RC 55 1 41 36 30 26 31 40 1781 GLP 24 49 96 cw 41 o 45 38 22 49 28 24 1806 GLP 92 41 91 MW 42 o 69 28 1 o 55 82 4 1 1435 Mwen Moja 39 85 MM 44 o 32 60 1 o 32 20 51 1372 LSO (P40g/IOO seeds) and five med1um s1zed seeds (30-40g/IOO seeds) Among late matunng lmes 11 are Canad1an Wonder type 7 are Rosecoco and each of Red Hancot and Mwen Moja Of the twenty lmes 14 are large seeded and 6 have med1um s1zed seeds GraJO y1elds The fifty lmes also were selected on the bas1s of therr average y1eld over the nme env1ronments AH the lmes selected except K33/38A and the K25/13A had y1elds over 2 t ha 1 generally heav1er than the check cult1vars K33/38A a med1um matunty lme was selected because of 1ts seed charactensllcs (Red Hancot type) and lugh levels of d1sease res1stance espec!ally to angular leaf spot and C B B There were s•gruficant dúferences among lmes and env1ronments Generally all lmes gave heav1er 90 ytelds dunng the long ram season than the short rams Buruchara and Tyagt (1979) also reported better ytelds dunng the long ram season probably due to better m01sture supply Although relattvely htgher dtsease levels were recorded dunng the wetter seasons yteld reductton was mmtmtzed by reststance to vanous dtseases Average yteld was greatest among the late matunng group (2628 3 kg ha 1) and poorest among early matunng !mes (2363 6 kg ha 1) Two early matunng !mes K7/6A and K7/26B produced ytelds over 2 600 kg ha 1 Three late matunng !mes (M262/13 M262/35 and M355/21) denved from trradtated Canadtan Wonder (GLP 24) had ytelds over 3 t ha 1 The results of thts study mdtcate that select10n for tmproved dtsease reststance seed charactensttcs and gram yteld was effecttve Thts ts tJDportant m vtew of the fact that dtseases are a maJor hmttmg factor to producttvtty m farmers fields m thts regton (Ktmant et al 1990) However reststance wtthout constderatton for consumer preferences for seed charactensttcs would constram raptd adoptton of the promtsmg !mes when they are released Thts aspect also was constdered The hnes were screened under a wtde array of growmg condtttons and therefore exposed to the v anous strams of the maJOr pathogens whtch are known to extst The next part of thts work wtll mclude on farm tests and evaluatton of consumer preference and cookmg qualtty pnor to release of the new vanettes The selectton of !mes of dtffenng matunty wtll help to develop culttvars swted to dtffenng lengths of growmg season REFERENCES Assefa H (1990) Bean rust tts tmportance eptdemtology and control m the eastem Afnca productton system In J B Smtthson (Ed ) Proceedmgs of the Second Workshop on Bean Research m Eastem Afnca, Natrobt Kenya 58 March 1990 CIAT Afncan Workshop Senes No 7 pp 43 64 Buruchara, R and Tyagt A P ( 1987) Adaptatton and reststance m bean to angular leaf spot and rust m Kenya In R A Ktrkby (Ed ) Proceedmgs of a workshop on Bean Research m Eastem Afnca, Mukono Uganda, 22 25 June 1987 CIA T Afncan Workshop Senes No 2 pp 102 110 Gomez K A and Gomez A A (1984) Staltsttcal Procedures for Agncultural Research John Wtley and Sons New York Gndley HE (1990) CIATs role m bean genettc tmprovement m Eastem Afnca In J B Smtthson (Ed) Proceedmgs of the Second Workshop on Bean Research m Eastem Afnca Natrobt Kenya 5 8 March 1990 CIAT Afncan Workshop Senes No 7 pp 210 216 KtJDaru P M Gtthm S M and Kamau J K (1990) Brcedmg bean for reststance to dtseases In J B Smtthson (Ed) Proceedmgs of the Second Workshop on Bean Research m Eastem Natrobt Kenya, 5 8 March 1990 CIA T Afncan Workshop Senes No 7 pp 188 195 Munene S M W (1992) Retatl market survey of dry bean culttvars sold m Kenya Nattonal Horttcultural Research Centre Thtka KARI/CIAT Natrobt Kenya Musaana S M and Opto A F (1 990) Regtonal collaborattve research proJect on common bactenal bhght Xanthomtmas campestns pv phaseoil (Smtth) Dye of common bean (Phaseo/us vulgans L ) In J B Smtthson (Ed ) Proccedmgs of the Second Workshop on Bean Research m Eastern Afnca, Natrobt Kenya, 5 8 March 1990 CIAT Afncan Workshop Senes No 7 pp 24 34 91 Owera, S A P (1990) Analysis of serotypes and strams of Bean Common Moswc VIrus (BCMV) m countnes with CIA T s Regional Progrwnme on Bean m Eastem Afnca In J B S m Ithson (Ed ) Proceedmgs of the Second Workshop on Bean Research m Eastem Afnca, Nwrobi Kenya 58 March 1990 CIAT Afncan Workshop Senes No 7 pp 63 77 Sengooba, T and Male Kayiwa, B S (1990) Progress m studies of phoma bhght of common bean m Eastem Afnca In ] B Smithson (Ed) Proceedmgs of the Second Workshop on Bean Research m Eastem Afnca Nwrobi Kenya 5 8 March 1990 CIAT Afncan Workshop Senes No 7 pp 35-42 van Rheenen HA (1979) DivefSity of food beans m Kenya Economic Botany 33 448-454 van Rheenen HA Oluoch PO and Mwgw S G S (1984) Release of dry bean vanehes (Phaseo/us vu/gans L ) m Kenya Nahonal Horticultura! Research Stahon Techmcal Bulletm No 3 MIRistry of Agnculture and Livestock Development Nwrobi Kenya 92 DISCUSSION SESSION 111 BREEDING FOR DISEASE ANO INSECT RESISTANCE Cbatr M Ftscbler Rapporteur A F Opto Paper by Tberesa Sengooba Bu ruchara Is the ongiR of the straiRs of BCMV found on wtld host plants known? Sengooba The studtes camed out IRdtcate that the straiRs ongiRated most hkely IR the reg10n but we are not sure yet Therefore we call them BCMV hke tsolates Further studtes are necessary Paper by W Songa AJanga OngiRally you used severa! tsolates but IR the end you were USIRg only one Where dtd tlus tsolate ongiRate? Why are you now USIRg only one tsolate to test for reststance ? Songa The tsolate used was from dry bean 1 IRtended to narrow the volume of germplasm before multtlocallonal testJRg IR the regton where a mtxture of IRdtgenous tsolates wtll be used Bu ruchara The obJecltves of your sub proJect are to develop swtable screemng methodology screen germplasm for reststance and develop a regtonal nursery What ts the hnk between these objecttve and utdtzalton of thetr results by breeders? Songa 1 should have saJd at the begmmng that germplasm screemng ts conducted IR close collaboratton WJth the breeder The reg10nal nursery ts for the purpose of etther releasiRg tdenttfied reststant culttvars straJght to farmers tf they have other acceptable agronomtc characters or for use as sources of reststance IR the breediRg programme The next eructa! step after estabhshiRg the regtonal nursery ts to JRJUate a breediRg programme for the development of reststant vanettes and therefore a seed based technology to manage the dtseases Opto Why dtd you use only one tsolate IR the evaluatJOn of IRoculatton methods? Yet tt has been reported that there are IRteracltons between tsolates and IROculatton methods 1 assume you wtll be evaluattng bean germplasm after your IRoculalton studtes 1 suggest that IRStead of USIRg one tsolate (tsolate 1 O) use a mtxture of tsolates otherwtse you m ay get escapes Songa 1 used one tsolate (tsolate 1 O) whtch 1 found very pathogemc and a fast grower on arttfictal medta to reduce the germplasm for subsequent screemng PromtsiRg genotypes selected for multJ locattonal testJRg wtll then be re screened usiRg tsolates IRdtgenous to the test locatton A SIRgle tsolate ts sattsfactory for developiRg an effecttve IROCulatton method siRce 1 was usiRg a known htghly suscepttble genotype for the expenment Your suggestton to use a mtxture of tsolates whtle evaluatJRg germplasm to avotd escapes ts well taken Sengooba In field screenmg wtthMacrophomma phaseolma don t you somettmes have comphcattons from other root rol pathogens? How do you handle thts problem? Songa Each genotype ts grown IR double rows and the control row ts used for correctJon SIRce dtseases other than Macrophomma phaseo/ma should mfect the control as well Indeed 1 agree WJth you that when many other root rots are IRvolved the evaluatJon ts far from easy and can be unrehable 93 Tesfaye Besb1r 1 suggest use of m1xed 1solates for screemng for res1stance lo M phaseolma because otherw1se you m ay lose the best genotypes Paper by Tesfaye Besb1r M1t1ku Halle In your conclusmn you md1cated that the d1sease pressure 1s expandmg from year to year ls tlus because you are explormg areas h1therto unsurveyed or because susceptible vanetles are bemg mtroduced m prevmusly surveyed areas? Tesfaye Besb1r D1sease pressure 1s mcreasmg m prevmusly surveyed areas because farmers use the1r own mfected seeds from season to season Seogooba Is there any breedmg effort to combat anthracnose m Eth10p1a? Th1s 1s a d1sease where sources of res1stance are fauly well documented and there 1s a need lo concentrate on breedmg for res1stance whde the patholog1st concentrates on collectlon of 1solates and study of the1r vanatlon so that he can subsequently play a ma¡or role m evaluatmg breeders matenals Tesfaye Besb1r So far we do not have any hne bred for reSIStance to anthracnose m Eth10p1a We pass res1stant vanetles lo the breeders for future use and make a strong follow up on th1s M1t1ku Halle We have been mformed that a vanety wh1ch was res1stantto a certam 1solate m severa! locatlons •s now breakmg-down Th1s 1 beheve 1s a challenge to breeders and patholog1sts Would you comment on how th1s vanety wh1ch 1s cons1dered lo be res1stant m Latm Amenca Afnca and many locatlons m Eth10p1a succumbed only m one s1te al Sodo? Tesfaye Besb1r Th1s can be answered only by collectmg races from dúferentlocatlons and 1D1prov1ng screemng techmques Paper by F Malum Racb1er Why d1d you choose lo use only 98 genotypes whde there are many more genotypes al Th1ka? Malun1 1 dec1ded lo work w1th a hundred !mes lo start w1th because th1s number 1s manageable As sorne of these are re¡ected as susceptible other !mes wdl be tested Bu ruchara You d1d not show whether and how your research act1v111es w1ll prov1de serv1ce lo other researchers who are mterested to know whether the1r matenals are res1stant lo angular leaf spot? Malum 1 w1ll be collaboratmg w1th other sc1ent1sts m the reg1on whereby they can send me the1r matenals for testlng Already 1 am collaboratmg w1th the un1vers1ty of Nwrob1 and we are testmg dúferent !mes for res1stance to ALS as well as other d1seases Sc1ent1sts mterested lo know whether theu matenals are res1stant lo ALS w1ll be welcome lo send them lo me for testmg Op10 Is your sub pro¡ect only for Kenya or the whole of eastern Afnca? Malum The sub pro¡ect covers the whole of eastern Mnca 94 Paper by P M K1man1, A W Mwang'ombe and J W KlmenJu Gndley Do you now have suffic1ent mformat1on for release of the supenor !mes tested m your programme? K1man1 Y es to a large extent but we would st1ll hke to evaluate them under a WJder range of cond1bons mcludmg on farm tnals m the next three seasons m all seven provmces of Kenya KanyagJa In your presentabon you swd you have found some vanebes wluch are res1stant to parbcular d1seases and some are lugh y1elders Are you gomg to mclude farmers m your on farm tnals? lúman1 We are gomg to start soon Musb1 In your presentat1on you menlloned that m some locabons you fwled to moculate the plants How sun1lar are the two seasons m those env~ronments where you couldn't artúic1ally moculate? K1man1 Locat1ons were clustered accordmg to cond1bons and to artúic1ally moculate one that 1s representat1ve There 1s more d1sease m wetter seasons Tenaw Workayebu More than one d1sease was observed m the same plants In your study d1d you study the d1seases separately or together? K1man1 In the IRJtial stages (F, F,) we rated d1seases separately and then we used mulbple moculabons for selected lmes Burucbara Do you tlunk that farmers need to be mtroduced earher m your breedmg process? Has your evaluabon been based on farmer managed or on stat1on cond•bons ? Kiman• Y es but the •ssue 1s how early 1 th1nk a breeder should develop the matenals lDlbally and consult WJth farmers on •ssues of mterest wluch he m ay not be sure about (e g seed types preferences) but actual testmg of !mes m farmers fields should come much later when the number IS reduced Evaluallon has been done on stabon We plan to test the selected !mes m farmers fields under monocrop and assoc1ated croppmg Th1s WJll help Idenllfy wluch !mes are swted to specific croppmg systems Otsyula Are you gomg to use zonal means or rely on nabonal mulll locabon tesllng only? Don't you th1nk that 1f locat•ons are very vanable the means m1ght be m1sleadmg? K1man• The fmal evaluallon wiii be based on spec1fic agro-ecolog•cal zones to determme wluch cultivars are best m those areas 1 e specific adaptab1hty It wiii be of mterest to see ñ any of the !mes have general adaptab1hty Op10 Wh1ch 1solate of Xanthomonas campestns pv phaseob (causal agent of CBB) d1d you use m screemng your crosses ? Ktman• We used a mixture of •solates from dlfferent bean growmg areas 95 Geoeral dtscusston P M Klm8Dt There ts on gomg debate whether to 8IDI at smgle gene reststance or polygeruc (honzontal) reststance Expenence m other crops shows that polygeruc reststance ts more durable If lmes are screened m a range of dlfferent envwnments we can assume that we test for durable reststance Musa8Da Pathologtsts should tsolate and culture the partJcular tsolate (race) that has mfected the donor paren! Thereafter exJstmg sources of reststance have to be screened agamst tlus partJcular race and ú any prove reststant to tt use gene pyramtdmg or back crossmg to wprove that wportant donor paren! whtch has broken down Opto From expenence wtth BCMV CBB and now anthracnose Etluopta seems to be very dúferent as far as tsolates of pathogens are concemed (e g necrobc 8trams of BCMV are present m most countnes of Afnca but are absent from Etluopta some very aggresstve strams of the CBB pathogen are only found m Etluopta but not m other Afncan countnes one vanety wluch t8 reststant to all races of the anthracnose pathogen t8 suscepbble m Etluopta) 1 suggest that the breeders treat Etluopta as a spec1al case when breedmg vanebe8 for the whole regton Seogooba It seems that much work ts gomg on m parallel at tlus moment (e g crop los8 studtes carned out for each cbsease) Much bme and mformabon ts lost There 1s a need for a closer collaborat1on amongst patholog1sts and between breeders and patholog1sts Commeot There are some problems of coordmabon and exchange of mformabon Valuable lmes are lost because they prove to be suscepbble to a plll'tlcular cbsease but other useful agronom1c trwts are not cons1dered Gndley 1 thought th1s problem was dtscussed before Agronomtc trwts are recorded the same bme as d1seases are scored Mus88Da (Maktnt paper) ALS comes m very early m Uganda One hundred lmes 18 not enough for tnJbal screenmg there should be about a thousand lmes 1 suggest you contact other countnes m order to obtam more lmes for screenmg Musbt What 1s the ongm of GLP 2? Musaana GLP 2 ongmally came from Uganda, where 1t 18 called K20 lt was released m Uganda m 1968 at F 8 stage Burucbara ls there a need for closer mterrelabonslups among the sub proJects workmg on d1seases? Klrkby 1 suggest that tlus 1m portant pomt should be dtscussed m the workmg group on Thursday Opto Each sc1enttst workmg on a plll'tlcular dtsease 1s carrymg out crop loss studtes Can we develop a standarcbzed procedure/methodology to assess crop loss due to d1seases at the farm leve) Rono Y es but we should frrst screen !mes at hot spots for each cbsease separately m order to have a base 96 Bu ruchara Dtseases must ftrSt be pnonttzed accordmg to tmportance for each envuonment so we have to evaluate each dtsease separately m order to estabhsh tite relattonshtp between dtsease level and yteld loss At farm level we face a mtxture of dtseases and tite questton ts whetlter we can tdenttfy a common metltodology to assess yteld loss 97 \ 2 7 CCI ~~~0 SESSION IV INTEGRATED MANAGEMENT OF DISEASES AND PESTS BEAN RUST IN EASTERN AFRICA RESEARCH RESULT HIGHLIGHTS 1990-1992 Habtu Assefa lnsbtute of Agncultural Researcb, Nazretb, Etb10p1a ABSTRACT Bean rust IS a wtdespread and economtcally tmportant dtsease of beans m Afnca A survey of farmers fields prov1ded mfonnahon on the relattve •mportance of ru~t m a mulhplc pathosystem where other fohar dtseases co ex1st Crop loss stud1es suggcst thc damagmg potenhal of rust espec1ally 10 suscephble entnes The effechveness of vanetal mtxlurcs m reducmg d1sease ep1dem•cs and the vanab1hty of genotypes for components of parhal res1stance suggest means of future rust control strateg1es Future stud1es necd to addrcss researcb arcas such as the effects of mtercrops htological control phystologJc races and peñonnance of rust res1stant entnes across reg10ns Understandmg of rust cpidemtology m these and other areas should fonn a bas1s for developmg an effechve mtegratcd rust management strategy INTRODUCTION Numerous bean dtseases are reported ID Afnca, among wh1ch bean rust caused by Uromyces appendzculatus has a w1de geograph1c dtstnbutlon (W al lace 1939 Leakey 1963 Howland and Macartney 1966 Edje el al 1973 Wamoelo 1973 Patel 1975 Allen 1983) Research IDfonnalton on the eptdem10logy of bean rust and understandiDg of bean rust status under farmers c~rcumstances IS badly needed Lack of knowledge of the geograpluc d1stnbutlon of bean rust 1ts relahve 1mportance vzs a vzs other follar d1seases ec:onom1c 1mportance phys10logtc races b10log•cal control and ep1dem•c development ID vanetal mixtures and ID IDtercrops has restncted the development of res1stant vaneltes w1th w1de adaptaUon potenllal Bec:ause of th1s a rust sub projecl was proposed ID 1987 to understand the ep1dem 10logy and control of bean rust ID Eastem Afnca The m&JOr focuses of the research were follar dtsease survey crop loss assessment pathogen1c1ty analys1s vanetal mixtures and vanetal res1stance Eth10p1a acted as a coordiDatJng center and collaboraiiDg countnes mcluded Uganda Rwanda Kenya Zamb1a, Maunttus Zaue and Madagascar Except m Uganda, the mam area of collaboralton remams the bean rust reg10nal nursery so most of the mfonnatton contamed tn th1s report 1s from research conducted m Etluop1a Results of the 1988 and 1989 expenments have been reported elsewhere (Habtu Assefa 1990) Tlus report summanzes results obtamed from the 1990 1991 and 1992 expenments BEAN CROP SURVEY Surveys of bean crops and d1seases were conducted m 1990 1991 and 1992 m the maJor bean growmg areas of Etluop1a Central Rtft Valley and Southem Westem and Eastem Reg10ns 98 The surveys revealed IDlportant dúTerences among reg10ns The Central Rtft V alley ts charactenzed by monomodal ramfall (June to September) and beans are culttvated as a monocrop once yearly mamly as a cash crop The dommant vanety ts Mextcan 142 Farmers netther apply fertthzer nor weed There ts a large vanabon m sowmg date mamly dependmg on the ttmmg of the first showers In thts area, IDlportant dtseases of beans are rust anthracnose and CBB Bean rust ts found wtdely scattered and seventy ts htghly concentrated In the wetter zones anthracnose ts do m mant but where temperatures are warmer and ramfall IIDltltng CBB ts most prevalen! In areas where farmers use good healthy seed the mctdence of anthracnose ts greatly reduced The southem regton ts charactenzed by a btmodal ramfall pattem and beans are grown twtce each year (July October and February May) etther m monocrop or assoctatton wtth enset mwze coffee sweet potato or potato They are grown mamly for food the dommant vanety bemg Red Wolwta Because of a good extenston program farmers practtse row plantmg weedmg and fertthzatton whtch offers better yteld potenbal (800 I 200 kg/ha) However plant populattons are sparse due to lack of seeds and as m the Central Rtft V alley sowmg dates are extremely vanable dependmg on rwnfall and preceedtng crops Dtseases mclude rust anthracnose CBB and angular leaf spot Rust ts both dommant and wtdespread The mctdences of anthracnose CBB and angular leaf spot are shght and htghly scattered Red Wolwta ts suscepbble to all these dtseases but perhaps due to the farmers pracbce of usmg healthy clean seed and weed free fields the mctdences of anthracnose and CBB are mucb reduced In the westem arcas both bush and pole beans (chmbers) are grown Pole beans are tradttiOnally grown as garden crops Bush beans are grown as monocrops or mtercropped wtth mwze or sorghum Ftve dtseases are found assoctated wtth beans rust anthracnose CBB angular leaf spot and floury leaf spot Due to the humtd condtbons prevwlmg m the west angular leaf spol and floury leaf spot are dommant In pole beans the maJor dtsease ts phoma (ascochyta) bhght and ts found m mosl gardens Scattered but shgbt mctdence of rust ts found m pole beans The eastem htghlands of Ethtopta grow beans as monocrops or mlercropped wtth mwze sorghum or chat Farmers m thts regton tradtttonally grow mtxtures of beans of dúTerent seed colours and stzes Due to secunty problems only a IIDltted vtstt was made lo thts regton and the resull obtamed ts only prehmmary From thts IIDltted survey rust and CBB are the two dtseases found wtdely dtstnbuted The large vanabon m cliDlate mfluences the level and type of dtsease occumng m these regtons Of the stx dtseases menboned m the survey report rust anthracnose and CBB are most wtdespread whtle angular leaf spot floury leaf spol and phoma bhgbt have IIDltted dtstnbulton restncted to weslem arcas of Ethtopta There ts also wtde vanabon Wtthtn regtons attnbulable to crop agronomtc and cliDlabc factors Further analysts of the survey data should reveal assoctaltons among agronomtc pracbce chmattc factors and dtsease sevenbes ASSESSMENT OF LOSSES Informabon on the IDlpact of bean rust on bean crops ts very IIDltted m Afnca A preliDltnary resull on the IDlportance of bean rust m beans m some parts of EthiOpta ts gtven m a prevtous report (Habtu Assefa, I 990) Thts study presented the results of a smgle factor and cnttcal slage analysts In 1990 1991 and 1992 field expenments were destgned to mcorporate other crop and dtsease factors 10 determme the relabve IDlportance of rust m a multtple factor phenomena The study was conducted at Ambo m I990 and 1992 and at Debre Zetl m 1991 and 1992 Dtsease levels were mantpulaled by means of fungtctde apphcabon at several spray day mtervals Crop and dtsease assessments were made at weekly mtervals 99 The results of the two field expenments mdtcate that of the four yteld components assessed seed ytelds and seed wetghts vaned most due to changes ID spray treatments Spray treatments also mduced changes m leaf area 1Ddex IDtenstty of rust and other dtseases and amount of dead ttssue At Ambo seed yteld losses of O 84 3% were recorded m Mextcan 142 and O 29 6% m 6R 39S The range of loss m seed we1ght was O 16 9% for Mex1can 142 and O 11 S% for 6R 39S The nmge of seed y1eld loss ID the Debre Ze1t expenment was 0-42% The y1elds attamed were respecttvely 1 S6 217 and 186 g/m' for Mex1can 142 and 6R 39S at Ambo and for Mextcan 142 at Debre Zett Of the four other factors stud1ed (LA! rust other dtseases dead ttssue) treatments had most effect on 1 Al and rust seventy The treatments had no stgmficant effect on the seventy of other dtseases and the amount of dead ttssue Overall the results suggested a poss1ble relat1onsh1p wtth y1eld loss under both env1ronments Seeds per pod was an unrehable parameter to determme the effects of v anat1on ID rust seventy VARIETAL MIXTURES The use of vanetal mixtures 1s common ID trad1t1onal Afncan bean product1on systems The effecttveness of vanetal m1xtures ID controlhng fungal d1seases ts well documented (Leonard 1969 Johnson and Allen 1975 Shatk 198S Mundt and Leonard 1986) The effects of bean genotype m1xtures on the development of rust was exammed under field condtttons m Ethtopta (Ambo and Debre Ze1t) and Uganda (Kawanda) m 1990 and 1991 Dueto h1gh IDterplot mterference as a result of poor performance of the soybean guard rows data collected ID Kawanda revealed no stgruficant vanat1on among treatments At Ambo and Debre Ze1t outs1de mterference was at an acceptable level and the results suggested that growmg m1xtures of res1stant (Negro Mecentral) and suscepttble (Mex1can 142) cult1vars resulted ID a low rate of dtsease expans1on and IDCrease than growmg a suscepttble genotype alone The effecttveness of vanetal mtxtures IDcreased wtth IDCreasmg levels of res1stant vanettes ID the m1xture M1xtures wtth less than 20% suscepttbles were always more effecttve than mixtures w1th greater proport1ons of suscepttbles PARTIAL RESISTANCE STUDIES Part1al res1stance (PR) a type of res1stance that causes a reduced eptdemtc bwld up of a pathogen desp1te a suscepttble mfect1on type (Zadoks and Schem 1979 Parlevhet 1981) can be expressed at d1fferent phases dunng the hfe cycle of a pathogen In determmmg the rate of ep1demtc bwld up latency penod 1Dfect1on effic1ency sporulatton capactty and sporulatton penod have been used as est1mates of PR m several pathosystems The e!Tects of genotypes leaf age and spore dens1ty on latency penod mfectton effictency sporulatton capac1ty and IDfecttous penod were stud1ed m the bean bean rust pathosystem Ftfteen genotypes three plant ages and three spore dens11tes were compared ID a completely randomtsed des1gn ID a greenhouse study at Melkassa Research Center The study revealed w1de vanatton ID both latency penod (LP) and mfectton effic1ency (lE) m response to changes m genotypes plant age and spore dens1ttes LP was mfluenced by genotypes plant age and to sorne degree by spore dens1ty Among the 15 genotypes tested LP was 9 S 16 5 11 5 17 S and 11 5 15 O days respecttvely when moculattons were performed 1 O 20 and 30 days after planttng BA T 338 1 C rematned res1stant (no pustules were observed) under all treatment combmat1ons Ex Rtco 23 (Awash 1) and A 176 recently released vanettes exh1b1ted htgh degrees of PR by showmg much IDCreased LPs LP also mcreased w1th IDcreasiDg age of plants and decreased shghtly as spore dens1ty IDCreased lEs were greatest for genotypes Ky Wonder 765 Jaltsco 33 Ky Wonder 760 and Brown Speckled and least for D1acol Caltma and !CA 15541 No rust was observed on BAT 338 IC and Ex lOO Rico 23 at 15 days after moculatlon lE was also affected by age of plants and spore dens1ty These results suggest the ex1stence of considerable vanatlon m LP and lE D1fferences m LP and lE among genotypes leaf ages and spore dens1ty suggest LP and lE to be unportant components of PR wluch can be used m the select10n of race non speclfic res1stant genotypes REGIONAL NURSERY lmprovement and select1on of res1stant vanetles form the bas1s of rust control strateg1es Smce 1989 sets of bean entnes have been composed and d1spatched to several countnes IR Afnca (Uganda Maunt•us Rwanda, Tanzama and Zamb1a) for rust evaluatlon across d1fferent env1ronments To date results are avadable only from Uganda and Eth1op•a The rust reg10nal nursery was composed of 80 entnes at Kawanda (Uganda) and 103 entnes at Ambo (Etluop•a) In 1990 and 1992 there was a good d1sease pressure at Ambo but the rust seventy was shght at Kawanda In 1991 the reg10nal nursery was not grown IR Eth10p1a but m Kawanda the tnal was conducted Wlth lugh d1sease pressure In Kawanda test entnes were evaluated al R5 R6 R 7 R8 and R9 stages of growth 24 were reSIStan! 43 1Rtermed1ate and 13 susceptible In Ambo 40 entnes were res1stant 43 1Rtermed1ate and 22 susceptible V anet1es such as PAN 134 and BA T 448 proved res1stant m both locat10ns REFERENCES Allen D J (1983) The Pathology of Trop1cal Food Legumes D•sease Res1stance IR erop lmprovement Wdey and Sons New York 413 pp Edje O T Mughogho L K and Ayon Dadu U W V (1973) Agronomy expenments on phaseolus beans Research Bulletm No 4 Ldongwe Malaw1 pp 38 67 Habtu Assefa (1990) Bean rust 1ts 1mportance ep•dem1ology and control IR the eastern afnca bean product10n system In J B Sm1thson (Ed) ProceediRgs of the Second Workshop on Bean Research IR Eastern Afnca, Nrurob1 Kenya 5 8 March 1990 eJAT Afncan Workshop Senes No 7 pp 43 62 Howland A K and Macartney J e (1966) East Afncan bean rust stud1es East Afncan Agncultural and Forestry Journal 32 208 210 Johnson R and Allen D J (1975) Induced res1stance to rust d1seases and 1ts poss1ble role IR the res1stance of multlple vanetles Annals of Apphed B1ology 80 359 363 Leakey eL A (1963) French beans and the1r d1seases IR Uganda BulletiR No 4 Department of Agnculture Kampala, Uganda 3 pp Leonard K J (1969) F actors affectiRg rates of stem rust IRcrease IR m1xed plantiRgs of susceptible and res1stant oat vanetles Phytopathology 59 1845 1850 Mundt e e and Leonard K J (1986) Analys•s of factors affectiRg d1sease IRcrease and spread IR m1xtures of •mmune and susceptible plants m computer s•mulated ep1dem1cs Phytopathology 76 832 840 Partlevhet J E (1981) Race non speclfic d1sease res1stance In J F Jenkyn and R T Plumb (Eds) 101 Strateg•es for the Control of Cereal D1seases Blackwell Sc•entúic Pubhcallons Oxford pp 47 54 Patel P N (1975) D1sease problems m gram legumes m Tanzama In R A Cure and K O Racrue (Eds ) liTA Collaborators Meellng on Gram Legume Improvement Ibadan N1gena, pp 86 88 Shwk M (1985) Race non spec1fic res1stance m bean cult1vars to races of Uromyces appem:hculatus and 1ts correcllon w1th leaf ep1dermal charactensllcs Phytopathology 75 478-481 Wallace G B (1939) French bean d1seases and bean fly m East Mnca East Mncan Agncultural and Forestry Journal 5 170 175 Wwnoelo L S (1973) Notes on field d1seases of beans Bean Research Pro¡ect Th1ka, Kenya, 15 pp Zadoks J C and Schem R D (1979) Ep1dem10lo8} and Plant D1sease Management Oxford Umvemty Press New York and Oxford 427 pp 102 STUDY OF BEAN RUST IN MADAGASCAR DISEASE SURVEY AND VARIETY RESISTANCE TRIAL ~CJ A'fRabakoanbanta and G Rakotomalala 2 1 ÚL.i • L Centre Nabonal de la Recbercbe Apphquée au Developpement Rural, FOFIFAIDRA, Antanananvo Madagascar ABSTRACT A dtsease survey showed that rust was the most tmportant d1sease of early and late sown beans m the mam growmg season of the H1gh Plateaux Ascochyta bhght was most 1mportant m m1d season beans m Antsuabe and dunng the dry season m AnJtro Moramanga The rust reachons of 25 vanelles were evaluated exposed to natural mfechon at four locahons Rust was mmor at Antsuabe but severe on suscepttble vanettes at Namsana Cala and Ambatobe Several vanehes exh1btted mmor rust m sorne locattons lktmmba Argentino and GOiama Precoce were rust free m all four nursenes INTRODUCTION lt 1s known that several d1seases affect the bean crop and conshtute 1mportant constramts to bean product1on m Madagascar Among these d1seases rust caused by Uromyces appendtculatus should rece1ve spec1al attenhon Substanhal y1eld losses (18 100%) due to rust mfestahon have been reported m Latm Amenca (Schwartz and Galvez 1980) Rust IS w1despread throughout Madagascar but 1ts 1mportance IS not known as no study has ever carned out to evaluate the econom1c loss 11 causes Moreover 1ts mc1dence and seventy are mfluenced by season croppmg system and culhvars Th1s SJtuahon renders any study of d1sease assessment comphcated and led us to propose a speclfic proJecl wh1ch was approved by the East Afncan RegiOnal Bean ProJect Steenng Comm1tee m 1991 The mam obJechves of the proJect were to assess and control crop damage due to rust to develop res•stant or toleran! bean vanehes for each bean growmg reg1on and croppmg system and to •denhfy the races of rust ex1stmg m the country MATERIALS AND METHODS To assess the 1mportance of rust a survey of bean d1seases was conducted m bean growmg reg10ns m the H1gh Plateau of Madagascar and on the expenmental fields of research stahons F1ve bean d1seases were cons1dered rust anthracnose ascochyta bhght angular leaf spot and root rots D1seases were evaluated usmg a ratmg scale of 1 to 6 where 1 s•gmfied very Importan! and 6 neghg1ble To ach1eve the second objecl•ve 25 bean vanet1es (Table 1) were tested for therr react10n to rust at four representat1ve locahons and at dlfferent limes of sowmg The expenmental des1gns used were a tnple latt•ce or a completely random1zed block m three rephcahons dependmg on the avadab1hty of space at each locahon Each plot compnsed five rows 4 m long and 40 cm apart Organ•c and mmeral fert1hzers were apphed al sowmg tilDe We rehed on natural mfect1on at all four locatJons Reachon to rust was evaluated dunng the developmental stages R6 (flowenng) R8 (pod fillmg) and R9 (physiologJcal matunty) on a scale of 1 to 9 where 1 = highly reSIStan! and 9 = highly susceptible Class•ficahon mto resistan! or susceptible was based on the percent of leaf area covered by rust pustules 103 We were unable lo work on the th1rd objecl1ve lo 1denllfy rus! races ex1stmg m Madagascar as the dúferenllal culllvars and bean rus! nursery sen! from CIA T were not released from local quarantme Table 1 Ongms of bean vanelles used m tnals Vanelles Ongms A 410 AFBYAN IJ Blanc de MaJunga Local Pmtado Bras1l Menakely Local Black Turtle Soup South Afnca Bean Redlands Collecllon CALA No 35 Rosmah G2 Brasil Gallaroy Collecllon CALA N" 21 PH 14 Prospecllon IBPGRIFOFIFA Hauts Plateaux M/car Lmgot blanc Local Rouge de Majunga Local Zebra South Afnca Il"mmba AFBYAN 11 Argentmo CIAT PH 19 14 ProspecllOn IBPGR Hauts plateaux M/car Grat10t Collecllon CALA N° 23 Gmama Precoce Bras1l Can oca AFBYAN 11 B1co de Oro Bras1l Ex RICO 23 AFBYAN 11 RanJonomby Local Small Coffee A South Afnca Octopan South Afnca Tsaram 1anankavy Local Royal Red K1dney South Afnca RESULTS D1sease survey The relat1ve 1mportance of the five classes of bean d1seases m e1ght locallons 1s shown m Table 2 The locallons s1tuated m central (H1gh Plateaux) and eastem areas of Madagascar can be class1fied mto four groups accordmg lo growmg penod In the flrSI three locallons of the H1gh Plateaux (Nan1sana Bets1zarama and Anvommamo) where sowmg was durmg the mam growmg season rus! was the most 1mportant d1sease followed by anthracnose angular leaf spot and ascochyta bhght 104 Table 2 lmportance of bean d1seases on expenmental statlons and fanners fields Locat1on Nan1sana Bets1zarama Anvommamo Antsuabe Ankazobe Ambatobe Am batondrazaka Cala AnJITO Moramanga D1sease scores 1 ANT' Rust ALS ASC ROT 5 2 3 3 5 6 3 6 5 3 6 5 4 3 2 6 2 6 4 5 5 4 6 5 6 6 6 2 6 6 6 6 6 Penod Vanet1es observed observed Jan Apr 92 25 entnes m vanety tnal Dec 91 Menakely Mar 92 Lmgot blanc Jan Apr 92 Lmgot blanc Menakely Black Turtle Soup Feb May 92 25 entnes of vanety tnal Mar Jun 92 Lmgot blanc Apr Jul 92 25 entnes of vanety tnal Aug Nov 92 25 entnes of vanety tnal Jun Sep 92 Local vanet1es 1 1 = very 1mportant 6 = neghg1ble 2 ANT = anthracnose ALS = angular leaf spot ASC = ascochyta bhght ROT = root rots In Ants1rabe where sowmg was m the m1d season (the mam growmg season begms m November) the most prevalen! d1sease was ascochyta bhght followed by angular leaf spot and anthracnose Rust was not 1mportant although 1t was observed m a few vanetles In two other locabons of the H1gh Plateaux (Ankazobe and Ambatobe) where sowmg was dunng March Apnl rust was unportant The other d1seases were neghg1ble m Ankazobe but angular leaf spot and anthracnose were notlceable m Ambatobe In the eastem part of the country m CALA and AnJITO Moramanga bean was grown as an off season crop dunng the dry season Rust was not 1mportant but ascochyta bhght was severe at AnJuo Moramanga Vanety res1stance tnal The reactlons of the 25 bean vanet1es to rust at four locatlons are shown m Table 3 In Nan1sana e1ght vanetles were 1dent1fied as h1ghly res1stant as no d1sease symptoms were observed on them They were G01an1a Precoce Canoca lkm1mba Argentmo Royal Red Kldney Octopan Pmtado and Ex R1co 23 Gallaroy and Grat10t were susceptible The vanety Octopan was lughly susceptible to anthracnose 105 Table 3 Reaction of 25 bean vaneties to rust at Narusana (NNS) Antstrabe (ATS) Ambatondrazaka (CALA) and Ambatobe (ABT) Dtsease reactions 1 Vaneties NNS ATS CALA ABT A 410 3 1 1 Blanc de MaJunga 3 2 1 Pmtado 2 1 3 9 Menake1y 3 2 1 9 Black Turtle Soup 3 2 6 Bean Redlands 3 3 Rosmha G2 3 Ga11aroy 8 3 7 PH 14 1 3 9 Lmgot b1anc anJ 3 9 Rouge de MaJunga 3 1 1 9 Zebra 4 2 6 9 lktmmba 1 Argentmo 1 PH 19 14 4 2 9 Gratiot 8 5 Gotanta Precoce Can oca Btco de Oro 3 9 Ex Rtco 23 3 1 RanJonomby 4 9 Sma11 Coffee A 4 1 9 Octopan 3 9 Tsaramtanankavy 4 7 Ro y al Red Ktdney 7 1 1 = absence of symptoms 3 = reststant 5 = mtermedtate 7 = susceptible 9 = htgh1y suscepttble NNS = Nantsana ATS = Antmabe ABT = Ambatobe In Antstrabe rust mfestation occurred wtth mmor seventy on only four vanettes Menakely Blanc de MaJunga, PH 19 14 and Zebra Symptoms of ascochyta bhght and angular 1eaf spot were observed on all vaneties In CALA shght rust symptoms were observed on the vanety Zebra wluch was thus constdered suscepttble There was no rust on the remauung vaneties Fmally m Ambatobe stx vanehes were found to be htghly reSIStan! to rust Gotanta Precoce A 410 Rosmah G2 Ex Rtco 23 lkuumba and Argentmo Btco de Ouro Lmgot b1anc Small Coffee A Octopan Zebra Menakely PH 19 14 and Ranjonomby were htghly susceptible The vanety Gallaroy was susceptible Thus three vanettes were found lughly reststant at both Narusana and Ambatobe lkiDimba, Argentmo and Gotarua Precoce 106 DISCUSSION AND CONCLUSIONS Rust appears to be the most unportant d1sease dunng the mam growmg season m central arcas of Madagascar Temperature and hum1d1ty dunng tlus penod favour mfecllon by the pathogen Dunng the dry season wh1ch nms from June to November rust was not 1mportant m CALA and AnJIIO Rust occurred on sorne vanehes m CALA and Ants1rabe but was absent from most vanehes Absence of symptoms was not dueto speclfic res1stance but to unfavourable env1ronmental cond11lons wluch mlub1ted the development of the rust pathogen Thus the unportance of rust was dependen! opon envuonmental cond11lons Such evaluahon was based solely on v1sual observahon lo gam an early understandmg of the unportance of rust m relahon to other d1seases More prec1se estunates would be obtamed from a study of y1eld m relat10n lo the seventy of the d1sease Rust was first observed m the preflowenng stage at Ambatobe on a few vanehes wh1ch were later found h1ghly susceptible but d1d not appear on most vanet1es untll pod format1on and pod fillmg The seventy of symptoms was obv10usly dependen\ on the lime when rust occurred Res1stant vanehes were •denllfied only m Nan•sana and Ambatobe where all classes of react1on were observed Also reachon of d•fferent bean culhvars was vanable dependmg on locat10n reflectmg the vanabll11y of the pathogen PERSPECTIVES understand the d•stnbut1on and vanahon of rust pathogen under field cond11lons m Madagascar des1gn control methods wh1ch m ay confer stable res1stance lo des1rable bean vanet1es WORK PLAN FOR THE FUTURE 1dentúy mam bean growmg arcas mfested w1th rust and evaluate 1mportance of d1sease study vuulence d1stnbut10n for each croppmg type 1dent•fy races usmg d•fferenhal vanet1es prov1ded by CIA T screen germplasm for res1stance m bean growmg reg10ns REFERENCES Schwartz, H F and Galvez, G E (1980) Bean Productlon Problems CIAT Cal• Colombia 107 / ' 2 7 OCT 1~98 COLLABORATIVE RESEARCH PROJECT ON COMMON BACTERIAL BLIGHT OF BEANS A F Opto and M S Musaana NARO Kawanda Agncultural Researcb Instltute, Kampala, Uganda ABSTRACT StudJCs of breedmg methods and resJSlance of beans lo common bhght were conducted 1 he nature and cxtcnt of vanabll1ty of Xanthomona.J campe.Jtru pv phaseolr (Xcp) tts transmtsston and surv1val and y1eld losses assoctated wtth the pathogcn were also studted Dtfferences ex1st m levels of res1stance between leaves stems pods and seeds on the same plant Gene achon controlhng res1stance m most of the crosscs studtcd was addthve but was mfluenced by the growth stage at whrch data were recorded The pathogemc vanahon of Xcp was quanhtahve on Phaseolus vulgans and quahtahve on P acutlfollus There were d1fferences m Xcp transm1sston effic¡ency among bean genotypes The seed to pnmary seedlmg mfechon ratio rangcd bctween 1 1 and 1 3 hfteen spec1es of weeds and two non host crops supported cp1phyhc populahons of Xcp Y 1eld losses ranged from 61 7% m suscephble genotypes to ms1gmficant m res1stants JUSTIFICATION Common bactenal bhght (CBB) caused by Xanthomonas campeslns pv phaseoll ts a maJor d1sease of beans m eastem Afnca lt 1s the second most prevalen! dtsease of beans tn Uganda after angular leaf spot (Sengooba 1985) lt 1s ranked second m tmportance m Malawt thtrd m ZBire and Ethmpta fourth m Kenya stxth m Rwanda and seventh m Tanzanta and Zambta A regmnal sub project was mthated m 1987 lo mvesltgate dtfTerent aspects of the dtsease m order lo devtse effechvc and cconomtc control measures for farmers m thc regton The rcsults obl81ncd betwcen 1987 and 1989 were reported m an earher workshop (Musaana and Opto 1990) The prcscnt report mcludes rcsearch and results obtamed from 1990 to 1992 OBJECTIVES To study the pathogemc vanahon of Xanthomonas campestns pv phaseoll (Xcp) ID eastem Afnca 2 To contiDue tdenhfyiDg entnes for the Eastem Afncan Regmnal Common Bhght Nursery 3 To IDcorporate resJstance to CBB mio landraces and estabhsh quanhtaltve dtfTerences among res•stant sources wtlh respect to suscepllbJhty to CBB 4 To study the ID!errelatmnshtps between res1stance lo CBB and quahty lrBils m common bean 5 To study the stages where selectton ID segregatiDg populattons JS rehable 6 To estabhsh the relattonshtps between seedhng and adult plan! restslance and compare greenhouse and growth cham ber methods for predtciiDg field reststance 108 7 To detemune whether there are dlfferences among genotypes m theu ab1htv to transout CBB w1th a v1ew to selectmg for low seed transm•ss•on effic•ency 8 To study the surv1val of Xcp on weeds non hosts and mfected debns and m s01l 9 To determme crop loss due to CBB RESULTS The results w1ll be descnbed for each obJecllve m the order g1ven above PathogeDic vanauon of Xcp 10 Eastem Afr1ca Nmety three Xcp 1solates were collected from five countnes m eastem Afnca as follows Uganda (68) Etluop1a (13) Tanzan1a (7) Rwanda (2) and Kenya (3) The vanallon of the Isolates was Imtially stud1ed usmg growth charactensllcs on media The med•a used were MXP (a semi selecllon media for Xcp} yeast dextrose carbonate agar (YDCA) Kmg s media B (KMB) and Nutnent Broth Yeast (NBY) KMB and NBY were used to detect the brown p1gment produced by the fuscous vanant (Ramos el al 1991) The 1solates dlffered m the1r growth charactensllcs on media Three quarters of the •so lates collected were fuscous vanants and one quarter were yellow The fuscous vanants were slower growmg and smaller m s1ze than the yellow types The Isolates were grouped mto 15 phage types but there were no correlations among phage type pathogemc1ty and geograpluc ongm Thuty Isolates were selected for testmg on 20 common bean and 8 tepary bean genotypes on the bas1s of the contrasllng envuonments of collection All the Xcp •solates tested mduced sorne react1on on the 20 common bean genotypes (Table 1) There were dlfTerences m aggreSSiveness of the 1solates There were significan! (P7 mm water soaked area around the cut) ' 17 1solates wh1ch mduced no reacllon on any of the e1ght genotypes of Phaseolus acuhfobus were 1046 1040 1042 1030 1029 1096 1090 1 O 11 1112 1099 1033 1074 1066 1002 1007 1026 and 1043 Eastera Afncan Regtonal Common Bactenal Bhght Nursery (EARCBBN) The EARCBBN 1s composed ofbean !mes that are reSIStan! to CBB m the reg10n The present nursery mcludes 70 entnes from Eth10p1a, Uganda Kenya Tanzama Rwanda Burund1 and Malaw1 In 1991 the nursery was evaluated m Uganda Rwanda and Eth1op1a In 1992 11 was evaluated m Rwanda Eth1op1a, Tanzan1a Zrure and Kenya Results have not been rece1ved from Tanzan1a and Zrure Lmes m tlus nursery can be ullhzed by breeders m nat10nal progr810ems for 1mprovmg res1stance to CBB The breeder has ullhzed sorne of the !mes m th1s nursery to 1mprove the res1stance of acceptable bean vanet1es from Uganda, Eth10p1a Rwanda and Tanzan1a The entnes w11l be changed penod1cally dependmg on the avrulabd1ty of new genotypes reSIStan! lo Xcp TransmiSSIOD effic1ency Ten ehte bean breeders !mes from d1fferent countnes m eastem Afnca and the five most aggress1ve Xcp 1solates (Op1o 1991) were used for tlus study The bean !mes mcluded K20 R WR 136 239 B b 1 GLP 585 2439 B b 1 Awash 1 Cal 96 Roba 1 ICA Lmea 64 and MCM 585 Kasuka Nywele and Kanyebwa were susceptible controls and XAN 112 was a res1stant control The Xcp 1solates were 1068 1073 1069 1010 and 1029 110 There were stgnúicanl dtfferences {Pts and 1mprovmg y1elds and confirms prev1ous observallons made 10 greenhouse tnals (Buruchara 1991) lt 1s thought that the effects of the leucaena m ay be dueto mcreased m1crob1al acllvlty and IDiprove ment of nutnllonal status resultmg from liS decompos111on Leucaena was the organ1c amendment most apprec1ated by collaboratmg fanners dunng all the seasons tested Des•rable attnbutes c1ted were 1 reducllon of loss of plants due to root rots 2 mcrease 10 y1eld 3 mercase 10 vegetallve growth (for leaf consumpllon) and 4 pos1!1Ve residual effect on sorghum grown after beans The m81D constramt c1ted was avadabd1ty of suffic1ent quanlllles but farmers showed mterest lo produce the green manure as hedgerows or on contours Ra1sed beds and ndges Rrused beds had no effect on d•sease seventy or y1eld 10 1991 A and B 10 e1ther on stallon or on fann tnals As a result farmers d1d not cons1der them useful opt1ons 10 the management of roo! rots They also regarded theu h1gh labour demands as addillonal d1sadvantages Th1s was the bas1s for mod•ficat•on and subsequent testmg of ndges In on stallon tnals rrused beds s•gmficantly IDiproved 115 dry matter productton The efTect of ndgmg was apparent m 1992A when ramfall was heavy dunng the seedhng stage and root rots were severe Plant mortaltty due to dampmg-ofT of the local vanetal mtxture was reduced by about 40% at both V4 and R6 stages and yteld was mcreased by 139% (Table 2) The advantage of usmg ndges wtth the reSIStan! vanety RWR 221 was small (7%) In 19928 the rams were relattvely poor and there was no effect of ndgmg on dtsease seventy and yteld Table 2 Effect of vanety and ndgmg on seventy of root rots and yteld m on fann tnals at Runymya 1992A season % plant loss Y teld advantage Dtsease Yteld (% LM wtth V4 V6 seventy (kg/ha) out RD) Treat Vanettes ment 92A 928 92A 928 92A 928 92A 928 92A 928 ---- Local m txture RD 46 5 11 4 51 o 34 6 38 9 390 672 +RD 280 10 4 30 2 28 2 16 o 935 737 139 9 RWR 221 RD 12 8 10 4 13 7 19 6 18 o 1670 1620 328 141 +RD 7 1 83 78 19 1 97 1786 1562 358 132 CV(%) 33 5 27 9 32 3 37 6 32 9 35 9 35 4 ---- LM = local m txture RD = flat +RD = ndged 1 = plant loss at V 4 and R6 expressed as % of seed sown 2 = dtsease seventy as % hypocotyl and root ttssue covered wtth lestons = prured treatment means stgmficantly dtfTerent (pe me lude host plan! res1stance cultural prachces and chemicals chicJly as seed trcatmcnt Moderate sourccs of reststance have been Idenllfied and these are m use m brcedmg programmes to mcorporatc reststance mto local vanehes An evaluahon of vanous cultural methods such as carthmg up mulchmg and 1mproved fert1hty md1cate that mulchmg of f1eld plots reduced plan! mortahty from BSM attack by 38% compared lo the control and that mulchmg combmed w1th 1mproved sml fert1hty reduced plant mortahty evcn further l-ohar apphcahon of certam botamcal peshctdes such as alcohol extract of neem sccd powdcr and aqueous extract of Tephros1a leaves also reduced mfestahon by BSM and mcrcascd ytelds Fteld evaluahons of these and other taches m an mtegrated system are now m progress m small scale farmer s1tuahons INTRODUCTION Bean stem maggots (BSM) (Ophwmy1a spp) are cons1dered the pnnc1pal msect pests constrrumng bean producllv1ty m many of the crop s growmg envnonments m Afnca and As1a Threc spec1es O phaseob O spencerella and O centrosemat1s are known to attack the crop but then d1stnbut1on and 1mportance vary w1th locallon and season The naturc of damage caused by the dlfTerent spec1es 1s qu1te S1m1lar Young plants w1lt and d1e In older plants stcms crack and lodgmg may ensue Damage 1s most severe when seedhngs are attacked and m stress s1tuallons (mferllle sotls drought or d1sease) BSM often causes total crop frulure Vanous methods have been proposed for thc control of bean stem maggot (BSM) m beans These mclude chem1cal apphcallon notably hndane or endosulfan sced drcssmg (Lays and Autnque 1987) cultural pracllces mcludmg earthmg up (Moulla 1944) and mcreased plant populallon (Tsedeke Abate 1990) and change of sowmg dates The effic1ency of these methods vanes w1th lime of apphcallon and env1ronmental cond11lons and sorne of them m ay be mcompat•ble w1th the trad1t10nal pracllces of sorne commumlles Sources of res1stance ex1st m vanous germplasm access10ns but have not been adequately ullhsed al fann level A pnnc1pal ob¡cct1ve of the entomology network m the CIA T reg1onal bean programmes 1s to develop IPM strateg1es Wlth adequate flex1b1hty for use by rcsource poor bean growers Many chemtcals for BSM control have been reported but they are unava•lable lo fanners m many cncumstances and m other s1tuat1ons then use 1s often mcompallble w1th fanncr pracllce wh1ch makes cultural control methods more appropnate lo the systems of rcsource poor fanners Th1s paper reports on progress m 1denllfymg components for poss1ble IPM strateg1es for bean stem maggots HOST PLANT RESISTANCE Over three thousand germplasm access10ns and CIA T breedmg hnes largely compnsmg matenals m store al the Sehan Agncultural Research lnslltute Arusha Tan/.ama havc bccn screened for BSM 149 resistance Methodology IS based on mfestallon levels and plant mortahty due to BSM attack As BSM population acbvity vanes over bme populabons were morutored through trappmg and mspecbon of field plants Test entnes were sown to comcide with pest mfestation of about 4 msects/plant and plants were morutored regularly for mfestallon and damage Resistance was categonzed by the distnbutJon of the means and multJples of the standard deviation Results from the preliiDmary evaluation mdicated that only low to moderate levels of resistance exist m tlus set of matenals (Figure 1) The performance of matenals categonzed as moderately resistan! was compared agamst Lyamungu SS treated Wlth endosulfan (Table 1) Wlule the susceptible check (Lyamungu SS untreated) suffered 34% mortality due to BSM several of the test entnes (G 12670 x G 4727 2 7126/DR 670 x G 5701/D 145 Montcalm 4 86 EP 5022 B and TMO 126) performed simiiarly to the resistant check Table 1 Emergence stand counts (STE) total seedlmg mortality (TSM) number of bean stem maggots/dead plant (BSM/DP) and total (TM) and percentage (%M) mortality of most resistan! entnes m prehmmary evaluatJon at Sehan ---- BSM/ Entnes STE TSM DP TM %M G 12670 X G 4727 2 22 o 07 00 33 33 7126/DR 670 X G S701/D 145 37 S 1 S 40 44 44 Montcalm 4 21 o 1 S 25 56 56 G 13936 X A 487 29 o 20 43 72 72 TMO 237 25 S 20 39 75 75 86 EP 5022 B 27 S 25 45 87 53 81 ce 62 x Horsehead 40 o 35 23 89 77 Royal Red x Canadian Wonder 2 22 o 30 36 10 3 86 TMO 126 31 S 3 S 6 1 10 8 34 BAT 1337 x G 6592 2 34 o 40 00 12 o 12 o ACV 8331 23 S 35 45 15 o 15 o Cbecks Lyamungu 85 37 2 16 S 83 44 4 34 4 Lyamungu 85 + endosulfan 37 S 1 8 30 49 40 ZPv 292 38 o 10 8 33 289 23 4 Mean 28 2 93 46 33 4 29 6 LSD (P 15 plants/plot) m both treatments but mortaliiies due to BSM alone were only about SO% of the total Also the numbers of BSM per dead plant were relatively few suggesllng an mteracbon between BSM and other factors m the express10n of dam age observed 150 Figure 1 Relatlve levela of realatance In germplaam evaluated at Aruaha " entrlea 70 80 50 40 30 20 10 o R MR INT Realatance ratlng R realstant MR moderately reslstant INT lntermedlate MS moderately susceptible S susceptible MS S Table 2 Total seedhng mortal1ty (TSM) mortaltty due to bean stem maggots (MBSM) number of bean stem maggots/dead plant (BSM/DP) percent plant mfestat10n at five W AE (%PI) and seed ytelds/plot m BSM Reststance Reconfirmatory Nursery at Sehan TSM MBSM BSM/DP %PI Yteld Entnes + + + + + G 5773 15 7 15 o 10 7 97 49 47 86 7 86 7 1430 1411 G 2072 14 o 12 o 57 63 42 3 8 80 o 93 3 1501 1380 Smon 70 20 53 1 7 52 23 93 3 86 7 1733 1621 G 6725 19 3 70 16 o 43 73 20 93 3 73 3 1214 1341 G 3844 17 7 15 o 10 7 77 30 58 100 3 86 7 1325 1619 ZAA 12 130 70 40 30 69 22 86 7 93 3 1606 1894 BAT 1373 97 11 o 53 50 36 23 93 3 80 o 1379 1507 ZPv 292 40 1 o 20 03 08 00 93 3 100 o 1921 2136 LY 85 18 7 1 3 16 7 1 o 39 07 93 3 73 3 1655 1859 Mean 13 9 86 89 46 43 27 90 7 86 o 1504 1574 LSD 43 39 23 12 6 698 = wtthout endosulfan seed dressmg + = wtth endosulfan seed dressmg 151 Our other stud1es show strong mteract10ns between BSM mfestahon and root d1sease mfect1on on seventy of damage express1on Th1s was confirmed m a screenhouse study where bean plants were grown on sml mfested w1th Fusanum oxysporum and exposed to BSM when plants were m the V 1 stage m a faetona( des1gn Plant mortahty was s•gmficantly mcreased m plants exposed lo both adversanes than to e1ther alone (F•gure 2) To remove tlus confoundmg mterachon proteehon agamst root d1sease and other adversanes •s recommended when assessmg BSM Infestat1on Crosses between resistan! access10ns and adapted cult1vars have been m111ated al both CIA T and m T anzanta through a Reg1onal Collaborahve Research Sub pro¡ect Early results md1cate that the res1stance 1s transferable CULTURAL CONTROL Vanous cultural control methods (lime of sowmg crop rotabon plantmg dens1ty eartlung up and mulchmg) that are used by farmers were constdered and sorne of these were evaluated for therr potenllal m BSM damage control The treatments were (t) heapmg of sotl at the base of plants dunng fmt weedmg 2 3 WAE (earthmg up) (n) mulchmg wtth chopped banana leaves (111) apphcat1on of morgan•c ferllhzer at recommended rates (enhanced fertthty) (tv) endosulfan seed dressmg at 5 g of 47% WP per kg of seed (v) control (seeds sown on the flat Wlthout any of the above treatments) and (vt) vanous combmat10ns of these treatments In general none of the treatments affected plant emergence stgmficantly even though mulchmg seemed to mduce ettolat10n of seedhngs Mulchmg also mduced shght yellowmg of the leaves but these symptoms dtsappeared before the plants reached growth stage V4 Plant mortal1ty began as early as 16 DAE and contmued unlll about 40 DAE after whtch mortal1ty was s•gnmcantly reduced (F•gure 3) BSM mfestat10n (5 msects/dead plan!) and subsequent plant mortal1ty (11 plants/plot) were moderate Treatments wtth chem1cal seed dressmg showed the most effecbve control of BSM Mulchmg was the only smgle non-chemtcal treatment that reduced plant mortal1ty s•gn•ficantly below that of the control Total plant mortal1ty was reduced m all the mulch treatments even though mulchmg d1d not reduce •nfestat10n per se BOTANICAL PESTICIDES Certam plant extracts reputed to have msecttctdal propert1es were evaluated alongs1de endosulfan seed dressmg for therr performance agamst BSM These were (•) neem (Azad1rachta md1ca) seed extract (NSE W) m aqueous solutlons (n) NSE AL m alcohol (111) Tephrosw leaf ¡wce solubon and (1v) mwze leaf ¡wce The extracts were d1luted to 1 O% and sprayed on to the plants untd dnppmg at three day mtervals from emergence to flower bud Imllallon Plants were momtored for feedmglov•positiOn punctures (as an mdex of BSM adult actlVIty) BSM 1nfestat•on levels plant mortal1ty and y1eld Endosulfan seed dressmg had no effect on adult BSM actlVIty but reduced 1nfestallon (Table 3) NSE AL and Tephros1a ¡wce reduced ovipOSIIlon/feedmg puncture counts md1catmg a deterrent effect from these substances These reducllons m BSM acllvlly on test plots were reflected m mfestat10n levels plant mortal1ty and y1elds Mwze ¡wce and NSE m water had no effect on BSM There were direct and s1gmficant correlat10ns between BSM actlVIty and Infestat10n levels plant mortal1ty and yteld 152 E F 10 30 Total dead planta Figure 2 The effecta of the lnteractlon between BSM and Fuaar.um wllt on bean plan! mortallty Con !rol Fua 1 Fua 2 Fua 1 •BSM Treatment Fua 2 BSM Figure 3 Effect of cultural practica on plan! mortallty due to BSM Number of dead planta --M -+-S --'j<-- E M FS -a-Ms --*- EFM ~Control 25 20 15 10 5 o 15 17 19 21 23 25 27 29 31 33 Daya aftar plant emergence earthlng up M mulchlng fertlllzatlon S aeed dressing 153 BSM -A- E 35 37 Table 3 Effects of botamcal pest•c•des on BSM ovJposJtJon and 1Dfestat10n plant mortal1ty and y•eld Ov•pos•hon/ BSM/ Cumulat1ve Total Y•eldl feediDg plant BSM plant plot punctures (R5) seo re loss (g) Control 90 3a 73 430 38 3 191 Ma•ze Jmce 88 3a 95 376 41 5 177 Tephros1a JUICe 47 7b 6 1 300 32 7 232 NSE W 85 Oa 78 324 35 5 174 NSE AL 43 2b 73 240 25 o 274 Endosulfan 94 8a 3 5 66 72 338 DISCUSSION Most bean farmers are resource poor and do not rely on purchased 1Dputs ID the1r pest management taches Such farmers are unhkely to adopt ng1d packages but w11l select components that they can read•ly afford Any IDtegrated management strategy developed for use by farmers should therefore be fleXIble w1th ophons for step by step adopt1on of IDdiVIdual components The key components cons•dered ID the present study were host plant resJstance cultural control and botarucal pestJcJdes all these are renewable w1th1D the farm env1ronment and farmers do not need extra fiDanc•al resources to acqmre them They would however need educahon ID the1r use and management Some of the components need mod•ficatJons to 1mprove the1r effic•enc•es and cons•derat10n needs to be g1ven lo other components ID d1fferent farmiDg systems In th1s study there were s•gmficant correlahons between ov•pos•t•on (feediDg punctures) mfestat1on levels plant loss and y1eld levels These relat•onsh1ps m ay be evaluated further for use across vanet1es ID pred•ctiDg potenhal y1eld loss and to determiDe the econom1c threshold levels needed lo JUShfy the cost of 1Dputs or operahons as well as servmg as a bas•s for schedulmg measures mmed al reducmg pest damage lnd1ces such as ov1pos•t•onlfeedmg punctures would also help farmers recogmse early s•gns of attack and make management dec•s•ons Other components that would fit mto a management strategy IDclude (1) prophylact•c treatment (e g seed dressiDg) ID arcas where the pest •s endem1c (such chemJcals need system1c qua!Jhes and to be relahvely pers1stent) (n) remedia! apphcahon of chem•cals (such chem•cals would essenhally be system•c or at least penetrahve ID nature to reach the pest wh1ch spends 1ts enhre developmental stages w1tlun the plant t1ssue) (m) sowiDg date adJustment ID arcas where penods of peak occurrence of damagiDg populahons are well known to avo1d plant exposure lo these populatJons The effect of cropp1Dg systems on the IDCJdence and damage caused by BSM needs lughhghtiDg The 1Dteract10ns of sml mfert1hty and root d1sease w1th BSM attack on the seventy of damage express10n suggest the need for a mulhd•sc•phnary approach to the development of IPM strateg•es for BSM 154 REFERENCES Lays J F and Autnque A (1987) La Mouche du Hancot F1che Techmque No 008 Serv•ce de Prevulgansat1on D•v•s•on de la Defense de Vegetaux ISABU BuJumbura Maulla A ( 1944) The beanfly Melanagromyza phaseoll ln Annual Report Department of Agnculture Mauntrus 1944 Port Lou•s Maunllus pp 16 17 Tsedeke Abate (1990) Stud1es on genet1c cultural and chenucal methods for beanfly Oph10my1a phaseoll (Tryon) (D1ptera Agromyztdae) contrul PhD D•ssertatton S1mon Fraser Umvers•ty Vancouver B C 199 pp 155 DISCUSSION SESSION IV INTEGRATED MANAGEMENT OF DISEASES AND PESTS Cbrur W K Rono Rapporteur F Maktnt Paper by Habtu Assefa Quest10n Is 20% of a destrable susceptible componen! wtth 80% of a less demable reststant vanety an acceptable practtce as evaluated by farmers? Response Of the two vanetles m thts tnal MeXJcan 142 and Negro Mecentral only Mextcan 142 ts acceptable to farmers Thts tnal should be tned agam wtth an acceptable reststant vanety but the study does show the proport10n of suscepttble and reSJStant that would be needed Bu ruchara The proportton of the susceptible componen! m the mtxture •s mfluenced also by farmers preferences Studtes conducted m Zrure to 1Dcorporate reststant components m farmers mtxtures showed that farmers had no obJeclton to 25% of the reststant componen! 1Dcorporated but obJected to 50% Paper by A Rabakoanbnnta and G Rakotomalala Sengooba lt may be good to harmoruze the gradiDg scale so that the range from tmmune to very susceptible •s conststenl m the tables ID your paper In the gradmg scale 1-6 the numbers 1 lo 6 were arlutranly asstgned lo dtfferent dtseases to classúy them ID order to gel an overvtew of therr relattve tmportance Number 1 means flfSI ID tmportance because of 1ts htgh frequency and seventy whereas the gradiDg scale 1 9 whtch 1s a standard scale for evaluatiDg a reactlon to a parttcular dtsease was used to classtfy the host plants These two gradmg scales have notlung ID common Questton There seems to be constderable vanabthty m dtsease scores for each culttvar 1 e rated suscepttble ID one area and restslanl ID another Do you attnbule thts to vanable envrronmental condtltons or vanabthty ID pathogen? Rabakoanbnnta 1 thmk the vanabthty 1s due both lo envrronment and the pathogen Bu ruchara In your evaluat10n of the 25 vaneltes 11 does appear that al two sttes (Narusana and Ambatobe) dtsease levels were lugh but m the other two dtsease levels were low or the race consltlutlon •s dúJerent lkmtmba 1s reststant ID all your sttes whereas 11 ts very susceptible m Rwanda Thts suggesls dtfferences m races between the two countnes Paper by A F Opto nnd S Musaana Quesllon You mdtcated that much ofthe reSJSiance to CBB comes from lepary bean (P acuhfohus) You also mdtcated maternal effects ú tepary bean •s used as female How crossable are the two 1 e P vulgariS and P acutlfollus? Dtd you have any problems ID the F 1 and F 2 generattons? Answer The two sources used were mterspecúic hybnds made ID Braztl and sent to us from Umverstty of Nebraska UsiDg them as females gave a lugher frequency of reststant genotypes 156 Paper by R Burucbara, U Scbe1degger and L Sperhng Tesfaye Besb1r As you know root rot attacks crops m patches how do you keep the umfornuty of the pathogen m the soll dunng evaluat10n? Burucbara We use fields where moculum levels are h1gh and umform But we also carry out artificial moculallon to venfy res1stance AJanga What 1s the mechan1sm by wh1ch apphcat10n of organ1c manure reduces root rot problems m beans? ls 11 the effect of m1crob•al actJVJty or mcreased fert1hty due to the organ1c m alter? Burucbara We thmk that m1crob•al actJvJty 1s mcreased when we add organ1c amendments and some of the m•crobes have an antagomstJc effect to s01l borne pathogens Some of the organ•c amendments (e g agroforestry legummous spec1es) mcrease s01l fert1hty wh1le others (e g sawdust) do not It depends on the type of orgamc m alter QuestJon D1d you find any of the organ1c amendments aggravated root d1seases or d1d all of them 1mprove the sJtuat10n? D1d you check the compos•llon of the organ1c amendments you used? Burucbara We used organ1c amendments m the form of green manure of agroforestry spec1es Those used had e1ther pos1t1ve or no effects but none aggravated root rot d1seases The compos•llon of some of the orgamc amendments were checked Paper by M S Nabdy Klrkby The plants found to be used by farmers m bean storage should be •denllfied by a botan1st (e g Nmrob1 Museum prov1des a serv1ce)? Total control of Zabrotes can be ach1eved through use of a smgle gene for res•stance and th•s paper shows that excellent control of Acanthoscebdes can be ach1eved by s1evmg Both results are from research stations 1 suggest that the workmg groups address the 1ssue of acceptabiiity to farmers and transfer of the technology to ach1eve 1mpact morder to onent the sub project for future acllviiies? Nabdy Some of the plants were from Tanzama we w11l arrange to collect them for Identification On farm tnals Wtll begm and acceptabdJty Wlll be tested Solar heat d1smfestat1on should however be conllnued on stahon to arnve at safe temperatures and exposure limes that do not render the seeds mviable? Question You menlloned several tradihonal herbs and methods used m control of bruch1ds? Do you have plans to mvesllgate and quant1fy the1r effecllveness m the control of bruch1ds? How effecllve are they compared to commerc1al msecllc1des? Nabdy Y es Most are however JUSI repellents and therefore not effecllve m kllhng bruch1ds Sahb In some countnes chem1cal control of bruch1ds proved to be very effecllve 1 wonder why you have not tned to use such a method? Nabdy Limited avallabihty of chem1cals at the on farm level cost often too h1gh shelf hfe hm1ted msecllcide m1suse sowmg m parts of Uganda mvolves puttmg seeds m the mouth and sp1ttmg and msecllcide use 1s dangerous 157 Ampofo Chemtcals are sometunes mcompattble wtth farmer practtces In some areas farmers pul seed m thetr mouth and sptt out dunng sowmg Chemtcal apphcatton wtll patson them The obJecttve here ts to develop components that the farmer can use to control bruchtd damage te chemtcal and non chem tcal Ampofo Two methods are bemg compared here solar heat treatment and stevmg In essence they are the same Solar heat allows adults to escape and when the beans are rebagged eggs are lefi behmd Stevmg dtrectly removes both adults and eggs from the beans Mecharucal stevmg explams the mechantsm of bruchtd (Acanthoscehdes obtectus) removal through solar heatmg Mulagolt What control measures should be mstttuted to preven! or mtmmtze field mfestatton b) bruchtds? Stevmg may be labonous and tune consummg Nahdy Frequent sunmng soon afier harvest Questton Some farmers menttoned that debns reduces bruchtd mfestatton How much debns was m your unsteved beans? Nahdy Unsteved beans had no debns Debns does not reduce bruchtd mfestatton Ndentu What losses occur dunng stevmg? Nabdy Mtmmal losses Paper by J H Ndentu and J.J Anyango Wortmann Your survey has ytelded much mformatton on farmers curren! pest management/control practtces What are the tmphcattons for future research? What role wtll farmers play m thts research Ndentu Develop an IPM package On farm tnals on IPM to mvolve farmers m the development of a package Aberra Deressa One of the shdes mdtcated that farmers have more knowledge than extenston agents (tf 1 correctiy understood) Why ts tt so? Ndentu No The shde attempted to show a dtfferent aspect It ts the farmers source of knowledge quened as farmers never went to extenstomsts for mformattan Questton Where do farmers obtam thetr Frenchlsnap bean seed? Are the beans under tmgatton or are they ramfed ? Ndentu They mamly obtam thetr seeds from seed campantes Beans are grown under tmgatton dunng the off season and under ramfed condtttons durmg the two ramy seasons Mtcbteka You mdtcated that farmers spray snap beans more than 15 ttmes Don t you thmk thts wtll affect Kenya s markets espectally m Europe? Ndentu Y es and as result we should teach our farmers what to spray and when Thts can be done through extenstan staff of the Mmtstry of Agnculture 158 Tenaw Workayehu Farmers spray many limes before flowenng This seems costly What was the response of farmers towards the cost and Ume when mterviewed? Ndentu They complamed about the cost of chemicals but the crop seemed profitable to them The farmers have no other acllviiles except farmmg and thus never complamed about the lime General d•scuss•on In the fmal general discussion Il transp•red that damage due to sorne msects (e g miihpedes cutworms bollworms) IS underest1mated These can cause up lo 100% loss (e g cutworms at emergence) lt was menlloned that d1eldnn and aldnn were very effecllve agamst s01l pests but have been w1thdrawn due to their tox•c•ty and ll •s because of this the problem has mcreased Diazban (msecllcide) IS recommended to farmers for s01l pests Pawpaw Impregnated with furadan can be used agamst gianl miihpedes Furadan can also be used agamst other bean maggots Methods of assessmg yield losses related lo particular diseases or pests were discussed Two approaches were descnbed The first mvolved controlhng all other factors except the one bemg studied and performmg muluple regression analyses mcludmg all problems The analys1s assumes components are uncorrelated and th•s IS usually mcorrect Therefore sub sets of uncorrelated components should fJISI be exammed Another approach 1s to consider the distnbution of diseases One area may have one or two diseases and the losses they cause can be assessed D1seases vary from season to season and the losses can be assessed accordmg to the d1seases present al the lime However If pnonllnng d•seases •s needed then losses must be assessed md1vidually Susceptible mtermediate and resistan! genotypes should be used to estUDate potential losses Note that the same genotype can be resistan! m one environment and suscepllble m another Environments also have a role e g m a fertiie area losses wdl be less than m an mfertile area even If there IS mfestat10n Therefore Il IS not a foolproof exerc1se Chemical usage was also discussed Chemicals have to be Imported are costly and are health hazards It was suggested that an mtegrated approach IS best Resistance IS most effecllve but cultural methods should be mcluded and chemicals are preferably avoided Root rots m ay be UD portan! m reg10ns other than the Great Lakes A speaker was mterested to know whether CIA T IS mterested m domg work similar to that m the Great Lakes m other reg10ns Symptoms caused by root rots can also be caused by other factors e g BSM lf there are mdicallons of a root rol problem CIA T wiii assist Makmg beds for the control of root rots m ay mcrease BSM damage In northem Rwanda where ramfall IS high this pracllce IS common In southem Rwanda where BSM can be a problem there IS less ramfall and rrused beds or ndges are not used For BSM control grasses and weeds can be buned m the ndges This Improves the s01l and mcreases fertihty and reduces losses because the plant IS more vigorous but does not reduce BSM mcidence Rust resistance was discussed m relation to the race Situation and to the different types of resistance avrulable When workmg with a pathogen Isolates should be collected from beans throughout the region of mterest and used for evaluation Greenhouse studies are des~rable to disllngUish vertical and parllal resislance Another approach IS to test a nursery of suscepllble mtermediate and resistan! genotypes across countnes lkimmba IS a susceptible check m Uganda and Rwanda but m Madagascar Il IS resistan! SUDIIarly for BSM JkmUDba was the best variety m Burundi but worst m Shangwa (Truwan) but tlus was mrunly an adaptatiOn problem 159 -- Breeders are concemed when they obtam a very reststant genotype as tls reStStance ts probably govemed by a smgle gene and ts hkely to break down sooner or later Other tratts whtch have to be constdered are seed type and yteld There was concem wtth the stage at whtch farmers become mvolved KARI s emphasts ts lo start wtth the farmer before any research ts done Wtth bruchtds farmers were mvolved However some technology has to be tested before farmer mvolvement There are advantages and dtsadvantages m early or late parttctpallon of the farmers Wtth root rots farmers were mvolved early and thts was advantageous because practtces unacceptable lo farmers were dtscarded after one season and subslltuted by acceptable pracllces Thts led to early adopllon of the technology lt was pomted out that both farmers and extenstontsts should be targets lt was concluded thattoo much lime should not be spent on stallon and that farmers should be mvolved early Problems of germplasm exchange were noted Thts should be addressed by Dm:ctors of Research of affected countnes and ti was agreed that CIA T should produce an updated annotated check hst of pathogens and pests for every countty m Afnca Thts ts m progress and wtll be com ptled pubhshed and sent lo quarantme servtces to help allevtate thts problem 160 2 1 OCT 1S98 EVALUATION OF BEAN GENOTYPES AND RHIZOBIA STRAINS FOR NITROGEN FIXATION POTENTIAL ON TWO SOIL TYPES IN ETHIOPIA Mttlku Hade Alemaya Untverstty of Agnculture, Dtre Dawa Etbtopta ABSTRACT Four dtfferent expenments were conducted to evaluate the mtrogen fixahon potenhal of bean genotypes and rhtzobta strams on Alfisols and Verhsols In an evaluahon of four bean culhvars sole and m assoctat1on wtth two sorghum vanetles moculatton mcreased the ytelds of Black Dess1e 13% m assoctahon wtth the tall sorghum and by 100% m assoctahon wtth the short sorghum All culhvars responded to moculahon when sole cropped although the responses were small In the rhtzob1a screenmg all 20 strams mcreased bean dry matter and N content and most tmproved nodulahon on both sotls Seven strams mduced better ytelds than the unmoculated control on the Alfisol and four on the Verttsol The apphcahon of N mcreased bean dry matter and N content but depressed nodulat10n We exammed the responses of mne bean genotypes on an Alfisol and ten others on a Verhsol to moculahon wtth a mtxture of rhtzobta strams lnoculahon tmproved the nodulahon of all genotypes on each sotl Y te id responses vaned among genotypes Apphcahon of 46 kg ha 1 N mcreased the ytelds of Mextcan 142 by 26 % on an Alfisol and by 30% on a Verttsol both mcreases bemg htghly economtc Further screemng of strams and genotypes under dtfferent croppmg systems and of strams for perststence and competlhveness ts recommended INTRODUCTION In Ethtopta hancol bean ts commonly grown m the 1 400 2 000 mas[ range IDcludiDg the Rtft Valley Except m hmtted areas where ti ts grown ID monoculture the culttvatton of beans ts mamly ID assoctahon wtth other cereals coffee and fruti crops The average nat10nal yteld ts very poor when compared wtth the yteld obtamed on research slattons (Amare Abebe 1987 Mtttku Hade 1990) due lo losses through dtseases pests and poor sotl fertthty (Tsedeke Abate 1990) and smallholder farmers can not afford lo apply fertthzer (Storck el al 1991) Prevtous studtes showed the agronomtc benefits of growiDg beans ID assoctalton wtth cereals and demonstraled the need for IDveshgaltons of mtrogen fixalton (Dagnew Selasstes 1981 Amare Abebe andA Btrhanu 1984) Ltke any other legume beans fix atmosphenc mtrogen Explotlahon of btologtcal mtrogen fixatton through moculahon wtth rhtzobta would be a cheap allemattve to mtrogenous fertthzers whtch are unavadable lo smallholders lnoculatton of field beans wtth rhtzobta rarely mercases graiD yteld ID Afnca (Davts 1982) or LaiiD Amenca (Graham 1981) However although beans are poor mtrogen fixers (LaRue and Patterson 198 1) IDOculalton wtlh sorne strams of rhtzobta has produced ytelds comparable wtth those obtamed from apphcatton of htgh levels of mtrogen (Ktpe Nolt and P1Deda 1988) V anabthty m nodulatton and yteld of genotypes moculaled wtlh spectfic strams of Rh1zob1um has also been observed (Ktpe Noll and PIDeda 1988) The objecltve of thts study was to evaluate and screen rhtzobta and bean genotypes sutlable for contrasiiDg sotl types m dtfferenl croppiDg syslems 161 MATERIALS AND METHODS Tbe effects of moculatmg bancot beans IDtercropped w1tb sorgbum The experunent was conducted on a Rhodustalf (low N pH and avadable phosphorus) m a spht spht plot des1gn rephcated three limes Four released vanet1es of beans (Mex1can 142 Ex R1co 23 Black Dess1e and local) and two sorghum vanet1es (ETS 2752 tall and IS 9333 short) were mtercropped m plots of 4 5 x 4 4 m Peal based moculant of Stram 274 was apphed al planllng At 50% flowenng s1x plants were sampled for nodulat1on count Al matunty gram y1eld was determmed al 14 percent m01sture content Screenmg of rb1Zob1a for nodulabon and y1eld The expenment was conducted on two s01l types (Ustert degraded Haplustalf) m a random1zed complete block des1gn rephcated five limes Twenty strams of rh1zob1a obtamed from CIA T were compared w1th the apphcat1on of 100 kg N ha 1 and w1thout N The moculants were all peal based and apphed at plantiDg to Ex R1co 23 The beans were planted ID furrows spaced 40 cm apart and 20 cm between plants In the +N plots urea was apphed ID four spht apphcallons of 25 kg N ha 1 Sorghum was sown on each s1de of the bean furrows two weeks pnor to plantiDg beans to deplete s01l rutrogen At pod fillmg s1x bean plants were sampled from each furrow for sconng nodulallon and shoot dry matter (DM) determiDallon At harvest gram y1eld was determmed at 14 percent m01sture GraiD N was determiDed by the m1cro Kjeldahl method Tbe effects of miXed rh1Zob1a on tbe nodulabon and y1elds of bean genotypes on two sod types Nmeteen genotypes obtamed from CIAT were evaluated for nodulallon and graiD y1eld m a spht plot des1gn rephcaled three limes The mam plots were m1xed strams (613 652 and 274) N and +N Sub plots were genotypes Nodules were counted at 50% flowenng Gram y1eld al harvest was adjusted to 14 percent mo1slllre Tbe effect of d1fferent levels of n1trogen on tbe y1eld of Ma1can 142 on two sod types N1trogen ID the form of urea at O 23 46 and 69 kg ha 1 was apphed at sowmg on plots of 4 5 x 4 4 m Mex1can 142 a released cult1var was planted m rows of 40 cm and 10 cm between plants m RCBD w1th three rephcat10ns on a Rhodustalf and a Vert1sol Nodule numbers were evaluated al 50% flowenng Gram y1eld was recorded al harvest adjusted lo 14 percent mo1sture content In all expenments standard analys1s of vanance procedures were apphed usmg MSTAT C RESULTS AND DISCUSSION Tbe effects of moculabng bancot beans mtercropped w1tb sorgbum The results of the moculallon experunents under 1Dtercropp1Dg are summanzed ID Table 1 Unmoculated plants developed abundan! but small IDeffecllve nodules Inoculated plants developed large effect1ve nodules Ex R1co 23 developed fewer nodules than the other culllvars sole-<:ropped and ID assoc1a11on w1th sorghum Black Dess1e produced the most effecllve nodules when IDoculated ID both systems lnoculat1on depressed the y1eld of Ex R1co 23 Local and Mex1can 142 m assoc1at1on w1th both tall and short sorghum The y1elds of Black Dess1e were 1mproved by mocula11on m 162 assoctallon wtlh bolh sorghum vanelles All vanettes responded to moculatJon and produced lherr best gram ytelds m monoculture The vanatJon m yteld of lhe vanelles may be attnbuted to lhetr compattbthty for mtercroppmg Compellllon for nutnents by sorghum reduced bean ytelds Table 1 Effect of moculatJon on nodule number and gram yteld of four vanelles of beans mtercropped wtlh two vanetJes of sorghum grown on a Rhodustalf CultJvars No Y teld (kglha) lnoculat10n of effictency Sorghum Bean nodules +1 (%) ETS 2752 Ex Rtco 23 80 514 243 111 5 ETS 2752 Black Desste 95 429 743 +73 2 ETS 2752 Mextcan 142 98 312 331 +61 ETS 2752 Local 100 647 307 110 7 IS 9333 Ex Rtco 23 56 542 775 +21 o IS 9333 Black Desste 123 660 1326 +101 o IS 9333 Mextcan 142 104 1248 721 73 o IS 9333 Local 88 950 1345 +42 o Ex Rtco 23 64 841 1002 +19 1 Black Desste 176 785 929 +18 3 Mextcan 142 136 950 1274 +34 1 Local 128 1379 1606 +16 5 SE(+) 30 2 193 o 327 7 1 = umnoculated + 1 = moculated Screenmg of rbtzobta for nodulatton and yteld Apphcatton of N depressed lhe nodulat10n of beans (Table 2) Maxtmum nodulatton was obtamed by moculat10n wtlh stram 899 on bolh sotl types All strams enhanced DM productJon compared wtlh lhe N control ApphcatJon of N mcreased plant mtrogen contents Stram 2 mcreased N m beans by 438% on lhe Alfisol and Stram 632 by 225% on lhe Verttsol The gram N contents of urunoculated ( N) plants were less Iban fertthzed (+N) plants Thts shows lhat mdtgenous rhtzobta are meffectJve m fixmg mtrogen Four strams (879 2 7100 and 144) produced 2 15% more gram Iban lhe yteld obtamed wtlh the apphcatJon of 100 kg N ha 1 on lhe Verttsol On lhe Alfisol seven strams (2 7100 144 113 151 5 7033) mcreased lhe yteld of Ex Rtco 23 by up to 43% Except for Stram 640 all strams produced Iugher gram ytelds Iban lhe negattve control ( N) on lhe Alfisol but only nme strams oulytelded lhe N control on lhe Verttsol Strams performed better on lhe V ertJsol Iban on lhe Alfisol supportmg the need for further screenmg 163 Table 2 The effect of d1fferent rh1zob1a strams on dry matter (DM) N content and nodule number of Ex R1co 23 grown on a degraded Alfisol DM g/3 Strams plants 113 45 899 7033 2 879 144 151 5 115 +N 274 7136 639 7100 949 348 632 640 N 7202 948 9 11 8 55 7 95 7 04 672 6 48 6 31 6 28 5 84 5 83 5 53 5 33 5 11 5 05 4 79 4 63 4 29 4 00 3 08 2 05 Alfiso1 Nodule Seed DM N no /6 y1e1d g/3 (%) plants (kg/ha) p1ants o 131 85 o 162 48 o 142 104 o 135 85 o 172 65 o 151 66 o 114 71 o 121 68 o 113 54 o 116 41 o 210 31 o 131 69 o 128 89 o 115 61 o 1 18 52 o 135 59 o 113 60 o 044 74 o 043 48 o 032 47 756 636 621 727 1026 638 786 738 771 606 718 565 643 624 935 538 577 419 249 413 568 421 10 14 15 77 15 53 11 14 15 24 15 15 15 08 14 05 11 67 12 14 13 37 12 62 17 72 12 96 15 66 11 22 14 32 13 47 11 63 5 58 16 13 11 67 Veril sol Nodule Seed N no /6 y1eld (%) plants (kg/ha) o 123 136 o 126 39 0119 125 o 129 72 o 119 61 o 161 66 o 119 45 o 140 86 o 108 56 o 127 58 o 251 31 o 154 72 o 138 89 2144 1286 1740 1504 2217 2459 2189 2004 1806 1771 2146 1125 1872 o 119 o 122 o 175 o 175 32 1914 82 2199 52 1619 48 1733 o 198 40 1798 o 115 62 1619 o 061 47 1857 o 142 44 1979 o 126 63 1752 SE (+) 1 33 O 011 13 8 96 8 e v (%) 34 1 2 304 o 024 16 5 258 2 31 2 +N = umnoculated fert1hzed w1th N N = umnoculated unfert1hzed Tbe effects of m1xed rb1zob1a on tbe nodulat10n and y1elds of bean genotypes on two sod types S1gmficantly (P200 ppm Mn respechvely 177 MANAGEMENT OF SOILS WITH HIGH MANGANESE lt ts recogmzed that oxtdalton and reduclton of Mn compounds control the amounts of Mn avatlable In Uganda mulch ash manure composts hme and adjustment of the P Ca rallo have been suggested for amehoralton of the harmful effects of excess Mn (Jones 1976 Le Mare 1977 Zake 1986) Oxtdalton may reduce the avatlabthty of Mn lo the extent that defictency occurs whtle reducmg condtttons may lead to accumulalton of toxtc levels of Mn m sotls Ooberemer (1966) found that both beans and soybeans developed nodules and fixed N saltsfactonly at very low pHs provtded Mn toxtctty was not a hmtltng factor Other factors mfluence the avatlabthty of Mn m sotls The roots of some crops probably play an acltve role m promotmg dtssolulton of Mn oxtdes through the expresston of shon hved reducmg compounds (Bromfield 1958) Wonmann and Sengooba (1990) reponed that beans mtercropped wtth banana took up more Mn and were more affected than sole crop beans lt ts not yet ascertamed whether excess Mn was washed down from banana leaves mulchmg wtth banana leaves led to subsequent release of Mn on decomposttton mulchmg stmply encouraged the avatlabthty of Mn and thus more uptake by beans or banana root exudate played an acttve role Compactton of sotls ts also known to rwse the levels of avatlable Mn Compaclton seems to mcrease contact between the roots and Mn oxtdes or blocks the captllary movements of Mn Mn also mteracts wtth other elements wtthm both sotls and plants The elements whtch have been found to affect Mn nutnlton mclude Fe P Ca and Mg and an excess of one can decrease the uptake of the other and cause defictency There are also repons that P fenthzers mcrease Mn uptake by plants (Page 1963 Larsen 1964) Thts could be due to the actd solut10n that dtffuses through the sotl from a band of monocalctum phosphate whtch carnes a htgh concentralton of Mn (Lmdsay el al 1959) SCREENING BEANS FOR MN TOXICITY TOLERANCE Followmg earher observaltons (Neenan 1960) of vanetal dtfferences m the tolerance of wheat and barley to sotl actdtty Foy el al (196 7) found stmtlar vanetal dtfferences m dry beans snap beans hma beans cotton and tomatoes Foy el al (1973) showed that the dtfferences were denved from vanattons m senstltvtty to Mn and Al toxtctly and the relattve requtrements of P and bases Thus a raltonal sctenhfic basts was estabhshed for the seleclton of !mes adapted to a parttcular stress as well as breedmg for tolerance whtch became vtable opltons for tmprovmg productton m the presence of toxtc or defictent supphes of plant nutnents Effons have been made elsewhere to select crop plants that tolerate adverse sotl condtltons usually toxtc levels of exchangeable Mn and Al and defictent levels of exchangeable P and some bases Thus there ts potenttal lo screen and select bean genotypes that thnve well al toxtc levels of Mn m Uganda Thts offers the posstbthty of reducmg requtrements for hme P and posstbly other fenthzers for the produclton of bean crops on sotls wtth Mn toxtctty OBJECTIVES Screen 280 bean genotypes for tolerance to Mn toxtctly 2 Venfy and adapt a raptd laboratory techmque for screenmg for Mn toxtctly tolerance 3 Develop appropnate techmques for the control of Mn toxtctty and assoctaled problems 178 MATERIALS AND METHODS The fltSt cycle of the Afncan Network for Select10n for Edaph1c Stresses (ANSES) nursery compnsed 280 entnes contnbuted by part1c1patmg nahonal programmes m Afnca Cntena for the select10n of these entnes was ev1dence for tolerance to one or more edaph1c stresses and that they be well adapted vanehes e1ther released or m advanced stages of testmg In 1991 the ANSES nursery was grown at Lyamungu m Tanzama (for low P evaluahon) at Mulungu m Zrure (h1gh Al) 8Ulkwe m Uganda (h•gh Mn) and at Nakasongola also m Uganda (low N P) Select10n for tolerance to lugh soll Mn avallab1hty was accordmg to one of the s1x entena h1gh Mn y1eld 15 x stress symptoms at V4 (leaf colorat10n) h1gh Mn y1eld 25 x stress symptoms at V4 (leaf coloratlon) h1gh Mn y1eld 15 x stress symptoms at R 7 (brown specks) h1gh Mn y1eld 25 x stress symptoms at R7(brown specks) rallO of h•gh Mn y•eld to adequate fert1hty (Nakasongola) y1eld 8ased on these entena, 124 entnes that appeared toleran! of Mn tox•c•ty were selected Fourteen that appeared susceptible were selected to develop a rap1d screemng techmque for tolerance to h1gh Mn Tnal des•gu and layout Number of eutnes Season 1 (19918) 280 Season 2 (1992A) 124 Season 3 (19928) 36 Season 4 (1993A) 36 Des1gu Random1zed complete block of 2 rephcates m Season 1 and 4 rephcates m season 2 lathces of 4 rephcates m Season 3 and 3 rephcates m season 4 Randomu:ahou In Seasons 1 and 2 entnes were grouped as chmbmg or non-chmbmg and random1zed w1thm groups For the th1rd and fourth seasons random1zahon was based on a square latt1ce Plot su:e Plots were of two rows m Seasons 1 and 2 three m Season 3 and four m Season 4 al! were 3 m long and spaced O 5 m apart Plots were O 8m apart Plants were 1 O cm apart Wlthm rows Paths Across the rows (between decks or ranges) 1 m m w1dth Check cultJvars Canoca for non-clunbers G 2333 for chmbers Local checks have also been mcluded EvaluatJou mcludes emergence score vegetahve v1gour at V4 R5 Mn tox•c•ty symptoms at V 4 R5 brown specks at R 7 d1seases msects num bers of plants harvested and plot y1eld There w111 also be fohar analySIS at R5 and R7 total above ground b10mass and Mn uptake m shoot at R7 and soll nutnent status at R5 and R 7 RESULTS AND DISCUSSION Work so far mcludes a) prehmmary surveys of solls h1gh m Mn b) tnals on the management of expenmental s1tes and e) A N SES collaborat1ve research 179 Prehmmary surveys of sorls b1gb m Mn (Experunent 1) So1ls and leaf samples were collected from areas md1cated to be assoc1ated w1th (1) h1gh Mn but moderate to lugh pH Kyebe Catena near Bwkwe Kok1 Catena Buruh Catena (Wobulenn) and Namulonge m the central Reg1on and (u) h1gh Mn and Al w1th low pH Busheny1 and Kabale m &Jor bean growmg are as of southwestem U ganda Analyses of s01l and leaf samples showed that avallable Mn vanes between 200 and 640 ppm Moderately toleran! plants can accommodate up to 40 ppm Mn m the s01l solut1on (Andrew 1976) Results of analyses are shown m Tables 1 2 and 3 Table 1 Chem1cal charactenst1cs of s01ls w1th excess Mn and moderate pH pH Mn p K Ca N OM Al (ppm) (ppm) me/IOOg me/IOOg % % me/IOOg Bu1kwe (1) 57 640 36 7 o 58 3 13 o 18 6 55 na (u) 46 450 25 7 o 45 1 88 o 11 5 73 o 33 (m) 52 320 30 8 o 26 1 56 o 21 8 19 na (1v) 60 540 37 o o 51 3 06 o 25 7 37 na Narnulonge Sendusu 60 200 55 2 1 22 5 94 018 6 50 na Nalumuh 59 600 31 7 1 73 8 44 o 14 7 02 na Kmmantungo 6 1 410 25 5 1 54 719 o 21 810 na Nasuye 63 300 25 1 1 60 7 50 o 11 4 80 na Luwero (Wobulenz1) Sempa 1 6 1 510 23 5 o 58 3 75 o 25 4 00 na Sempa 11 62 380 42 9 1 60 3 13 o 22 4 51 na Kyootamugavu 69 240 28 7 2 88 3 25 o 14 5 17 na Wab1ymJa 63 460 35 8 o 90 469 o 13 5 00 na Kolu (Rakru) Lwebula 1 57 356 1 1 o 13 30 o 11 2 51 na Lwebula 11 59 502 43 o 26 55 o 21 6 04 na Lulagala 56 560 1 1 o 13 40 o 18 2 96 na na = not analysed 180 Table 2 Chem1cal charactenst1cs of leaves from s01ls w1th excess Mn and moderate pH Mn p K Ca S1te Crop ppm % % % Bu1kwe (1) Beans 842 o 31 1 o o 68 (u) Beans 640 o 52 1 5 1 03 (m) Beans 450 o 47 07 o 59 (•v) Beans 750 o 42 09 o 65 Namulonge Sendusu Beans 290 o 73 1 00 o 77 Nalumuh Soybeans 140 o 68 o 55 o 44 Kmmantungo Soybeans 160 o 57 o 90 o 70 NaSirye Groundnuts 190 o 52 1 20 o 92 Luwero (Wobulenz1) Sempa 1 Beans 240 o 25 o 35 o 12 Sempa 11 Beans 620 o 42 1 00 o 75 Kyootamugavu Beans 340 o 57 o 80 o 62 Wab•ymJa Beans lOO o 31 o 65 o 53 Table 3 S01l analySIS of s01ls w1th excess Mn and Al pH Mn p K Ca N OM Al (ppm) (ppm) me/lOOg me/lOOg % % me/IOOg Busbeny• Rubare 1 47 301 15 5 o 13 4 00 o 11 3 79 na Rubare 11 46 314 11 o o 30 3 50 o 18 2 63 na Busheny• D F 1 40 247 27 o 05 1 00 o 21 4 11 1 95 Ka bale Kachwekano 1 43 240 09 o 38 3 70 o 25 12 83 3 30 Kachwekano 11 52 320 00 o 33 3 70 o 28 10 73 na Kachwekano III 42 480 00 o 17 1 45 o 14 6 66 2 10 Kachwekano IV 44 560 00 o 38 3 25 o 42 9 95 3 80 Tnals on the management of exper•mental s•tes (Expenment 2) On the baSIS of the results obtamed m Expenment 1 a smtable area was selected m Bu1kwe (Kyebe Catena) where currently screemng expenments are bemg carned out Another area has been secured m Sempa (WobulenZI) to wh1ch screemng tnals w•ll be extended m 1993A 181 Management of tnals that have been conducted mcluded compacho'l furrowmg and NPK and hme apphcahon Prehmmary results show that compacllon greatly mercases Mn concentrallon m the so•l and the amount taken up by bean plants (Tables 4 and 5) Furrowmg has not shown a clear response Th•s could be due lo heavy ram washmg apphed fen1hzers from adjacent plots and concentratmg them m the furrows makmg them more fenlle than the surroundmg plots Add•t•ons of NPK espec•ally K appeared lo counteract the adverse effects of Mn tox•c•ty (Tables 4 and 6) L1mmg had no cons1stent effect (Table 7) but tended lo decrease y1eld Table 4 Effects of K apphcat•on furrowmg and compact10n on s01l chem•cal charactenst•cs al Bwkwe m 1991A Treat pH Mn p K Ca Na N Total ment ppm ppm me/IOOg mefiOOg me/IOOg % P(ppm) Expenmeot 1 (farmer's field) K 52 320 30 75 o 26 1 56 o 17 o 18 130 +K 5 1 440 30 66 o 38 1 88 o 17 o 25 84 Expenmeot 11 Control 48 350 30 60 o 45 1 88 o 22 o 18 150 Furrowed 49 260 30 45 o 51 2 50 o 20 o 11 165 Compacted 46 450 25 66 o 45 1 88 o 22 o 11 160 Table 5 Effects of furrowmg and compacllon on bean leaf chem¡cal analySIS m Expenmenl 11 al Bu1kwe m 1991A % ppm N p K Ca Mg Mn Fe Cu B Al Zn Na Control 3 26 o 39 2 27 o 98 o 35 264 171 12 32 400 42 15 Furrowed 3 33 o 37 2 27 1 03 o 36 332 212 12 27 558 40 28 Compacted 2 96 o 29 2 34 097 o 27 842 336 10 21 887 34 15 AnalySIS by courtesy of Agncultural Analyt•cal Serv1ces Laboratory Penn Stale UmvefSlly UmvefSlty Park PA 16802 U S A 182 Table 6 Effects of N P and K apphcahon on leaf chem1cal charactenst1cs m Expenment 1 (farmers tield) at Bu1kwe m 1991A Treatments %P %K %Ca Mn(ppm) NP 1 o 47 o 70 o 59 450 NP 2 o 31 o 50 o 50 340 NP 3 o 31 o 40 o 44 220 NP-4 o 37 o 50 o 50 250 NPK 1 o 47 o 70 o 56 300 NPK 2 o 52 o 80 092 160 NPK 3 o 25 o 85 o 68 350 NPK-4 o 31 o 70 o 59 340 NP 5 o 42 o 60 o 53 370 Table 7 Effects of hmmg on s01l chem1cal charactenshcs at Bmkwe m 19908 Treat pH Mn p K Ca Na N Total ment ppm ppm me/IOOg me/IOOg me/IOOg % P(ppm) LO 57 640 36 70 o 58 3 13 o 20 o 18 105 Ll 62 320 36 75 o 70 4 06 o 20 o 18 250 L2 60 540 37 01 o 51 313 o 22 o 21 255 L3 67 170 38 72 o 58 4 38 o 22 o 18 165 A prehmmary screenmg tnal of 16 entnes (Table 8) was carned out m Bu1kwe Severe symptoms of Mn toXIclty were v1s1ble In tenns of y1eld the best tive entnes were all small seeded and the seeds of three of these were black 183 Table 8 Effects of Mn on the ytelds of 16 entnes and of hme and NPK on K20 Fohar Mn V anety Vtsual (ppm) mean yteld seo re Entnes R5 (g/plot) R5 Black Desste 184 44 5 3 Rto T•baJt 151 89 7 4 IPA 7419 161 81 9 4 95059 164 76 8 2 Caltma 164 48 9 3 A 283 207 59 5 1 ZPv 292 117 42 7 2 P1Dtado 129 37 4 3 AFR 88 126 18 7 2 EMP 84 142 49 3 BAT 41 156 61 o 4 BAT 271 180 37 o 4 BAT 477 137 60 1 2 94000 137 85 8 Ponllo SIDteltco 242 111 5 2 Canoca 120 60 8 3 K20 (LO) 104 417 K20 (LI) 394 K20 (L2) 418 K20 (L3) 123 335 K20 (NP) 320 326 K20 (NPK) 440 425 LO L3 = levels of hme vtsual ratiDgs VO R5 1 e from genniDaiJOn lo preflowenng ytelds of first 16 entnes g/hne for K20 g/plot ANSES Collaborat•ve Researcb Sub ProJecl Based on tests of 280 entnes ID 1991 124 entnes (Table 9) were selected for the tnal al Bwkwe ID 1992B The rankiDg of vaneltes for tolerance was IDCOnstslent wtth the prevtous season SUA 90 and AFR 298 whtch ranked top and second for tolcrance (detenniDed by stress symptoms and yteld) ID 1991B were 22nd and 30th ID 1992A Thts can be parttally attnbuted to charactensttc patchy dtstnbulton of excess Mn ID the field In order lo counteract such defects a stmtlar screemng expenment was sown ID Sempa (WobuleDZI) thts season (1993A) In thts tnal Canoca and Caltma dtd not perfonn accordiDg lo expectatton and Rubona 5 out perfonned K20 among the vanettes that have been released lo farmers 184 Table 9 Bean genotypes selected from 230 prom•smg vanehes for tolerance to low P low N and h1gh Mn (select10n based pnmanlly on y1eld under stress over two seasons of testmg H1gh Mn Low P LowN CAL 32 (RA YT 18) RWR 382 MCM 5001 AFR 542 (PYT LS 9) RAB 482 (RIYT 43) ZPV 292 RWK5 RWK 8 NEPA 29 BAT 25 MMS 250 (RIYT 1) Black Dess1e G 5053 (PYT 1-4) PEF 6 (PYT LS 6) OBA 1 AFR 88 RWK 5 DOR 404 Em 40 CLK 13 PV A 774 (RIYT 36) AND 61 PEF 14 (PYT LS 8) PAD 126 AFR 300 MUS 97 (RIYT 5) A 197 BA T 85 (VEF 79) AFR 544 (PYT LS 4) XAN 76 (RIYT 34) RAB 445 (RA YT 8) 6088 AFR 378 A 321 MMS 224 (RA YT 9) CAL 96 IZ 0201475 ZAN 76 Rubona 5 GLP 585 AFR 403 (RA YT 24) SUG 69 XAN 76 (RIYT 34) MCM 5001 AFR 531 Muy1ga XAN 76 (RIYT 34) AND 871 RAD 52 (RA YT 8) BRU 22 LRK 29 RAO 55 (RA YT 14) Pmtado RWR 982 433 RAB 76 (RIYT 30) IZ 0201240 DOR 375 (RA YT 30) MMS 253 (RIYT 33) UrugeZI PAD 114 (PYT MS 2-4) lk1mmba AND 829 OBA 1 Ponllo Smtehco SUA 90 MUS 18 (RAYT 31) RAO 55 (RA YT 14) AFR 476 ZAN 76 OBA 1 RWR 980 Black Dess1e Cahma A 120 (VEF 80) Canoca 433 AFR 544 (PYT LS 4) MMS 243 (RIYT 11) MMS 232 (RIYT 19) AFR 13 PAI 112 NIC 116 (RIYT 10) RWR 221 MMS 224 (RA YT 9) Canoca Urubonobono SUA 90 BAT 85 (RIYT 27) AFR 298 PEF 14 (PYT LS 8) PAI 112 Lyamungu 85 BAT 85 (RIYT 27) GLP 585 NEPA 38 RWR 382 RAO 52 (RIYT 8) KID 34 (PYT LS 17) AFR 544 (PYT LS 4) At BUikwe m 19928 the scores for brown speck and stress at V 4 were rather vanable (CV s of 44 7 and 54 7% respect1vely) and d1fferences among entnes were not s•gmficant However MCM 5001 wluch w1th CAL 96 has recently been released to farmers was the best y1elder m 19928 (T able 1 O) and 1n 1992A md1catmg that recent releases are better adapted than prev1ous vanehes to poor sods However R WR 221 wh1ch •s well adapted to poor sods m R wanda does not peñorm well m Uganda but desp1te sorne mcons1stences m peñormance small seeded vanehes shll show greater tolerance to Mn tox•c•ty than large seeded vanehes Th1s conforms w1th findmgs m South Amenca and espec•ally Brazd 185 Table 10 Ytelds (g/hne) of entnes m htgh Mn ANSES Nursery al Butkwe m 19928 Entnes Ytelds MCM 5001 685 ZPv 292 411 NEPA 29 392 Black DeSSie 542 OBA 1 403 DOR 404 327 PVA 774 (RIYT 36) 349 PAD 126 439 A 197 490 XAN 76 (RIYT 34) 753 AFR 378 462 CAL 96 369 Rubona 5 413 SUA 69 409 AFR 501 438 ANO 871 542 LRK 29 338 RWR 982 457 IZ 021240 500 Urugezt 591 AND 829 309 SUA 90 280 AFR 476 386 RWR 980 446 A 120 (VEF 80) 657 AFR 544 (PYT LS-4) 306 AFR 13 260 RWR 221 674 Urubonobono 410 Lyamungu 85 417 MCM 2001 381 Canoca 333 NEPA 38 274 K20 252 RWR 382 670 KID 34 (PYT LS 1 7) 507 Mean 441 S E (±) 73 9 cv (%) 334 Work for seasons 1993A and B wdl contmue accordmg to the stated obJecttves 186 ACKNOWLEDGEMENTS 1 would hke lo acknowledge w1th apprec1allon that Reg1onal Collabora!Jve Research Sub ProJect Fundmg has ass1sted me w1th 19928 (1 e July 1992 March 1993) and the m11lal part of 1993A expenments Prev1ously 1 have been asSJSted out of ANSES Funds thanks to Dr Charles Wortmarm REFERENCES Andrew C S (1976) Screenmg trop1cal Iegumes for Mn tolerance In M J Wnght (Ed) Plan! Adaptallon to M mera! Stress m Problem S01ls Comell Umvers1ty Ithaca N Y pp 329 340 Bromfield S M (1958) The properlles of bJOlogJcally formed manganox1de 1ts avadab1hty lo oats and 1ts solu!lon by root washmgs Plant and S01l 9 325 337 Chenery E M (1954) A prehmmary study of Al and the tea bush Plan! and S01l6 174 200 Chenery E M (1960) An lntroduct10n to the S01ls of Uganda Protectorate Memo1rs of the Research DlVlsJOn Senes 1 S01ls No 1 Uganda Department of Agnculture Entebbe Doberemer J (1966) Manganese toxlclty effects on nodulallon and N fixallon of beans (P vulgans L) m ac1d s01ls Plan! and SOJ124 153 166 Foy C D Arm1ger W H Flemmg A L and Zaumeyer W J (1967) Dlfferent1al tolerance of dry bean snapbean and l1ma bean vanelles to an ac1d s01l h1gh m exchangeable alumm1um Agronomy Joumal 59 561 563 Foy C D Flemmg AL and Schwartz J W (1973) Oppos1te alumm1um and manganese tolerances of two wheat vanelles Agronomy Joumal 65 123 126 Foy C D (1976) 0JfferentJal Al and Mn tolerances of plan! spec1es and vanelles m ac1d solls C1encJa e Cultura 28 150 155 Jones E (1976) S01l productlVlty In M H Amold (Ed ) Agncultural Research for Development The Namulonge Contnbut1on Cambndge Umvers1ty Press U K pp 43 76 Le M are P H ( 1977) Expenments on the effects of phosphorus on manganese nutnllon of plants 1 11 111 Plant Soll 4 7 593 606 607 602 621 630 Neenan M (1960) The effects of s01l acldlty on the growth of cereals w1th part1cular reference to the d1fferentJal react1on thereto Plan! and Soll 12 324 328 Wayland E J (1921) Annual Report for 1920 of the Geolog1cal Survey of Uganda Govemment Pnnter Entebbe Wortmarm C S and Sengooba T (1990) InvestJgatJOns of banana bean mtercroppmg m Uganda Presented at the F1rst Uganda Nallonal ScJenllfic Conference Kampala Uganda 10 15 Decem ber 1990 Zake J Y K ( 1986) Prel1mmary findmgs on the mvesllgallons of the causes of ¡nfertJhty ( Lunyu ) m some Uganda solls Proceedmgs of S S S E A E1ghth Annual General Meetmg Kampala Uganda 1986 187 ' ... j V r .- .., / ' 2 1 OCT 1998 SCREENING FOOD BEAN (PHASEO/ US V U/ GAR/S L ) GENOTYPES FOR TOLERANCE TO LOW PHOSPHORUS G O Rach1er, R M Otsyula and N Amb1ts1 Kenya Agncultural Research Instltute Reg10nal Research Centre Kakamega Kenya ABSTRACT Progn .. .;;c; made m ~crccmng hcan gcnotypc'1 for tolerancc to low '\mi pho-,phoru\ t\ dt..'icnbcd 1 he 'iotl P leve) o; of a c;crccmng 'ittc at thc Regtonal Re'icarch Centre Kakamcga havc bccn \aho;factonly dcplctcd by growmg 'icvcral cropo; With addl.d N but no P A collcct10n of 434 local bcan gcrmplasm lmcs has bccn ohtamcd from thl.. Natwnal llortlcultural Rc'icarch Centre 3l rhtka and cva}uatcd for thc1r growth habtts days to flowcnng 'iC(.d 'illl.'i dt<¡C3'il. TC.,I'il80Ct.. and sct.d yteldo;; J hrcc hundrcd Jmcs havc bccn <;c)cclt..d for o;crcenmg for tolerance to P dcficu .. ncy INTRODUCTION Thc scrcenmg of bean culllvars toleran! to low phosphorus (P) ava•lab1hty m smls 1s part of a largcr effort mvolvmg severa( nallonal bcan prograrnmes m Afnca to screen for tolcrancc lo edaph1c strcsscs mcludmg Jow P and N and h1gh Al and Mn In Kenya screenmg for low P stress 1s conducted at thc Reg10nal Rcscarch Centre Kakarncga Th1s work started m thc 1990 short rams (SR) and by thc 1992SR culllvars had been 1dcnllficd for scrccmng and the screemng field had been suffic1ently deplctcd to low lcvels of P Thc actual screcnmg for low P tolerancc w•ll start m thc 1993 long rams MATERIALS AND METHODS Dunng 1991 and 1992 the screenmg field was dcplctcd of P Th1s was necessary smcc fields on thc stat1on do not show P dcfic1cncy due to contmuous use of fert1lu.crs Thc screemng field 1s su1tablc to enable scrcenmg of many matcnals over a number of seasons A mau.c bcan mtcrcrop sorghum and soybeans were grown on the field and fert•l.,.cd w1th mtrogen but not P and all above ground crop res1ducs removed from the ficld Sml analyses md1cate that sml P levels have been sahsfactonly depleted (Tablc 1) and compare well w1th P lcvels m farmers fields 434 germplasm lmes were acqmred from Nat10nal Hort•cultural Research Centre Th1ka m 1992 Sceds of these matenals were mul!lphcd m smglc rows of 3 m D1arnmomum phosphate fert1lu.cr was apphed at the recommendcd rate at plantmg D1scases and pests were controlled usmg D1thane M45 and DIIUmon The matcnals were (a) characten~.cd for growth hab•t and sccd su.c (b) evaluated for reachon to common d1scascs on a scalc of O 5 and (e) evaluated for general adaptab1hty and y~eld 188 Table 1 P levels (ppm) of samples of top and sub smls from three pomts m evaluahon field at Kakamega m 1991LR and 1992SR Sample 2 3 Season Top Sub Top Sub Top Sub Evaluat1on field 1991LR 13 13 9 13 13 11 1992SR 8 JO 6 4 8 8 Farmers' field 8 6 JO 6 8 6 RESULTS AND DISCUSSION Of the 433 genotypes evaluated 205 (47 3%) were determmate m growth hab1t and 228 (52 7%) were mdetermmate Tune to flowenng ranged from 40 to 52 days w1th the earhest to flower bemg concentrated among the determmate types (Table 2) Table 2 Days to flowenng of determmate and mdetermmate genotypes at Kakamega Days to Growth hab1t 50% flowenng Determmate lndeterm mate 40 42 154 14 43-44 25 26 45-46 6 31 47-48 7 124 49 50 4 29 51 52 2 2 Total 198 226 Among the 409 genotypes evaluated for seed SJze 107 (26 2%) were charactenzed large seeded 245 (59 9%) were charactenzed medmm and 57 (13 9%) were charactenzed small seeded The mam d1seases recorded dunng the season were rust and angular leaf spot followed by anthracnose Scores greater than than 3 were exlub•ted by 165 genotypes for rust and 6 7 for angular leaf spot 189 Seed y1eld ranged from zero to 534 g/3 m row (Table 3) A determ10ate genotype (GLPx 1206) produced the heav1est y1eld followed by the 10determ10ate GLPx 73 Among the first fifty best y1eld10g l10es 27 were 10detenn10ate and 23 determmate Table 3 Frequency d1stnbu1Ion of seed y1elds (g/row) of l10es grown dunng the 1992SR Seed y1elds Number of (g/row) hnes o 100 46 101 200 86 201 300 151 301 400 100 401 500 43 Over 501 3 CONCLUSIONS Three hundred (about 70%) of the total 433 l10es were selected as entnes for screemng for low P tolerance dunng the 1993 long rams The selecllon cut-off po101 was a y1eld of 201 g/row and above The selecllon entena were seed y1eld general adaptab1hty d1sease reacllon Among the selected lmes 156 (52%) were detenn10ate and 154 (48%) were 10detennmate lndetenn10ate genotypes performed relallvely badly as shown by the percentage of total plants present al m1d season (52%) compared to harvest (48%) and by the compos111on of the reJecled matenals (63 2% 10determ10ate and 36 8% determ10ate) MAJOR CONSTRAINTS (1) The fundmg of the sub proJeCI was h1ghly apprec1ated s10ce 11 enabled the work lo start The US$ 500 prov1ded for the penod July 1992 March 1993 proved hm1ted for the acllv111es of the 1992SR and of the 1993LR wh1ch start at Kakamega 10 February/March (n) lt was not feas1ble to obtam matenals from outs1de Kenya due lo stnngent quarant10e measures at Muguga PLANS FOR 1993 (LR) (1) To screen the local bean matenals selected as entnes for tolerance to low P (n) To part1c1pate 10 the mult1 locat1on test10g of the entnes selected from the first cycle of the ANSES 190 REFERENCES CIAT (1 992) M mutes of Steenng Comm1ttee Meetmg of the CIA T Reg10nal Programme on Beans m Eastem Afnca Nazret Eth1op1a, 20 24 June 1992 Schwartz, H F and Pastor Corrales M A (1989) Bean Produchon Problems m the Trop1cs Second ed1t1on CIA T Cal• Colombia Sm1thson J B (Ed) Proceedmgs of the Second Reg1onal Workshop on Bean Research m Eastem Afnca, NIIIJ'Obl Kenya 58 March 1990 CIAT Mncan Workshop Senes No 7 Susan Amaya (Ed) Potent•al for F1eld Beans m Eastem Afnca Proceedmgs of a Reg1onal Workshop held m Ldongwe Malaw1 9 14 March 1980 CIAT Cal1 Colomb•a 226 pp 191 SESSION V GENETIC TOLERANCE TO SOIL CONSTRAINTS Cblllr Sthm Nabdy Rapporteur Wayne Vouogqutst Paper by Amare Abebe (preseoted by W Y ouogqutst) QoestJoo Stabthty analySJS tdeoufied two Imes that had slopes a httle above 1 05 Entnes wtth slopes less than 1 00 perfono better m poorer envJIOnments Otd you fmd any such lmes? Youogqutst Y es BA T 798 had a slope of O 72 but tts mean yteld was hght so that the two selected lmes were better peñonoers even m the poorer envtronments Questlon lt ts posstble to examme a stabthty analysts graph as arranged m four quadrants In whtch quadrants were the selected types found? Youogqutst The selected types would he m the upper quadrants If however one looked at a plot of slope vs devtallons from regresston then the selected types would be m the quadrant of lugh slope and lugh devtallons from regresston wluch would mdtcate some dtfficulty for accurate predtcatton of response to drought Paper by Mttlku Hade QuestJoo lt appears from your Tables 7 and 8 that mtrogen levels of the sotls are already htgh Wouldn't tlus adversely affect responses to seed moculauon? Mttlku Hade No not really lt ts the mteracltons wtth the other hmttmg nutnents that are of more concem These need to be exam med further QuestJon Have you been momtormg the changes that occur m the vanatton m the strams m your mtxtures over ltme? Mltlku Hade The mtxture expenment compares competttton among local strams to determme whether the strams perstst over ltme One stram of note ts 899 wluch seems to perstst Paper by Patnck Jjemba Commeot The effects of applymg mtrogen and symbtosts wtth the Rhtzobtum are confused smce they are apphed together JJemba Smce there was httle effect of N fertthzer there was probably httle mteraclton due to the apphcauon of feltlhzer w•th the Rhtzobtum strams Commeot Kmdly descnbe the fertdtzer regtme JJemba A low starter dose of N (JO 20 kg/ha) was added to promote the growth of the beans pnor to the onset of effect•ve nodulatton Phosphorus •s added for much the same reason lt ts needed for effecltve nodulauon and N fixauon 192 Paper by Habtamu Admassu Quesuon Were s01l samples taken lo confino that there was mtrogen defic1ency m the expenmental plots? You ment1oned d1sease symptoms m the test matenals Were N defic1ency symptoms observed and 1f so how severe were they? Habtamu Admassu S01l analyses have not yet been completed However mtrogen defic1ency symptoms were seen m the precedmg crops of mmze The s1te selected for the low N screenmg had been scheduled for so ti tests severa! years ago E ven though the mmze crop showed defic1ency symptoms 11 appears that the N leve! 1s too htgh or has a great degree of vanab1hty lt would be useful to block out the s1te mto h1gher or lower N leve! arcas Paper by V1ctor Ocbwob Quesuon lt 1s mterestmg lo note that the !mes MCM 5001 and CAL 96 found tolerant to htgh manganese so1l cond1Uons m your tnals are also the ones that have recently been released based on the1r supenor performance on farm Perhaps 11 1s demable to conduct your testmg al on farm s1tes? Ocbwob Thts could be done We would then need to obtmn sotl analyses to conf1rm what the farmers are saymg about the ferttl1ty of therr farms Quesuon The steenng comm1ttee may not be convmced that Mn tox1c1ty 1s a senous enough problem to warrant mvestmg more resources m 11 Do you have data on the extent of Mn toXICity problems? Ocbwob One dúficulty of obl8lmng such mformallon 1s the unrehable nature of sotl Mn tests The tests md1cate low Mn levels due to the drymg that 1s normally used pnor to nmmng the test procedure Quesuon What are the levels for concem of Mn m the s01l? Ocbwob There 1s no absolute answer to th1s quest10n For some crops the upper level1s 40 ppm but for beans we beheve 11 m ay be as htgh as 200 ppm Paper by G1deon Racb1er Quesuon Is 11 poss1ble lo lay out the screenmg tnals m blocks? Th1s would help account for some of the vanallon that has been observed Racb1er Vanab1hty m the tesllng 1s h1gh therefore some fono of blockmg may be of value m esbmatmg thts source of vanat1on m the test results Comment A nearest netghbours analys1s may be more appropnate than some forms of blockmg Racbter The tnals have already been planted for thts year Quesuon How wtdespread ts P defic1ency m westem Kenya? Racb1er 1t ts a problem smce the farmers tend not lo use P fertthzers 193 QuestJon Were there severe defic•ency symptoms m your tnals? Racb1er There were severe sym ptom s m sorghum and m wze but not m beans Commeot Fertihzer apphed to the mwze IS formulated for the mwze It has been observed that by mtercroppmg beans the beans use th•s fert•hzer dúferenllally and that the mwze suffers as a result General discuss•on or soii coostramts H1ddeo buoger It IS often diflicult for farmers to apprec1ate exactly the problems of poor soii nutnent avwlabihty On farm tnals would help to educate farmers lo become aware of the problems mvolved Drougbt Physiologisl have a wtde range of tests that can be used to Idenllfy drought response m the field mcludmg pore tests water pressure and osmotic potential Would these be appropnate m Idenllfymg drougbt toleran! vaneties? These tests can be used but the pnmary pomt to remember IS that manúestauon of drought ddiers between bean growmg areas In many cases drought toleran! Imes are !hose that res1st d1sease or msect pressures specútc to dry conditions Phys•olog1cal stud•es set up m one location where drought IS expenenced al dúfenng tunes of the year and accompan1ed by h1gh temperatures may be mappropnate lo other areas where drought IS assoc1ated With cool temperatures late m the growmg season Work has started to Identúy lmes that are drought tolerant durmg four penods seedmg lo seedhng stage seedhng stage to flowenng flowenng lo pod format1on and grlliD filhng Tlus should help m Identifymg lmes that have specútc responses lo drought Curren! drought screenmg procedures have been haphazard 11 IS unportantto Identúy specútc cnt1cal penods and devise good repeatable screenmg methodology to evaluate matenal for spec1fic stress condiiions 8Iolog~cal mtrogeo ruauoo 11 IS diflicultto cnticize work on BNF smce IIIs such an unportant trwt On the other hand results have been urumpressiVe and one wonders ú more effort should be expended on th1s top1c Stud1es of rutrogen fixauon w•th soybeans have shown posiiive responses lo moculation but wtth phaseolus beans the results have not been so clear Perhaps more stud1es need lo be conducted of the compellllve abiiity of local strlliDs and less emphas•s placed on exollc strwns wh1ch m ay not be very compellllve m local envirOnments Some bean vanelles have been found lo fix up to 100 kg Nlha though tlus IS rare and not found m locally acceptable bean culllvars M8Dg8Dese If bananas are assoc1ated w1th the mc1dence of Mn toxicity problems m beans IS the solullon to stop growmg so many bananas m westem Uganda? So far the results are not conclus•ve and such a reactioo would be premature The rh1zosphere of banana roots IS typ•cally of lugher pH than the surroundmg so1l S mee bean roots wiil grow m close association w1th banana roots 11 IS m tlus zone that 11 IS most hkely that the bean roots are p1ckmg 194 up the excess Mn One tnal of 16 bean genotypes showed that the mtercropped beans had tw1ce the Mn levels of the bean genotypes m monoculture So1l pathogens cause confus10n m the proper 1dentdicat10n of sod defic1ency symptoms How can one BVOld mlSdlagDOSIS? It has been observed that there 1s an assoc1a11on between low K m the sods and the mc1dence of root rots lt was found that the apphcallon of coffee hulls (source of K) to pots growmg beans reduced d1sease mc1dence 195 .&;. ¡ r r • ... ~ 2 7 OCT 1998 SESSION VI INTEGRATED CROP ANO SOIL MANAGEMENT MINIMUM TILLAGE IN MAIZE BEAN PRODUCTION SYSTEMS IN KENY A Jobo G N Muthanua K.A R 1 Regtonal Researcb Centre, Embu, Kenya ABSTRACT On fann research expenments on mm1mum hllage m matZe and matZe bean mtercroppmg were camed out dunng the Short Rams (SR) of 1991/92 and Long Rams (LR) of 1992 m three agroecolog1cal zones (AEZs) of Upper M1dland (UM2 UM3 and UM4) of K1ambu and Embu J)¡stncts of Kenya The effects of convenhonal hllage (two hand weedmgs) pre emergence alachlor post emergence bentazon fanners method and zero (no hll) on crop performance and sml charactenshcs were evaluated and farmer assessment of the treatments obtamed Drought affected the crop m both seasons Zero hllage unproved the stands of ma!Ze and beans and produced greater b10mass taller ma1ze plants m less clayey s01ls more bean pods per plan! and larger bean seed y1eld In add1hon crops were less affected by drought and so!l eros10n was mmmtal Farmers method was similar to convenuonal tdlage m sotl mampulahons Plant dens1hes were less W!th the fanners method but on clayey s01ls crops performed better W!th farmers method and convenuonal hllage than w1th other treatments Pre emergence alachor+hnuron resulted m a good crop comparable lo convenhonal hllage In beans post emergence bentazon apphcat1on delayed matunty reduced pod number and caused swollen plan! bases Ma1ze plants were temporanly lodged therr prop roots deformed and growth tw1sted However when mmsture was avallable the problems m ma¡ze were overcome Bentazon gave poor control of grasses and Galmsoga and Leonotrs spp INTRODUCTION Convenhonal crop produchon conSJSts of pnmlll)' and secondlll)' hllage and one or two handweedmgs Thts ensures that the crop grows m a weed free envuonment Convenhonal hllage exposes and churns soil and subJects tt to eroston by water and wmd Because of the dtsastrous effects of eroston on s01l produchvtty and the need to conserve m01shlfe there ts a general trend from convenhonal to mmunum hllage Mtmmum hllage IDVolves ehmiDahon of excesstve hllage (Ross and Meml 1990) Excesstve hllage not only accelerates eroston but also destroys soil phystcal properttes (Lal 1976) Mmunum hllage has been observed to IDcrease organtc matter ID troptcal sotls (Thomas el al 1983) to conserve motsture and reduce eroston On farm research on miDtmum tillage was tmhated ID K.Jambu and Thtka Dtstncts after on statton research confumed that the hllage system was feastble for maJze bean croppmg systems The obJectlves of mmunum tillage on farm research were to a) assess the apphcabthty of ttllage prachces under farmer ctrcumstances b) understand farmers mtmmum hllage crop productton systems e) assess the tmportance of s01l eroston d) assess water mfiltrahon and water storage m the s01l e) study crop growth and yteld under dtfferent hllage methods and f) assess the effects of hllage methods on soil phystcal and chemtcal charactenshcs 196 MATERIALS AND METHODS An mformal d•agnost1c survey was conducted m K1ambu and Embu D1stncts dunng the 1991/92 SR With the objechve of leammg the hllage methods prachsed by farmers and findmg w•th farmers treatments for on farm tnals that would mmmuze tlllage operahons and yet be feas1ble m farm s•tuahons The methods adopted for the tnal had lo be compatible w•th m111ze bean mtercrops smce the commodJtJes are grown m assoc1ahon Weed management had also to swt Intercrop culture The treatments selected were 1) convent10nal prachce (pnmary and secondary tillage and two handweedmgs) 2) pnmary and secondary tlllage and post emergence bentazon apphcahon 3) pnmary and secondary t•llage and pre-emergence alachlor apphcahon 4) farmers method and 5) zero tlllage (no tlll) ne•ther pnmary nor secondary tlllage (use of glyphosate or paraquat to control m•hal vegetahon and apphcahon of e1ther pre-emergence or post emergence herb•c•de A random1zed complete block des•gn was used w•th farms as rephcahons Gross plot s1zes were vanable but net plots were 5 x 3 m The measured parameters were expressed on a hectare bas1s M111ze hybnd 512 was planted m UM2 and UM3 spaced at O 75 x O 3 m Katuman1 com pos•te was planted m UM4 spaced at O 9 x 3 m Bean vanety GLP 2 was planted at an mtra row spacmg of O 1 m UM4 was planted With GLP 1004 (MweZI moJa) m two rows between two m111ze rows w1th an mtra row spacmg of O 15 m M111ze was fert1hzed w1th 250 kg/ha of 23 23 O fert•hzer wh•le beans were fert1hzed w1th 100 kg/ha of DAP (18 46 O) RESULTS AND DISCUSSION Crop performance Dunng the 1991/92 SRs m111ze was affected by drought wh1ch occurred JUSI before tasselhng at all sJtes M111ze wdted early m all treatments except zero tdlage where w1ltmg occurred much later No m111ze y1elds were real1zed though a few cobs were produced m zero hllage plots In UM4 (Munyu) on bght soii the m111ze was eaten by sqwrrels except m zero tdlage plots where trash protected the seedhngs F armers noted zero hllage as a soluhon to the squurel problem Beans were also affected by drought but some y1elds were real1zed Zero hllage treatment had v1gorous crop growth desp1te the drought Post emergence apphcahon of bentazon adversely affected bean growth and development The farmers method resulted m poor stands and y1elds probably because of overcrowdmg of beans and low populat10n Dunng the 1992 LRs m111ze performed well m all s1tes Weed control was sat•sfactory except m bentazon treated plots where grasses dommated Wdd p1gs porcupmes and dogs destroyed the m111ze m UM4 Katumaru Compos•te matured earher than the farmers vanety Farmers md1cated that future vanebes for the area should be H511 or H512 wluch they normally grow though the arca •s too dry for them In Embu m111ze was senously affected by drought and the plants were used as cattle feed However zero tdlage plots produced more b1omass Some bean y1eld was real1sed m UM2 and UM3 In UM4 beans f111led due to drought after the first r~~~ns were followed by a dry spell Resown beans were damaged by bean stem maggots and the rem111nder were trampled by w1ld an1mals feedmg on the m111ze 197 Pl1111t bagbt Mmze was shghtly taller w1th zero tdlage than Wlth other treatments Tlus confmns that zero t1llage 1s more conduc1ve to mmze growth than other tdlage pract1ces as also observed by Blevms ( 1983) and Ph1lhps and Young (1973) In heavy clays the farmers method and convent10nal tdlage treatment resulted m taller plants than other treatments Under zero ullage pre-emergence treatments caused large deep cracks wh1ch m1ght have mterfered Wlth roots Blevms (1983) also observed that sods Wlth slow mterval drmnage propert1es respond poorly to no tdlage Table 1 The effects of tdlage on plan! he1ght (m) of mmze grown m UM2 UM4 (hght sods) and UM4 (clay sods) dunng 1991/92 SRs Pods per pl1111t Tdlage method Zero úllage Convent10nal tdlage Pre-emergence alachlor Post-emergence bentazon Farmen; method UM2 1 4 1 29 1 32 1 28 1 35 UM4 1 4 Clay SOII UM4 1 15 1 40 1 15 o 87 1 35 In UM2 pods per plan! were most m zero ullage and fewest w1th the Carmen; method In UM4 the beans were almost a sole crop smce most mmze seeds had been removed by sqwrrels except m the zero tdlage plots where all the mmze grew E1ght pods/plant were produced by pre-emergence alachlor and s1x by zero ullage No pods were harvested from post-emergence bentazon because of phytotoJUCity Table 2 The effects of tdlage on number of pods per bean plant grown m UM2 and UM4 dunng 91/92 SRs --- --- Tdlage method UM2(GLP 2) UM4(GLP 1004) ----- Zero tdlage 45 6 Convenuonal tdlage 40 58 Pre-emergence alachlor 39 78 Post-emergence bentazon 32 o Farmen; method 32 29 198 Bean seed y1eld Zero llllage produced the largest bean y1elds al all s1tes Post emergence bentazon produced poor y•elds because of phytotox•c•ty Pre-emergence alachlor resulted m larger bean y•elds than convenllonal t11lage Table 3 The effects of llllage pracllces on seed y1elds {kg/ha) of beans grown m d1fferent ecolog•cal zones dunng 1991/92 SRs Tlllage methods UM2 UM3 UM4 Zero llllage 372 313 579 Convenllonaltlllage 292 69 330 Pre-emergence alachlor 334 139 428 Post-emergence bentazon 129 69 Farmers method 134 208 163 lnfiltrat1on rates Jnfiltrallon rates were measured m UM2 and UM4 lo detennme the effects of tlllage pracllces on water percolallon and the potenllal runoff and eros1on dunng ramstonns Table 4 The effects of tlllage pracllces on •nfiltrat10n rate (mis/mm) m UM2 and UM4 m 1991/92 SRs Farmers Pre Zero Post Convent method emergence llllage emergence IOn al Time (mm) UM2 UM4 UM2 UM4 UM2 UM4 UM2 UM4 UM2 UM4 57 3 7 54 42 66 57 42 42 42 57 3 28 20 26 1 9 28 24 20 1 9 22 28 5 28 20 26 1 9 28 24 20 1 9 22 28 10 28 1 3 1 6 1 3 20 1 3 1 2 08 1 8 1 2 20 24 09 1 3 08 25 1 1 1 2 06 1 4 09 30 20 08 1 1 07 22 09 1 o 06 1 2 08 60 1 4 05 09 05 1 4 07 08 04 1 o 05 UM2 s01ls had lugher 1nfiltratiOn rates than UM4 s01ls due to 1ower c1ay content Treatment effects were not very clear 199 M01sture assessment F anners parttctpaled m evalualton of effecl of m01sture defictls They reported thal wtltmg occurred much laler under zero ltllage than other treatmenls and the planls were larger In clay sotls convenltonal ttllage and the fanners method resulled m larger planls Agronomtc assessment Thts was how the farmer saw the crops growmg weed assessmenl ease of operalton converuence and requtrem enl Post-emergence bentazon treatment F anners were scepltcal aboul tls adoplton smce ti adversely affecled the crop and dtd nol control grasses and Galmsoga Pre-emergence alachlor treatment Fanners were sattsfied wtth crop peñormance and weed control They would hke lo see tts effecl on weed control dunng excesstvely wet seasons They thought herbtctdes were expenstve espectally when ratns fatled ConventJonal ullage The fanners felt tt was labonous al planlmg but easy to weed Zero ttllage F anners felt ti was easy lechnology resultmg m a good crop but would hke lo see tt m a more favourable season Pnces of berbtctdes and lechntcal knowledge were a constraml lo adoplton They satd they can try ti wtth proper advtsory servtces The method delerred squtrrels Farmers' method They mdtcated thal thts was easy to plant bul they losl m lerms of ytelds labour m weedmg and crop stand Crop assessment Vaneues a) Fanners dtd nol wanl Katumant Compostle m UM4 because of early matunty assoctated wtth damage by wtld arumals b) Fanners preferred GLP 2 to GLP 1004 recommended for UM4 Ytelds Wben asked thetr optruon about ytelds fanners mdtcated that zero ltllage appeared besl followed by pre-emergence conventtonal farmers method and then posl-emergence Bean seed appearance followed stmtlar trends Sotl eroston Fanners observed thal sotl eros10n was IDlmense m all treatmenls mvolvmg pnmary and secondary ltllage No eros10n was observed wtth zero ttllage Soll properttes Sotl analyses tndtcaled that sotls m all areas were low m mtrogen and phosphorus Potasstum was parttally suffictenl Orgamc carbon was also very low and accordmg lo Thomas el al (1983) matntenance of organtc carbon m troptcal sotls tS tmportanl for crop productton 200 CONCLUSIONS 1 Dunng penods of droughl the crop m zero llllage plols performed very well 2 Benlazon was detnmenlal lo both mwze and beans 3 Planl popula11ons are low m farmers fields 4 There IS need for synchromzed matunty lo av01d damage lo crops by w1ld ammals 5 Bean y1elds were besl from zero tdlage 6 Posl-emergence bentazon resulted m low bean y1elds 7 Pre-emergence alachlor treatment out y1elded convenhonal llllage by 30% m bean y1elds 8 Zero hllage outy1elded convent10nal llllage by 83% 9 S01ls m UM2 had faster mfiltrallon rates than UM4 s01ls 1 O Zero ullage resulted m lugher mfiltrat10n rate dunng the first m mute than other treatments than other treatm ents 11 Zero ullage delayed mo1sture stress lmmed1ately rwns ceased 12 SqUirrels could not remove mwze seeds m zero tdlage plots 13 Seed qual1ty assessment revealed that zero llllage resulted m better bean seeds and post emergence w1th poor seeds 14 S01l analySIS revealed that the so11s m the two d1stncts were low m total mtrogen organ1c carbon and phosphorus PotassiUm was also lackmg ACKNOWLEDGEMENTS 1 am thankful to CIA T for fundmg th1s research KARI for fac1htatmg the centre d1rectors of NHRC Tluka Mr M1ch1eka and RRC Embu Mr Gachanja for fac1htatmg movement to the s1tes and office serv1ces K1ambu and Embu DAOs and thetr extens1on staff for ass1stance and part!Clpallon m the research Messrs Mwlu M1chem and Nyaga (KARI centres stafl) Mama and Ms Machana (Munyu Sec School stafl) for the1r ass1stance m field operallons 1 also thank the farmers whose ass1stance made th1s research a success Dr C Wortmann m part1cular has been very resourceful REFERENCES Jaetzold L and Schm1dt H (1983) Farm Management Handbook IIB Mm1stry of Agncullllre Nwrob1 Kenya Jaetzold L and Schm1dt H (1983) Farm Management Handbook IIC Mm1stry of Agnculture Nmob1 Kenya pp 2 58 Lal R (1976) No t1llage effects on sod propert1es under d1fferent crops m Westem N1gena Joumal of Sod Sc1ence Soc1ety of Amenca 40 762 768 Mutham1a J G N (1990) Zero llllage m bean producllon Proceedmgs of the Second Workshop on Bean Research m Eastem Afhca CIAT Afhcan Workshop Senes No 7 pp 372 376 Phdhps S H and Young Jr H M (1973) No Tdlage Farmmg Remmann Assoc1ates M1lwaukee W1sconsm Ross and Meml (1990) Apphed Weed Sc1ence Thomas G W Blevms R L and S H Plulhps (1983) No tdlage m the Trop1cs In No T1llage Agnculture Pnnc1ples and Pracllces R E Ph1lhps and S H Ph1lhps (Eds ) Van Nostrand Remhold Company Inc pp 270 301 201 '- 2 7 OCT 1998 EFFECT OF WATER HARVESTING SYSTEMS ON BEAN MAIZE INTERCROPPING IN ARID AND SEMI ARID LANDS OF KENYA DO Mocboeka, A M Ndegwa and G W Mbugua KARI Natoonal Hortocultural Researcb Centre Tboka Kenya ABSTRACT An cxpcnmcnt was tmtlated to mvcshgatc thc cffccts of water harvcstmg methods m bcan mat7c mtercroppmg o;yo;tcms m and and o;cmt and lando;; (A ~A L) of Kcnya Thc sth .. selcctt .. d for prchmmary studtes was a fanncrs ftcld located m Agro J-.cological /onc 5 m Gatuanyaga arca of K1ambu D1stnct Central Provmcc l our watLr harveshng mcthod'i Wt..n .. comparcd VIZ p1t catchments contour and hnc he ndgco;; and farrners prachce wh1ch was the control Bcan and mat7e ytelds were stgmficantly better m all water harvestmg systcm~ than m the control rhc heavoest bean yoclds ( 1 319 kg/ha) were rccordcd m thc ptl catchmcnt system llowevcr construct1on of the ptts was lahour mtcnstvc Contour (974 kglha) and ltm .. he ndgong (9l3 kglha) also resulted on faorly good yoelds 1 hcsc treatment• had an addcd advantagc -;mee the he ndges wcrc eastcr to construct 1 hcse mthal results mdtcatc that the water harvestmg concept can he uhh.led successfully m the A S A 1 s of Kt.nya and could be extended to othcr countnes of castcm Afnca 1 he hypothcsts w11l bt. furthcr tested m subsequent seasons INTRODUCTION Dry bcan (Pha 15 cm) have very low nutnent reserves They are poorer than the top hon~.ons so cultural practices have tended lo Improve the surfacc soii Each farmer has fields on hiiitops stccp slopes valley bottoms and colluvial smls and has nce fields On steep slopes topsoii ts raptdly exhausted and washed away by crosion At the bottom of the hiii there are colluvial deposiis and the topsml IS decper Thcse soils are more fertile than those on the slopes AGRICULTURAL TECHNIQUES AND SOIL MANAGEMENT The mrun crops cultivatcd on lanely are maizc bean cassava potato soybcan sweet patato peas cocoyam and arrow root (especially m Ambohibary) Mixed croppmg IS common Dunng the mrun season (October January) beans are always mtercropped with mau.e Somettmes thcrc are two or three assoeiated crops such as cassava mruzc beans or patato mru~.e bcans soybean Puro stands of beans are culhvated dunng the second scason (February May) One hundred percent of fanners plant bcans dunng the first season Dunng the second season 1 00% of farmers plant beans m Anlanifotsy and 67% m Ambohibary Twelve percent plant beans dunng wmter (July October) m Antanifotsy Beans are planted throughout the toposequence The most Importan! positions are on slopes and bottoms of the hiiis Farmers practtce complex crop rotat10ns mamly patato or sweet potato followed by beans mtercropped with mru~.e or other crops dunng two or three seasons then fallow or potala agam Thirty percent of farmcrs do not pracltse rotalton Sixty pcrcent of farmcrs practtse fallow for 1 lo 2 years with estimated 1and su.e rangmg from O 05 ha to 1 5 ha Fallows are pracltscd bccausc 235 land has bccome mcreasmgly mfert1le but also because of lac~ of manure and mputs and cash to h1re labour Table 2 So•l charactcnshcs of Amboh1bary and Antan1fotsy Sml charactenshcs Amboh1bary Antan1fotsy Geology complcx fonnahon m•gmat1les of trachyte gne1ss andcs1te w1th m~easch1sls basalt1c rccovcry substratum Color (Munscll code) brown rcdd1sh brown rcdd1sh to strong red lo red Topography h11ly and stony gcntle slopcs Culhvatcd slopes 10 30% 2 10% V!SllCd 5 and 7 5 ycars 5 and 7 5 ycars Eros1on 1mportant modcratc pH l 2 5 rangc 4549 4 l 5 2 ( sml water) mean 4 73 4 91 CEC meq/lOOg range 2 88 15 14 l 88 24 79 (cobalhhcxamm) mean 6 53 10 09 Exchangcablc Al rangc () 57 8 43 o 44 7 71 (mcq/lOOg) mean 2 86 3 41 Al (Kamprath rangc 62 90 58 92 Cocffic•cnt %) mean 79 81 Phosphorus range 1 8 4 7 l 6 8 4 (Olsen ppm) mean 3 2 83 All farmers apphcd manurc to thcu liclds but thc quanhty var1cd accordmg to thc amount av3llablc When there IS a lack of manurc m31~-C and bean sccds are sown togcthcr m thc samc holc A fe" farmcrs apphed morgan1c fcrtllll.crs (NPK ll 22 16 or urca) but only m small amounts ( 16 50 kg/ha) Othcrs d1d not hkc chcm•cals becausc thcy cons1dcrcd thcy dcstroycd sml structurc In Amboh1bary lo mercase thc quanhty of manurc farmers bum vcgctahon and add thc ashes lo manurc m1xed w1th salt In Antan1fotsy farmcrs havc a tcchmcal sk11l m processmg the1r farm manure thcy cover 11 lo 1mprove 1ts quahty Phosphorus uptakc by bcan crops 1s mhlbltcd as shown by leaf analys1s In general thcrc 1s P delie1ency and a suffic1cnt leve! of K In Am boh1bary thcrc 1s suffic1cnt Ca and Mg and lcaf N 1s adequate In Antan1fotsy severa! cases of N Ca and Mg delic1enc•cs were found Plant v1gour was evaluatcd al both s•tes The cvaluat10n rangcd bctwcen 4 and 8 w1th an average of 7 Bean growth was very poor dcprcsscd by an abnonnal drought dunng Dcccmber Most farmers do not terrace slopcs except m Tokotan1tsara whcrc anlHJros1on pract1ccs are apphed on stccp slopes Most farmers prachse dcep hllage When thc topsmls are cxhaustcd thcy •mprovc the sml fert1hty by deep d1ggmg dunng land prcparat10n Land prcparahon •s done w1th spade along the slopcs The sowmg lmes are also madc m th1s way Th1s pract1ce speeds up opcrahons but causes sml cros10n Land dctenorat1on 1s also aceclcratcd by bummg 236 • Farmcrs are fully awarc of sml fcrt1hly Thcy class1fy 11 accordmg lo colour and tcxlurc Thcy rcported that thc y1clds obtamed from bcans culllvatcd m vallcy bolloms and on colluv1al smls are tw1cc or thrcc limes grcatcr than y1clds from bcans culllvatcd on thc slopcs Farmcrs grow land races Menakely IS the common cult1vatcd vanety on lanely because 11 1s well adapted to margmal smls and 1s relat1vely reSISianl lo pests and d1seases Menakcly has small dark red seeds and a h1gh y1cld bul commands thc lowcsl pnce on the markct Thc mosl prcfcrred vancllcs havc large wh1tc greco or pale-colourcd secds Thcy are preferrcd for thCir laste and command a h1gh pncc Bul they are very susccpllblc lo pcsls and d1seascs and y1eld poorly on tanely bcmg beller smted lo fcrt1le smls The asscssmcnt of bcan y1clds m farm cond11lons 1s very d1fficult bccausc farmcrs bcgm lo harvesl beans as soon as poss1ble and contmuc up lo thc dry pod stage Y~eld est1matcs he m general between 300 and 800 kg/ha w1th a mean of 400 kg/ha (B1gol el al 1988) Farmers cons1der the poor y1elds lo be due to pests and d1seases wh1ch cause losses of 1 O 75% w1th an average of 50% Poor sml fert1hty 1s also cons1dcrcd a maJor cause of poor y1clds Thc mosl w1despread msecls are Apoderu' humerabs and Pyrame1s spp wh1ch allack lcaves Thc mosl 1mportant sml msects are cutwonns wh1ch occur cvery scason The only 1mportant d1scasc recorded dunng the survey was common bactenal bhght Force field aoalys1s to 1mprove bean y1elds Dnvmg forccs awarencss of sml mfert1hty awareness of thc low y1cld 1m portancc of bean erops for food and meo me w1lhngness lo lry new techmqucs w1sh to gel new vanelles w1sh lo work w1th rescareh land ava1lab1hty sk1ll m farm manurc proccssmg use of ash scvcral croppmg scasons mulllplc croppmg systcms prescnce of farmers assoc1allons categon'.c beans accord1ng to sml fert1hly RESEARCH NEEDS Restrammg forces alummmm loxlclly and low P sml poor land preparallon and absence of tcrracmg pests and d1seases lack of 1m pro ved or cert1fied seeds lack of 1mplements chem~eals unava1lablc or too expcns1vc crop rotat1on accordmg lo needs msuffic1cnt cattle for transport or manurc An 1mportant aspect of th1s d1agnost1c survey 1s to study lhc poss1b1hty of mvolvmg farmers m part1c1patory rescarch Therc 1s a nccd to carry out cxpenmcnts under farmcrs cond1hons and managcment and to use farmers entena of cvaluat1on of results (Tnpp and Woollcy 1989) 237 Control of pests and d1seases IS the mam pnonty A bean pests and d1seases survey should be conducted to obtam accurate data on these problems A study of b10log1Cal control strateg~es w1ll be very relevan! Ex•stmg farmer organ11.allons should try to obtam cred1t and purchase chem•cals and other mputs (for example spray pump seeds ferllhsers) Attenllon should be pa1d to s01l conservallon and management wh1ch req01res close collaborallon between extens10n research and farmers There 1s a need to estabhsh land preparallon measures (llllage anll-eros•on bands) to av01d eros1on on slopes New var1elles should be tested for tolerance to low P and h1gh Al compared lo landraces More effic~ent crop rotat10ns should be 1denllfíed and tested Techmques of proccssmg compost and manure should be strengthened Agronom1c pracllces m general should be rev1ewed w1th farmers REFERENCES B1got Y Rakotondrasata M F M and Randnamahad1manana J F (1988) Le Cas du Hancot el des Legummeuses a Vocallon M1xte Fourragere el Foresllere sur les Hautes Terres Malgaches FIS Fevner 1988 Boyer J (1976) L alummmm echangeable mc1dences agronom•ques evaluallon el correct10n de sa tox•c•te dans les sois trop1caux Cah1ers ORSTOM Sene Pedolog1que XIV 4 259 269 IBSRAM (1987) Land development and management of ac1d s01ls m Afnca In Proceedmgs of the IBSRAM Sess10n of the F1rst Reg1onal Semmar on Latent1c S01ls Matenals and Ores Oouala Cameroon January 21 27 1986 Oldeman L R (1990) An Agrochmallc Characten,.atiOn of Madagascar lntemallonal S01l Reference and lnformat10n Centre Wagemngen Raverom1ha¡a H (1992) Atlas CIRVA AntSifabe FOFIFA ORO Eq01pe Recherche Oeveloppement CIRVA OOR 2 Ants1rabe Rolhn O and Rabary B (1991) Enquele sur les systemes de culture du hancol dans le Vakmankaratra Rapport Programme Legummeuses FOFIFA/OOR PPI Stemer K G (1990) Manuel d Expenmenlallon en M1heu Paysan pour les Pro¡ets de Oeveloppemenl Rural Oeutsche (GTZ) GmbH Eschbom Tnpp R and Woolley J (1989) The Planmng Stage of On Farm Research ldenllfymg Factors for Expenmentallon Mex1co O F and Cah Colombia CIMMYT and CIAT 238 2 7 \.\C1 \998 HARICOT BEAN DOUBLE CROPPING WITH MAIZE, WHEAT, TEF ANO IRISH POTATO UNDER RAINFED CONDITIONS IN THE SOUTHERN RIFT VALLEY OF ETHIOPIA Tenaw Workayebu and Waga Mazeng1a lnstJtute of Agncultural Researcb, Awassa Etb10p1a ABSTRACT Double croppmg 1s commonly prachsed wiihm the southem nft valley of Elhiop1a fanners grow hancot bean after harveshng medJUm to late matunng crops such as matzc grown for tts green cobs We mvesttgated the system to seek better crop combmahons and conduct an economtc evaluahon The y1elds of double croppcd hancot bean vaned among years due to changes m mmsture reg1mes and sowmg dates whtch wcre govemcd by thc lime of harvcst of !he precedmg crop The best y1elds were ob!amed from banco! bean grown after lnsh polalo wheat or tef H1gher gross mcome was obtamed from double cropped !han from monoctopped hancot bean INTRODUCTION PopulatJon growtb has resulted m a shortage of farm land part1cularly m the southern nft valley of Eth10p1a (ClMMYT 1990 C1MMYT 1992) wluch has affected crop productton Doub1e-croppmg (growmg and harvestmg two crops from the same field m the same year) offers a means of mcreasmg y1eld per umt area so as to feed the larger populallon Accordmg to surveys (Getahun Degu el al 1991 Tenaw Workayehu 1990) growmg hancot bean as a precursor or successor to mwze tef wheat and 1nsh potato 1s common pracllce m Ars1 Negelle Shashcmene S1damo and Wolay1ta d1stncts Farmers crop vanettes m part1cular mwze are medJUm to late matunng For the purpose of double croppmg farmers harvest ma1ze as green cobs lo prepare the 1and for the next crop A number of stud1es have demonstrated the value of double croppmg (Crabtree el al 1990 Dan1els and Scott 1991 LeMah1eu and Bnnkman 1990) The precedmg crop can remove so1l motsture and nutnents espec•ally 1f 11 •s h1gh y•e1dmg Dan1els and Scott ( 1991) observed that the depletJon of sotl water by wheat and vanat10n m rwnfall affected the y1eld of the followmg soybean crop but desp1te the redueed y•cld of double-cropped soybean better econom1c retums were ach1eved from wheat/soybean double croppmg than from e1ther crop grown alone Crabtree el al (1990) reported a y1eld reducllon of 22% from double cropped soybean because of madequate and unevenly dJstnbuted rwnfall LeMahteu and Bnnkam an ( 1990) reported y1clds rangmg from 60 lo 105% of soybean alone from double-cropped soybean followmg barley wheat and rye wh1le soybean grown after oat y1elded 38 lo 57% of soybean alone due lo late sowmg of the soybean crop No 1nformat•on 1s avwlable on the double croppmg of hancot bean aftcr harvestmg cereal crops for thelf grwn y1eld m Eth10p1a The objecllves of th1s study were lo measure the y•elds of hancot bean double-cropped after mwze tef whcat and lnsh potato grown for thelf grwn/tubers 2 scek better y•e1dmg crop com bmat1ons and 3 determme the econom1c benefits of the system 239 11 • f l , ' • t.~' MATERIALS AND METHODS The study was conducled for three consecul1ve years ( 1986 1988) al lwo research SI les (Awassa and Ars1 Negelle) ID the southem nft valley of E1h10p1a The s01ls are sandy loam al Awassa and clay loam al Am Negelle The cultivars used were Kaluman1 Compos11e (early matunty) and A511 (med1um) mwze Dz 01 354 (med1um) lef local (medmm) lnsh polalo Dashen (med1um) whcal and B 935 (med1um) hancol bean Each vanety was grown as precursor or successor lo hancol bean The sowtng time for the firsl crops was lhe firsl week of Apnl (Tablc 1) Han col bean was sown as a monocrop for companson al the op11mum sowiDg times wh1ch were w1th1D lhe firsl 20 days of Junc al Awassa and the whole of June al Ars1 Negelle All crops were harvesled for the.r gram/luber y1elds The recommended fertlhzer rates ( 41 kg/ha N for mwze and 18 kglha N for other crops and 46 kg/ha P,O,) were apphed DAP was broadcasl and IDCOrporaled al planiiDg wh1le urea was s1de-dressed lo mwze al knee he1ght Recommended seed rates were used Rwnfall for Awassa and harvcst dates and grwn and tuber y1elds were recorded The expenmental des1gn was a randoml7.ed complete block w1th three rephcates Ind1v1dual year and combiDed analyses of vanance wcre conducted Econom1c analys1s was carned out usiDg the mean market pncc of each crop for each of the three seasons Table 1 Sowtng and harvestiDg dates ID double cropp1Dg tnals at Awassa and Am Negelle 1986 88 Awassa Ars1 Negelle PrecediDg Hancot Precedmg Hancot crop bean crop bean Years Crops Sown Harv Sown Harv Sown Harv Sown Harv 1986 Mw~.e 1 9/4 20/8 25/8 30/12 Mwze' 9/4 8/8 18/8 30/11 Wheat 14/4 20/7 9/8 20/11 Tcf 9/4 18/7 30/7 6/11 14/4 4/8 Insh potato 9/4 1517 30/7 1111 14/4 10/7 23/7 20/11 Hancot bean 10/6 10/10 21/7 20/10 1987 Mwze1 1/4 31/7 18/8 20/12 Mwze' 1/4 16/7 3/8 10111 27/3 20/7 27/7 10/11 Wheat 27/3 2517 7/8 10/11 Tef 1/4 717 1717 1111 27/3 12/7 21/7 20/10 Insh potato 1/4 517 17/7 29/10 27/3 16/7 20/7 19/10 Hancol bean 13/6 11/10 27/6 19/9 1987 Mwze1 9/4 15/9 20/9 26/12 Mw7.e2 9/4 20/8 1/9 8/12 13/4 19/7 8/8 12111 Wheat 13/4 25/8 30/9 Tef 9/4 18/7 29/7 4/11 13/4 26/8 8/9 20/11 1nsh potalo 9/4 29/7 2/8 4/11 13/4 2517 6/8 20111 Hancot bean 14/6 5/10 20/6 6110 1 A511 2 Katuman1 Compos1te 240 RESULTS AND DISCUSSION In 1986 ramfall al Awassa was good m Apnl Junc and Scptcm bcr but poor m October Decem ber Total ramfall was 21% more than the long tenn mean (Table 2) In 1987 ramfall was good m May but poor m June Septcmber and total ramfall was 6% less than the long tenn mean In 1988 better ramfall occurred m Apnl and June October but total ramfall was 10% lcss than the long tenn mean Table 2 Awassa mean monthly ramfall 1986 1988 and long term means 1972 1991 Months 1986 1987 1988 Means March 44 4 125 9 16 4 71 5 Apnl 115 3 87 1 102 8 110 5 M ay 2579 246 4 93 4 144 1 June 152 6 59 1 106 9 105 2 July 195 7 104 5 121 3 138 8 August 167 o 105 5 129 4 139 8 September 160 2 75 7 215 5 140 5 October 46 1 95 3 71 o 778 Novembcr 20 1 00 24 29 4 December 32 2 23 60 21 2 Total 1159 3 899 5 859 1 957 6 The ytelds of second-cropped hancot bean over the three years ranged from O 3 to 2 2 t/ha at Awassa (Table 3) and O 2 8 t/ha al Arst Negelle (Table 4) The hghtest yteld at both sttes was from hancot bean after mau.e Better growth and yteld were obtamed from hancot bean after Katumant Compostle mruze than after A511 The heavtest ytelds (2 O tlha al Awassa and 1 8 tlha al Arst Negelle) were obtruned from hancot bean after lnsh potato The vanatton m hancot bean ytelds among years resulted from vanatmn m sowmg date due to the preeedmg crop Depletton of sotl water by htgh yteldmg crops such as mruze also affected bean performance and yteld Table 3 Mean ytelds m double croppmg tnals al Awassa m 1986 88 Crop Other crops Hancot bean pmg system 1986 1987 1988 Mean 1986 1987 1988 Mean Bean!wheat 1 9 24 2 1 2 1 25 25 08 1 9 Bean!m ruze1 1 8 27 22 22 25 1 7 1 4 1 9 Bean!tef 06 06 07 06 28 22 05 1 9 Bean/~otato 68 66 00 45 27 2 1 1 3 20 Mruze lbean 59 65 50 58 03 03 05 04 Mruze2/bean 49 53 32 45 1 4 1 3 08 1 2 Teflbean 1 2 05 06 07 1 5 2 1 2 1 1 9 Potatolbean 79 64 10 1 8 1 1 9 22 1 9 20 Bean alone 2 5 1 4 28 22 cv (%) 17 3 38 6 22 6 SE± 03 06 02 1 A511 2 Katumant Compostle 241 Table 3 Mean ytelds m double croppmg tnals at Arst Negelle m 1986 88 Crop Other crops Hancot bean pmg system 1986 1987 1988 Mean 1986 1987 1988 Mean Bean/wheat 2 1 20 1 1 1 7 37 36 08 27 Bean/m ruze' 1 3 2 1 07 1 4 28 35 07 23 Bean/tef 1 5 1 4 09 1 3 38 4 1 08 29 Bean/potato 37 35 o 08 24 37 3 7 07 27 Mruze'lbean 25 24 o 08 1 7 09 1 1 1 4 1 1 Mruze'lbean 36 1 8 27 08 o 04 Teflbean 1 5 09 1 2 06 1 9 04 09 Potatolbean 13 9 78 11 9 11 2 1 9 28 07 1 8 Bean alone 2 1 29 27 26 CV% 25 9 20 2 51 6 SE(±) 05 05 04 Hancot bean produced better ytelds after the harvest of lnsh potato wheat and tef when planted early Aecordmg to Dantels and Scott (1991) htgh yteldmg crops extrae! large quanhttes ofsml water from anthests to phystologtcal matunty whtch coupled wtth seasonal vanatton m rrunfall can deplete the mmsture avrulable for the followtng crop (m thetr case soybean) The yteld losses at the two sttes vaned wtth amount and dtstnbuhon of rrunfall and the ttme of harvest of the precedmg crop The average yteld loss of double-cropped hancot bean ranged between 9 and 82% at Awassa and 31 and 65% at Arst Negelle Thts result agrees wtth that of Dantels and Scott (1991) who reported pronounced effects ofthe precedmg crop and rrunfall on double-cropped soybean Crabtree el al (1990) and LeMahteu and Bnnkman (1990) reported stmtlar findmgs lt ts observed that hancot bean planted as a precedmg crop m helg had a comparable yteld wtth the monocrop hancot bean Over years the heavtest grrun yteld was obtruned from hancot bean after tef and Insh potato at Awassa and hancot bean after lnsh potato at Arst Negelle (Table 5) ECONOMIC ANALYSIS Double croppmg can be vtewed as a means of booshng crop productton effictency thereby mcreasmg rehtrns Thts study has shown the feastbthty of producmg hancol bean after the harvesl of crops m parttcular mruze for thetr grrun Desptte the poor bean ytelds economtc returns procured from double croppmg are better than those from monocrop hancot bean (Table 5) 141% at Awassa and 48% al Arst Negelle Thts result agrees wtth those of LeMahteu and Bnnkman (1 990) who reported benefits from double croppmg 242 Table 5 Mean yoelds (tlha) of hancol bean al Awassa and Arso Negelle 1986 1988 Croppmg o/oof syslem 1986 1987 1988 Mean check Awassa Mwze1/ bean 03 03 05 04 18 2 Mwze2/bean 1 4 1 3 08 1 2 54 5 Tef /bean 1 5 2 1 2 1 1 9 86 4 Polalo/ bean 1 9 22 1 9 20 90 9 Bean (mono-crop)2 5 1 4 28 22 LSD(pludies of ~nap bcan!t ha ve :,hown thc uc;e of poor quaht) c;cLd to be onc of thc mnJor constramts to .,nap bcan produchon 1 hts paper dt.scnbes thc produchon use and J¡:,tnhuhon of :,nap bcan st..ed m Kcnya lt also tru ... s to 1dcnhfy thc con:,tramt-. that mhtbtt thc ust. of good quahty Sl.Ld IIV(.. rt.gt:,tc..n. .. d companu.s wl.rt. found to be producmg ct.rhfit.d snap bcnn sced thcn .. wut. also mdavJdual famu.rs supplymg :,eed although thtc; \\-BS on a smallu 'iCalc '\LLd'i of 35 vanchcs of c,nap bcan an. bcmg produccd m Kcnya but wc cncountcrcd only fivc varu.t&cs wtlh farmcrs 1 he total ncrcagc undcr snap bcan sced m 1990/91 wa• 4 585 acres 60o/ of wh1ch were dc•hned for cxport 1 ho•c found mvolvcd m dtstnbutmg secd mcludcd snap bcan cxportmg agcnb rctatlus parastatals agcnts of snap bcan canmng factonc'i and snap bcan farmcr'i 1 he pnct.. of good quahty 'iccd wao¡ 30 40% grcatcr than that sold by farmcrs "omc constramts mh1h1hng tht.. ust.. of good quahty sccd wcrc htgh pnccs unavallahihty m local kto'ik'i and unccrtamty of tht.. quahty of ccrhf1cd sced INTRODUCTION Sccd quahty can be a dcc•s•vc factor m thc profit or loss of growers enterpnses A fanner sowmg poor quahty non-cert1fied seed may lose not only the cost of seed but also the whole value of the expected crop due lo seed borne d1seases and pests poor v1gour and plant stand Low quahty seed and poor avwlab1hty have been Jdenllfied as the pnnc1pal constramts to the rap1d d•ITus10n of ne" vanelles and 1mprovement of crop product1on m the developmg world H1gh quahty sccds g1ve h•gh gennmallon rates rap1d emergencc and v1gorous plants Although snap bcans have become a maJor forc1gn exchangc camer Kenyan fanncrs are sllll ach1evmg smallcr y1elds than fanncrs m othcr snap bcan producmg arcas m thc world Vanous stud1es havc shown poor quah(y sccd to be one of thc maJor constrwnts to snap bcan producllon m Kcnya An mercase m snap bcan y1elds by Kcnyan fanncrs can only be ach1eved 1f good quah(y ccrt1ficd seeds are made ava•lable to growcrs at the nght lime and place and al rcasonablc pnces The a1m of th1s study 1s lo •denllfy the constramts hm1llng the use of ccrt1fied seed and lo suggest poss1ble solullons The study 1s cxploratory and prehm mary data are gathered m order lo shed hght on the real naturc of thc problem METHODOLOGY Nme d1stncts have been •denllfied as 1mportant snap bean growmg areas they mclude Meru Embu Machakos Murang a Nyen K~ambu Kmnyaga Kakamcga and Bungoma The reg1stercd seed compan1es wh1ch produce snap bean secd have also beco •denllfied Producllon d1stnbullon and consumpt10n stagcs of the secd are bemg stud1ed An mfonnal survey JS bemg conducted lo collcct the reqmred mfonnat10n At the consumpt10n level snap bean growcrs m vanous d1stncts are lo be VJSJted and mfonnallon on the secd (ype vanety source and constrwnts 10 seed acqu•s•llon 1s to be sought through mterv1ews and d1scuss•ons Al the producllon stage mfonnat10n 1s bemg sought from reg•stered seed compan1es and contracted sccd growers lnfonnallon on seed d•stnbut1on from pomt 308 of productton lo consumplton leve( ts bemg sought from traders and other bodtes mvolved m seed dtstnbulton Ftve of the maJor snap bean seed growmg arcas and two of the mam regtstered seed compantes have already been vtstted RESULTS AND DISCUSSION The followmg seclton gtves a general mdtcatton of the data that has been collected so far Sources of seed Sources of seed vaned among regtons and among farmers wtlhm the same regton Farmers who were producmg snap beans on contrae! for a parttcular exporlmg company were provtded wtth the seed by the company through thetr buymg agenls Thts pracltcc was mamly found m westem Kenya and lo a lesser extent m central Kenya Farmers who wcrc producmg snap beans wtlhoul a contrae! arrangemenl obtamed seed from any sourcc dependmg on preference and avatlabthly of seed Thts was the mosl common pracltce m central Kenya Regtslered seed compantes were the most frequently menltoned so urce 33 1% of thc farmers havmg bought the seed from them Snap bean exporlmg compantes were also a maJor source of seed as 24 5% of the farmers satd that thcy had purchased sccd from thcse compantes through thctr agcnts Other sources of seed were snap bean growers (14 5%) the Horltcultural Crops Developmenl Authonty (10 1%) and farmers own sced (10 1%) There was also bagged unlabcllcd seed whtch ongmated etther from the crop reJected by field mspcclors or from snap bean growers who let thctr crop maturc and dry after pnces fell below economtc levcls Only 21% of thc farmers mtervtewed recetved advtcc on the besl seed lo plan! Farmers gavc vanous rcasons for thetr preference of sced sourcc Sceds from sorne exportmg and canmng agenls was preferred becausc thcy were supplymg new varteltes of snap bcans whtch were htgh yteldmg had a lower percentage of reJected pods and consumcd lcss labour for ptckmg Many farmers were relymg on netghbounng farmers seed or seed m local shops as ti was much cheaper and more readtly avatlable than seed from regtstered sccd compantcs Other farmers were plantmg thetr own sced because no costs wcre mcurrcd Farmcrs ctled quahty avatlabthly and pnce as thc mam problcms wtlh the vanous snap bean sced sources Quahty Seed quahty problems ctled by farmcrs mcludc poor gcrmmatton percentages off types thtck pods wtth curly ttps and low ytclds Thc farmers rarely assoctated sced wtth the dtscases and pests attackmg thctr snap bean crop The sources whtch were most frequently menltoncd as havmg quahty problems were farmers own seed nctghbours sced unlabclled sced and sorne secd lots from regtstered sced compantes Avatlabthty Whereas farmers own and netghbours sccd had no avatlabthly problems all thc ccrltfied seed sources (regtstered seed compantcs and bcan exportmg company agents) dtd Ccrttfied seed was not readtly avatlable when needed and so farmers resorted to usmg thetr own sced nctghbours sced or any other seed avatlable from the local ktosks Certtfied sced was confined mamly lo large towns and shoppmg centres and rarely found m rural arcas whcrc farmers are located New vanettes were unavatlable m shops and could be obtamed only from agents of snap bean cxportmg compantes Farmers mrunly plantcd thc Monel vanety onl} a few "ere plantmg thc ncw vanettes HCL and Glona 309 Proce Farmcrs found all sourccs of ccrtoficd sccd hoghly pnccd rangiRg from Ksh 65 lo 70 for Moncl and from Ksh 345 lo 350 for the new vanchcs The pncc of ccrtoficd Moncl sccd comparcd lo thc pncc of sccd bought from snap bcan farmcrs or local shops doffcrcd by Ksh 30 35 The hoghcr pnce of snap bean secd than of other secds was thc m aiR rcason for the sm all plots of land under snap beans Avwlabohty of the sced on credo! eased the cash constraiRl omposed by thc hogh pnces Secd product10n Therc are five regoslcrcd snap bean sced mcrchants m Kenya Thcsc companocs produce sccd on contract woth farm,rs Thc company usually provodcs farmers woth sccd for bulkiRg on credo! Othcr mpuls that may also be provodcd IRcludc fcrtolu.crs and peshcodcs and also ficld mspcctors Thcsc cosls are later rccovcrcd whcn thc farmcr dchvcrs hos crop lo thc company s dcpol or al a spccoficd collccl10n centre Companocs pwd farmcrs al doffcrcnt ratcs rangiRg from Ksh 14 lo 24 pcr l..g dchvcrcd Thc maJor snap bcan sccd produciRg arca os L01tokotok Othcr arcas whcrc sccd os produccd IRCiudc Naovasha Kotalc ls10lo Machakos Mcru Rumuruh Mwca and Narok Thc total numbcr of varochcs of snap bean sccd beiRg produeed IR Kcnya os 35 woth cach company produciRg doffcrcnt vanchcs (Appcndox 1) Sorne companocs wcrc omportiRg brccdcrs sccd from Europc and Amen ca and bulkmg ol locally whole thc rcsl rccyclcd sccd severa! limes bcforc changiRg ol Thc total acrcagc contractcd by thc companocs for the purpose of sccd bulkiRg m thc 1990/91 scason was 1 855 ha aboul 40% of ot bemg destmcd for thc cxport markcl Thorty pcrccnt of farmers sold secd lo othcr farmcrs Thcse farmcrs lcft thcu crop lo maturc and produce secd Thos maiRiy happcncd whcn snap bcan pnccs fcll thus makmg furthcr pockmg uncconomoc Sorne farmcrs contractcd lo produce sccd for sced companocs sold ol lo rctaolcrs Thos was usually sccd that had bccn rcJCCted by field 1Rspeclors due lo doscasc or IRadcquatc osolahon from othcr bcan vanches Thos secd was usually sclcctcd but rarely dresscd by the farmcr who was sclhng ot Of thc farmcrs who plantcd theu own seed 73% carncd out a sclcchon proccdurc wholc 55% of thcm drcsscd thcu sccd woth a prolcchve fungocodc Soap bean seed dostrobullon cbanoels Thesc are all thc opcrahons mvolvcd m moviRg snap bcan sccd from po1Rl of productoon lo place of consumphon IR thos case thc farmcr (Fogurc 1) Vanous IRdovoduals and mshtutoons are IRvolvcd IR channciiRg thc sccd from produccrs lo consumcrs and varoous dostnbuhon mcthods wcrc cncounlcrcd Cootract arraogemeots Sorne snap bcan cxportiRg companocs wcrc IR a conlracl arrangcmcnt woth growcrs whcrcby thc company dchvcred thc sccd lo farmcrs on credo! through the~r agcnls Thc agcnts provodcd thc secd maiRiy lo womcn s or any organu.cd farmers group thcy also provodcd IRdovodual farmcrs woth secd Thc cxportmg companocs usually bought secd from rcgostcrcd sced companocs although sorne wcrc buyiRg from snap bcan farmcrs and dchvcnng ol lo farmcrs Of thc farmcrs mtervocwcd 24 5% wcrc obtaiRIRg thcu secd through thos kiRd of arrangcmcnt Hortocultural Crops Developmeot Autbonty (HCDA) Thos os a govcmmcnt parastatal IRvolvcd IR thc promohon of produchon and markctmg of Kcnyan hortocultural products Thos parastatal buys sccd from sorne regoslcrcd sced companocs and dostnbulcs 11 lo thcu sclhng centres namcly dovosoonal agncullural officcs or chocfs camps 10 1% of the farmcrs IRlervocwcd swd thal thcy bought thc sccd from HCDA 310 F1gure 1 Snap bean seed d1ssem1nat1on channels Importad seed ~ For e;¡rport / Snap bean Req1stered Contracted farmer 1 seed company farmer 1 ! 1 ~ 1 1 1 1 1 J, 1 1 ' 1 Snap bean BCA Ma1n KGGCU 1 1 export1nq depot seed depot 1 company reta1ler 1 1 1 ! ' Req1onal Branches r depot Reta1lers 1n L----.1.--- ---- other towns ----- ... -------- ------1 and shopp1nq 1 -:, \lt centres r---- Company's 1 1 1 ~ aqent ,¡, 1 1 i ,__________ ., Ch1ef's 1 : 1 camp or 1 1 DAEO's 1 1 off1ce 1 1 1 1 1 1 1 1 1 ~ ' ' ' 1 lwomen's 1 qroups and farmers' SOC18t18S 1 : ' 1 1 1 1 v v' ' v ' ~ \ ' ' l Ind1v1dual farmers Key cert1f1ed seed----------- non-cert1f1ed seed--------- 311 Regutered seed compa01es Thts was the seed that was planted by most (33 1 %) farmers mtervtewed The two maJor seed compantes packed thetr seed mamly m two kg packages and to a lesser extent m one kg packages The remammg compantes packed thetr seed m 50 or 90 kg bags The two maJor regtstered campantes m arketed thetr sccd through (1) wholesalers located m Natrobt these wholesalers m tum sold the seed to retatlers m dtfferent towns and smaller retwlers m the large markets and also to mdiVIdual farmers and (2) the Kenya Gram Growers Co-operattve Umon (KGGCU) whose branches are found tn every maJOr town m the cauntry sorne KGGCU branches m snap bean growmg arcas dtd not stock snap bean seeds Other seed campantes sold thetr produce through snap bean exportmg agents HCDA and to mdtvtdual large scale farms Snap bean farmers Farmers were also supplymg a large number (23 1%) of other farmers wtth sccd They sold the seed at thetr farms or through local shopkeepers who m tum sold ti to other farmers Retatlers Retatl shops stocked snap bean seeds from vanous sourccs mcludmg 1) regtstered seed campantes whose seed ts usually packed m one or two wcll labclled kg packages and 2) cantracted snap bcan sccd growcrs and othcr snap bean farmers thts seed was netthcr packaged nor labelled DISCUSSION The factors found to be affectmg farmers dectstons on the type of secd to plant were 1) Thc pnce of the sccd campared to thc pncc of the produce Most farmcrs found ccrttlicd seed too htghly pnced and uneconomtc to use espectally dunng pcnods when snap bcans pnccs were low 2) Unccrtwnty on the avwlabthty of good qualtty sccd whcn ti ts needed and the unavwlabthty of thts seed at nearby shoppmg ktosks 3) Unccrtwnty on the qualtty of seed Thts ts usually based on the prevtous performance of the seed 4) Lack of cash or credtt to purchase htgh qualtty seed 5) Lack of knowledge of the advantages of plantmg good quahty sccd 312 In order lo encourage farmers lo plant good quahty seed 11 1s 1mportant lo 1) lncrease awareness among farmers of the bcnefits of usmg good quahty sced Th1s m ay be ach1eved by dcmonstratmg the profitab1hty of good quahty sced dunng barv.as and ficld days and by demonstrat1on plots 2) lmprove standards of field mspecllon and cert1ficallon of quahty sced to chmmatc uncertamty about the quahty of cert1ficd sced 3) lncreasc the avmlab1hty of quahty secd by prov1dmg 11 lo local k1osks 4) Improve farmers purchasmg powcr by prov1dmg h1m w1th cred1t fac1hl1cs m thc fonn of seed 5) Reduce the h1gh costs of cert1fied sced lo a leve! that farmers can afford H1gh costs result from poor organ1zat1on of sced mulllphcallon d1stnbu11on and storage REFERENCES CIAT (1989) A spec1al study on snap beans Bcan Program Annual Report 1989 Workmg Document No 68 pp 297 306 De Jong J J (1961) Seed D1stnbullon and Trade Agncultural and Hort1cultural Sceds FAO Pubhcallon No 55 Romc pp 121 153 Emery G C el al (1992) Intemat10nal Snap Bean Producllon and D1stnbullon Snap Beans m thc Developmg World CIAT Pubhcallon 195 Cah Colomb1a pp 277 293 Koster W G and Basuk1 R S (1991) Markctmg systems rcsearch A comprehens1ve and mtegrated approach for understandmg and 1mprovmg market performance Actae Hort1culturac 270 205 213 Mathengc F N (1974) lntroducllon lo qual1ty control Paper prescnted m a FAO/SIDA Seed Trammg Course Kenya Omunym M E (1983) Dry Bean D1seases and Pests of Econom1cal lmportance m Kenya and The1r Control Gram Legumc Project Nallonal Hort1cultural Research Centre Th1ka Sm1thson J B (Ed ) 1990 Proceedmgs of the Second Workshop on Bean Research m Eastem Afnca CIAT Afnca Workshop Senes No 7 pp 381 391 313 • • t Append1x 1 Vanelles of snap bean produeed seed compan1es and arcas under seed producllon 1990 1992 Vanety Producmg company Acreage (ha) Year Super Kenya H1ghland Co 162 1990/91 MICCO 64 Kak1 283 Cropper 125 Content 220 Bmgo 10 Agora 273 Bano " 114 Blue Royal 130 Tdf 357 MT86 Hort1tech 8 Na1tec 685 N90 79 Red Beauty 64 S1mpson 6 Solare 8 T1lla 30 Vemadon• 107 Contender 79+ Grcen Tec " 18 1990/91/92 Purple Tec 2 Stnngs Bean Wh1te 14 Tech 86 Monel• East Afncan Seed Co 259 1990 92 Super m1shm* Kenya Seed Co 45 1990/91 Sk1l 75 Extra Fme K K1plol Seed Co 147 Extra Fme KA 11 5 1992 Extra Fme KB 1 5 Katum an1 B 11 16 1991 K1plol Red 10 Dark Red K1dney 10 L1ght Red K1dney 10 314 G393i.,B ? 1 nrT ~~" ANALYSIS OF BEAN SEED CHANNELS IN THE GREAT LAK~ RltGtbN " Lou1se Sperhng CIAT ISAR Rubona Botare Rwanda ABSTRACT Interv1cWs wtth fannero; m f;)outh K1vu Provmcc of /.31n.. <>outhcm Rwanda and thrcc art.aon A In /_Áluc and Burund1 substanhal arcas wcrc also grown on lowland mar.,hcAlXUUA l •upportcd hcan rcmarch suh proJccts 1s dc•cnhcd w1th cmphao;ts on thosc m whtch 1 arvaman 'iCJcnUo;tc; wen .. mvolvcd In thc drought sub-proJCCt nur'icru .. o; at '-,chan and Mtwalem m fat17anta ldt..ntlficd o;tx hnc'i whach perfonned wcll undcr drought o;trc'i'i In tnal'i m Malawt drought tmposcd dunng vcgetattvc growth deprcssed total bwma" lcaf arca canopy hc1ght and w1dth pod numhcr and sccd y1cld Canopy charactcn!-.hc'i wcre unaffccted by drought dunng rcproduchvc growth Dommo ¡x.rformcd wcll whcn 'itn .. ,c;cd dunng vcgctahvc growth and four othcr hnco; whcn drought was 1mposcd dunng rcproducttvc growth 1\ survcy m northcm 1 arvan1a establishcd that farmcrs wcre conccmcd about thc mercase.. m drought problt...ms whtch thcy attnbutt .. d lo dl.fon. .. statwn Cro..,!>L.., of drought toiLrant and adapted hnes have beco made m /ambta In thL bt..an stLm maggot (BSM) sub-projccl cros!>eo., havc bt..Ln madl. m 1 aJVama of lkiDtmba and ZPv 292 (ll~M reSISta ni) WJth 1 yamungu 85 Dore de Kuundo and Canad1an Wondcr 1 c;ts of parents and 1 2 and 1- 3 populahons suggc'it that rcs1stancc 1s prLdomiDantly addtttvl. Nematodl. 'ipt..Cll.'i mfLshng heans ID northcm Tarvama have bt..en JdenhfJCd and a start made ID mapp1Dg then dp,tnhuhon BLans are ¡mportant altemate host'i for coffLC and banana nematodes Res1stance has ht..en locatLd among local bcan germplasm 1 cchnology has beco developed for screcmng for lolcrance lo P dcf1ctency m bcans and hnLc; that pcrform well ID low P condttlons havl. lx.t..n Jdt..nllfiLd 10 the 1-Jrst AN~I S Nursery A survey of farmcrs grow10g mat7e and besos m ac;c;ocJalton has been conducted m northem 1 aJVama Progrese; to date w1th thc <;ub-proJects t!> Lncourag10g and rcsults are avatlablc for scJenllsts 10 other regtons INTRODUCTION The common bean (Phalltutc ycar 000 U~$ PNl l~ABlJ l~AR Ull l~AR l~AR PNl PNl UNR ClAI PNl PNl lSAR l~AIJU PNl PNl lSAR PNl PNI l~AlllJ l~AR PNI PNl l~AillJ PNI l~AR PNl l~ABU PNI PNl ISAR l~AR I'Nl ClAl (.1¡\ 1 PNl l~AR (.1¡\ 1 I~AillJ I~AIJU ISAR 91 16 90 2 2 93 1 4 92 o 90 1 7 88 3 o 89 16 90 1 3 89 2 1 90 3M 92 1 2 93 1 7 92 1 4 93 2 4 93 o 4 9l O S 90 o 9 91 1 7 89 1 3 92 17 89 2 6 92 2 2 90 2 o 92 2 3 93 1 4 93 o 9 90 1 2 93 2 6 92 1 4 93 O S 92 1 1 90 2 o 92 1 1 90 2 8 90 1 7 93 o 9 93 1 7 90 1 1 93 1 1 93 2 1 90 7 2 718 !-,octo Agronomy economtc component compont..nt • • • • • • •• • • • • • • • • • 15 • • • • • • • • • • • • • • • • 18 Nat10nal Agncultural Rcscarch ISABU = Burund1 ISAR = Rwanda PNL = Zauc UB = Umvcrs1ty of Burund1 UNR = Nallonal Umvcmty of Rwanda 347 Summary of obJeCtlves and selected results of reg1onal research sub proJects Common bacter1al bhgbt (CBB) thrcatcns bcan productlon espec1ally m lower altitudes Cons1dcrcd of secondary 1mportance for thc reg10n 11 was mcluded m the research agenda afler problcms arose w1th susceptible new vanetles The maJor actlvlly 1s rcs1stanee brecdmg camed out m two lo\\land bean research stat10ns m Za1rc Halo bhgbt was cspcc18lly notonous m thc h1ghland arcas of Burund1 whcre se, eral releascs made ten years ago are susceptible The sub proJCCI 1s malong back-crosses w1th thosc releascs and sources of rcs1stancc of local ongm Black root scrccnmg was cons1dcred ncccssary bccause of the more and more acll\e brcedmg programmcs m thc rcg10n Thcy often have to use 1 gene matcnal as sources of res1stancc wh1ch makes 11 ncccssary lo scrccn obtamed matenals for thc prcsence of thc unprotected 1 gene Natlonal programmcs w1ll not relcasc !mes w1th unprotectcd 1 genes Exploratory tnals showcd that a s1mple des1gn usmg sced mfcctcd AFR 13 spreadcr rows m ay be very effie~cnt m dctcctmg 1 gene !mes Stud1es of pathogemc var1at1on are conductcd for anthracnosc and angular leaf spot (ALS) and havc the followmg goals first a rcg10n w1de samphng 1s to g1ve a general p1cture of race d1stnbut10n mtcns1vc samphng m currcntly uscd or poss1blc 'hot spots should show how thc rcg1onal race spcctrum IS reprcscnted m the hot spots Th1s then allows us lo claboratc a more effic1cnt strategy for d1sease evaluat1on and gene dcploymcnt Prefcrably th1s 1s done m onc hot spot undcr art1fic1al moculatlon w1th raccs occumng naturally therc Y el 11 m ay be ncccSSIU) to work m two or more hot spots lo cover thc whole race spectrum In thc worst (most cxpens1ve) case moculat10n w1th all races found m thc rcg1on may be ncccssary wh1ch would be done m grcenhouses Anthracnose 1s dcalt w1th by two sub proJCCis In R wanda rcs1stance brccdmg produces so me severa! hundrcd F2 populatlons per year wh1ch are thcn subjected lo field moculat1on (Gasana and Buruchara 1992) and later lo moculatlons w1th raccs 1dent1ficd m Rwanda m thc screcnhousc In Burund1 a patholog1st conccntrates on mappmg thc anthracnose racc spectrum and contrastmg 11 w1th cxtens1vcl) sampled 'hot spots Both sub proJccts are coordmated m such a way that d1rect compar1sons are poss1blc (e g samc set of dlfTcrcntlals) and should allow for dcvclopmg a more cfficiCnl (reg1onal) brcedmg strategy to deal w1th th1s pathogcn The Ascocbyta sub proJCCI complcmcnts res1stancc brccdmg w1th rescarch on cultural mcthods lo control the d1seasc Angular leaf spot (ALS) 1s togcthcr w1th anthracnose the cconom1cally most 1mportant d1seasc m the reg1on (Buruchara 1992) A sub proJCCI on rcs1stance brecdmg startcd m 1989 and has airead) 1dent1ficd prom1smg !mes m Zaue wh1ch are now also m on farm tcstmg m Rwanda Latcr a stud) of pathogemc vanatlon was 1ml1ated confirmmg lo date thc vahd1ty of Mulungu (1750 mas!) as a hot spot for ALS An carher sub proJect on ALS (concludcd m 1989) focuscd on the cfTects of mcludmg rcs1stant components mto farmers m1xturcs lt was shown that proport1ons of 25 and 50% of thc rcs1stant vanety A 285 reduccd the dcvelopment of ALS also on susceptible farmcrs vanctlcs (PyndJI and Trutmann 1992) and that a m1xturc contammg 50% of A 285 y1cldcd as muchas (or even more than) A 285 alonc and cons1derably outy1eldcd local mixtures (PyndJI and Trutmann 1989) Root rots bccame a top1c for bean productlon m 1988 whcn a maJor outbrcak destroycd bean crops m large arcas of the southcm lcss fert1le arcas of R wanda A first sub proJcct conccnlrated on spcciCs determmat1on rcspons1blc for dampmg-<>fT as a bas1s for subscqucnt screcnmg of matenal for res1stance and tolcrance The mam problem for rcs1stance brecdmg 1s that severa! speciCs are mvolved 348 (Rusuku 1991) wh1ch makcs rcs1stance breedmg slow Thercfore short tenn solut10ns have to be found m the form of cultural pract1ces By mcorporatmg fast decomposmg b1omass (fohage of sorne legummous agro forestry spec1es) shortly before plantmg beans 11 was poss1ble lo reduce dampmg-off and d1sease seventy and to mercase y1elds cons1derably (Buruchara 1995) In fact the effect was so ev1dent that farmers who have long been exposed to the conccpt of agro forcstry for sml fert1hty 1mprovement but d1d not adopt 11 havc now startcd lo grow thcse spcc1cs lo control root rots D1seases and thcu mteract10n m vanctal m 1xturcs are stud1cd m a sub pro¡cct lo sec 1f thc encouragmg results ach1cved w1th ALS can also be realw:d w1th othcr d1seases A spec~al challenge of th1s sub pro¡cct 1s lo find a rcahst1c approach lo extens10n of the conccpt lt w11l always be farmers who dcs1gn thc1r spcc1fic m1xtures but m th1s case rcscarch not only prov1dcs components (var1elles) but also thc b10log1cal pnnc1pals on how bcst they are mtcgratcd mto farmer des1gncd (customu.cd) m1xturcs Mult1ple res1staoce 1 e the developmcnt of bcan vanelles that are res1stant to severa! d1seases occurnng m a ceo ~.one 1s the ulllmate goal of all brecdmg efforts m thc reg10n The two sub pro¡ccts look for the most cffic1ent way to ach~eve th1s In both sub pro¡ccts makmg ava1lablc scgregatmg populallons (F,) to other brcedmg programmes should allow for a short term benefit of reg10nal collaborallon Bean stem maggots have becn stud1cd cxtcns1vely m Burund1 over thc last ten years Rcccntly a sub pro¡cct was 1mllated to lcarn more about thcu mteracllons w1th root rots Another sub pro¡ect looks mto the poss1b1hty of non-chcm 1cal control Bananas are the most frcquent mtcreroppmg partncrs for beans m thc rcg10n Onc sub pro¡ect 1s addrcssmg thc qucst10n whcther a separate screenmg programme 1s nccessary lo select vanclles su1table for growmg m banana plots As m Uganda (Wortmann et al 1992) no gcnotypc x systcm mteracllons were found w1th bush type beans but w1th chmbcrs such mteracllons ex1st (C1shahayo el al 1992) The quest1on now 1s whether performance undcr bananas may be pred1ctcd by fanners dunng evaluat10n ofnormal sole crop tnals Chmbers wcre unlll recently rarely planted under banana and m sorne arcas not cven bush bcans are assoc1ated A second sub pro¡ect looked mto the agronomy ofthe chmber banana assoc1allon m an arca of low sml fcrt1hty Therc th1s assoc1at10n m ay deal w1th two problems at a lime Sml fcrt1hty m the banana plots 1s the h1ghcst on the wholc farm {Elukesu 1992) and banana stands and res1ducs may prov1de an altemallvc for stakmg chmbers Tnals have shown that the potcnllal of th1s assoc1at10n 1s such that 11 mc1tes farmcrs to plant chmbcrs mto the1r bananas even 1f 11 means a considerable changc m thc trad111onal gender pattcm of respons1b1ht1es Together w1th farmers severa! opt10ns wcre developcd wh1ch rcplace woodcn stakes part1ally or fully as support for the beans w1th banana lcaf fibers and banana pscudostems (Elukcsu 1992) Intercroppmg beans w1tb ma1ze 1s common m sorne arcas of thc Great Lakes As for bananas the quest10n arose whethcr a separate screemng program was necdcd lo 1den11fy su1table genet1c matcnal for th1s assoc1allon Both on stat1on tnals and reacllons from collaboratmg farmers show that for the common mau.c gcnotypes less v1gorous chmbers are needcd 1f mau.c 1s to rcplacc wooden stakes Farmers stake the present chmbmg vanet1cs whcn mtercroppcd w1th mau.c lt was shown that breedmg tnals may well be done m rows (eas1er to managc on stat1on) mstead of the broadcast plantmg usual for farmers B1olog~cal N1trogen F1sabon (BNF) 1s the top1c of three sub pro¡ects Fmt results w1th a selected Rh1zob1um strrun on local vanetal m1xtures have shown that the effect of Rh1zob1um moculallon 1s only moderate (12% y1eld mercase) Work 1s therefore proceedmg on the thrcc components of BNF Rh1zob1um strruns (where many local 1solates are mcluded) thc bean vanety and sml cond11lons as they affect BNF {mcludmg cond111ons wh1ch may be altered by cultural pract1ces) The goal 1s lo 349 bcltcr targct thc use of Rhtzobwm Espcc1ally for chmbcrs wh1ch are often grown as a smglc vancty results show that response lo moculatlon m ay be h1ghly profitablc (Hakmmana el al 1992) Response also secms to be more cons1slcnt on plots whcre organ1c manurc has bccn apphcd the scason prcccdmg thc tnal Produchon of beans on ac1d solls 1s frcqucnt m the rcgwn In thc contcxl of th1s sub proJect pnmary screcmng for tolcrancc to alum m mm toxlclty 1s conductcd More rccently tnals havc beco conductcd lo allcv1atc alummmm tox1C1ty w1th greco manure Fert1hzat10D of bcans w1th mmcral fcrt1hzcrs 1s bcmg stud1cd m a s1mplc rotatlon ovcr severa! ycars ID Burund1 where miDeral fcrt1hzers are read1ly ava1lable lo farmcrs Effects of chmbmg bean product1on on soll fertll1ty are bcmg cxammcd as chmbcrs w1th the1r h1gher y~elds are hkcly to mercase export of nutnents from thc s01ls as com pared to bush beans Drougbt tolerance 1s 1mportant espcc1ally m lowcr altitudes The sub proJcct concentratcs on sclectlon under drought cond1t1ons wh1ch are obtaiDcd by varyiDg plantmg dates Productlon under drought stress 1s bcmg stud1ed ID var1ctal mixtures Adaptat10n to valley bottoms 1s sought m two d1fferent ccolog1cal cond1t1ons Productwn of beans on res1dual m01sturc m vallcy bottoms 1s hkcly to rcqUire very d1fferent genotypcs to thosc grown dunng thc more 1mportant ramy season Farmer expenmentat10n concepts are 1mportant to undcrstand as thc network s strategy leaves research and fine tumng of many aspccts cxphc1tly to farmcrs (vanetal cvaluat1on for qual1ty charactenst1cs des1gn of vanetal m1xtures plantiDg dates and dens1t1cs etc Sche1deggcr 1991) A first study shows the extent of farmer expcnmcntatlon All of thc 80 farmcrs 1Dierv1ewed ID Za1re (only farmers w1thout contacts w1th rcscarch or extenswn wcre cons1dered) had expenmented on the1r own w1th scveral altemat1ves of growmg chmbers Chmbcrs are a ncw tcchnology ID thc arca and th1s 1Dtens1ve farmer cxpcnmentatlon has takcn place only ovcr thc last 2 3 ycars Farmer percept10ns of s01l fert1hty are stud1cd ID a ncw sub proJect w1th thc goal of more cffic1cntly IDvolviDg farmers ID the dcvelopment of respective technolog1cs Chmber promot10n was ongiDally conce1ved as a sub prOJCCt to systcmatlcally study d1ffcrent altematlves and prercqu1s1tes for the promotlon of th1s prom1s1Dg opt1on G1ven thc very dynam1c adoptlon of chm bcrs by R wandan farmcrs o ver the last four ycars the sub proJect now focuses more on leamiDg most from th1s dcvelopment for the benefit of thc two other countnes and of other tcchnolog1cs Stakc produchon ongiDally part of th1s sub proJect dcvelopcd ID!O a sub proJect of 1ts own when thc goal was no longer to develop poss1b1hhcs as a prercquiSitc for chm ber adoptlon but rather lo offer optlons for sustaiDed use of chmbcrs Chmber adopt1on 1s beiDg stud1ed ID Zrure w1th two goals studyiDg soc1o-<:conom1c and agronom1c cond1t1ons for chmber adoptwn should help lo bettcr target promotlon ID other arcas and careful planniDg and documentatlon of thc study should constltute progress ID methodology lmpact and adopt10n stud1es ID the rcg1on pose severa! mcthodolog1cal problcms thc most 1mportant ID relatlon to vanehcs beiDg that most beans are grown ID m1xtures Several methods for measunng adoptlon were tested and compared 350 Farmer partJCJpalJOD ID breedmg m ay help specd up vanety development and result m vanelles that are more acceptable lo farmers Earher results showed that farmers can pul lo use a much w1der range of vanelles than convenllonal breedmg schemes can produce The sub proJCCI compares a scheme w1th full respons•b•hty for selcctmn g•ven lo farmers hke the mtermed1ary y1eld tnals w1th the convenllonal Rwandan scheme A new sub proJect conducted m Za1re a1ms al 1mplementmg farmer part•c•pallon m brccdmg by workmg through local NGOs and extensmn agenc1es Herc the effcct of farmer mvolvement on genellc dJversJty used al farm level w1ll be stud1cd Dynam1cs of local mJxtures JS stud1ed lo better understand the evolullon of m1xtures over lime and how th1s JS mlluenccd by the mcorporallon of 1mprovcd vanelles The compos•t•on of vanetal mixtures changes cons1derably betwcen seasons WJthout dehberate selecllon Farmers adjust vanetal compos111on lo corree! for th1s but somellmes they purposefully const•tute d•ffercnt m1xturcs for d1ffercnt seasons and they ofien add or subtract enllre com ponents Th1s mteractJon of b1ology and man may have 1mphcallons for var1ety development extensmn strategJCs ep1demmlogy and genet1c dJversJty Seed systems are crucJal for ensunng that new vanelles become ava1lable lo farmers The sub project stud1ed ex1stmg systems to 1denllf)' the most promlSing pomts and llows lo mJect the seed of new vanelles lt was found that formal channels reach a very small percentage of farmers Most farmers try out a new vanety on small scale Test sales of new var1elles m such tnal quantJIJes (50 250 g) showcd that farmers read1ly prud two lo three limes the market pnce for common secd (Sperhng el al 1993) The new sub project on vanety d1ffusmn JS studymg farmer to farmer d1ffus•on al vJllage level LJmJtmg factors for bean producllon are bcmg stud1ed al the m1cro level lo better understand the 1mportance of d1fferent constramts and the1r mteracllons Nursery mult1phcallon Regmnal nursenes and tnals are mulllphed centrally m Rwanda for subsequent dJstnbullon lo all test s1tes CONCLUSIONS AND FUTURE PERSPECTIVES RESAPAC has made bean research m the Great Lakcs more efficJCnt by dJvJdmg respons1b1hlles between 1ts partners m other words by avmdmg duphcat1on Even where duphcat1on stJII seems lo pemst the md1v1dual actors are well awarc of 11 and 11 JS ofien mtentmnal respondmg lo speclfic SJtuallons In dJscussJons w1th the1r management and pohcy makers bean programme rcsearchers m the threc countnes regularly stand out by knowmg exactly what Js done m terms of bean rcsearch m ne1ghbounng countnes and throughout Afnca and how th1s complements the1r nat•onal efforts Th•s dJvJsJon of rcsponsJbJhlles m the context of RESAPAC Js the result of ten years of evolut1on S1mple exchange of mformat1on was crucJal for thc partners lo know eachother Common plarmmg and executmn of nursery evaluatmns further helped to bUJld confidence m thc strcngths of cachother These werc 1mportant mtermcd•ate steps towards JOmt planmng resultmg m a d•v•s•on of rcsponsJbJhlles between partners 351 Reg10nal collaborat10n m RESAPAC was spec11ically effic1cnt m the followmg Sltuahon shanng the work of d1sease evaluat10n by takmg advantage of ecolog1cal d1ffercnccs between the d1fferent rcsearch stahons and the concept of hot spots (reg10nal nursenes) reg1on w1de stud1es w1th S1m1lar methodolog1es (seed systems) development of a rcsearch methodology m one s1te (farmer part1c1pahon m brcedmg 1mpact/adophon stud1es) dcvelopment of 1deas and ophons m onc s1tc to make adaphve research m othcr s1tcs cas1er and faster (mtroduchon of chmbers stakmg mtercroppmg chmbers w1th bananas) Vanehcs are thc most cv1dent output of reg10nal collaborat10n wh1ch can be transferrcd w1th relahvely httle further tcstmg to other arcas Agronom1c prachccs and ophons to overcomc soc1o cconom1c constramts are oftcn more s1tc spcc11ic Many proposals for sub proJects m thcse domruns havc bccn refuscd by thc Stecnng Commlttce for the1r s1te spec11iC1ty Y el m order to makc more progrcss m non gcnehc solut1ons 11m ay be JUStllied m the futuro lo support more proJCCts rummg at thc development of ophons for spec11ic sets of agro-ccologlcal cond1hons RESAPAC has shown that 1f opt10ns are adapted and adopted by the target farmers adapt1ve rcsearch needed lo dcvclop S1m1lar opt10ns for other arcas and cond1hons 1s much eas1cr and faster Bottom up approach to management of RESAPAC 1s cruc1al to thc success of the network Most potent1al researehers part1c1pate m plannmg workshops and thus feel comm1tted lo the m1d tenn plannmg framework The Steenng Comm1ttee has severa) 11m es res1sted the temptat10n of 1mposmg sub proJccts cven 1f thc respective top1c had bcen g1ven h1gh pnonty m the plannmg framework All sub proJects lo date werc 1mhated by teams of md1v1dual sc1enhsts Th1s ensures thmr commltment to the work In sp1tc of th1s bottom up approach RESAPAC has demonstrated that 11 1s poss1ble to change the oncntat10n of research and to respond qmckly to new S1tuat10ns In 1993 the allocat10n of resourccs lo the thrce groups of constrrunts as shown m Table 3 1s reasonably close lo thc goals set m 1989 Sclf-cvaluat10n 1s cruc1al m ensunng cffic1ency and transparency w1thm RESAPAC lt takes place al two mtervals annually all sub projects are evaluated techmcally dunng the Rcg10nal Scmmar m a peer rev1ew process and sub proJecl leaders have to g1ve the1r own account on Cl F arm leve! product•on constramts bcttcr undcrstood and rcflectcd m nat10nal work plans Annual nat1onal bcan rcsearch work plans ava1lable Rcv1cw mcctmgs on bean rcscarch held regularly Bcan rescarch pnonllcs devcloped formally approved and rev1ewcd pcnod•cally lmproved ut1hsat•on of avrulablc resourccs by NARS through more cost-cffccllvc methods More tcchnology bcmg adoptcd by farmcrs Numbcr of rcscarch pubhcallons 357 ObJeCtlve 2 To 1mprove sustamabd1ty of the Network Amendmenl> lmprovcd flows of mformahon among na110nal programmcs e g roulmc c1rculahon of na110nal bcan rcscarchcr hsls na110nal slralcg1c pnonhcs annual bcan rescarch plans and annual rcports More sub proJccls should spcc1fy thc mlcrachons lo be calalyscd among part1c1panls mcludmg across counlncs Pan Afncan collaborahon would be part1cularly cffechve 111 sorne arcas such as drought and lhe devclopmcnl of chmbmg beans (both for stratcgy devclopment and for d1stnbut10n of germplasm) Grcatcr focus by thc Slccnng Comm1ttce (SC) on overcommg problems cspcc1ally through mulh d1sc1phnary approaches Thc SC could also define and pubhc1sc 11s balance among arcas of mtervenhon (b10hc vs ab10t.c constramts tcchnology transfer trammg etc) Rcg1onal workshops workmg group mcctmgs tnals and nurscncs should contmuc Contmuahon of momlonng tours rcce~vcd strong endorscment lndicaton At least 20% of farmers collaboratmg m tnals have adopled new tcchnology Bean y1eld mcreased by 5% and produchon by 7% across thc reg10n m 3 ycars ObJectlve 3 To reduce h10t1c and ab10t1c productmn constramts tbrougb genet1c 1mprovement Amendment> Countncs vary grcatly m the cxtent lo wh1ch they havc attemptcd lo larget the collcchon of local gcrmplasm and mercase germplasm d1vcmly by mcans of mulhplc relcascs of new vanehes Thc nccd for more cxchange of gcrmplasm among countncs was a rccumng thcmc Gcrmplasm nurscncs organ1scd by agro-ecolog1cal I.oncs (and m sorne case on a pan Afncan bas1s) req01rc more attenhon m the~r 1mplcmentahon lndicaton Nat10nal gcrmplasm collcchons catalogued and Simple low-cost rchable storage methods m use Nat10nal collechons duphcated elscwhcre for safcty Bctter rcprcscntahon of 1h1s I.onc m global collechons W1dc gcne11c array avwlablc for selcchon by farmcrs and by rcsearchcrs Eastem Afnca 7.onal nurscry and y1eld tnal (EAZBEN and EAZBYT) m opcrahon and brcedcrs sccd d~rectly exchanged bclween nat10nal programmcs More bean var1chcs rclcased 2 3 ncw vanehcs pcr I.onc of m1crvcn110n Al lcasl 10 advanccd hncs developed per I.one of mtervenhon Mulhple vanety rcleascs acceptcd as dcs1rable prac11ce 358 ObJectlve 4 To 1mprove croppmg systems Amendmen/1 G1vc more attcnllon lo non gcncllc solut1ons lo b10t1c constramts e g IPM lmprovcd ullhsallon of ava1lablc rcsourccs by farmcrs lndlCalor< lncrcascd producllv1ty m targct arcas (e g m low potcnt~al or margmal cnv1ronments bcan producllon mcreascd by 5% through 1mprovcd croppmg systcms) Losscs from targct pests and d1scases rcduccd ObJecllve 5 To mcrease tbe market potentlal of beans Amendmentv Much progrcss was notcd m asscssmg markct prcfcrcnccs but furthcr cfforts are Jusllficd Thc dcvclopmcnt of ncw bcan products such as the Kcnya samo1.a warrants followmg up m othcr countncs Wh1le cxport trade m snap bcans 1s wcll documcnted thc 1mportant cross bordcr tradc m dry beans deserves s1m1lar attcnllon Indlcaton lncreased markct demand for bcans Storagc losscs duc lo bruch1ds rcduccd al lcast 10% m targct 1.oncs Add a study on human nutnllonal aspects mcludmg bcan quahty ObJectlve 6 To 1mprove tecbnology transfer Amendmenl< lt should be a maJor Nctwork acllv1ty lo mercase farmcrs part1c1pa11on m rescarch On stallon evaluallons by farmers has bccn tncd m sorne countncs but clscwhcre needs more encouragcmcnt Rcsearchcrs nccd more cxposurc lo FPR tcchmqucs Dcvclopmg rcscarch cxtcns1on hnkagc by rcc1procal mv1tallons lo mcetmgs IS 1mportant but not adcquatc Expenmcnt w1th mcxpcns1vc rcsearch-<:xtcns10n hnkagc approachcs dunng on farm tcstmg and a1m al sohd output of tcchmcal bullctms Too httlc 1s bcmg done outs1dc thc Grcat Lakcs reg10n on documcnllng non formal sccd systems that could be used m d1sscmmatmg ncw vancllcs Fmancl31 support hcrc would be useful A pan Afncan bcans ncwslcttcr would be apprcc1atcd 359 Indica/o" Sub pro¡ect on non fonnal seed systems m operatmn m all countnes where these systems are not currently ullhsed Non fonnal seed systems better understood Pamphlets ava1lable to extensmn and farmers on new agronom1c pract1ces and on vanet1es At least one evaluatmn VISII annually by farmers to each bean research statmn m the regmn Al least one technology per 'one selected by farmers from on stallon tnals and bemg tested by farmers More farmer managed tnals m all '.ones At lcast one farmer des1gned In al m each '.onc FPR trammg for all d1sc1phncs m bean rescarch Al lcast onc FPR coursc held m cach pnnc1pal group of rcscarchers/tcchmclans Each researcher demonstrates that knowledge gamed from FPR IS mcorporated m h1slher programme Farmers m all ma¡or soc1o-econom1c categones have better understandmg of the fonnal research agenda At least 25% of a sample of farmers m each 'one have tned al least one new vanety released w1thm prevmus threc years SPECIFIC INDICATORS SUGGESTED FOR CURRENT REGIONAL SUB PROJECTS (a) Resource poor and sem1 ar1d env1ronments Sub proJeCt Ind1cators Vanety development for sem1 and arcas (Kenya) Drought tolerance (Ethmp1a) Selected genotypes perfonn well m on farm tnals Tolcrance lo low mtrogen s01ls (Ethmp1a) and evaluated by nallonal bean program Regmnal nursery of selectcd hnes d1stnbuted Bmlog1cal mtrogen fixat1on (Eth10p1a) Mm1mum llllage (Kenya) Cost effccllve good retum to labour F armers adopt the technology Water harvestmg (Kenya) T cchmcal m anual produced 360 (b) H1gher ramfall env1ronments w1th potenhally h1gher levels of externa( mputs Anthracnosc (Eth10p1a) Y 1cld los ses asscsscd ID thc rcg10n Pathogcn raccs 1denhfied ID arcas al nsk 15 advanecd liDes w1th rcs•stancc ava1lable Phoma bhght (Uganda) 1 O rcs1stant vanehes av31lable Y 1eld losscs determ IDCd ID m 31n arcas al nsk Rust (Eth1op•a/Madagascar) Two or threc res•stant vanehes released 20 res1stant liDes advanccd ID natl progr310mcs Frcnch bcan vanehcs devclopmcnt 5 advanced liDes w1th 1mproved rust res1stance ID (Kenya) on farm tnals 1 00 scgrcgaiiDg populat10ns al F, collechon of snapbcan gcnotypcs undergoiDg charactensahon IPM ID French beans (Kenya) Numbcr of 1Dscehc1des rcduccd from 24 lo 3 Farmers usiDg altemahves lo pest•c•des IDCrcascd from 6% lo 80% Peshc•dc res1dues reduced lo a level acceptablc lo the export m arket (e) S01l related coostramts Tolerance lo low phosphorus s01ls Toleran! vanehes 1denhfied and adoptcd (Kcnya) Parental liDes •dcnhfied and uscd ID crosses V anetal screemng method ava1lable Tolerance lo mangancse tox•c•ty Rap1d lab screcmng techmquc av31lablc (Uganda) Toleran! m atcnals 1denhficd Farmcr adopt1on of toleran! vanches Toleran! genotypcs uhhsed ID brccdiDg Res1stance lo Macrophomma (Kenya) Ava•lab•hty of res1stant matcnals Effechve screcniDg method ID use Res•stant liDes uscd ID brccdiDg Rcs1slanl var1chcs adoptcd ID dry arcas Plant nutncnt lluxcs (Kcnya) Databasc dcvclopcd on nutnent transfer Management of ac1d s01ls (Madagascar) (not allemptcd( Farmer part1C1patory rcscareh on s01l No of tnals sueeessfully completcd fert1hty (Uganda) No of farmers adopiiDg prachces No of sc•enhfic papers pubhshed Bean stem maggot (Eth10p1a) Res•stant sources •denhfied Res•stancc brecdiDg progr310me ID opcrat10n Cultural control mcthods developcd 361 (d) Seed related constraiDts Seed d1ssemmat10n channels (Kenya) Survey completed and findmgs documented Recommendallons d1ssemmated Seed d1ssemmat10n methods (Eth10p1a) No of farmers rece1vmg seed and amounts d1stnbuted documented annually Adopt10n and pers•stence of vanelles assessed Bruch1ds (Uganda) Technolog1es generated res1stant vanelles and management pracllces are avrulable Technolog1es made avrulable w1thm reg10n (pubhcallons avrulab1hty of vanelles) Tcchnology adopted by farmers Angular leaf spot (Kenya) ALS pathogen vanatJon understood m the reg10n Losses quanllfied Res1stant sources •dentJfied Reg10nal res•stance nursery d1stnbuted Common bactenal bhght (Uganda) Pathogemc vanallon understood Pan Afncan nursery d1stnbuted and ul1l".cd m 5 countncs Res1stance •s mcorporated mto 6 landraces More vanelles w1th CBB res•stance are released Presence or absence of lmkage of res•stancc w1th undes~rable trruts determ med Bean common mosa1c v1rus (Uganda) 500 lmes screened for res1stance m 10 countnes Reg10nal nursery d•stnbuted 100 genotypes screened for seed transmJssJbJhty lmproved procedure for large scale scrccnhouse screemng 50 suspected w1ld hosts evaluated Crop losses assessed PLENARY SESSION TO DISCUSS WORKING GROUP REPORTS The role of farmers 1s menlloned m all sub prOJCCts but why 1s th1s not exphc1t m the EABRN organw111onal chart? Agreed that the chart needs lo be mod•fied accordmgly ls seed qual•ty really of concem lo farmer producers of th1s crop? Most avrulable studJCs suggest that producmg clean bean seed 1s not econom 1c ( expens1ve seed hule y•eld benefit and no y•eld benefit beyond the first season) Excepllons seem lo be snap beans and dry beans m Mauntms both probably presenl new requ~rements m th•s respect Should reg10nal germplasm nursenes be decentral1sed (1 e organ1sed separately for spec1fic constrrunts by the pnnc1pal researcher or sub proJect) or centrahsed (w1th the CIAT reg10nal programmc)? lt •s log•sllcally eas1er lo send out a smgle un1fied nursery but th1s means more work for collaborators m evaluatmg 11 There was a eonsensus m favour of sub proJects (and others) developmg more spec•fic targcted nursenes 362 Should thc pcrfonnancc md1cators bcmg dcvclopcd for thc Nctwork and for md1v1dual sub projects be apphcd by Nctwork mcmbcrs or should those outs1dc the Network have the respons1b1hty for momtonng? Part1c1pants agreed that md1cators should be used by each sub proJeel m self-evalua!lon w1th resultmg mfonna!lon bemg prov1ded m rcports for others (e g thc Commlttee of D1rectors) to fCVICW In conclus10n the Stcenng Comm•ttec •s expccted lo prov1dc feedback to sub proJects on the1r perfonnancc md1cators as soon as poss1ble REFERENCE Rcg10nal Programmc on Beans m Eastem Afnca (1992) Planmng Framework for the Eastem Afnca Bcan Research Network In M mutes of Armual Mectmg of the Stecnng Commlttee held al Nancth Eth10p1a 20 24 June 1992 pp 14 19 363 CLOSING ADDRESS Mrs M N Wabule Assostant Dorector (Hortoculture), Keoya Agrocultural Research lnstotute' Mr Chaonnan Dostmguoshed Guests CIA T Offictals Partocopants Ladoes and Gentlcmen 1 feel much pnvtleged lo be mvtted lo come and close thos workshop whoch 1 constder to be vcry omportant because beans play a great role m human nutnlton m eastcm Afnca lt os therefore tmportant that bcan scoenttsts should develop appropnatc tcchnology qmckly m order lo mcct thc evcr mcrcasmg demands of thts commodtly 1 bchcvc workshops of thos naturc wtll help a great deal lo exchangc tdeas on thc lates! dcvclopment of thos crop 1 havc noted wtlh grcat sattsfactoon that the workshop has drawn sctenttsts of vanous countncs who are pracltltoncrs m thos field lt os my behef that m the course of your fivc days dchbcralton yo u havc been able lo examme the bean crop much more closely and tdcnltfy sorne tcethmg troubles affecltng tl 1 would assume that you have m addotton come up wtth pracltcal suggesttons on how these problems can be sol ved m order lo tmprovc bean productoon 1 must assure you that KARI wtll cnltcally study your recommcndaltons and see how best thcy can be omplemcnted for thc sake of asstsltng fanners Mr Chatnnan bcforc dcclanng thts workshop offictally closcd allow me lo make sorne few remarks "hoch 1 constder lo be omportant lo bean produclton m Kenya We all know that beans play a Htal role m the eco no m y of thts country as has been clearly rccogm7.cd by govemmcnt m tls vanous pohcy papcrs and statements notably thc scss10nal paper No 4 of 1981 on Natoonal Food pohcy and thc scss10nal paper No 1 of 1986 on Economtc Managemcnt for Rcncwed growth woth whoch 1 bcheve sorne of you are qmtc famthar The first of thcse papers mamly revolvcs around produclton of sufficoent food and gcneralton of employmcnt to cater for our rapod growth of populatton prcsently esltmatcd lo be over 22 molhon peoplc and expected lo JUmp lo over 35 molhon peoplc by thc tum of the century Bcans as a food crop plays an tmportant role m mcctmg thcsc challcngcs partocularly m the arca of nutnt10n cmployment forctgn cxchangc cammg and mcomc gcncratton Although food and snap bcans are tmportant m thts country thcy are not wothout problems Therc are thosc problcms rclatcd lo produclton whoch mvolvc quahty m snap bcans and poor ytclds m food bcans To a largc cxtcnt thcse affcct thc lcvcl of productton and thc quahty of produce lt m ust be clcarly undcrstood that use of sub standard mputs by fanncrs m ay not only rcsult m rcduccd yoelds but m a) m thc long run result m mcrcased buold up of dtseascs and pcsts whtch can be a threat lo futurc productoon Wc must also encouragc cffecltvc feedback from fanncrs as thcy also havc thcor own expcncnccs whtch could be useful whcn mtcgratcd wtth rcscarch findmgs Fmally 1 must pomt outthatthc knowledgc gathercd from thos workshop woll serve no useful purposc unlcss tl rcaches the fanncr m thc manner he can undcrstand so that he wtll be ablc to omprove hts fannmg pracltces ltherefore trust that you woll dossemmatc the mfonnalton acqmred lo the fanners Woth thcsc fcw rcmarks tl os my plcasurc lo declare thts workshop offictally closed Thank you 'Presented by Mr D O Mlchleka D1rector KARI Natlonal Hortlcultural Research Stat1on Thlka 364 N ame Canada Gcorgc Weber Eth10p1a llabtamu Admassu Mclaku Ayclc Aberra Dcrcssa 1 cshoml. Gmna Alchgnc Kcfyalcw "'"oa1t f<.cgas'ia ~cnaytt Y ctnclx.rk fc•fayc Bcshu PARTICIPANTS LIST Dlsclplml. Agncultural Off1ccr Agrooom1st Plaot Brccdcr Rcscarch/1 xtcoIRI IW Sahh H Sahh Nahonal Bcan Coordmator Agncultural Rl.scarch Corporatlon Shend1 Research Stahon PO Box 33 Shend1 rix 50009 TXBOWD SD 366 N ame Tanzan1a Clemence S Mush1 Roger A Knkby J K O Ampofo Wayne YoungqUist Rwanda Robm Buruchara Urs ~che1degge• 1 omse Sperlmg Uganda V!ctor A Ochwoh fhcrcsa fiicngooba Asmast 1 ma Opto Patnck K Jjemba M1chael Ugen A Sophy Musaana Bcatnce Male Kaytwa M Sll•m Nahdy lloward Gndley Charles Wortmann 1 1schler Martm USA 1 dward R1cc PARTICIPANTS LIST (~onlinued) Nahonal C.oordmator Coordtnator 1 ntomolog1ADUUA 1 Regwnal Programme on Beans m \outhem Afnca Schan Agncultural Rcsca.rch lnshtute PO llox 2704 Arusha lel 255 57 2268 lax 255 57 8557/8264 Tlx 42106 CANWIII Al TI CIA f Rcg10nal Programme on Beans m the Grcat 1 ake< Regwn ll P 259 Butarc Tel 250 30446 hx 250 30599 Tlx 22604 Dcpartmcnt of 'i01l !iictence Makercrc Umverstty P O Box 7062 Kampala Nahonal Agncultural Research Organ"ahon (NARO) Namulongc Agncultural Research Inslltute PO Box 7084 Kampala NARO Kawanda Agncultural Rcsearch lnshtutc PO llox 7065 Kampala CIA 1 Kawanda Agncultura.l Research lnshtutc P O Box 624 7 Kampala 1 el 256 41 567670n4 1 ax 256 41 567635 Wmrock lntcmahonal Smte 600 1611 North Kent St Arlmgton Va 22209 1 el 1 703 5259430 ~ax 1 703 5251744 367 PUBLICATIONS OF THE NETWORK ON BEAN RESEARCH IN AFRICA Worksbop Senes No 1 No 2 No 3 No 4 No 5 No 6 No 7 No 8 No 9 No 10 No 11 No 12 No 13 No 14 Proceedmgs of lhe Bean Fly Workshop Arusha Tan,.ama 16 20 November 1986 D J Allen and J B S m tlhson (Eds) Proceedmgs of a Workshop on Bean Research m Easlem Afnca Mukono Uganda 22 25 June 1986 R A Ktrkby (Ed) Proccedmgs of a Workshop on Sml Fertthty Research for Bean eroppmg Systems m Afnca Addts Ababa Elhtopta 5 9 Seplember 1988 e S Wortmann (Ed) Proccedmgs ofa Workshop on Bean Yanelallmprovemenl m Afnca Maseru Lcsotho 30 January 2 February 1989 J B Smtlhson (Ed) Acles du Trotsteme Semmauc Reg10nal sur L Amehorallon du Hancol dans la Rcgton des Grands Lacs Ktgah Rwanda 18 21 Novembre 1987 P Nyabyenda and J He Davts (Eds) Proceedmgs of Ftrsl SADee Reg10nal Bean Research Workshop Mbabane Swanland 4 7 Oclober 1989 J B Smtlhson (Ed) Proceedmgs of Second Workshop on Bean Research m Easlem Afnca Natrobt 5 8 March 1990 J B Smtlhson (Ed) Acles de 1 Aleher sur la Ftxallon Btologtque d A'ole du Hancol en Afnque Rubona Rwanda 27 29 Oclober 1988 P Nyabyenda A Hakutmana J Ktpe Nolle J H C Davts and W Graf (Eds) Acles du Qualncme Semmmre Reg10nal sur L Amehorallon du Hartcol dans la Reg10n des Grands Lacs Bukavu Zatrc 21 25 Novcmbre 1988 P Muktsht J He Davts and U e Schetdegger (Eds) Proeeedmgs of a Workshop on Nallonal Research Plannmg for Bean Produclton m Uganda Kampala Uganda 28 January 1 Fcbruary 1991 W Gnsley (Ed) Proceedmgs of lhe Ftrsl Meelmg of lhe Pan Afncan Workmg Group on Bean Enlomology Nmrobt Kenya 6 9 Augusl 1989 J K O Ampofo (Ed) Progress m lmprovemenl of Common Bean m Easlem and Southem Afnca Proceedmgs of lhe Nmlh SUA/eRSP and Second SADeC/CIAT Bean Research Workshop Morogoro Tan,.anta 17 22 Seplember 1990 J B Smtlhson (Ed) Proceedmgs of a Workmg Group Meelmg on Vtrus Dtseases of Beans and Cowpca m Afnca Kampala Uganda January 17 21 1990 D J Allen (Ed) Proceedmgs of lhe Ftrsl Meelmg of lhc SADeCteiAT Workmg Group on Droughl m Beans Harare Ztmbabwe M ay 9 1 1 1988 O T EdJe (Ed) 368 No 15 No 16 No 17 No 18 No 19 No 20 No 21 No 22 No 23 No 24 No 25 No 26 No 27 No 28 Proceedmgs of the F trst Pan Afncan Workmg Grop Meetmg on Anthracnose of Beans Ambo Ethtopta February 17 23 1991 R A Buruchara (Ed) Acles du Cmqmeme Semmatre Regtonal sur 1 Amehoralton du Hancot dans la Regton des Grands Lacs BuJumbura Burundt 13 18 Novembre 1989 1 N"menya W Graf and U C Schetdegger (Eds) Acles du Stxteme Semmatre Reg10nal sur 1 Amehoratton du Hancot dans la Regton des Grands Lacs 21 25 Janvter 1991 P Nyabyenda and U C Schetdegger (Eds) Acles de la Confcrcncc sur le Lanccmcnt des V ancles la Produclton el la Dtstnbulton de Semcnccs de Hancot dans la Rcgton des Grands Lacs Goma Zatre 2 4 Novcmbre 1989 L Spcrhng (Ed) Rccommcndaltons of Workmg Groups on Croppmg Systcms and Sotl Fcrtthty Rcscarch for Bcan Produclton Systcms Natrobt Kenya 12 14 February 1990 O T EdJc and C S Wortmann (Eds) Procccdmgs of Ftrsl Afncan Bean Pathology Workshop Ktgah Rwanda 14 16 Novembcr 1987 J B Smtlhson and P Trutmann (Eds) Sotl Fcrtthly Rcscarch for Mau.c and Bcan Productton Systcms of thc Eastern Afnca Htghlands Proceedmgs of a Workmg Group Mcctmg Thtka Kcnya 1 4 September 1992 C S Wortmann and J K Ransom (Eds) Acles de 1 Ateher sur les Stratcgtes de Seleclton Vanetalc dans la Regton des Grands Lacs Ktgah Rwanda 17 20 Janvtcr 1991 L H Camacho and U C Schetdcgger (Eds) Proccedmgs ofthe Pan Afncan Pathology Workmg Group Mcctmg Thtka Kcnya 26 30 May 1992 R A Buruchara and U C Schctdcggcr (Eds) Proccedmgs of a Workshop on Bcan Rescarch Plannmg m Tan/.anta Uyolc Rcscarch Centre 18 24 May 1992 C S MUsht and W C Youngqmst (Eds) Sccond Mectmg ofthc Pan Afncan Workmg Group on Bcan Entomology Hararc 19 22 Scptcmbcr 1993 J K O Ampofo (Ed) Bcan lmprovemcnt for Low Fertthty Sotls m Afnca Procecdmgs of a Workmg Group Mcctmg Kampala Uganda 23 26 May 1994 C S Wortmann (Ed) Thtrd SADC/CIAT Bcan Rcscarch Workshop Mbabane SwvJiand 5 7 October 1992 D J Allcn (Ed) Proccedmgs ofThtrd Multtdtsctplmary Workshop on Bean Rescarch m Eastcrn Afnca Thtka Kcnya 19 22 Apnl 1993 J B Smtthson (Ed) 369 Occas10nal Pubhcabons Senes No No 2 No 3A No 38 No 4 N S Talckar 1989 AgromY7Jd Pests of Trop1cal Food Legumes a B1bhography R A Kukby J B Sm1thson D J Allen and G E Hab1ch (rev1sed by J Mullmba) 1989 CIAT TraiDIDg ID Afnca J B Sm1thson 1990 F1rst Afncan Bean Y1eld and Adaptat1on Nursery (AFBYAN 1) Part 1 Performance ID lnd1v1dual Envuonments J B Smllhson and W Gnsley 1992 F1rst Afncan Bcan Y1eld and Adaptat10n Nursery (AFBY AN 1) Part 11 Performance across Env1ronments C S Wortmann 1992 Assessment of Y1eld Loss caused by B101lc Stress on Beans ID Afnca No 5 C S Wortmann 1992 lnterprctallon of Fohar Nutnent Analys1s ID Bean the D1agnos1s and Rccommendallon lntcgrated System No 6 No 7 No 8 No 9 No 10 No 11 No 12 No 13 No 14 No 15 C S Wortmann C Bosch and L Mukandala 1993 The Banana Bcan lntercropp1Dg System ID Kagera Reg1on of Tanzama Results of a D1agnosllc Survey J K O Ampofo 1993 Bean Stem Maggot Research Methods A TramiDg Course al BuJum bura Burund1 1 8 Novem ber 1991 D P G1ga J K O Ampofo S Nahdy F Negas1 M Nah1mana and S Nch1mb1 Msolla 1993 On Farm Storage Losses to Bean Bruch1ds and Farmers Control Strateg1cs a Travelhng Workshop ID Eastem and Southem Afnca J Mullmba 1993 A TraiDIDg Manual for Bean Rcsearch M F1schler 1993 Bean Gcrmplasm Conservallon based on Seed DryiDg w1th S1hca Gel and Low Mo1sture Slorage C S Wortmann and D J Allen 1994 Bean Producllon Env1ronments ID Afnca Charactensllcs and Constramts L Sperhng U C Schc1degger R A Buruchara P Nyabyenda and S Munyanesa 1994 lntcns1fy1Dg Producllon among Smallholder Farmers The lmpact of lmproved ChmbiDg Beans ID Rwanda L Sperhng 1994 Analys1s of Bean Secd Channels ID the Grcat Lakes Reg1on South K1vu Zwrc Southem R wanda and Selcct Bean Growmg Zones of Burund1 J B Sm1thson HE Gndley and W C Youngqu1st 1995 Sccond Afncan Bean Y1eld and Adaptallon Nursery (AFBY AN 11) L Sperhng U Sche~dcggcr and R Buruchara 1995 Enhancmg Small Farm Seed Systems Pnnc1ples Denved from Bean Research ID the Grcat Lakes Reg1on 370 Reprmt Senes No 1 No 2 No 3 D J Allen M Dessert P Trutmann and J Voss Common beans m Afnca and the1r constramts In H F Schwartf and M A Pastor Corrales (Eds ) Bcan Produchon Problcms m thc Trop1cs 2nd Ed CIAT Cah Colombia pp 9 31 A K Karcl and A Autnquc 1989 lnsccts and other pcsts m Afnca In H F Schwart7 and M A Pastor Corrales (Eds ) Bcan Produchon Problems m the Trop1cs 2nd Ed CIAT Cah Colomb1a pp 455 504 J B Sm1thson O T Edje and K E G11ler 1993 DiagnoSIS and correchon of sml nutnent problems of common bcan (Phaveoluv vulganv) m thc Usambara Mountams of Tan7.ama 1993 Journal of Agncultural Sc1ence 120 233 240 No 4 C S Wortmann T Sengooba and S Kyamanywa 1992 Banana and bean mtcrcroppmg research factors affectmg bean y1cld and land use effie~ency Expcnmcntal Agnculturc 28 287 294 and No 5 No 6 No 7 No 8 No 9 No 10 C S Wortmann and T Sengooba 1993 The banana bcan mtercroppmg systcm bean gcnotypc x croppmg systcm mtcract10ns F1cld Crops Rcsearch 31 19 25 C S Wortmann 1993 Contnbut1on of bcan morpholog1cal charactcnshcs to wecd supprcss10n Agronomy Joumal 85 840 843 L Spcrhng and M E Locvmsohn 1993 The dynam1cs of adophon d1stnbuhon and mortal1ty of bean vanchcs among small farmcrs m Rwanda Agncultural Systems 41 441-453 M S Nahdy 1994 Bcan s1cvmg a poss1blc control measurc for thc dncd bean bcctlcs Acanthoscelldes obtectuv (Say) (Colcroptcra Bruch1dac) Joumal of Stored Products Rcscarch 30 65 69 and An add1honal character for sexmg thc adults of thc dncd bean bcetlc Acanthoscelldes obtectus (S ay) (Colcroptcra Bruch1dac) Jo urna! ofStorcd Products Research 30 61-63 C S Wortmann M Isab1rye and S Musa 1994 Crotalana ochroleuca as a green manure crop m Uganda Afncan Crop Sc1cncc Journal 2 55 61 L Sperhng M E Locvmsohn and B Ntabomvura 1993 Rethmkmg thc farmcrs role m plant brccdmg local bcan expcrts and on stahon selcct10n m R wanda Expcnmental Agnculturc 29 509 519 K E G1llcr F AmiJCC S J Brodnck S P McGrath C Mush1 0 T EdJc and J B Sm1thson 1992 Tox1c conccntrahons of1ron and mangancsc m leavcs of Phaseolus vulgarlS L growmg on freely-dramcd smls of pH 6 5 m Northcm Tan7.ama Commumcat1ons m Sml Sc1cncc and Plan! Analys1s 23 1663 1669 371