CIP in 1997 International Potato Center Annual Report International Potato Center Av. La Universidad 795 La Molina Apartado 1558 Lima 12, Peru E-mail : cip@cgnet.com On-line at: http://www.cipotato.org CIP. 1998. CIP in 7997. International Potato Center Annual Report. Lim a, Peru. ISSN 0256-6 311 Press run: 2,500 May 1998 Contents A Year to Remember El Nino: A Dress Rehearsal for Global Warming? Virus Cleanup Boosts Chinese Sweetpotato Production Getting the Numbers Right Milestone Reached in Bacterial Wilt Research Integrated Control of Bacterial Wilt Paying Off in East Africa Late Blight Project Initiated a Year Early; Damage Reports Increasing Genotype X Environment Biotechnology Speeds New Potato Development Brazil Achieves Seed Self-Sufficiency Producing Pesticide-Free Sweetpotatoes TPS Hybrid May Eliminate Need for Seed Tubers Breeding Deep-Rooted Potatoes 1997 Briefs Board of Trustees Donor Contributions in 1997 Finance and Administration Staff in 1997 Selected Scientific Publications 1997 Research in 1997 Training in 1997 Research Partners Cl P's Global Contact Points The Consultative Group on International Agricultural Research 4 6 10 12 13 14 16 19 21 24 26 28 30 31 32 33 34 36 41 44 50 53 56 58 A Year to Remember -4 Th e child shown in the photograph on the following page is symbo li c of milli ons of poor people in deve lop ing countries w ho benefit from CGIAR research on root and tuber crops . For producers and consumers, new root and tuber c rop techno logies represent alternatives for achiev ing food security and protecting the env ironment, both at an affo rd able pri ce. Thi s fact was underscored by a 199 7 study that showed potatoes and sweetpotatoes account fo r a considerab ly greater percentage of th e food grown in developing countri es than was previously beli eved. Acco rding to the study, produced by a CGIAR intercenter work ing group, annual growth rates for potato now stand at a remarkab le 4% and show no sign of slowing down. Negati ve predictions for sweetpotato also appear to have missed the mark. Not onl y is sweetpotato production increasing, product io n is tak ing place in some of Asia and Africa ' s poorest regions. CIP scientists be lieve th at w ith additi onal improvements, it wi ll be possible to use sweetpotato fo r a greater number of industrial uses, thus c reat ing a stronger and more lu crati ve market fo r farmers . Th e use of sweetpotato for feeding animals may also relieve th e pressure on th e internation al grai n market and possibl y even stabilize the prices paid by developing countri es for food and feed. To sustain these advances, however, w ill require conti nued techno log ica l innovat ion through resea rch and training, along w ith stronger scientific partnershi ps. An example of the type of effo rt that w ill be needed can be fo und on page 10 of thi s report. Entitl ed Virus Clea nup Boosts Chinese Sweetpotato Production, th e story describes how a brokered tec hnol- ogy developed in industrialized countri es was adapted to developing wor ld conditions and extended through one of Cl P's training programs to low income fa rm ers in China. In this instance a tissue culture tec hnique, we ll-known in the United States and Europe for controlling v iru s diseases, was used to boost sweetpotato product ion on an est im ated 300,000 hectares . CIP economi sts believe that th e tech no logy, w hich is curren tl y being extended to other sweetpotato-producing regions in China, may eventu all y account fo r the Center's single greatest impact in developing countries. Th e example of a brokered technology extended through CIP undersco res the importance of maintaining strong relationsh ips w ith a va ri ety of partn ers. It also demonstrates how it is possible for resea rch centers such as CIP-a ll of w hich have limi ted resources-to provide investors with broad impact that meets CG IAR goa ls fo r productivity, sustain ab ili ty, eq uity, and env ironmental friendliness. The importance of such partnerships was further underlin ed this past year by El Nino. In Peru , CIP co ll aborated w ith the Ministry of Agr icul ture to alert fa rm ers to th e dangers of the El Nino and to provide technological opt ions for dealing w ith major shifts in temperature and rainfall. By all accounts, the 199 7-98 El Nino created near-perfect conditi ons for late b li ght infecti on in the high Andes and may have helped to sp read more v irulen t forms of th e disease. Th e v irtu al collapse of a CIP-developed Peruvian potato culti va r (see page 20) hi gh- li ghts the dangers invo lved in dependence on just a few majo r cul t iva rs and underscores the need for clones w ith more durab le res istance . Happil y, field trial s of th e Center's second generation of late blight-resistant materials showed considerabl e promise during the yea r. As a result, the chances of achieving durable resistance that can be applied in a range of different environments appears to be better than at any time in recent years. Even so, improved varieties cannot be expected to do the job on their own. In the future, farmers will need to combine the planting of disease-resistant cultivars with sound manage- ment techniques, a practice known as integrated disease management (IDM). IDM is now a major element of CIP's late blight work. It is being pursued in cooperation with a variety partners, including many of the agencies working under the umbrella of the Global Initiative on Late Blight (GILB). Through GILB, CIP is working to increase scientist-to-scientist interaction and make better use of existing resources. The first genotype by environment study involving a root and tuber crop, for example, will be generating results in 1998 with the cooperation of scientists in eight countries. It is a striking example of how researchers, by pooling funds, facilities, and talent, can tackle a global problem that would have been beyond their individual resources. To achieve this type of integration across all elements of our research agenda, Center scientists worked throughout 1997 to put the final touches on the Center's project-based man- agement structure. The new system, which is fully supported by our on-line project budgeting system and newly developed CIP management information software, is designed to bring greater focus to our research priorities and stimu- late innovation by giving greater flexibility and responsibility to scientists on the front line. Starting in 1998, the new system puts day-to- day control of project funds and operations in the hands of some of our youngest and most capable researchers. It should also help to create a broader base of research managers needed to tackle the difficult problems that lie ahead. While it is too soon to show practical results, early indications are that the system is stimulat- ing innovation and new research partnerships. If the experience of 1997 is any guide, innovation and partnership must go hand in hand if we are to achieve food security and environmental goals at affordable prices. Hubert Zandstra Director General 5 El Nifio: In certain ways 1997-98 El Nino may be remembered as a dress rehearsal for global warming. Along Peru's coastal desert, directly adjacent to the center of the El Nino phenomenon, farmers produce potatoes during the winter growing season and sweetpotatoes year-round. This year temperatures were 3 to 5 degrees above Even so, the immediate effects of higher temperatures were mixed. El Nino: A Dress Rehearsal for Global Warming? -8 In the Canete Valley south of Lima, potato yields were cut in half; but in other coastal areas they were essentially unchanged. In the high Andes, two phenomena were observed. In northern Peru, higher rainfall led to severe outbreaks of late blight. And in the southern Andes drought and higher temperatures reduced frost damage, but led to early plant maturity and lower yields. In the case of sweetpotato, the area planted in the Canete Valley increased 50 % and production was believed to be higher than any year in the past decade, probably in response to hotte weather and higher pest pressure on other crops. CIP economi sts be li eve El Nino provided an indi ca ti on of w hat could be in store if globa l wa rmin g is severe. If temperatures ri se substan- ti all y, fa rmers w ill change how and w here they grow po tato and sweetpotatoes. To accommodate climate change th ey w ill need va ri et ies th at are in creas ingly heat and drought to lerant and res istant to pests and di seases . Sin ce the last El N ino in 1982-83 , CIP pl ant b reeders have been buildin g a co ll ecti on of potato va ri eti es that are heat tol erant, ca rry v iru s res is- tance, and are ear ly maturing. Two c lones bred for use along Peru ' s coastal desert look parti cul arl y promi sing, y ie lding 30-40 tons per hecta re in ju st 1 00 days. CIP sc ienti sts say that these potatoes req uire less wate r than the best commerc ial va ri eti es and are suitable fo r process ing. Se ri es of both improved potato and sweetpotato va rieti es have also been developed in cooperati on w ith the Uni ve rsid ad Jorge Basadre Grohmann in Tacna, Peru , and the European Economi c Community M ajes Pro ject. Marginal Areas Facing Danger It is imposs ible to say w hat th e overall impact of c limate change w ill be. The secondary effects of g lobal warming, such as changes in rain fa ll pattern s and yea r- to-year tempera tu re va ri ab i I ity, are not we ll understood , and coul d have markedl y different consequences in different pl aces . Some areas-reg ions prone to frost, for exa mple- could benefit from wa rmer temperatures but suffe r from drought. O thers areas, such as tropi ca l low land s, could suffe r from heat stress, bu t benefi t from hi gher atmospheric levels of ca rbon diox ide. Center economi sts beli eve, however, i f c l imate change is gradu al, most farmers should be abl e to adapt by adju sting pl anting dates and changing crop va ri eti es. " In general, major producti on zo nes should no t be adverse ly affected," says Robert H ijmans, a CIP geographi c in fo rm ati on speciali st . "The danger is in marginal areas w here crops are already pu shing the l im its of hea t, drought, and pests." Hijmans says the extent of global w arming remains unclea r, but temperatu res are pred icted to ri se betw een 2 and 5 degrees by the middle of the next ce ntury, as they did in Peru during the 1997 El Nino . Clim ate change appea rs not to have bee n much of a probl em in the past. But it mi ght become one as popul ati on grows, and if c limate change is large and deve lops mo re qui ckl y than expected . In that event, the fl ow of techno log ies w i 11 need to increase so th at fa rmers ca n cope w ith mo re difficult problems. Late b li ght di sease, Hijmans notes, would likely increase from a combin ati on of higher temperatu res and rainfall. CIP Advises Peru on El Nino Much depends on the farm ers' skill s, says CIP Director Genera l Hubert Zandstra. " Peru v ian potato fa rmers w ere adv ised ea rl y by the Ministry of Agriculture of the onset of another Nino. Kn owing its effects, many produ cers shi fted their plantings to coo ler, hi gher altitud es . In doi ng so, they kept produ ct ion and pri ces at prev ious yea rs' leve ls, although the qu ality of the crop was poorer." " Center scienti sts worked cl ose ly w ith Peru vian agri cultural offic ials, " Zandstra adds, " by recom- mending spec if ic management programs to farm ers on how to dea l w ith increases in heat and rain fal l. " Aside from effects on yie ld , higher temperatures and humidity produ ced signifi ca nt changes. Farmers on Peru's central coast, for exa mpl e, were forced to nearly tripl e pesticide use as in sect populations exploded. In southern Peru , outbreaks of a trad itionally minor aphid-like pest (Russelliana solanicola), led to an increase in an unu sual strain of potato v irus Y, for which the in sect is a vecto r. Insect Populations Expand "A lmost all insect pests of potatoes do better in hi gher temperatures," says CIP entomo log ist Fausto Cisneros. "U nder normal co nditi ons, we mi ght see three generations of a particular in sect during the growing season. When temperatures rise, the I ife cycle is shortened, and there may be five generat ions of the sa me insect. In some cases, in sects that coex isted for years with a crop can suddenl y become importa nt problems. Hi gher popul ations ca n also increase the speed at w hi ch pests adapt and become resistant to pesticides," Cisneros adds. "The most importan t lesson of this yea r' s El Nino," Zandstra concludes, " is that the entire agricultural commun ity needs to be better p re- pared and have access to a strategic reserve of technology th at w ill all ow farmers to adapt. Th at mea ns research, new technological opti ons, and improvements in our abi lity to forecast change. It also mea ns better exte nsion, so th at farmers can access new technology and put it to work befo re disaster strikes ." LAREPUBLICA During the 1997-98 El Nino, much of Peru's highly-productive coastal desert farmland re- sembled flooded Asian ricefields. Potato yields fell by half in many locations. 9 Virus Cleanup Boosts Chinese Sweetpotato Production - 10 China, the world's largest producer of root and tuber crops, is also the first developing country to benefit on a large scale from technology designed to eliminate virus diseases in sweetpotato planting materials. According to recent reports, Chinese sweetpotato farmers are planting an estimated 330,000 hectares of virus-free sweetpotato annually in Shandong Province alone. The value of this technology over the past four years is estimated at $80 million and growing. CIP econom ist Thomas Walker notes th at the work is an excellent examp le of how intern at ional researc h centers can broker technologies from indu striali zed countri es and extend them to the deve lop ing wo rld . The v iru s c lea nup techniques bein g used in China, he says, are based on hi gh techno logy tissue culture tec hniques developed in industriali zed countri es. "CIP' s ro le," he says, "was to identify a tec hnol ogy th at cou Id be taken off the she lf, adapt it to deve loping cou ntry needs, and help China' s sc ientists modify it to loca l conditi ons." Impact Through Training The ori gi n of the project dates bac k to 1987 w hen CIP co ndu cted a small training course on v iru s detection techniques. The next year, Center sc ienti sts, in cooperation wi th co l leagues at the Asian Vegetable Research and Deve lopment Center, organ ized a ti ssue culture training work- shop at the Xuzhou Sweetpotato Resea rch Center on Chi na' s east coast . According to Dapeng Zhang, w ho served as a translator and now heads CIP's sweetpotato breeding project, 30 of Ch in a's top sweetpotato resea rchers attended. Its main focus was on developing symptom-free ti ssue culture plantlets. He att ributes th e success of the course to the fact th at most participants were youn g sc ienti sts eage r to app ly hi gh techn o logy to the country's agri cultural problems. "We also had exce ll ent instructors from CIP," he adds, among them John Dodds and Masa lwa naga, both now directors of resea rch at other CGIAR centers. M.IWANAGA Followi ng a five-year per iod of adapti ve resea rch by Chinese sc ienti sts, c lose ly supported by CIP virologists, large-sca le pl antin g of virus-free sweetpotato began in 1994, mostl y in Shandong Prov ince. Presently, about 40 percent of Shandong's 700,000-hectare sweetpotato growing area is planted to v irus-free materi als. If extensi on targets are met, that figure w ill rise to 80 percent, coverin g more th an half a million hectares by the end of 1998. The produ ction of v iru s- free cutt ings begins with meristem ti ssue cultures that are used to produ ce virus-free pl antl ets in heated greenh ouses during the winter. The plants are replanted to nethou ses in the spring. From there, v irus-free seed roots are produced in the autumn to generate v in e cuttings, which then serve as a source of planting materi al for the summer crop. Because two fi eld-multipli cations per year are poss ibl e, 500 v irus-free plantlets are sufficient to prod uce planting mater ial for 13,000 hectares within two years, a highly impress ive fi eld mul t ipli cation rate for a root crop. Impressive Yield Advantages Yield advantages are equall y impress ive. In tests conducted at nine sites with five va ri et ies, average produ ct ivity ga ins were about 40 percent, but ranged as high 160 percent. But productivity ga ins disappear after three or four years. For example, an older Chinese variety, cultivar Xindazi , showed a yield adva ntage of 350 percent in the first year, 130 percent in the second and third yea rs, but only 14 percent in the fourth year. At that point, farmers need to be resupplied with fres h pl anting materi als. W alker notes that the program has been implemented without investment in spec ialized facilities. " You would be hard pressed to come up with better conditions for economic impact than those embodied in the Shandong v irus-free propagation prog ram," he says. That in c ludes a limited gestati on time for resea rch (the results he notes were achieved largely through training), swift transfer of technology; huge potential for area coverage; and relati ve ly high unit benefits. Added to th at are hi gh yields, emerging export dema nd, and the fact that fa rmers do not have to change any of their exist ing practices. A back-of-the-envelope ca lcul ation gives the project a net present va lu e of about $250 milli on at a 10 percent discount rate. The estim ated internal rate of return is 120 percent, w ith annual net benefits already exceeding $40 milli on ca lcul ated over 30 yea rs. Assuming the diffusion data refl ect rea lity, one could vary these assumptions by several orders of magnitude and still not affect the results all that much, Walker adds. " In all likelihood, this work has had more economi c impact than any other project, perhaps even more than the aggregate of all other CIP projects combined," he says. Walker notes th at a forma l impact case study wi ll be co ndu cted in 1998 by the CIP economi cs and virology groups, in assoc iat ion with biol og ists at the sweetpotato program of the Shandong Crops Research Institute and economi sts at the Center for Chinese Agricultural Po li cy. CIP has worked in Ch in a sin ce the establ ish- ment of its scientifi c li aiso n office in the 1980s. Co ll aborat ive resea rch is conducted under a fo rmal agreement w ith the Chinese Academy of Agricultural Sciences of the Ministry of Agricul- ture. Cll' -BEljl NG A single CIP training program in 1988 led to major increases in China's sweetpotato production. 11 Getting the Numbers Right Revised projections for major food commodities, including roots and tubers, show a highly promising future for potatoes and sweetpotatoes in developing countries. The new estimates indicate that the two ci:.ops taken together will account for at least 6.5 percent, and potentially as much as 9.9 percent, of the value of all major food com- modities produced in the year 2020. "The new numbers, " says CIP economist Grego ry Scott, "demonstrate that potatoes and sweetpotatoes will maintain their relative impor- ta nce and wi ll increase in importance relative to ce rea ls. The projections were produced by the Internati onal Food Po l icy Resea rch In stitute and CIP, in co ll aborati on with the Centro Internacio nal de Agricu ltura Trop ica l. Growth rates for potato are particularly robust (about 4% annua l ly) and show no sign of slowing down, espec ial ly in As ia, says Scott. W hat is remarkab le is that as potato production in devel- opi ng countri es in creased from 75 million tons ann uall y in 1988 to over 100 million tons today, the average annu al growth rate increased from 2.5% to more than 4% . Growth in area and y ield contributed to the increased production. This contrasts w ith earlier projecti ons founded on a 3.9% average annu al rate of decline in area planted. "The d iscrepancy between past projec- tions and actual trends has become increas ingly apparent in rece nt yea rs," he adds. Calculating for Poverty Recent FAQ data also show a turnaround fo r sweetpotato. Average annual growth rates in production are now c lose to 1 percent per annum and risin g (figu re ri ght). The turnaround is large ly because of the increas ing use of sweetpotato in China for processing and for animal feed. Because sweetpotato is grown mostly in Ch ina' s poorer inland reg ions, these uses are helping to increase rural income and red uce poverty. G iven this fact, Scott believes the ca lcul ations previously used by the CGIAR to establi sh research priorities underes- t imated the importance of sweetpotato to the poor. Moreover, the massive use of sweetpotato fo r animal feed red uces grain impo rts and, in the process, rel ieves the pressure on internatio nal grain prices fo r other developing countri es, Scott says . Grow rate (%) 6 .0~----------------~ 5.0 4.0 3.0 2.0 1.0 o+-~----.------,----,----r---,-------i 4 8 12 16 23 10-year intervals• Annual average growth rates for potato production and area (source: FAO) . Million tons 115 105 95 85 75 65 0+---~---------....._.-~-~ 1984 - 86 1987 1989 1991 1993 11995 --- 2010 Actual and projected growth in potato production in developing countries (source: FAO/CIP)_ Grow rate (%) 6.0 ~------------~---~ -- Production 4.0 --Area 2.0 -2.0 4 8 12 16 10-year intervals• Annual average growth rates for sweetpotato production and area (source: FAO). (•) 1 =1961-63 to1 971-73; 23=1984-86 to 1994-96. 23 Milestone Reached 1n Bacterial W i It Research CIP pathologists have reached a milestone in bacterial wilt research that vastly increases their ability to detect the bacterium responsible for the disease (Ralstonia solanacearum). The procedure, which multiplies the bacteria in samples to be tested in the standard NCM-ELISA technique (nitrocellulose membrane, enzyme- linked immunosorbent assay) was refined by CIP bacteriologist Sylvie Priou. It is one million times more sensitive than previously available serological methods used to detect latent infection in potato tubers. Priou's research is part of a co ntinuing effo rt at CIP to deve lop more effecti ve and less expensive di sease detecti on kits fo r deve lopin g countri es . The new kits are currentl y being di stributed in 15 deve l"oping countri es on three continents. Because th ey are so simple to use, they should p lay an impo rtant ro le in stimul at ing in fo rmal seed sys- tems and in eva luating germpl as m fo r res ista nce. According to highl y conservati ve estimates, the new kit, w hich costs $2 00, can be used to eva lu- ate the equi va lent of 2,000 tons of seed tubers, enough to pl ant 1 ,000 hectares of bacteri al w i It- free potatoes. Bacteri al w ilt is con sidered to be the number- two constraint to potato producti on in deve loping countri es. Yi eld loss estimates vary considerabl y, but can reach 95 percent w hen the disease is tu ber-borne. "Bacteri al w ilt is most effective ly contro ll ed by eliminating infected tu ber seed befo re it reac hes fa rmers' f ields," says Pri ou. "Seed taken from in fec ted fi elds often ca rri es latent infecti on, even if it comes from hea lthy-looking pl ants." " Bacteri al w ilt is diffi cul t to co ntro l," Pri ou notes, "because it is transmitted not onl y by seed, but is also found in the so il. " Beca use there are no known chemi ca ls th at control bacteria l w ilt, fa rmers mu st rely on c lea n seed as we ll as inte- grated management practi ces to ensure a hea lthy crop," she says. Such management practi ces in clude crop ro tation, minimum till age, the pl anting of to lerant var ieti es, and general crop san itati on. Prec ise methods for co ntro lling the di sease and for produci ng c lean seed vary consid- erabl y. For example in East Afri ca, nat ional prog rams working in co ll aborati on w ith the PRAPAC E resea rch and deve lopment network produce disease-free pl anting materi als with cuttin gs from in v itro stock. Another way to reduce the effects of bacteri al w il t is by planting true potato seed, an approach that has been used successfull y in As ia, most notab ly in the Red Ri ver Delta of V ietn am. Bacteri al w il t is also an important drawback to potato production in Latin Amer ica. Accord ing to recent reports, the di sease is seri ously limiting produ ct ion in southern Brazil , northern Argentina, Venez uela, Peru , and th e Domini ca n Republi c. The movement of large quantities of seed from infected areas is be li eved to be respon- sibl e. In response, CIP has organized wo rks hops and trainin g courses to alert research instituti ons and government pl ant hea lth serv ices to the prob lem. The workshops recommended acti ons to reduce di sease outbrea ks th rough integrated management, qua rantine, and the production of hea lthy seed. "Thi s last recommendation," says Lui s Sa lazar, a CI P virolog ist and head of CIP' s new Crop Protect ion Department, "wou Id have been diffi cul t to ensure w ith out th e new detecti on methods ." Sa laza r, w ho was a member of the orig inal team that deve loped the ELISA process in th e 1970s, notes th at the refin ed tec hniques are extremely practica l fo r deve loping countri es. Not onl y are they far more sensit ive, but they are more accurate and less expensive to use than the best previously ava il ab le techniques . A colony of Ralstonia solanacearum, the pathogen responsible for bacterial wilt. A CIP- developed process has vastly increased the accuracy of serological tests. 13 Integrated Control of Bacterial Wilt Paying Off in East Africa Potatoes are a food security crop in East Africa; production is increasing at an annual rate exceeding 4%. In Uganda's Kabale District nestled in the East African Highlands, rapid population growth has led to smaller, more fragmented farming plots, continuous cropping, and depleted soils. Potato is Kabale's most important cash crop. In the good years, growers plant 25,000 hectares and harvest between 150,000 and 200,000 tons, or a third of Uganda's total output. The most serious production constraints are bacterial wilt, late blight, and the degeneration of seed stocks. The problems are intertwined. To control th e hi ghl and type of the disease, Berga Lemaga, a CIP patho log ist, works on contro l strategies w ith the CGIAR and ASAR ECA Africa n H ighl ands Ini t iat ive and Uganda's Nati onal Agr icu ltura l Researc h O rganizati on (NARO ). But progress has been slow. Even if the d isease coul d S.PRIOU be erad icated abovegrou nd, the bacteri a can surv ive in the ground fo r long periods. Conse- qu ent ly, f ighting bacteria l w ilt requires an in te- grated approach; no sing le measu re is suff icient by itself. Affordable and User-Friendly Work ing w ith fa rmers, Lemaga and his NARO counterpa rts have des igned an affordab le, user- fr iendly package of cul tura l pract ices . " Fo r hea lth y pl ants, fa rmers shoul d use w ilt-to lerant var iet ies and c lea n seed," he says . "They are taught to hill up around their seed tube rs immed iate ly after pl ant ing, and up root and destroy w i lted pl ants immediately. " M in imal cul t ivati on is the ru le, a pract ice that avo ids wounds w hi ch in tu rn pro- mote in fecti on. On 46 fa rm s w here ~ h e new package was appl ied, yie ld in creases averaged almost 50 percent over four seasons. "The onset of bacteria l w il t was de layed," Lemaga said , "and the number of di sease-free pl ants was mu ch higher." To entirely rid the so il of the d isease, Lemaga's team is eva luating rotat ion sequences that reduce the amount of bacteri a in the so il and also im- prove fe rtility. The best cropping patte rns so fa r combine maize, w heat, and bea ns. Sta rtin g w ith fi elds that had a 90 to 100 percent in fec ti on ra te, Lemaga po inted out that just one maize or w heat crop reduced the rate to 79 percent, and th at bea ns fo ll owed by maize in two success ive seasons brought it down below 25 percent. Afte r such treatments, y ields on test pl ots at NARO's Kalengyere Stati on went up dramati ca ll y, from 3.2 to 11 tons per hectare. With low-fertility so il s, addi tional measures are required . A leguminous green manure crop adds nitrogen and organi c matter to the so il. The impact of such efforts w ill be short-I ived, however, if fa rmers rein fec t the so i I by pl antin g infec ted seed potatoes. Breaking the Infection Cycle In cooperati on w ith the Afri ca n Highl ands Initi ati ve, NARO, NGOs such as Afri care, and loca l seed growers, CIP is attempting to brea k th e cyc le of in fec ted seed and low y ields. The strategy is to produce c lea n seed in quantity fo r three or four popul ar va ri eti es in w hat is desc ri bed as a fa rmer- based, flu sh-out system. Th at mea ns a regular influ x of v irus-free seed stoc ks eac h year, mul t ipli- cati on by smai I-sca le seed growe rs, and then d irect sa le to fa rmers. Seed stocks are continu- ously repl aced or " flu shed out," w hi ch red uces d isease buildup . CIP initi ated the fa rmer-based seed project in 1996. Target countri es include Ethi op ia, Kenya, and Uganda; all are parti c ipants in the Afr ica n Highland Initi ati ve. Together, they produce 1.3 milli on tons of potatoes a yea r on approx imately 215,000 hectares. The project's ini t ial v irus-free seed stock, about 25 0,000 seedl ing tubers a yea r, is produced at the Kenya Agri cultural Resea rch lnstitute's quarantine stati on at M aguga . Th ese stoc ks go to nati onal programs in Ethi op ia, Kenya, and Uganda fo r fa rmer-based producti on. In Ugand a, the stoc k goes to NARO's Kalengyere resea rch stat ion. Dr. J.J. Haki za, head of NARO's potato program, ex pl ains that the Kalengyere stati on multi p li es th e stock from M aguga by taking cuttings from v iru s- free mother pl ants (1 00 mother pl ants ca n pro- duce 50,000 seed tuberl ets) . The stati on does not, however, convert all the v irus-free seed tubers from M aguga to mother pl ants. M ost go directl y to the fi eld fo r t rad iti onal multipli cati on, w hi ch yields about 10 tuber lets fo r each seed tuber pl anted . In thi s way the stati on has the fl ex ibility to contro l costs by shi ft ing to mother pl ants and rap id multipli cati on, Hakiza says. NGOs li ke Afri ca re got some of the seed, but most is bought by members of Uga nda's seed producers associat ion. "Wh en fa rmers bu y seed directl y from an establi shed seed grower, they kn ow it is of hi gh quality," says Steven Tindimobona, chairman of Uganda's Nati onal Seed Potato Producers Asso- c iat ion. "When they buy in the open market, li ke ly as not, it is already in fec ted w ith bacteri al w il t and v iru ses. Starting out w ith c lean seed is a great advantage. " Farmers w ho invested in better seed showed a definite y ield adva ntage. In Uganda's Kabale Di stri ct, multi p li cat ion rates increased fro m 3 to 6, and in Kenya fa rmers repo rted a multi p li ca tion rate as hi gh as 7, up from 4 or 5 in prev ious yea rs. In Ethi opia, y ields went from 8 to 25 tons per hectare. Production of clean potato seed in the East Africa highlands is a key to controlling bacterial wilt. S. l'RIOU Late Blight Project Initiated a Year Early; Damage Reports Increasing - 16 Altho_!Jgh research results are still coming in, CIP may look back on 199A' as pivotal in the fight to control late blight disease, says Wanda Collins, CIP deputy d·rector general for research. Because late blight was selected as the Center's number one research priority for the mid-term planning period beginning in 1998, it was decided to initiate work a year early. As part of this effort new staff were recruited, funds redirected, and new facilities constructed. Late blight research currently receives about 10% of the Center's resources. One of key the decisions made during the year was the appointment of Rebecca Nelson as late blight project leader. Nelson, a research patholo- gist, leads a team of 20 national and international scientists working in 11 subprojects in Lima and at sites in Africa, Asia, and other parts of Latin America. "We now have a team in place made up of specialists from pathology, breeding, molecular biology, geographic information systems, and the social sciences," says Collins. Late Blight Bad and Getting Worse "Indications ;are that the late blight problem is bad and getting worse, " says Nelson. Throughout the Andean region , late blight was exacerbated in 1997 by a particularly severe El Nino event that brought with it above-average temperatures and rainfall , conditions perfect for late blight. ''CIP cooperators throughout the world pretty much agree that we are dealing with a new, far more destructive disease than ever before. Chemicals Late Blight Damage Estimates 1997 50 40 30 20 10 0 that have proven effective in the past are not going to do the job in the future ," she adds. Three developments over the past year were particularly troubling. The first was a series of reports confirming a breakdown in the effective- ness of the systemic fungicide metalaxyl. Until now, metalaxyl has been the potato farmers' most effective tool for combating older forms of the disease. The second was the continued spread of a new, more aggressive form of the late blight fungus (Phytophthora infestans). Although the fungus in the Peruvian populations still showed the Al mating type, molecular marker work at CIP demonstrated that it belongs to one of two new migrant populations that have devastated potato crops worldwide. The new populaitions show broad-spectrum virulence believe