Suresh, L.M., Dave Hodson, Yoseph Alemayehu, Francis Mwatuni, Isaac Macharia, Berhanu Bekele, Daniel Bomet, Claver Ngaboyisonga, Katemani S. Mdili, Ken Msiska, David Kamangira, Mudada, N., and B.M. Prasanna Monitoring and tackling Maize Lethal Necrosis (MLN) in Eastern and Southern Africa from 2014 to 2024 Seed Quality assurance and technological advances for climate change adaption towards sustainable food and nutrition security. MLN Surveillance Overview • Maize in Sub-Saharan Africa is a critical food crop with 40 million ha, largely grown by smallholders. • MLN affected maize first in Kenya in 2011 and became a major threat to production. • MLN, a transboundary disease being addressed by multipronged approach and surveillance is the Key to all the efforts. • To date MLN is around 20% incidence in eastern Africa and has not been reported in Southern Africa Maize area under harvest and production over view 2023 0 2000000 0.5 1.5 1 6000000 2 3 2.5 10000000 3.5 4.5 4 0 4000000 8000000 12000000 Zambia Zimbabwe Malawi Kenya Uganda Tanzania Rawanda Ethiopia Area harvested Production Productivity Maize Agro ecology – SSA (Thanks: Yoseph Beyene) Maize Lethal Necrosis (MLN) - Status Disease Symptoms Maize is affected by several pests and diseases and affects the crop, the crop loss globally is around 22%. In Sub–Saharan Africa, the crop productivity is about 1.5 tons per ha as compared to 5.5 tons/ha globally, the decreased crop productivity is due to various stress and poor input management. MLN is a viral disease caused by combined infection of maize with Maize Chlorotic Mottle Virus (MCMV) and any of the Potyviruses infecting cereals, especially Sugarcane Mosaic Virus (SCMV). The disease was first reported in Africa, particularly in Kenya in September 2011, and since then reported in Uganda, Tanzania, Rwanda, D.R. Congo, and Ethiopia. MCMV SCMV MLN Taiwan Contaminated MLN - Disease Transmission and Management Insect Mechanical Crop Debris Rigorous Monitoring & Surveillance Breeding & Deploying MLN Resistant Varieties Capacity building, communication Outreach Safe germplasm exchange and distribution MLN-free Seed Production & Exchange Agronomic Management MLN Management Susceptible Host MODE OF TRANSMISSION DISEASE MANAGEMENT MLN Surveillance The International Maize and Wheat Improvement Center (CIMMYT) is leading collective efforts to control the spread of Maize Lethal Necrosis (MLN) disease that appeared in eastern Africa in 2011 and is considered the worst threat to the region’s food security in decades. The aim is to coordinate regional efforts to strengthen the response to the rapid emergence and spread of MLN in sub- Saharan Africa. Its activities will result in: ✓ an effective MLN surveillance and monitoring system. ✓ an established community of practice comprising seed companies and national plant protection organizations, ✓ harmonized protocols for detecting MLN-causing viruses in commercial seed lots, ✓ a model for voluntary, private sector-driven MLN/MCMV containment, ✓ the development of appropriate diagnostic and management strategies. Rigorous MLN/ MCMV - Monitoring & Surveillance Optimization of MCMV diagnostic protocol using immunostrip and surveillance system using digital ODK platform. Training NPPO’s, SME’s and NARS for MCMV diagnosis and disease surveillance. Conducting MCMV surveillance in ESA during 2016-2024. Updating the MLN surveillance data (country wide) in MLN web-portal. Preventing the spread of MLN, especially Maize Chlorotic Mottle Virus (MCMV), from the MLN-endemic countries in easternAfrica to non-endemic countries in SSA. 0 1000 2000 3000 Survey Points 4000 5000 6000 Rwanda Zambia Malawi Kenya Ethiopia Uganda Zimbabwe KSC Tanzania C o u n tr ie s MLN Survillance in SSA 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 MLN Surveillance – 2014-2024 progress • MLN surveillance is done using immunostrips. – Commercial farms – Seed-growing farms – Dealer seeds (ELISA) Sample Collection • Identify the field • Collect 6 samples • Bulk and diagnose • Confirm the MCMV presence with immunostrip. Methodology Diagnosis ODK tool MLN Toolbox • Collect 6 samples and bulk • Grind samples with buffer • Dip immunostrip in a small quantity of sap • Confirm the virus presence • Report the presence or absence of virus in ODK tool • Download ODK app • Fill the form with all the details • Submit the form • Log in to your account • Validate the data • Approve • Publish the data MLN Technical Manual: Prasanna BM (ed). 2021. Maize Lethal Necrosis (MLN): A Technical Manual for Disease Management. CDMX: CIMMYT Overview Data + Tools Platform Lab Analysis KE ET MW R W TZ U G ZM Z W Public Information (MLN Portal, Institutional Websites…) Validation, QC, Approval Field Surveys ++ Data Data Data Seed Surveys MLN Status in Eastern and Southern Africa • Established a strong MLN surveillance network in eastern and southern Africa • MLN – still a challenge in eastern Africa and contained to southern Africa. Maize MLN Frequency map [Eastern Africa: Kenya, Uganda, Tanzania, Ethiopia, and [ Southern Africa: Zambia, Zimbabwe, and Malawi] Rwanda] MLN Field Survey frequency chart MLN Status in Eastern Africa Kenya, Uganda, Ethiopia, Rwanda, and Tanzania • During 2023, it is noted around 20-25% of the surveillance samples observed with MLN. • MLN surveillance is mainly project-supported, except in Rwanda, where the efforts are on a sustainable basis. • Key factors for MLN prevalence: Use of MLN-susceptible commercial hybrids, less crop rotation, porous transboundary mechanism. Kenya Ethiopia Rwanda Tanzania*Uganda MLN Status in Southern Africa Zambia, Zimbabwe, and Malawi Zimbabwe Zambia Malawi • 1169 data points for 10 years • MLN has not reported • Trained personnel and network with partners • Collaboration • 3100 data points for 10 years • MLN has not been reported • Surveillance including Tanzania D.R. Congo borders • Collaboration with partners • 2635 data points for 10 years. • MLN has not been reported so far • Collaboration with local partners • Trained personal • Limited surveillance Survey with stakeholders Transboundary quarantine mechanism – status (2023) • During the survey, there are 32 borders, 5 ports, 6 airports, 5 testing centers, 27 checkpoints, and 2 quarantine facilities identified in Kenya, Uganda, Zambia, and Zimbabwe. • Very few quarantine facilities (2) to tackle the maize seed movement. • Porous borders, checkpoints, ports, and airports to handle the large volume of seeds and grain movement. • Less or no infrastructures (including digital) in most of the countries in ESA to handle the large volume of seeds in ports, borders, and checkpoints. • The present transboundary mechanism is very weak and hence there is a high probability of any emergence of transboundary pests and diseases through seeds/grain in ESA. Transboundary locations in ESA – 2023 overview 10 0 20 30 40 50 60 80 70 Kenya Uganda Zimbabwe Country / Transboundary locations Zambia Total N u m b e rs Quarantine facility Check point and Port Border and port Check point Testing Center Airport Ports Borders Models for predicting P&D risks and shifts due to climate change and other factors Target Countries and Partners: Kenya (KEPHIS), Uganda (NARO), Tanzania ( PQPS), Zambia ( PQPS), Zimbabwe (PQSI) Study of various predisposing factors for MLN spread including weather, seed movement, quarantine system arrangement, host prevalence or cropping period in selected countries in Eastern and Southern Africa. • Highly porous borders, lack of quarantine and testing facilities, inadequate diagnostic centers and insufficient trained personnel, limited laboratory facilities to handle bulk volumes of seeds and grains observed in general • Host prevalence and cropping period for MLN spread Survey, and data on seed movement into and out of target country for the last 3-4 years for understanding on safe exchange of seeds and grains being finalized 20 18 16 14 12 10 8 6 4 2 0 Border Points Air Port Testing facility Quarantine facility Total N u m b e r Existing transboundary mechanisms Transboundary quarantine mechanism study Kenya Uganda Tazania Zambia Zimbabwe Status of Transboundary quarantine mechanism in ESA MLN sites with Climate similarity in Sub SaharanAfrica Strong Moderate Weak Capacity Building since 2016 Training conducted to various partners in SSA on • MLN disease diagnosis and surveillance • MLN disease diagnosis and management • MLN Disease-free seed production steps 0 500 25 1000 20 1500 2000 N u m b er o f P eo p le Countries Research institutions Training to NPPO's NARES and Seed growers in Kenya Capacity Building - MLN diagnosis and Management Since 2016 40 NPPOs Seed companies Seed Growers 0 5 10 15 30 35 Kakamega Naivasha Naivasha Muguga Naivasha Male Female Naivasha Mazowe Taveta P ar ti ci p an ts 16% 12% 8%64% CAPACITY BUILDING (> 5000 MEMBERS) NPPOs Seed companies Research institutions Seed Growers MLN Management Practices and Steps to produce MLN-free Seed Have a community of practice among the seed producers and the seed company with guidance from NPPOs. On-farm farmer and seed company visits to ascertain the status of MLN disease and monitor implementation of harmonized MLN management checklists. Training of stakeholders on the use of the checklists. Maintain a track record of maize fields with no MLN infection, avoid growing the maize crop with MLN infection for seed multiplication. Promotion of MLN-tolerant maize varieties during field days and other forums for uptake. Creating awareness among the maize seed sector, and institutions on SOPs for producing and exchanging MLN-free commercial seed. Selection of field Preparation of field Use of Certified MLN-free seeds Use of Clean / disinfected farm tools and equipments Scouting,rouging,and clean crop cultivation Destroy infected plants and don’t feed animals Managing insect vectors Sorting healthy cobs Crop free period and crop rotation 1 2 3 4 5 6 7 8 9 Training – MLN diagnosis and Management 2022 • Technical backstopping on MLN diagnosis, was done to all NPPOs and SMEs in Kenya, Ethiopia, Uganda, Zambia, and Zimbabwe (687 with 506 male and 181 female). • Strong awareness to all NPPOs and SMEs to have regular MLN surveillance, for example, Rwanda is doing MLN surveillance on its own. • Timely education on MLN disease diagnosis, management, and producing MLN-free seeds to all NARES, SME’s , and Seed production growers in the region. Team Zambia Team Zimbabwe Team Malawi Communication resources Conclusion and Way forward Plant Health Initiative will mainly focus on mitigating the threats of MLN in Sub-Saharan Africa with the following objectives: Continue to monitor MLN in SSA for a better understanding of MLN management strategies. Strengthen partners to conduct disease surveillance, producing MLN disease free seeds. Collaborating with innovation platform on IPDM for mitigating the MLN threats. Reference: Boddupalli, P., Suresh, L. M., Mwatuni, F., Beyene, Y., Makumbi, D., Gowda, M., et al. (2020). Maize lethal necrosis (MLN): Efforts toward containing the spread and impact of a devastating transboundary disease in sub-Saharan Africa. Virus Res. https://doi.org/10.1016/j.virusres.2020.197943 . Acknowledgements: DR&SS Zimbabwe Thank you for your interest! Slide 1 Slide 2 Slide 3 Slide 4 Slide 5 Slide 6: Rigorous MLN/ MCMV - Monitoring & Surveillance Slide 7: Methodology Slide 8 Slide 9 Slide 10: MLN Status in Eastern Africa Slide 11 Slide 12 Slide 13: Transboundary quarantine mechanism – status (2023) Slide 14: Models for predicting P&D risks and shifts due to climate change and other factors Slide 15: Capacity Building since 2016 Slide 16: MLN Management Practices and Steps to produce MLN-free Seed Slide 17 Slide 18 Slide 19: Communication resources Slide 20 Slide 21 Slide 22