Tag: Maize Lethal Necrosis

Combatting maize lethal necrosis in Zimbabwe

Written by Julian Bañuelos-Uribe on January 8, 2024. Posted in Blogs, Explainers.

Maize is a staple crop in Zimbabwe, playing a vital role in the country’s agricultural landscape as food for its own people and an export good. However, behind every successful maize harvest lies the quality of seed and resistance to diseases and stresses.

Amidst the multitude of diseases that threaten maize crops, one adversary is maize lethal necrosis (MLN). Though not native to Zimbabwe, it is crucial to remain prepared for its potential impact on food security.

What is maize lethal necrosis?

MLN is a viral disease, caused by a combination of two virus diseases. The disease emerged in Kenya in 2011 and quickly spread to other countries in eastern Africa. The introduction of MLN to Africa was likely affected by the movement of infected seed and insect vectors. MLN has had a severe impact on regional maize production, leading to yield losses of up to 90%.

Recognizing the need to equip seasoned practitioners with the knowledge and skills to effectively diagnose and manage MLN, CIMMYT organized a comprehensive training on MLN diagnosis and management, targeting 25 representatives from Zimbabwe’s Plant Quarantine Services.

From students to experienced technicians, pathologists and plant health inspectors, this was an opportunity to refresh their knowledge base or an introduction to the important work of MLN mitigation. “This training for both advanced level practitioners and students is crucial not only for building competence on MLN but also to refresh minds to keep abreast and be prepared with approaches to tackle the disease once it is identified in the country,” said Nhamo Mudada, head of Plant Quarantine Services.

Maize plants showing maize lethal necrosis (MLN). (Photo: CIMMYT)

Expectations were diverse, ranging from sharpening understanding of key signs and symptoms to learning from country case examples currently ridden with the disease. With CIMMYT’s guidance, practitioners learned how to identify MLN infected plants, make accurate diagnoses, and implement management strategies to minimize losses.

“For over 10 years, these trainings have been important to raise awareness, keep local based practitioners up to speed, help them diagnose MLN, and make sure that they practice proper steps to tackle this disease,” said L.M Suresh, CIMMYT maize pathologist and head of the MLN screening facility in Kenya.

Identifying the specific MLN causing viral disease affecting a maize plant is the first step in combating MLN. Determining whether it is a biotic or abiotic disease is critical in establishing its cause and subsequent diagnosis. By implementing proper diagnostic techniques and understanding the fundamentals of good diagnosis, practitioners can bring representative samples to the lab and accurately identify MLN.

Tackling MLN in Zimbabwe

Initiated in 2015 at Mazowe as a joint initiative between the Government of Zimbabwe and CIMMYT, a modern quarantine facility was built to safely import maize breeding materials from eastern Africa to southern Africa and enable local institutions to proactively breed for resistance against MLN.

The MLN quarantine facility at the Plant Quarantine Institute is run by the Department of Research and Specialist Services (DRSS) and is mandated to screen maize varieties imported under strict quarantine conditions to ensure that they are MLN-free.

Training participants pose outside of the MLN screening facilities. (Photo: CIMMYT)

To date, CIMMYT and partners have released 22 MLN resistant and tolerant hybrids in eastern Africa. CIMMYT’s research and efforts to combat MLN have focused on a multidimensional approach, including breeding for resistant varieties, promoting integrated pest management strategies, strengthening seed systems, and enhancing the capacity of farmers and stakeholders.

“Support extended through valuable partnerships between CIMMYT, and the collaborations have played a pivotal role from surveillance to diagnostics and building capacity,” said Mudada.

Feedback and insights

Chief Plant Health Inspector for Export and Imports Biosecurity, Monica Mabika, expressed gratitude for the training. “It is always an honor when we have expert pathologists come through and provide a valuable refresher experience, strengthening our understanding on issues around biosecurity and learning what other countries are doing to articulate MLN,” she said.

Students learn how to screen maize plants for MLN. (Photo: CIMMYT)

Among the students was Audrey Dohwera from the University of Zimbabwe, who acknowledged the importance of the training. “I have been attached for 2 months under the pathology department, and I was eager to learn about MLN, how to detect signs and symptoms on maize, how to address it and be able to share with fellow farmers in my rural community,” she said.

With the knowledge gained from this training, practitioners are well equipped to face the challenges that MLN may present, ultimately safeguarding the country’s maize production status.

Ten years later: CIMMYT facilities in East Africa continue to make a difference

Written by Julian Bañuelos-Uribe on November 30, 2023. Posted in News.

CIMMYT and partners in Kenya recently marked the 10th anniversary of two major facilities that have been crucial for maize breeding in sub-Saharan Africa. The Maize Doubled-Haploid (DH) facility and the Maize Lethal Necrosis (MLN) screening facility at the Kenya Agriculture and Livestock Research Organization (KALRO) centers in Naivasha and Kiboko, respectively, have made immense contributions to the rapid development of higher-yielding, climate-resilient and disease-resistant maize varieties for smallholder farmers across the continent.

An aerial photo of the Naivasha Research Center. (Photo: CIMMYT)

“These two facilities have been instrumental in furthering KALRO’s mission to utilize technology in the service of Kenya’s smallholder farmers,” said KALRO Director General/CEO, Eliud Kireger. “They also exhibit the spirit of cooperation and collaboration that is necessary for us to meet all the challenges to our food systems.”

“Deploying a higher yielding maize variety may not be impactful in eastern Africa if that variety does not have resistance to a devastating disease like MLN,” said CIMMYT’s Director General Bram Govaerts. “These two facilities demonstrate the holistic methods which are key to working towards a more productive, inclusive and resilient agrifood system.”

Maize DH facility

Hybrid maize varieties have much higher yields than open-pollinated varieties and are key to unlocking the agricultural potential of maize producing countries. The doubled haploid process is an innovative technology producing within a year genetically true-to-type maize lines that serve as building blocks for improved maize hybrids.

Unlike conventional breeding, which takes at least 7 to 8 generations or crop seasons to develop parental lines, DH lines are generated within two seasons, saving significant time, labor and other resources. DH maize lines are highly uniform, genetically stable, and are more amenable to the application of modern molecular tools, making them perfect resources for breeding elite maize hybrids.

Workers in the Kiboko Double Haploid facility. (Photo: CIMMYT)

The aim of CIMMYT’s maize DH facility is to empower the breeding programs throughout the low-and middle-income countries in Africa by offering a competitive, accessible, not-for-profit DH production service that will accelerate their rate of genetic gain and fast-track development of improved maize varieties for farming communities.

Since 2017, the DH facility has delivered 280,000 DH lines from 1,840 populations of which 20% were delivered to public and private sector partners. CIMMYT maize breeding programs and partner organizations have embraced the use of DH technology, with many of the newest maize hybrids released in Africa being derived from DH lines. The facility has also served as a training ground so far for over 60 scientists and hundreds of undergraduate students in modern breeding technologies.

“Before 2013, DH technology was mainly employed by private, multinational corporations in North America, Europe, Asia and Latin America,” said CIMMYT’s DH Facility Manager, Vijay Chaikam. “But the DH facility operated by CIMMYT at the KALRO Kiboko research station is specifically targeted at strengthening the maize breeding programs by the public sector institutions as well as small-and medium-size enterprise seed companies in Africa.”

The maize DH facility at Kiboko, Kenya, was established with funding support from the Bill & Melinda Gates Foundation and inaugurated in September 2013. The facility includes an administrative building, seed quality laboratory, training resources, artificial seed dyer, a cold-storage seed room, a chromosome doubling laboratory, greenhouse and a state-of-the-art irrigation system to support year-round DH production in the 17-hectare nursery.

MLN screening facility

MLN is a devastating viral disease that can decimate farmers’ fields, causing premature plant death and unfilled, poorly formed maize ears, and can lead to up to 100 percent yield loss in farmers’ fields. Though known in other parts of the world for decades, the disease was first identified in eastern Africa in 2011. By 2015, MLN had rapidly spread across eastern Africa, including Kenya, Uganda, Tanzania, South Sudan, Rwanda, Democratic Republic of Congo and Ethiopia. CIMMYT scientists quickly discovered that almost all the commercial maize cultivars in eastern Africa were highly susceptible to the disease.

Against this backdrop, CIMMYT and KALRO recognized the urgent need for establishing a screening facility to provide MLN phenotyping service and effectively manage the risk of MLN on maize production through screening of germplasm and identifying MLN-resistant sources. The facility was built with funding support from the Bill & Melinda Gates Foundation and the Syngenta Foundation for Sustainable Agriculture, and inaugurated in September 2013.

Resistant and susceptible line at the Maize Lethal Necrosis facility. (Photo: CIMMYT)

“The MLN screening facility is a key regional resource in breeding for resistance to a devastating viral disease. The facility is indeed one of the key factors behind successful management of MLN and helping stem the tide of losses in eastern Africa,” said Director of the Global Maize Program at CIMMYT and One CGIAR Plant Health Initiative, B.M. Prasanna. “Fighting diseases like MLN, which do not respect political boundaries, requires strong regional and local collaboration. The successes achieved through the MLN Screening facility in the past 10 years embody that spirit of collaboration.” Indeed, farmers in the region now have access to over twenty genetically diverse, MLN-tolerant/resistant maize hybrids released in eastern and southern Africa.

The facility is the largest dedicated MLN screening facility in Africa and has evaluated over 230,000 accessions (over 330,000 rows of maize) from CIMMYT and partners, including over 15 national research programs, national and multinational seed companies. The facility covers 20 hectares, of which 17 hectares are used for field screening of germplasm. Dedicated laboratories and screen houses cover the remaining 3 hectares.

“MLN phenotyping service is conducted under stringent quarantine standards and the high-quality data is shared with all the CGIAR and public and private partners. The MLN screening service has helped breeding programs across the continent, aided in undertaking epidemiological research activities, and supported capacity building of students from diverse institutions, and regional stakeholders regarding MLN diagnosis and best management practices,” said CIMMYT’s Maize Pathologist in Africa, L.M. Suresh.

“The output of MLN resistant lines and hybrids has been remarkable,” said Director of Phytosanitary and Biosecurity at the Kenya Plant Health Inspectorate Service (KEPHIS), Isaac Macharia. “And the facility has strictly adhered to quarantine regulations.”

In Uganda, the MLN facility was crucial in the “release of the first-generation MLN tolerant hybrids and dissemination of MLN knowledge products that minimized the economic impact of MLN,” said the Director of Research of the National Crops Resources Research Institute, Godfrey Asea.

Peter Mbogo, maize breeder with Seed Co Group, said, “This is the only quarantine facility in the world where you can screen against MLN under artificial inoculation. It has been an excellent return on investment.”

Counties Urged To Scale Up And Adopt Pest Control Technologies

Written by Sarah McLaughlin on March 17, 2023. Posted in In the media.

Scientists from the International Maize and Wheat Improvement Center (CIMMYT) suggest counties in Kenya should scale up and accelerate the adoption of technologies that can control and prevent Maize Lethal Necrosis (MLN) and fall armyworm (FAW) to achieve higher maize yields.

Although the technologies exist, many farmers have little information on how to implement them.

Seed companies and senior officials from the Ministry of Agriculture could play a key role in disseminating information, as could mobile phone technology and emerging digital innovation platforms.

Read the original article: Counties Urged To Scale Up And Adopt Pest Control Technologies

Government of Zimbabwe recognizes CIMMYT for beneficial collaborations

Written by Tawanda Hove on February 16, 2023. Posted in News.

Dr Dumisani Kutwayo (second left) receives state of art Maize Lethal Necrosis test kits from Dr Wegary Dagne (second from right). (Photo: Tawanda Hove/CIMMYT)

The best results in combating pests and diseases exacerbated by climate change and protecting agricultural food systems originate from strategic partnerships between national governments and international research organizations. Such a synergy between Zimbabwe’s Department of Research and Specialist Services (DRSS) and the International Maize and Wheat Improvement Center (CIMMYT) was recognized for its effectiveness at an event hosted by Zimbabwe Plant Quarantine Services on January 9, 2023.

“The mandate of ensuring that Zimbabwe is protected from plant diseases and invasive pests is one which cannot be attained by government alone, but together with partners such as CIMMYT,” said Dumisani Kutywayo, Chief Director of DRSS.

Dagne Wegary Gissa, CIMMYT senior scientist in maize breeding, presented Kutywayo with the latest advanced PCR testing kits for detecting maize lethal necrosis. “We are committed to ensuring that we support Zimbabwe with improved maize and wheat varieties but also with rapid disease detection,” said Gissa.

Kutywayo and senior directors were given a tour of the plant quarantine services station, where they observed where all introduced maize seed is quarantined and tested before being incorporated into the local seed systems. Tanyaradzwa Sengwe, a seed health and quality expert, summarized the quarantine procedures and explained how the day-to-day operations between the two institutes are being implemented. This involves the management of imported seed, protocols of seed management and biosafety measures for the quarantine facility.

Government officials take part in a field visit of the quarantine facility set up by CIMMYT in Mazowe, Zimbabwe. (Photo: Tawanda Hove/CIMMYT)

Expanding partnerships

Zimbabwe can now accelerate its crop improvement programs, Gissa indicated, because CIMMYT has provided the government access to doubled haploid (DH) technology. This technology significantly shortens the breeding cycle from seven years to approximately 3-4 years. DH technology has become an integral part of many commercial maize breeding programs, as DH lines offer several economic, logistic and genetic benefits over conventional inbred lines. Further, new advances in DH technology continue to improve the efficiency of DH line development and fuel its increased adoption in breeding programs worldwide.

CIMMYT-Zimbabwe has facilitated access for Zimbabwe’s maize breeding program to a CIMMYT DH facility in Kenya. Busiso Mavankeni, the head of the Crop Breeding Institute, related how it was very expensive for governments of developing countries to keep up with the latest breeding technology trends and so collaborating with CIMMYT is helping Zimbabwe. “Having access to the DH facility has been a great boon to our breeding program,” said Mavankeni.

CIMMYT and Zimbabwe are also engaged in capacity building exercises; involving training sessions across a variety of food system frameworks. Nhamo Mudada, Head of Plant Quarantine Services, acknowledged the multiple trainings ranging from disease identification and prevention systems to entomology related concepts. “Our technical capabilities have increased significantly, and we strongly attribute this to CIMMYT’s knowledge sharing mandate,” Mudada said.

“This sustainability is enabled by ensuring that our systems can screen genetic materials coming into the country and detect diseases which may be foreign to the agroecological region. CIMMYT has, over the years, supported the government not only from a financial perspective but also from a technical capacity perspective.

“Having reliable partners such as CIMMYT who generously invest in government priorities helps our country to be well positioned against threats to our food security,” said Kutywayo, “The key for creating and maintaining sustainable innovation is for development partners like CIMMYT to work within existing national frameworks,” said Kutywayo. “As the adverse effects of climate change intensify, such strategic partnerships are the only way to establish appropriate responses.”

“Our goal is to serve as critical partners for Zimbabwe’s agrifood programs. We have dedicated ourselves to be a long-term partners and will provide as much support as we can to ensure Zimbabwe’s food security,” Gissa said.

AGG-Maize project registers impressive progress

Written by Susan Otieno on October 4, 2022. Posted in News.

Participants of the AGG Maize Mid-Term Review and Planning Meeting at CIMMYT’s Maize Lethal Necrosis Screening Facility in Naivasha, Kenya. (Photo: Dokta Jonte Photography)

The Accelerating Genetic Gains in Maize and Wheat (AGG) Project, which is halfway through its implementation, continues to register impressive achievements. At a meeting focusing on the project’s Maize component, held in Nairobi during July 25-28, B.M. Prasanna, Director of the Global Maize Program at the International Maize and Wheat Improvement Center (CIMMYT), highlighted the project’s major achievements in the opening session.

“One of the most important achievements of this project is increasing use of powerful tools and technologies to increase genetic gains in maize breeding pipelines in Africa,” said Prasanna. He noted that the AGG partners are showing keen interest in doubled haploid-based maize breeding. Prasanna pointed out that currently work is ongoing to produce third-generation tropicalized haploid inducers which, in combination with molecular markers, will support accelerated development of improved maize germplasm, a key objective of the AGG Project.

Prasanna also pointed out a significant increase in adoption of stress-tolerant maize in Africa – from less than half a million hectares cultivated under stress tolerant maize varieties in 2010, to 7.2 million hectares currently in 13 African countries, benefitting 44.5 million people. He explained that drought-tolerant maize is not only a productivity enhancing tool but also an innovation for improving the welfare of farmers. “It reduces the probability of crop failure by 30 percent and provides an extra income to farmers at a rate of approximately $240 USD per hectare, equivalent to about nine months of food for a family at no additional cost,” he said, adding that the essence of research is taking improved genetics to farmers and impacting their lives.

He noted there is remarkable progress in maize varietal turnover in sub-Saharan Africa, pointing out particularly efforts in Ethiopia, Uganda, Zambia and Zimbabwe, where old maize varieties, some dating as far back as 1988, have been replaced with newer climate-resilient varieties. Prasanna highlighted the need to engage with policy makers to put in place appropriate legislation that can accelerate replacement of old or obsolete varieties with improved genetics.

Prasanna stressed on the importance of rapid response to transboundary diseases and insect-pests. CIMMYT has established fall armyworm (FAW) screening facility at Kiboko, Kenya, and that more than 10,000 maize germplasm entries have been screened over the last three years. He applauded South Sudan for being the first country in sub-Saharan Africa to recently release three CIMMYT-developed FAW-tolerant hybrids. He said CIMMYT’s FAW-tolerant inbred lines have been shared with 92 institutions, both public and private, in 34 countries globally since 2018.

Kevin Pixley, CIMMYT Global Genetic Resources Director and Deputy Director General, Breeding and Genetics, encouraged the participants to continuously reflect on making innovative contributions through the AGG project, to serve smallholder farmers and other stakeholders, and to offer sustainable solutions to the food crisis that plagues the world.

B.M. Prasanna addresses partners at the KALRO Kiboko Research station in Kenya during an AGG field visit. (Photo: Dokta Jonte Photography)

Synergies across crops and teams

Pixley pointed out that though the meeting’s focus was on maize, the AGG Project has both maize and wheat components, and the potential for learning between the maize and wheat teams would benefit many, especially with the innovative strides in research from both teams.

Pixley referenced a recent meeting in Ethiopia with colleagues from the International Institute of Tropical Agriculture (IITA), the International Center for Tropical Agriculture (CIAT) and CIMMYT, where discussions explored collaboration among CGIAR centers and other stakeholders in strengthening work on cowpea, chickpea, beans, sorghum, millet and groundnut crops. He noted that maize, wheat and the aforementioned crops are all critical in achieving the mission of CGIAR.

“CIMMYT has been requested, since August of last year, by CGIAR to initiate research projects on sorghum, millet and groundnut because these crops are critical to the success of achieving the mission of CGIAR,” said Pixley. “So, we have recently initiated work on the Accelerated Varietal Improvement and Seed Systems in Africa (AVISA) project together with partners. This is the first step towards OneCGIAR. It’s about synergies across crops and teams.”

Collaborative research commended

The meeting’s Chief Guest, Felister Makini, Deputy Director General – Crops of the Kenya Agricultural and Livestock Research Organisation (KALRO), commended the collaborative research undertaken by CIMMYT and other CGIAR partners. She noted that the partnerships continue to build on synergies that strengthen institutional financial, physical and human resources. She attested that collaboration between KALRO and CGIAR dates back to the 1980s, beginning with training in maize breeding, and then subsequent collaboration on developing climate-adaptive improved maize varieties and training of KALRO technicians in maize lethal necrosis (MLN) screening and management among other areas.

Maize and wheat are staple food sources in Kenya and sub-Saharan Africa and as the population increases, new methods and approaches must be found to accelerate development and deployment of improved maize and wheat varieties. She challenged the partners to intensify research and come out with high-yielding varieties that are resistant or tolerant to a wide range of biotic and abiotic stresses.

The Inaugural Session also featured remarks from the representatives of the AGG funders – Gary Atlin from the Bill & Melinda Gates Foundation, Jonna Davis from the Foundation for Food and Agriculture Research (FFAR), and John Derera from IITA, an AGG project partner.

A total of 116 participants, including representatives from National Agricultural Research Systems (NARS) in 13 AGG-Maize partner countries in Africa and seed companies, participated in the meeting. Participants also visited the KALRO-CIMMYT MLN Screening Facility at Naivasha, and KALRO-CIMMYT maize experiments at Kiboko, Kenya, including the work being done at the maize doubled haploid and FAW facilities.

MAIZE partners announce a new manual for effectively managing maize lethal necrosis (MLN) disease

Written by Sarah McLaughlin on April 11, 2022. Posted in Features.

For a decade, scientists at the International Maize and Wheat Improvement Center (CIMMYT) have been at the forefront of a multidisciplinary and multi-institutional effort to contain and effectively manage maize lethal necrosis (MLN) disease in Africa.

When the disease was first reported in Kenya 2011 it spread panic among stakeholders. Scientists soon realized that almost all commercial maize varieties in Africa were susceptible. What followed was a superlative effort coordinated by the CGIAR Research Program on Maize (MAIZE) to mobilize “stakeholders, resources and knowledge” that was recently highlighted in an external review of program.

The publication of Maize Lethal Necrosis (MLN): A Technical Manual for Disease Management builds on the partnerships and expertise accrued over the course of this effort to provide a comprehensive “guide on best practices and protocols for sustainable management of the MLN.”

The manual is relevant to stakeholders in countries where MLN is already present, and also aims to offer technical tips to “‘high-risk’ countries globally for proactive implementation of practices that can possibly prevent the incursion and spread of the disease,” writes B.M. Prasanna, director of CIMMYT’s Global Maize Program and MAIZE, in the foreword.

“While intensive multi-disciplinary and multi-institutional efforts over the past decade have helped in containing the spread and impact of MLN in sub-Saharan Africa, we cannot afford to be complacent. We need to continue our efforts to safeguard crops like maize from devastating diseases and insect-pests, and to protect the food security and livelihoods of millions of smallholders,” says Prasanna, who is presently leading the OneCGIAR Plant Health Initiative Design Team.

A handful of improved maize seed from the drought-tolerant variety TAN 250, developed and registered for sale in Tanzania through CIMMYT's Drought Tolerant Maize for Africa (DTMA) project, in partnership with Tanzanian seed company Tanseed International Limited. It is based on material from CIMMYT-Zimbabwe, CIMMYT-Mexico, and Tanzania. (Photo: Anne Wangalachi/CIMMYT)

MAIZE delivers “valuable solutions” for critical needs, according to an external review

Written by Steven M on January 26, 2021. Posted in News.

The CGIAR Research Program on Maize (MAIZE) “uniquely fills a gap at the global and regional level, positioning it to continue catalyzing good science across borders,” according to a new report.

Commissioned by the CGIAR Advisory Services Shared Secretariat (CAS Secretariat), the report assesses the research-for-development program’s achievements and operations over the course of its second phase, from 2017-2019.

The reviewers commend MAIZE’s “valuable” technology transfer in the areas of double haploid production and stress-tolerance phenotyping, as well as its “proactive and productive” incorporation of crosscutting gender and youth focused issues in major projects such as Stress Tolerant Maize for Africa (STMA). They note that climate change is “central to all that the [program] is doing.”

In addition to the exceptional quality of the program’s scientific inputs and the overall quality of its outputs, the reviewers note the program’s capacity to mobilize “stakeholders, resources and knowledge to rapidly deliver valuable solutions for a critical need.” The review authors specifically note MAIZE’s efforts towards halting the spread of maize lethal necrosis (MLN).

While, like all CGIAR Research Programs, MAIZE is due to conclude at the end of 2021, much of the program’s pioneering work will continue under new guises, such as the Accelerating Genetic Gains in Maize and Wheat for Improved Livelihoods (AGG) project.

“As we move towards the implementation of One CGIAR, MAIZE’s expertise in increasing genetic gains in tropical and sub-tropical, stress-prone environments through the integration of advanced breeding methodologies, a strong phenotyping network for various abiotic and biotic stresses, improved agronomic practices, and a rich network of public-private partnerships for scaling and deploying climate resilient improved maize varieties in Africa, Asia and Latin America — not to mention its capacity to respond quickly and successfully to devastating transboundary diseases and pests through multidisciplinary and multi-institutional initiatives — will be extremely valuable,” says B.M. Prasanna, director of MAIZE and of the International Maize and Wheat Improvement Center’s (CIMMYT) Global Maize Program.

MAIZE — led by CIMMYT in partnership with the International Institute of Tropical Agriculture (IITA) — spearheads international, multi-stakeholder research for development to improve the livelihoods and food security of poor maize producers and consumers. It simultaneously seeks to strengthen the sustainability of maize-based agri-food systems. The program focuses on maize production in low- to middle-income countries — accounting for approximately two-thirds of global maize production — where the crop is “key to the food security and livelihoods of millions of poor famers,” according to the report.

“MAIZE provides a very robust platform for collaboration with our national partners, including private companies, community seed produces and other stakeholders. Through projects such as Drought Tolerant Maize for Africa (DTMA) and STMA, research has been able to provide innovative solutions to challenges that smallholder farmers face in their daily lives, such as drought, poor soils, and pests and diseases,” says Nteranya Sanginga, IITA’s Director General.

The review concludes that MAIZE “good management and governance practice are a strong foundation for the remainder of [the program’s] running.” The reviewers also recommend that the “excellent,” participatory application of theory of change thinking in the second phase of MAIZE be mainstreamed at the CGIAR system level moving forward. Key recommendations for the program’s final phase include:

Building on MAIZE’s “strong network of partners” by deepening these relationships into “multidirectional partnerships.”
Building on existing cross-cutting work on capacity development, climate change, gender and youth.
Diversifying and expanding MAIZE’s knowledge dissemination efforts to more deeply engage with include multiple and non-scientific audiences.

To read more, see the report summary or visit the CGIAR Advisory Services page.

Researchers and visitors listen to explanations during a tour of infected maize fields at the MLN screening facility in Naivasha, Kenya. (Photo: CIMMYT)

Fast-tracked adoption of second-generation resistant maize varieties key to managing maize lethal necrosis in Africa

Written by Rodrigo Ordóñez on January 19, 2021. Posted in Features.

Scientists are calling for accelerated adoption of new hybrid maize varieties with resistance to maize lethal necrosis (MLN) disease in sub-Saharan Africa. In combination with recommended integrated pest management practices, adopting these new varieties is an important step towards safeguarding smallholder farmers against this devastating viral disease.

A new publication in Virus Research shows that these second-generation MLN-resistant hybrids developed by the International Maize and Wheat Improvement Center (CIMMYT) offer better yields and increased resilience against MLN and other stresses. The report warns that the disease remains a key threat to food security in eastern Africa and that, should containment efforts slacken, it could yet spread to new regions in sub-Saharan Africa.

The publication was co-authored by researchers at the International Maize and Wheat Improvement Center (CIMMYT), Kenya Agricultural and Livestock Research Organization (KALRO), the Alliance for a Green Revolution in Africa (AGRA), the African Agricultural Technology Foundation (AATF) and Aarhus University in Denmark.

CIMMYT technician Janet Kimunye (right) shows visitors a plant with MLN symptoms at the MLN screening facility in Naivasha, Kenya. (Photo: CIMMYT)

Stemming the panic

The first reported outbreak of MLN in Bomet County, Kenya in 2011 threw the maize sector into a panic. The disease caused up to 100% yield loss. Nearly all elite commercial maize varieties on the market at the time were susceptible, whether under natural of artificial conditions. Since 2012, CIMMYT, in partnership with KALRO, national plant protection organizations and commercial seed companies, has led multi-stakeholder, multi-disciplinary efforts to curb MLN’s spread across sub-Saharan Africa. Other partners in this endeavor include the International Institute of Tropical Agriculture (IITA), non-government organizations such as AGRA and AATF, and advanced research institutions in the United States and Europe.

In 2013 CIMMYT established an MLN screening facility in Naivasha. Researchers developed an MLN-severity scale, ranging from 1 to 9, to compare varieties’ resistance or susceptibility to the disease. A score of 1 represents a highly resistant variety with no visible symptoms of the disease, while a score of 9 signifies extreme susceptibility. Trials at this facility demonstrated that some of CIMMYT’s pre-commercial hybrids exhibited moderate MLN-tolerance, with a score of 5 on the MLN-severity scale. CIMMYT then provided seed and detailed information to partners for evaluation under accelerated National Performance Trials (NPTs) for varietal release and commercialization in Kenya, Tanzania and Uganda.

Between 2013 and 2014, four CIMMYT-derived MLN-tolerant hybrid varieties were released by public and private sector partners in East Africa. With an average MLN severity score of 5-6, these varieties outperformed commercial MLN-sensitive hybrids, which averaged MLN severity scores above 7. Later, CIMMYT breeders developed second-generation MLN-resistant hybrids with MLN severity scores of 3–4. These second-generation hybrids were evaluated under national performance trials. This led to the release of several hybrids, especially in Kenya, over the course of a five-year period starting in 2013. They were earmarked for commercialization in East Africa beginning in 2020.

Maize Lethal Necrosis (MLN) sensitive and resistant hybrid demo plots in Naivasha’s quarantine & screening facility (Photo: KIPENZ/CIMMYT)

Widespread adoption critical

The last known outbreak of MLN was reported in 2014 in Ethiopia, marking an important break in the virus’s spread across the continent. Up to that point, the virus had affected the Democratic Republic of the Congo, Kenya, Rwanda, Tanzania and Uganda. However, much remains to be done to minimize the possibility of future outbreaks.

“Due to its complex and multi-faceted nature, effectively combating the incidence, spread and adverse effects of MLN in Africa requires vigorous and well-coordinated efforts by multiple institutions,” said B.M. Prasanna, primary author of the report and director of the Global Maize Program at CIMMYT and of the CGIAR Research Program on Maize (MAIZE). Prasanna also warns that most commercial maize varieties being cultivated in eastern Africa are still MLN-susceptible. They also serve as “reservoirs” for MLN-causing viruses, especially the maize chlorotic mottle virus (MCMV), which combines with other viruses from the Potyviridae family to cause MLN.

“This is why it is very important to adopt an integrated disease management approach, which encompasses extensive adoption of improved MLN-resistant maize varieties, especially second-generation, not just in MLN-prevalent countries but also in the non-endemic ones in sub-Saharan Africa,” Prasanna noted.

The report outlines other important prevention and control measures including: the production and exchange of “clean” commercial maize seed with no contamination by MLN-causing viruses; avoiding maize monocultures and continuous maize cropping; practicing maize crop rotation with compatible crops, especially legumes, which do not serve as hosts for MCMV; and continued MLN disease monitoring and surveillance.

L.M. Suresh (center-right), Maize Pathologist at CIMMYT and Head of the MLN Screening Facility, facilitates a training on MLN with national partners. (Photo: CIMMYT)

Noteworthy wins

In addition to the development of MLN-resistant varieties, the fight against MLN has delivered important wins for both farmers and their families and for seed companies. In the early years of the outbreak, most local and regional seed companies did not understand the disease well enough to produce MLN-pathogen free seed. Since then, CIMMYT and its partners developed standard operating procedures and checklists for MLN pathogen-free seed production along the seed value chain. Today over 30 seed companies in Ethiopia, Kenya, Uganda, Rwanda and Tanzania are implementing these protocols on a voluntary basis.

“MLN represents a good example where a successful, large-scale surveillance system for an emerging transboundary disease has been developed as part of a rapid response mechanism led by a CGIAR center,” Prasanna said.

Yet, he noted, significant effort and resources are still required to keep the maize fields of endemic countries free of MLN-causing viruses. Sustaining these efforts is critical to the “food security, income and livelihoods of resource-poor smallholder farmers.

To keep up with the disease’s changing dynamics, CIMMYT and its partners are moving ahead with novel techniques to achieve MLN resistance more quickly and cheaply. Some of these innovative techniques include genomic selection, molecular markers, marker-assisted backcrossing, and gene editing. These techniques will be instrumental in developing elite hybrids equipped not only to resist MLN but also to tolerate rapidly changing climatic conditions.

Read the full report on Virus Research:
Maize lethal necrosis (MLN): Efforts toward containing the spread and impact of a devastating transboundary disease in sub-Saharan Africa

Cover photo: Researchers and visitors listen to explanations during a tour of infected maize fields at the MLN screening facility in Naivasha, Kenya. (Photo: CIMMYT)

A farmer in Tanzania holds a handful of drought-tolerant maize seed. (Photo: Anne Wangalachi/CIMMYT)

Molecular breeding speeds development of better seeds

Written by Emma Orchardson on November 27, 2020. Posted in Features.

To adequately confront rapidly changing plant pests and diseases and safeguard food security for a growing population, breeders — in collaboration with their partners — have to keep testing and applying new breeding methods to deliver resilient seed varieties at a much faster rate using minimal resources. Molecular markers are essential in this regard and are helping to accelerate genetic gains and deliver better seed to smallholders across sub-Saharan Africa in a much shorter timeframe.

Progress made so far in molecular plant breeding, genetics, genomic selection and genome editing has contributed to a deeper understanding on the role of molecular markers and greatly complemented breeding strategies. However, phenotyping remains the single most costly process in plant breeding, thus limiting options to increase the size of breeding programs.

Application of molecular markers increases the ability to predict and select the best performing lines and hybrids, prior to selection in the field. “This enables breeders to expand the size of a breeding program or the populations they work on using the same amount of resources,” says Manje Gowda, a maize molecular breeder at the International Maize and Wheat Improvement Center (CIMMYT).

“There are three stages in the use of molecular markers: discovery, validation and deployment,” he explains. “At the discovery phase, the objective is to find molecular markers associated or tightly linked with the trait of interest, while also assessing whether the trait is more complex or easier to handle with few markers for selection.”

The molecular markers identified at the discovery stage are validated in independent bi-parental or backcross populations, and the marker trait associations — which are consistent across different genetic backgrounds and diverse environments — are then moved to the deployment stage. Here, they are considered for use in breeding either as part of marker assisted selection or forward breeding, marker assisted back crossing and marker assisted recurrent selection.

Screening for resistance markers

CIMMYT scientists have discovered several marker trait associations for crop diseases including maize lethal necrosis (MLN), maize streak virus (MSV), corn rust and turcicum leaf blight. All these trait-associated markers have been validated in biparental populations.

For MLN, after screening several thousands of lines, researchers identified a few with resistance against the viral disease, namely KS23-5 and KS23-6. These lines were obtained from synthetic populations developed by Kasetsart University in Thailand and serve as trait donors. Researchers were able to use these as part of forward breeding, producing doubled haploid (DH) lines by using KS23-6 as one parent and screening for the presence of MLN resistance genes.

“This screening helps eliminate the lines that may carry susceptible genes, without having to phenotype them under artificial inoculation,” says Gowda. “These markers are also available to all partners to screen for MLN resistance, thereby saving on costs related to phenotyping.”

Scientists also used these MLN resistance markers to introgress the MLN resistance into several elite lines that are highly susceptible to the disease but have other desirable traits such as high grain yield and drought tolerance. The marker-assisted backcrossing technique was used to obtain MLN resistance from the KS23-5 and KS23-6 donor lines. This process involves crossing an elite, commercial line — as a recurrent parent in the case of CIMMYT elite lines — with a donor parent line (KS23) with MLN resistance. These were then backcrossed over two to three cycles to improve the elite line carrying MLN resistance genes. In the past three years, more than 50 lines have been introgressed with the MLN resistance gene from KS23-6 donor line.

Aida Zewdu Kebede, a PhD student at the University of Hohenheim, sits next to an experimental plot for doubled haploid maize in Agua Fría, Mexico. (Photo: Thomas Lumpkin/CIMMYT)

An impetus to breeding programs

“The work Manje Gowda has been carrying out is particularly important in that it has successfully moved from discovery of valuable markers and proof-of-concept experiments to scalable breeding methods which are being used effectively,” says CIMMYT Trait Pipeline and Upstream Research Coordinator Mike Olsen. “Enabling routine implementation of molecular markers to increase selection efficiency of breeding programs in the context of African maize improvement is quite impactful.”

At CIMMYT, Gowda’s team applied genomic selection at the early stage of testing the breeding pipeline for different product profiles. “The objective was to testcross and phenotype 50% of the Stage One hybrids and predict the performance of remaining 50% of the hybrids using molecular markers,” Gowda explains.

The team have applied this strategy successfully each year since 2017, and the results of this experiment show that selection efficiency is the same as when using phenotypic selection, but using only 32% of the resources. From 2021 onwards, the aim is to use the previous year’s Stage One phenotypic and genotypic data to predict 100% of the lines. This will not only save the time but improve efficiency and resource use. The previous three-year Stage One historical data is helping to reduce the phenotyping of lines from 50% to 15%, with an increase in saving resources of up to 50%.

For the commercial seed sector, integrating molecular marker-based quality control measures can help deploy high-quality seeds, an important factor for increasing crop yields. In sub-Saharan Africa, awareness on marker-based quality has improved due to increased scientist and breeder trainings at national agricultural research systems (NARS), seed companies and national plant protection organizations, as well as regulators and policymakers.

Currently, many NARS and private sector partners are making it mandatory to apply marker-based quality control to maintain high-quality seeds. Since NARS and small- and medium-sized seed companies’ breeding programs are smaller, CIMMYT is coordinating the collection of samples from different partners for submission to service providers for quality control purposes. CIMMYT staff are also helping to analyze quality control data and interpret results to sharing with partners for decision-making. For the sustainability of this process, CIMMYT is training NARS partners on quality control, from sample collection to data analyses and interpretation, and this will support them to work independently and produce high-quality seed.

Such breeding improvements have become indispensable in supporting maize breeding programs in the public and private sectors to develop and deliver improved maize varieties to smallholder farmers across sub-Saharan Africa.

A farmer in Tanzania stands in front of her maize plot where she grows improved, drought tolerant maize variety TAN 250. (Photo: Anne Wangalachi/CIMMYT)

Efforts in controlling maize disease boosting steady supply of certified seeds

Written by Mary Donovan on October 5, 2020. Posted in In the media.

Efforts towards managing the Maize Lethal Necrosis (MLN), a viral disease affecting maize, have contributed to reducing seed production losses from 33 per cent to 16 per cent in the last four years, bolstering steady supply of maize seeds in the Eastern African region.

Unique partnership to transform maize breeding and production in Africa

Written by Marta Millere on August 26, 2020. Posted in Features.

Scientists part of the Seed Production Technology for Africa (SPTA) and the Maize Lethal Necrosis Gene Editing projects are leveraging innovative technologies to transform seed production systems and speed up the delivery of disease resistance in elite new hybrids. This research is helping smallholder farmers in sub-Saharan Africa to access high-quality seed of new hybrids that were bred to perform under stressful low-input, drought-prone conditions, including farming regions impacted by maize lethal necrosis (MLN).

Fast delivery of MLN-tolerant varieties

The fight against maize lethal necrosis (MLN) has persisted for almost ten years now.

Collaborative efforts in diagnostics, management and systematic surveillance have limited its spread and confined the disease to the eastern Africa region. However, ongoing work is required to efficiently develop MLN-tolerant varieties for smallholders in endemic areas and prepare for the potential further movement of the disease.

“Maize lethal necrosis still exists. It has not been eradicated. Even though it has reduced in its prevalence and impact, it is still present and is a latent threat in Ethiopia, Kenya, Rwanda, Tanzania and Uganda, with potential to spread further,” said B.M. Prasanna, director of CIMMYT’s Global Maize Program and the CGIAR Research Program on Maize.

“That is why the work of the gene editing project is critical to rapidly change the genetic component of those susceptible parent lines of popular hybrids into MLN-tolerant versions,” said Prasanna. Scientists will edit the four parent lines of two popular hybrids, currently grown by farmers in Kenya and Uganda, which are susceptible to MLN. The edited MLN-tolerant lines will be used to make MLN-tolerant versions of these drought-tolerant hybrids.

Through gene editing technology, the time it takes to develop hybrids using traditional breeding methods will be cut in half. By 2025, the edited MLN-tolerant hybrids will be available for planting on approximately 40,000 hectares by about 20,000 Kenyan farmers.

A non-pollen-producing maize plant (on the left) on farm trial in Zimbabwe. (Photo: Jill Cairns/CIMMYT)

Business as unusual

The unique seed production technology developed by Corteva Agriscience seeks to transform the seed production process in sub-Saharan Africa. This technology utilizes a dominant non-pollen producing maize gene to create female plants that are unable to produce pollen.

Seed companies that use seed production technology eliminate the need to detassel the female parent: a manual process through which tassels are removed from plants to prevent self-pollination and ensure that the intended male parent is the only source of pollen in the hybrid seed production field. Targeted small and medium-size seed companies could make significant savings to the cost of production if they were to eliminate manual detasseling. The method also helps to ensure the purity of the hybrid seed by removing the risk of unintentional self-pollination.

Hybrids produced using the seed production technology, characterized as 50 percent non-pollen producing (FNP), are unique since only half of the plants will produce pollen in the field. FNP hybrids re-allocate energy from the tassel and pollen production to grain formation, thus delivering an additional 200 kilograms per hectare yield advantage to the farmer. This represents a 10 percent productivity boost for farmers who will harvest approximately 2 tons per hectare, the average maize yield across sub-Saharan Africa. Farmers engaged in participatory research have demonstrated preference for FNP hybrids and associate the trait with higher yield and larger ear size.

As the first phase of Seed Production Technology for Africa (SPTA) wraps up, the collaborators are preparing for the next phase that will focus on commercializing, scaling up and increasing smallholders’ access to FNP. “This is among the unique partnerships funded by the foundation and I am hopeful that this incredible work will continue through the next phase,” said Gary Atlin, program officer at the Bill & Melinda Gates Foundation.

Resistant hybrid (on the right) grows beside a susceptible commercial check at the Kenya Plant Health Inspectorate Services' (KEPHIS) National Performance Trial. (Photo: CIMMYT) — Resistant hybrid (on the right) grows beside a susceptible commercial check at the Kenya Plant Health Inspectorate Services’ (KEPHIS) National Performance Trial. (Photo: CIMMYT)

A win-win collaboration

Research and development work under the SPTA and the MLN Gene Editing projects has immensely benefited from the support of public and private partners. Seed companies and national institutions have contributed to improving access to and knowledge of these technologies as well as creating a crucial link with farmers. Ongoing engagement with regulatory agencies through the different stages of the projects ensures transparency and fosters understanding.

In order to assess the progress of these two initiatives, representatives from regulatory agencies, seed trade associations, seed companies, national agricultural institutions and funders came together for a virtual meeting that was hosted on July 29, 2020.

“KALRO embraces partnerships such as those that are delivering these two projects. That synergy helps us to resolve challenges faced by farmers and other actors in various agricultural value chains,” observed Felister Makini, deputy director general of Crops at KALRO.

As the primary technology provider, Corteva Agriscience provides the seed production technology system on a royalty-free basis and grants access to key gene editing technologies, which are the foundation for the two projects. Corteva Agriscience is also actively involved in project execution through collaborative scientific support.

“We have appreciated the opportunity to work with CIMMYT, KARLO, Agricultural Research Council (ARC) of South Africa and the Bill & Melinda Gates Foundation to bring some of the technologies and tools from Corteva to address significant challenges facing smallholder farmers in Africa. We could not have done this alone, it requires the partnerships that exist here to bring forth these solutions,” said Kevin Diehl, director of the Global Seed Regulatory Platform at Corteva Agriscience.

Agency unveils seed resistant to disease

Written by Mary Donovan on August 16, 2020. Posted in In the media.

For more than a decade, Maize Lethal Necrosis Disease (MLND) has ravaged crops causing farmers to incur huge losses and threatening food security.

Kenya Seed Company (KSC) researchers through partnerships have developed a superior maize variety that can withstand the disease.

Fight against viruses, also in defense of maize and our food

Written by Mary Donovan on May 31, 2020. Posted in In the media.

A first outbreak of maize lethal necrosis was found in Kenya in 2011 and researchers immediately became active because they knew that timely action was needed to prevent irreparable damage. This viral disease was decimating maize fields and spreading rapidly in east Africa through contaminated insects and seeds.

A worker at the Naivasha MLN research station conducts a mock inoculation (Photo: Joshua Masinde/CIMMYT)

Battling devastating viral diseases, also in plants

Written by Jennifer Johnson on May 28, 2020. Posted in Features.

When a maize lethal necrosis (MLN) outbreak happened in Kenya in 2011, scientists knew they needed to act fast. This viral disease, new to Kenya, was decimating maize fields. Within a few years, the viral disease spread rapidly in eastern Africa, through both insect vectors and contaminated seeds. If the virus were to spread into southern or West Africa, it would spell disaster for the smallholder farmers across the continent who depended on maize as a staple crop and for their family’s income and livelihoods.

The International Maize and Wheat Improvement Center (CIMMYT) and its partners immediately took action to impose a strict seed quarantine and restrict the movement of seed between eastern Africa and other regions in Africa. In addition, they worked intensively on developing and disseminating improved maize cultivars with tolerance or resistance to MLN, undertook extensive surveillance efforts, and sensitized partners on the importance of producing and commercializing MLN-free seed.

Due to these efforts, in the last nine years MLN has not been reported in sub-Saharan Africa outside of eastern Africa.

On the occasion of a recent publication on Virus Research about how MLN was contained, we interviewed B.M. Prasanna, director of the Global Maize Program at CIMMYT and the CGIAR Research Program on Maize (MAIZE), to discuss the MLN success story, the global COVID-19 crisis, and the similarities in the challenge to tackle plant and human viral diseases.

B.M. Prasanna, Director of the Global Maize Program at CIMMYT and the CGIAR Research Program on Maize (MAIZE). (Photo: Alfonso Cortés/CIMMYT)

What were some of the extreme measures CIMMYT had to take to stop the spread of MLN?

The first step that we had to take in the fight against MLN was to rigorously analyze seed for any possible contamination with MLN-causing viruses and restrict movement of seed from eastern Africa to southern Africa.

The second most important step was to sensitize the national partners and the commercial seed sector about the danger of seed contamination with MLN-causing viruses, and how seed contamination can lead to the proliferation or spread of the disease.

The third important step was to build a new MLN quarantine facility in Zimbabwe, in partnership with the National Plant Quarantine Institute. Only when that quarantine facility was functional in 2017, we reinitiated transfer of research material from CIMMYT’s breeding hub in Kenya to CIMMYT in Zimbabwe. Only when the materials were certified to be MLN-free both in Kenya and Zimbabwe, through plant-by-plant analysis using immunodiagnostic kits, the seed was multiplied and further distributed to partners. So, the principle of containment and effective management is extremely important, whether it is a plant viral disease or a human viral disease.

We must note here that in terms of scale and intensity, as well as global effects and implications, any plant disease, including MLN, cannot be compared with a pandemic like COVID-19, which has affected every aspect of our lives.

How do you think the COVID-19 pandemic is going to impact our food systems?

We are indeed in a grim situation. The pandemic will undoubtedly have a serious effect on food security.

Many countries which do not have enough food reserves or those where the food systems are vulnerable to shocks like this are suffering. The people’s capacity to procure inputs for agriculture, including seed, is going to be affected too, as the markets are affected. This is really a serious situation that we all should be concerned about. The CGIAR has an important role to play, in terms of working closely with national partners and mitigating the impact of COVID-19 on agriculture.

We should be particularly worried about farmers, especially smallholder farmers, who are quite vulnerable to the ongoing challenge. Even without COVID-19, agriculture in many developing countries worldwide has been already under distress. Small and marginal farmers were often unable to find a market for their produce and earn sufficient income to support their families. Their livelihoods are fragile, and vulnerable to climate change and volatile market prices. The ongoing COVID-19 crisis is unfortunately compounding the crisis.

What lessons can agricultural research learn from this pandemic?

What do these pandemics or epidemics teach us? They remind us that systems need to be in place to prevent the proliferation of such diseases, whether it is plant diseases or animal diseases or human diseases. No country can be considered completely safe, and such diseases do not discriminate between a developed and a developing country, or the rich and the poor.

The second most important lesson is emergency preparedness. Whenever such devastating transboundary viral diseases show up, how quickly the country can respond — containing that infected area and not allowing the disease to spread, and then mitigating the damage systematically and quickly — is key. This is not the first time that a disease like MLN has emerged. There could be more serious viral or fungal diseases that could emerge in the future due to various reasons, including changing climates, international trade, movement of human beings, air currents, etc. There are multiple ways that diseases can go across continents, across countries within a continent, and within countries. Therefore, the key is how well we can capacitate the national systems to be able to proactively prevent, detect, and intervene very fast.

Another big lesson here for agricultural systems is that a problem that happens in some other continent cannot be ignored because you work in a different continent. What COVID-19 shows is that the world is far more connected than we think.

CIMMYT team members check for traces of the maize chlorotic mottle virus (MCMV) in maize plants during a visit to the MLN screening facility in Naivasha, Kenya. (Photo: Joshua Masinde/CIMMYT)

For you, what is the biggest takeaway from the MLN success story?

I won’t say it is still a complete success. Through intensive partnerships and efforts, we were able to prevent the disease from devastating maize production in millions of smallholder farmers’ fields in sub-Saharan Africa. Since 2014, there has been no new country in Africa — outside eastern Africa — that has reported an outbreak of MLN. That, to me, is a tremendous success.

The work is still not over. The journey has to continue. And we still need to make sure that countries are continuously protected from devastating diseases like MLN. MLN is still not eradicated from eastern Africa. It may not be even possible to completely eradicate this disease, as the two viruses that together cause it can survive not just on maize but on multiple grasses. We can however contain the disease and limit its impact through continued efforts, like what we have done for the past 7 or 8 years. But if we lower our guard, there is a very high likelihood that the disease can still spread to other countries in sub-Saharan Africa, especially the major maize-growing countries in southern Africa or West Africa. Efforts need to continue. So, let us continue to maintain a high vigil to protect the smallholders in Africa from transboundary diseases like MLN.

Read the full article on Virus Research:
Maize lethal necrosis (MLN): Efforts toward containing the spread and impact of a devastating transboundary disease in sub-Saharan Africa

Maize plants at the MLN screening facility in Naivasha, Kenya. (Photo: Jennifer Johnson/CIMMYT)

Screening cycle for deadly MLN virus set to begin in Kenya in January 2020

Written by Rodrigo Ordóñez on December 9, 2019. Posted in News.

The maize lethal necrosis (MLN) artificial inoculation screening site in Naivasha, Kenya, will begin its phenotyping (screening/indexing) cycle of 2020 at the beginning of January 2020, which will continue in four other intervals throughout the year. Interested organizations from both the private and public sectors are invited to send maize germplasm for screening.

In 2013, the International Maize and Wheat Improvement Center (CIMMYT) and the Kenya Agricultural & Livestock Research Organization (KALRO) jointly established the MLN screening facility at the KALRO Naivasha research station in Kenya’s Rift Valley, with support from the Bill & Melinda Gates Foundation and the Syngenta Foundation for Sustainable Agriculture.

MLN was first discovered in Kenya in 2011 and quickly spread to other parts of eastern Africa. The disease causes premature plant death and unfilled, poorly formed maize cobs, which can lead to up to 100% yield loss in farmers’ fields.

CIMMYT and partners are dedicated to stopping the spread of this deadly maize disease by effectively managing the risk of MLN on maize production through screening and identifying MLN-resistant germplasm. The MLN screening facility supports countries in sub-Saharan Africa to screen maize germplasm — for hybrid, inbred and open pollinated varieties — against MLN in a quarantined environment.

This is the largest dedicated MLN screening facility in East Africa. Since its inception in 2013, the facility has evaluated more than 200,000 accessions — more than 300,000 rows of maize — from more than 15 multinational and national seed companies and national research programs.

Partners can now plan for annual MLN phenotyping (screening/indexing) during 2020 with the schedule below. The improved and streamlined approach for MLN phenotyping should enable partners to accelerate breeding programs to improve resistance for MLN for sub-Saharan Africa.

2020 annual phenotyping (indexing/screening) schedule:

When the seeds are available	Planting period (planned)	MLN Screening / Indexing
December	Second week of January	MLN Indexing
March	Second week of April	MLN Screening
June	Second week of July	MLN Indexing
August	Second week of September	MLN Screening
October	Second week of November	MLN Indexing

More information about the disease and resources for farmers can be found on CIMMYT’s MLN portal.

Please note that it can take up to six weeks to process imports and clear shipments.

For assistance in obtaining import permits and necessary logistics for the upcoming screening, please contact:

L.M. Suresh
Tel.: +254 20 7224600 (direct)
Email: l.m.suresh@cgiar.org

CIMMYT–Kenya, ICRAF House
United Nations Avenue, Gigiri
P.O. Box 1041–00621
Nairobi, Kenya.