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.
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.
International scientists are working with regional and national partners in sub-Saharan Africa to catalyze local wheat farming and help meet the rapidly rising regional demand for this crop.
The specialists are focusing on smallholder farmers in Rwanda and Zambia, offering them technical and institutional support, better links to markets, and the sharing of successful practices across regions and borders, as part of the project “Enhancing smallholder wheat productivity through sustainable intensification of wheat-based farming systems in Rwanda and Zambia.”
“Work started in 2016 and has included varietal selection, seed multiplication, and sharing of high-yielding, locally adapted, disease-resistant wheat varieties,” said Moti Jaleta, a socioeconomist at the International Maize and Wheat Improvement Center (CIMMYT) who leads the project. “Our knowledge and successes in smallholder wheat production and marketing will also be applicable in Madagascar, Mozambique, and Tanzania.”
Harvesting wheat at Gataraga, Northern Province, Rwanda.
Maize is by far the number-one food crop in sub-Saharan Africa but wheat consumption is increasing fast, driven in part by rapid urbanization and life-style changes. The region annually imports more than 15 million tons of wheat grain, worth some US$ 3.6 billion at current prices. Only Ethiopia, Kenya, and South Africa grow significant amounts of wheat and they are still net importers of the grain.
“Growing more wheat where it makes sense to do so can help safeguard food security for people who prefer wheat and reduce dependence on risky wheat grain markets,” Jaleta explained. “We’re working in areas where there’s biophysical potential for the crop in rain-fed farming, to increase domestic wheat production and productivity through use of improved varieties and cropping practices.”
In addition to the above, participants are supporting the region’s wheat production in diverse ways:
Recommendations to fine-tune smallholder wheat value chains and better serve diverse farmers.
Testing of yield-enhancing farming practices, such as bed-and-furrow systems that facilitate efficient sowing and better weed control.
Testing and promotion of small-scale mechanization, such as power tillers, to save labor and improve sowing and crop establishment.
Exploring use of hand-held light sensors to precisely calibrate nitrogen fertilizer dosages throughout the cropping season.
Innocent Habarurema, wheat breeder in the Rwanda Agriculture and Animal Resources Development Board (RAB), cited recent successes in the release of improved, disease resistant wheat varieties, as well as engaging smallholder farmers in seed multiplication and marketing to improve their access to quality seed of those varieties.
“The main challenge in wheat production is the short window of time between wheat seasons, which doesn’t allow complete drying of harvested plants for proper threshing,” Habarurema explained. “Suitable machinery to dry and thresh the wheat would remove the drudgery of hand threshing and improve the quality of the grain, so that it fetches better prices in markets.”
Millers, like this one in Rwanda, play a key role in wheat value chains.
Critical wheat diseases in Zambia include spot blotch, a leaf disease caused by the fungus Cochliobolus sativus, and head blight caused by Fusarium spp., which can leave carcinogenic toxins in the grain, according to Batiseba Tembo, wheat breeder at the Zambian Agricultural Research Institute (ZARI).
“Developing and disseminating varieties resistant to these diseases is a priority in the wheat breeding program at Mt. Makulu Agricultural Research Center,” said Tembo. “We’re also promoting appropriate mechanization for smallholder farmers, to improve wheat production and reduce the enormous drudgery of preparing the soil with hand hoes.”
Participants in the project, which runs to 2020, met at Musanze, in Rwanda’s Northern Province, during February 5-7 to review progress and plan remaining activities, which include more widespread sharing of seed, improved practices, and other useful outcomes.
“There was interest in trying smallholder winter wheat production under irrigation in Zambia to reduce the disease effects normally experienced in rainfed cropping,” said Jaleta, adding that the costs and benefits of irrigation, which is rarely used in the region, need to be assessed.
Project participants may also include in selection trials wheat varieties that have been bred to contain enhanced grain levels of zinc, a key micronutrient missing in the diets of many rural Africa households.
“The project will also push for the fast-track release and seed multiplication of the best varieties, to get them into farmers’ hands as quickly as possible,” Jaleta said.
In addition to CIMMYT, RAB, and ZARI, implementing partners include the Center for Coordination of Agricultural Research and Development for Southern Africa (CCARDESA). Generous funding for the work comes from the International Fund for Agricultural Development (IFAD) and the CGIAR Research Program on Wheat.
NAIROBI, Kenya (CIMMYT) — When maize lethal necrosis (MLN) was first reported in Bomet County, Kenya, in September 2011 and spread rapidly to several countries in eastern Africa, agricultural experts feared this emerging maize disease would severely impact regional food security. However, a strong partnership across eight countries between maize research, plant health organizations and the private seed sector has, so far, managed to contain this devastating viral disease, which can wipe out entire maize fields. As another emerging pest, the fall armyworm, is making headlines in Africa, African countries could learn a lot from the initiatives to combat MLN on how to rapidly respond to emerging crop pests and diseases.
On November 19-20, 2018, the International Maize and Wheat Improvement Center (CIMMYT), national research and plant protection agencies and seed companies met in Nairobi to review the third year’s progress of the MLN Diagnostics and Management Project, supported by USAID. All participants agreed that preventing any spread of the disease into southern Africa was a great success.
“The fact that we all responded rapidly and productively to this crisis serves as a testament of the success of our collective efforts,” said CIMMYT’s Global Maize Program Director, B.M. Prasanna, while addressing delegates from Ethiopia, Kenya, Malawi, Rwanda, Tanzania, Uganda, Zambia and Zimbabwe. “That no new country has reported the MLN outbreak since Ethiopia last reported it in the 2014-2015 period, and that we have managed to keep it at bay from southern Africa and west Africa is no mean feat. It would have been a major food security disaster if the disease had spread throughout sub-Saharan Africa.”
However, the MLN Community of Practice warned that risks of severe outbreaks remain, with new cases of MLN reported during the MLN 2018 survey in several parts of Uganda.
Delegates from Rwanda discuss the country’s workplan at the 3-year MLN project review. (Photo: Joshua Masinde/CIMMYT)
Rapid response to a food security threat
MLN is caused by the combination of the maize chlorotic mottle virus (MCMV) and other common cereal viruses mostly from the potyviridae family — a set of viruses that encompasses over 30 percent of known plant viruses — like the sugarcane mosaic virus (SCMV). This viral disease can result in up to 100 percent yield loss and has devastated the incomes and food security situation of many smallholder farmers in the region.
CIMMYT, in collaboration with national agricultural research institutions, national plant protection agencies and seed sector partners, developed a multi-layered response system including real-time intensive surveillance, screening, and fast-tracking of the MLN resistance breeding program. Thanks to the MLN Screening Facility in Naivasha, Kenya, maize breeders rapidly discovered that most popular maize varieties were susceptible, which could expose poor farmers to the risk of losing their entire maize crops.
Using its global collection of maize lines and numerous crop improvement innovations, CIMMYT was able to develop and release at least 15 MLN-resistant maize varieties in just 2 to 3 years.
One important step was to understand how the disease spread. Epidemiologists quickly pointed out the necessity to work with the seed companies and farmers, as the virus could be transmitted through seeds. The project helped put in place the protocols for seed firms to adhere to for their products to be MLN-free. Affordable and simple seed treatment procedures yielded promising results. The project also created awareness on better farming methods for effective disease control.
National Plant Protection Organizations were mobilized to create intensive awareness. They were also equipped and trained on low-cost innovative field diagnostic tools like MLN immunostrips and the deployment of GPS-based mobile surveillance and reporting systems.
“For the first time, Rwanda was able to conduct a comprehensive survey on MLN in farmers’ fields, commercial seed fields and at agro-dealers. We are glad that through MLN management and awareness programs within the project, MLN incidences have declined,” said Fidele Nizeyimana, maize breeder and pathologist at the Rwanda Agricultural Board (RAB) and the MLN Surveillance team lead in Rwanda.
“Equally important is that the commercial seed sector took the responsibility of testing their seed production fields, made sure that seed exchange is done in a responsible manner and implemented voluntary monitoring and surveillance within their fields,” remarked Francis Mwatuni, MLN project manager at CIMMYT.
“I am happy that Malawi has maintained its MLN-free status as per the intensive MLN surveillance activities we conducted in the country over the last three years,” noted Johnny Masangwa, senior research officer and MLN Surveillance team lead in Malawi. “We are now able to monitor both seed and grain movement through our borders for MLN traces, courtesy of the lab equipment, reagents and training on laboratory analysis we received through the project”.
B.M. Prasanna, director of the CGIAR Research Program on Maize (MAIZE), discusses what the CGIAR offers in rapid response preparedness to newly emerging pests, diseases and crises.
The maize sector should remain vigilant
Daniel Bomet, maize breeder at Uganda’s National Agricultural Research Organization (NARO), warned that with new infections reported in the northern parts of his country, the maize sector needs to remain alert to the threat of MLN. “We need to step up MLN awareness and management programs, and require seed companies to follow the right procedures to produce MLN-free seeds to arrest this trend,” he said.
Tanzania Seed Association Executive Director, Bob Shuma, also warned that MLN could be spreading to the southern highlands of the country as the virus was detected in some seed shipments from three seed companies operating in that region. A comprehensive MLN survey in Tanzania will hopefully soon give an idea of the countrywide status of the disease in the country.
Conference speakers and participants noted that inefficient regulatory processes in maize seed variety release and deployment still stand in the way of rapid release of MLN resistant varieties to farmers across the region.
“How quickly we scale up and deploy the elite MLN-resistant and stress-tolerant varieties to the farmer is the next most important phase of the project,” Prasanna said.
The Kenya Plant Health Inspectorate Service (KEPHIS) General Manager, Phytosanitary Services, Isaac Macharia, said that with the support of the USAID Feed the Future program, the government agency has set up a team dedicated to assisting seed companies doing seed multiplication to fast-track the release of the MLN-resistant varieties to the market. Some Kenyan seed companies announced they will market MLN-resistant varieties for the next cropping season in March 2019.
As the project enters its last year, the MLN Community of Practice looks to ensure the fully functional pest surveillance and management system it has put in place is sustainable beyond the project’s life.
CIMMYT researchers Dave Hodson (left) and Francis Mwatuni (center) discuss MLN issues with another delegate during the 3-year MLN project review workshop. (Photo: Joshua Masinde/CIMMYT)
NAIROBI, Kenya (CIMMYT) — The CIMMYT family mourns the demise and honors the valuable contributions of Rwandan crop researcher Theodore Assimwe, who died on November 11, 2018.
An active and dedicated CIMMYT partner and one of eastern Africa’s most promising agricultural scientists, Assimwe was instrumental in Rwanda’s response to Maize Lethal Necrosis (MLN), coordinating pathogen surveillance and characterization and a key project for integrated management of the disease.
He was a pillar of the Rwanda Agriculture Board (RAB), with a well-recognized research track record in maize, cassava, and sweet potato. His capacity-building activities, together with those of CIMMYT, fostered the pursuit of advanced studies by numerous research colleagues.
His passion, commitment, and scientific rigor gained the respect of agricultural researchers, national plant protection organizations, and many other partners, including members of the global scientific community.
The CIMMYT community respectfully extends its sympathies and wishes for peace to the family of Assimwe.
