Maize grain heavily damaged by the larger grain borer and maize weevil. (Photo: Jessica González/CIMMYT)
According to the World Health Organization (WHO), 10% of the global population suffers from food poisoning each year. Aflatoxins, the main contributor to food poisoning around the world, contaminate cereals and nuts and humans, especially vulnerable groups like the young, elderly, or immune-compromised, and animals are susceptible to their toxic and potentially carcinogenic effects.
Fungi contamination occurs all along the production cycle, during and after harvest, so the mitigation of the mycotoxins challenge requires the use of an integrated approach, including the selection of farmer-preferred tolerant varieties, implementing good agricultural practices such as crop rotation or nitrogen management, reducing crop stress, managing pests and diseases, biological control of mycotoxigenic strains, and good post-harvest practices.
Monitoring of mycotoxins in food crops is important to identify places and sources of infestations as well as implementing effective agricultural practices and other corrective measures that can prevent outbreaks.
A bug problem
Insects can directly or indirectly contribute to the spread of fungi and the subsequent production of mycotoxins. Many insects associated with maize plants before and after harvest act as a vector by carrying fungal spores from one location to another.
International collaboration is key to managing the risks associated with the spread of invasive pests and preventing crop damage caused by the newly introduced pests. CIMMYT, through CGIAR’s Plant Health initiative, partners with the Center for Grain and Animal Health Research of the US Department of Agriculture (USDA) and Kansas State University are investigating the microbes associated with the maize weevil and the larger grain borer.
The experiment consisted of trapping insects in three different habitats, a prairie near CIMMYT facilities in El Batán, Texcoco, Mexico, a maize field, and a maize store at CIMMYT’s experimental station at El Batán, using Lindgren funnel traps and pheromones lures.
Hanging of the Lindgren funnel traps in a prairie near El Bátan, Texcoco, Mexico. (Photo: Jessica González/CIMMYT)
Preliminary results of this study were presented by Hannah Quellhorst from the Department of Entomology at Kansas State University during an online seminar hosted by CIMMYT.
The collected insect samples were cultured in agar to identify the microbial community associated with them. Two invasive pests, the larger grain bore and the maize weevil, a potent carcinogenic mycotoxin was identified and associated with the larger grain borer and the maize weevil.
The larger grain borer is an invasive pest, which can cause extensive damage and even bore through packaging materials, including plastics. It is native to Mexico and Central America but was introduced in Africa and has spread to tropical and subtropical regions around the world. Together with the maize weevil, post-harvest losses of up to 60% have been recorded in Mexico from these pests.
“With climate change and global warming, there are risks of these pests shifting their habitats to areas where they are not currently present like sub-Saharan Africa and North Africa,” said Quelhorst. “However, the monitoring of the movement of these pests at an international level is lacking and the microbial communities moving with these post-harvest insects are not well investigated.”
One of the world’s largest crop pathogen surveillance systems is set to expand its analytic and knowledge systems capacity to protect wheat productivity in food vulnerable areas of East Africa and South Asia.
Researchers announced the Wheat Disease Early Warning Advisory System (Wheat DEWAS), funded through a $7.3 million grant from the Bill & Melinda Gates Foundation and the United Kingdom’s Foreign, Commonwealth & Development Office, to enhance crop resilience to wheat diseases.
The project is led by David Hodson, principal scientist at CIMMYT, and Maricelis Acevedo, research professor of global development and plant pathology at Cornell University’s College of Agriculture and Life Sciences. This initiative brings together research expertise from 23 research and academic organizations from sub-Saharan Africa, South Asia, Europe, the United States and Mexico.
Wheat DEWAS aims to be an open and scalable system capable of tracking important pathogen strains. The system builds on existing capabilities developed by the research team to provide near-real-time model-based risk forecasts and resulting in accurate, timely and actionable advice to farmers. As plant pathogens continue to evolve and threaten global food production, the system strengthens the capacity of countries to respond in a proactive manner to transboundary wheat diseases.
The system focuses on the two major fungal pathogens of wheat known as rust and blast diseases. Rust diseases, named for a rust-like appearance on infected plants, are hyper-variable and can significantly reduce crop yields when they attack. The fungus releases trillions of spores that can ride wind currents across national borders and continents and spread devastating epidemics quickly over vast areas.
Wheat blast, caused by the fungus Magnaporte oryzae Tritici, is an increasing threat to wheat production, following detection in both Bangladesh and Zambia. The fungus spreads over short distances and through the planting of infected seeds. Grains of infected plants shrivel within a week of first symptoms, providing little time for farmers to take preventative actions. Most wheat grown in the world has limited resistance to wheat blast.
“New wheat pathogen variants are constantly evolving and are spreading rapidly on a global scale,” said Hodson, principal investigator for Wheat DEWAS. “Complete crop losses in some of the most food vulnerable areas of the world are possible under favorable epidemiological conditions. Vigilance coupled with pathogen-informed breeding strategies are essential to prevent wheat disease epidemics. Improved monitoring, early warning and advisory approaches are an important component for safeguarding food supplies.”
Previous long-term investments in rust pathogen surveillance, modelling, and diagnostics built one of the largest operational global surveillance and monitoring system for any crop disease. The research permitted the development of functioning prototypes of advanced early warning advisory systems (EWAS) in East Africa and South Asia. Wheat DEWAS seeks to improve on that foundation to build a scalable, integrated, and sustainable solution that can provide improved advanced timely warning of vulnerability to emerging and migrating wheat diseases.
“The impact of these diseases is greatest on small-scale producers, negatively affecting livelihoods, income, and food security,” Acevedo said. “Ultimately, with this project we aim to maximize opportunities for smallholder farmers to benefit from hyper-local analytic and knowledge systems to protect wheat productivity.”
The system has already proven successful, contributing to prevention of a potential rust outbreak in Ethiopia in 2021. At that time, the early warning and global monitoring detected a new yellow rust strain with high epidemic potential. Risk mapping and real-time early forecasting identified the risk and allowed a timely and effective response by farmers and officials. That growing season ended up being a production record-breaker for Ethiopian wheat farmers.
While wheat is the major focus of the system, pathogens with similar biology and dispersal modes exist for all major crops. Discoveries made in the wheat system could provide essential infrastructure, methods for data collection and analysis to aid interventions that will be relevant to other crops.
The Wheat Disease Early Warning Advisory System (Wheat DEWAS) project is bringing new analytic and knowledge systems capacity to one of the world’s largest and most advanced crop pathogen surveillance systems. With Wheat DEWAS, researchers are building an open and scalable system capable of preventing disease outbreaks from novel pathogen strains that threaten wheat productivity in food vulnerable areas of East Africa and South Asia.
The system builds from capabilities developed previously by multi-institutional research teams funded through long-term investments in rust pathogen surveillance, modelling, and diagnostics. Once fully operationalized, the project aims to provide near-real-time, model-based risk forecasts for governments. The result: accurate, timely and actionable advice for farmers to respond proactively to migrating wheat diseases.
The Challenge
Farmers growing wheat face pathogen pressures from a range of sources. Two of the most damaging are the fungal diseases known as rust and blast. Rust is a chronic issue for farmers in all parts of the world. A study in 2015 estimated that the three rust diseases — stem, stripe and leaf — destroyed more than 15 million tons of wheat at a cost of nearly $3 billion worldwide. Wheat blast is an increasing threat to wheat production and has been detected in both Bangladesh and Zambia. Each of these diseases can destroy entire harvests without warning, wiping out critical income and food security for resource-poor farmers in vulnerable areas.
The Response
Weather forecasts and early-warning alerts are modern technologies that people rely on for actionable information in the case of severe weather. Now imagine a system that lets farmers know in advance when dangerous conditions will threaten their crop in the field. Wheat DEWAS aims to do just that through a scalable, integrated, and sustainable global surveillance and monitoring system for wheat.
Wheat DEWAS brings together research expertise from 23 research and academic organizations from sub-Saharan Africa, South Asia, Europe, the United States and Mexico.
Together, the researchers are focused on six interlinked work packages:
Work package
Lead
Objectives
Data Management
Aarhus University; Global Rust Reference Center
Maintain, strengthen and expand the functionality of the existing Wheat Rust Toolbox data management system
Create new modules within the Toolbox to include wheat blast and relevant wheat host information
Consolidate and integrate datasets from all the participating wheat rust diagnostic labs
Develop an API for the two-way exchange of data between the Toolbox and the Delphi data stack
Develop an API for direct access to quality-controlled surveillance data as inputs for forecast models
Ensure fair access to data
Epidemiological Models
Cambridge University
Maintain operational deployment and extend geographical range
Productionalize code for long-term sustainability
Multiple input sources (expert, crowd, media)
Continue model validation
Ensure flexibility for management scenario testing
Extend framework for wheat blast
Surveillance (host + pathogen)
CIMMYT
Undertake near-real-time, standardized surveys and sampling in the target regions
Expand the coverage and frequency of field surveillance
Implement fully electronic field surveillance that permits near real-time data gathering
Target surveillance and diagnostic sampling to validate model predictions
Map vulnerability of the host landscape
Diagnostics
John Innes Centre
Strengthen existing diagnostic network in target regions & track changes & movement
Develop & integrate new diagnostic methodology for wheat rusts & blast
Align national diagnostic results to provide a regional & global context
Enhance national capacity for wheat rust & blast diagnostics
Information Dissemination and Visualization Tools
PlantVillage; Penn State
Create a suite of information layers and visualization products that are automatically derived from the quality-controlled data management system and delivered to end users in a timely manner
Deliver near real time for national partners to develop reliable and actionable advisory and alert information to extension workers, farmers and policy makers
National Partner Capacity Building
Cornell University
Strengthening National partner capacity on pathogen surveillance, diagnostics, modeling, data management, early warning assessment, and open science publishing
The vital tasks for each country to reduce its greenhouse gas (GHG) emissions and limited carbon outputs are daunting, especially with 2030 deadlines imposed by the Paris Climate Agreement only eight years away. National stakeholders would benefit greatly from roadmaps that identify realistic and achievable milestones to point the way forward.
Researchers at the International Maize and Wheat Improvement Center (CIMMYT) have provided just such a road map. Using easily available data, they developed rapid assessment methods and adoption costs for mitigation related to crops, livestock, and forestry to identify priority locations and actions. Their article, “Quantification of economically feasible mitigation potential from agriculture, forestry and other land uses in Mexico”, was published in Carbon Management.
Applying these methods for Mexico, researchers found a national mitigation potential of 87.88 million metric tons (Mt) of carbon dioxide equivalents per year.
“Faced with such an overwhelming issue like climate change, it can be difficult for an individual, an organization, and especially an entire nation to know where to start. We developed a rapid assessment framework, tested in India, Bangladesh, and Mexico, but we believe other nations can use our methods as well,” said Tek Sapkota, the project leader and first author of the paper.
The research specifically focused on climate change mitigation in agriculture, forestry, and other land uses (AFOLU). Agriculture and related land use change contributed about 23% of the world’s anthropogenic GHG emissions in 2016, and that number is expected to increase as more food needs to be produced for the world’s growing population.
Chickpeas planted on wheat residue under conservation agriculture. (Photo: Ivan Ortiz-Monasterio/CIMMYT)
The researchers’ starting point was to quantify baseline emissions and analyze the major sources of emissions. Mexico’s AFOLU sector is responsible for 14.5% of its total national GHG emissions. In Mexico’s agricultural sector, methane and nitrous oxide emissions arise from livestock activities (enteric fermentation and fertilizers), as well as from agricultural activities (soil management and field burning of crop residues). For land use, carbon dioxide emissions and removals result from changes in forest lands, pastures, agricultural land, wetlands, and settlements.
Activities identified for GHG mitigation in crop production included avoiding fertilizer subsidies, since those tend reward inefficient nitrogen use. Subsidies could be of use, however, in encouraging farmers to adopt more efficient nitrogen management. Precision levelling of crop fields can help to lower GHG emissions by reducing cultivation time and improving the efficiency of fertilizer and irrigation water and adoption of conservation agriculture practices, such as zero tillage.
“Adoptions of these practices will not only reduce GHG emissions, but they will also help increase productivity,” said Ivan Ortiz-Monasterio, co-author and Mexico coordinator of the study.
In the livestock sector, mitigation possibilities identified are the creation of official programs, financial support, and capacity building on composting and biodigester. In FOLU sector, researchers identified options such as zero deforestation and C offset in the C market.
In addition to mapping out the mitigation benefits of specific activities, researchers also considered the costs associated with implementing those activities. “Looking at these efforts together with the cost of their implementation provide a complete picture to the implementing bodies to identify and prioritize their mitigation efforts consistent with their development goals,” said Sapkota. For example, some efforts, like increasing nitrogen use efficiency, do not provide the most climate benefits but are relatively inexpensive to realize, while establishing and maintaining carbon capture markets provides large reductions in GHG, they can be expensive to implement.
Researchers examined publicly available AFLOU spatial data for each Mexican state. At the state level, AFOLU mitigation potentials were highest in Chiapas (13 Mt CO2eq) followed by Campeche (8Mt CO2eq), indicating these states can be considered the highest priority for alleviation efforts. They identified an additional 11 states (Oaxaca, Quintana Roo, Yucatan, Jalisco, Sonora, Veracruz, Durango, Chihuahua, Puebla, Michoacán, and Guerrero) as medium priorities with mitigation potentials of 2.5 to 6.5 Mt CO2eq.
“Our data driven, and evidence-based results can help the government of Mexico refine its national GHG inventory and its Nationally Determined Contributions target and monitor progress,” said Eva Wollenberg, the overall coordinator of the study and research professor of University of Vermont, USA. “This analysis further provides an example of a methodology and results to help inform future efforts in other countries in addition to Mexico.”
Cover photo: Low nitrogen (at the front) and high nitrogen (at the back) maize planted to address nitrogen use efficiency. (Photo: Ivan Ortiz-Monasterio/CIMMYT)
Mustafa Alisarli, Bolu Abant Izzet Baysal University rector, is awarded for hosting this symposium by the representative of the Turkish Ministry of Agriculture and Forestry, General Directorate of Agricultural Research and Policies (GDAR), Dr Suat Kaymak.
The International Maize and Wheat Improvement Center (CIMMYT) coordinated the VIII International Cereal Nematode Symposium between September 26-29, in collaboration with the Turkish Ministry of Agriculture and Forestry, the General Directorate of Agricultural Research and Policies and Bolu Abant Izzet Baysal University.
As many as 828 million people struggle with hunger due to food shortages worldwide, while 345 million are facing acute food insecurity – a crisis underpinning discussions at this symposium in Turkey focused on controlling nematodes and soil-borne pathogens causing reduced wheat yields in semi-arid regions.
A major staple, healthy wheat crops are vital for food security because the grain provides about a fifth of calories and proteins in the human diet worldwide.
Seeking resources to feed a rapidly increasing world population is a key part of tackling global hunger, said Mustafa Alisarli, the rector of Turkey’s Bolu Abant Izzet Baysal University in his address to the 150 delegates attending the VIII International Cereal Nematode Symposium in the country’s province of Bolu.
Suat Kaymak, Head of the Plant Protection Department, on behalf of the director general of the General Directorate of Agricultural Research and Policies (GDAR), delivered an opening speech, emphasizing the urgent need to support the CIMMYT Soil-borne Pathogens (SBP) research. He stated that the SBP plays a crucial role in reducing the negative impact of nematodes and pathogens on wheat yield and ultimately improves food security. Therefore, the GDAR is supporting the SBP program by building a central soil-borne pathogens headquarters and a genebank in Ankara.
Discussions during the five-day conference were focused on strategies to improve resilience to the Cereal Cyst Nematodes (Heterodera spp.) and Root Lesion Nematodes (Pratylenchus spp.), which cause root-health degradation, and reduce moisture uptake needed for proper development of wheat.
Richard Smiley, a professor emeritus at Oregon State University, summarized his research on nematode diseases. He has studied nematodes and pathogenic fungi that invade wheat and barley roots in the Pacific Northwest of the United States for 40 years. “The grain yield gap – actual versus potential yield – in semiarid rainfed agriculture cannot be significantly reduced until water and nutrient uptake constraints caused by nematodes and Fusarium crown rot are overcome,” he said.
Experts also assessed patterns of global distribution, exchanging ideas on ways to boost international collaboration on research to curtail economic losses related to nematode and pathogen infestations.
A special session on soil-borne plant pathogenic fungi drew attention to the broad spectrum of diseases causing root rot, stem rot, crown rot and vascular wilts of wheat.
Soil-borne fungal and nematode parasites co-exist in the same ecological niche in cereal-crop field ecosystems, simultaneously attacking root systems and plant crowns thereby reducing the uptake of nutrients, especially under conditions of soil moisture stress.
Limited genetic and chemical control options exist to curtail the damage and spread of these soil-borne problems which is a challenge exacerbated by both synergistic and antagonistic interactions between nematodes and fungi.
Nematodes, by direct alteration of plant cells and consequent biochemical changes, can predispose wheat to invasion by soil borne pathogens. Some root rotting fungi can increase damage due to nematode parasites.
Integrated managementFor a holistic approach to addressing the challenge, the entire biotic community in the soil must be considered, said Hans Braun, former director of the Global Wheat Program at CIMMYT.
Braun presented efficient cereal breeding as a method for better soil-borne pathogen management. His insights highlighted the complexity of root-health problems across the region, throughout Central Asia, West Asia and North Africa (CWANA).
Richard A. Sikora, Professor emeritus and former Chairman of the Institute of Plant Protection at the University of Bonn, stated that the broad spectrum of nematode and pathogen species causing root-health problems in CWANA requires site-specific approaches for effective crop health management. Sikora added that no single technology will solve the complex root-health problems affecting wheat in the semi-arid regions. To solve all nematode and pathogen problems, all components of integrated management will be needed to improve wheat yields in the climate stressed semi-arid regions of CWANA.
Building on this theme, Timothy Paulitz, research plant pathologist at the United States Department of Agriculture Agricultural Research Service (USDA-ARS), presented on the relationship between soil biodiversity and wheat health and attempts to identify the bacterial and fungal drivers of wheat yield loss. Paulitz, who has researched soil-borne pathogens of wheat for more than 20 years stated that, “We need to understand how the complex soil biotic ecosystem impacts pathogens, nutrient uptake and efficiency and tolerance to abiotic stresses.”
Julie Nicol, former soil-borne pathologist at CIMMYT, who now coordinates the Germplasm Exchange (CAIGE) project between CIMMYT and the International Center for Agricultural Research in the Dry Areas (ICARDA) at the University of Sydney’s Plant Breeding Institute, pointed out the power of collaboration and interdisciplinary expertise in both breeding and plant pathology. The CAIGE project clearly demonstrates how valuable sources of multiple soil-borne pathogen resistance in high-yielding adapted wheat backgrounds have been identified by the CIMMYT Turkey program, she said. Validated by Australian pathologists, related information is stored in a database and is available for use by Australian and international breeding communities.
Economic losses
Root-rotting fungi and cereal nematodes are particularly problematic in rainfed systems where post-anthesis drought stress is common. Other disruptive diseases in the same family include dryland crown and the foot rot complex, which are caused mainly by the pathogens Fusarium culmorum and F. pseudograminearum.
The root lesion nematode Pratylenchus thornei can cause yield losses in wheat from 38 to 85 percent in Australia and from 12 to 37 percent in Mexico. In southern Australia, grain losses caused by Pratylenchus neglectus ranged from 16 to 23 percent and from 56 to 74 percent in some areas.
The cereal cyst nematodes (Heterodera spp.) with serious economic consequences for wheat include Heterodera avenae, H. filipjevi and H. latipons. Yield losses due to H. avenae range from 15 to 20 percent in Pakistan, 40 to 92 percent in Saudi Arabia, and 23 to 50 percent in Australia.
In Turkey, Heterodera filipjevi has caused up to 50 percent crop losses in the Central Anatolia Plateau and Heterodera avenae has caused up to 24 percent crop losses in the Eastern Mediterranean.
The genus Fusarium which includes more than a hundred species, is a globally recognized plant pathogenic fungal complex that causes significant damage to wheat on a global scale.
In wheat, Fusarium spp. cause crown-, foot-, and root- rot as well as head blight. Yield losses from Fusarium crown-rot have been as high as 35 percent in the Pacific Northwest of America and 25 to 58 percent in Australia, adding up losses annually of $13 million and $400 million respectively, due to reduced grain yield and quality. The true extent of damage in CWANA needs to be determined.
Abdelfattah Dababat, CIMMYT’s Turkey representative and leader of the soil-borne pathogens research team said, “There are examples internationally, where plant pathologists, plant breeders and agronomists have worked collaboratively and successfully developed control strategies to limit the impact of soil borne pathogens on wheat.” He mentioned the example of the development and widespread deployment of cereal cyst nematode resistant cereals in Australia that has led to innovative approaches and long-term control of this devastating pathogen.
Dababat, who coordinated the symposium for CIMMYT, explained that, “Through this symposium, scientists had the opportunity to present their research results and to develop collaborations to facilitate the development of on-farm strategies for control of these intractable soil borne pathogens in their countries.”
Paulitz stated further that soil-borne diseases have world-wide impacts even in higher input wheat systems of the United States. “The germplasm provided by CIMMYT and other international collaborators is critical for breeding programs in the Pacific Northwest, as these diseases cannot be managed by chemical or cultural techniques,” he added.
Closing ceremony of the International Cereal Nematode Symposium. From left to right; Hans Braun, Brigitte Slaats, Richard Sikora, Grant Hollaway, Mesut Keser, Zahra Maafi, Richard Smiley, Mustafa Imren, Fatih Ozdemir, Amer Dababat. (Photo: CIMMYT)
Road ahead
Delegates gained a greater understanding of the scale of distribution of cereal cyst nematodes and soil borne pathogens in wheat production systems throughout West Asia, North Africa, parts of Central Asia, Northern India, and China.
After more than 20 years of study, researchers have recognized the benefits of planting wheat varieties that are more resistant. This means placing major emphasis on host resistance through validation and integration of resistant sources using traditional and molecular methods by incorporating them into wheat germplasm for global wheat production systems, particularly those dependent on rainfed or supplementary irrigation systems.
Sikora stated that more has to be done to improve Integrated Pest Management (IPM), taking into consideration all tools wherever resistant is not available. Crop rotations for example have shown some promise in helping to mitigate the spread and impact of these diseases.
“In order to develop new disease-resistant products featuring resilience to changing environmental stress factors and higher nutritional values, modern biotechnology interventions have also been explored,” Alisarli said.
Brigitte Slaats and Matthias Gaberthueel, who represent Swiss agrichemicals and seeds group Syngenta, introduced TYMIRIUM® technology, a new solution for nematode and crown rot management in cereals. “Syngenta is committed to developing novel seed-applied solutions to effectively control early soil borne diseases and pests,” Slaats said.
It was widely recognized at the event that providing training for scientists from the Global North and South is critical. Turkey, Austria, China, Morocco, and India have all hosted workshops, which were effective in identifying the global status of the problem of cereal nematodes and forming networks and partnerships to continue working on these challenges.
Climate change is an undoubted contributor to the global food crisis. Natural disasters and poor weather is leading to 193 million people facing acute food insecurity.
While food aid is vital, improving food systems and reducing reliance on food imports is the route to a long-term solution. In an article for the Des Moines Register, Cary Fowler, US government food security envoy, details the importance of developing reliable local production and well-functioning markets to support farmers.
The United States government’s Feed the Future initiative is addressing some of these challenges, such as by supporting the International Maize and Wheat Improvement Center (CIMMYT) to develop drought-tolerant maize, which is now planted on 17 million acres in Africa. This variety is making a significant difference to food security.
For the first time ever, a biotechnology team has identified vegetative storage proteins (VSP) in maize and activated them in the leaves to stockpile nitrogen reserves for release when plants are hit by drought, which also causes nutrient stress, according to a recent report in Plant Biotechnology Journal. In two years of field testing, the maize hybrids overexpressing the VSP in leaf cells significantly out-yielded the control siblings under managed drought stress applied at the flowering time, according to Kanwarpal Dhugga, a principal scientist at the International Maize and Wheat Improvement Center (CIMMYT).
“One of the two most widely grown crops, maize increasingly suffers from erratic rainfall and scarcer groundwater for irrigation,” Dhugga said. “Under water stress, nitrogen availability to the plant is also attenuated. If excess nitrogen could be stored in the leaves during normal plant growth, it could help expedite the plant’s recovery from unpredictable drought episodes. In our experimental maize hybrids, this particular VSP accumulated to more than 4% in mesophyll cells, which is five times its normal levels, and offered an additional, dispensable source of nitrogen that buffered plants against water deficit stress.”
Dhugga noted as well that the study, whose authors include scientists from Corteva Agriscience, the Bill & Melinda Gates Foundation, and the US Department of Agriculture (USDA), provides experimental evidence for the link between drought tolerance and adequate nitrogen fertilization of crop plants. “This mechanism could also help farmers and consumers in sub-Saharan Africa, where maize is grown on nearly 40 million hectares, accounts for almost one-third of the region’s caloric intake, and frequently faces moderate to severe drought.”
Scientists multiply and power up vegetative storage proteins in maize leaves as nutrient stockpiles for drought-stressed maize crops. Graphic adapted from: Pooja Gupta, Society for Experimental Biology (SEB).
Firpo was born in Montevideo, Uruguay, where he received a BSc degree as an agronomy engineer in 1997 from the University of the Republic, College of Agronomy. His PhD degree in 2008 was from the Department of Plant Pathology at the University of Minnesota (UMN). He began his career as a postdoctoral research associate with the Department of Plant Pathology and the USDA-ARS Cereal Disease Lab, and then became a research assistant professor in the Department of Plant Pathology at UMN in 2017.
Firpo has been a vital member in the global cereal rust pathology community and contributed substantially to the fight against Ug99 and other virulent wheat stem rust races that have re-emerged around the world and pose serious threats to food security. Firpo’s contributions are not only within the realm of research of great impact, but also include training 79 scientists and facilitating the establishment of a world-class research group in Ethiopia. He has worked to improve international germplasm screening in Ethiopia. As a postdoctoral research associate, Firpo’s first assignment was to search for new sources of resistance to Ug99 in durum wheat, used for pasta, and related tetraploid wheat lines. That project took him to Ethiopia, where an international Ug99-screening nursery for durum wheat was established at Debre Zeit Research Center. He worked closely with researchers from the Ethiopian Institute of Agricultural Research (EIAR) and the International Maize and Wheat Research Center (CIMMYT) to improve the methodologies for screening and to provide hands-on training to researchers managing the international screening nursery. During a period of 10 years (from 2009 to 2019), he traveled to Ethiopia 21 times to evaluate stem rust reactions of US and international durum wheat germplasm and completed the screening of the entire durum collection (more than 8,000 accessions) from the USDA National Small Grains Collection.
Firpo’s research on sources and genetics of stem rust resistance led to discoveries of valuable genetic resistance in durum and other relatives of wheat. These sources of resistance have provided the needed diversity to ensure the development and sustainability of durable stem rust resistance.
With frequent epidemics and severe yield losses caused by stem rust in eastern Africa, establishing a functional rust pathology laboratory to support international screening, as well as to monitor and detect new virulences in the pathogen population, became a high priority for the international wheat research community. Utilizing the onground opportunities in Ethiopia, Firpo and his colleagues at the CDL and UMN enthusiastically participated in building up the rust pathology lab at the Ambo Plant Protection Center of EIAR. Firpo traveled to Ambo 11 times to provide hands-on training to staff and to develop cereal rust protocols to suit local conditions. He worked closely with colleagues at CDL, EIAR, and CIMMYT to secure and upgrade facilities, equipment and supplies to a standard that ensures reliable rust work will be carried out. As a result, the rust pathology lab at the Ambo Center became the only laboratory in eastern Africa, and one of a handful in the world, that can conduct high-quality race analysis of wheat stem rust samples and provide vital and necessary support for breeding global wheat varieties for rust resistance. Currently, the laboratory is playing a critical role in the global surveillance of the stem rust pathogen and supports wheat breeding efforts led by EIAR, CIMMYT, and the USDA.
Firpo has been passionate in supporting capacity building of human resources in Ethiopia and elsewhere. He has been eager to share his knowledge whenever he encounters an opportunity to do so. In addition to the direct training of the staff at the Ambo Center, Firpo accepted invitations to provide training lectures and hands-on field- and greenhouse-based workshops on rust pathology at three research centers in Ethiopia. He prepared training materials, delivered a total of 12 lectures and 10 practical sessions in three Ethiopia national workshops in 2014, 2015, and 2017. These workshops enhanced human resource development and technical capacity in Ethiopia in cereal rust pathology; participants included a total of 64 junior scientists and technical staff from nationwide research centers. Beyond Ethiopia, he was responsible for developing and implementing a six-week training program in cereal rust prevention and control for international scientists. This training program, under the aegis of the Stakman-Borlaug Center for Sustainable Plant Health in the Department of Plant Pathology, University of Minnesota, provided an experiential learning opportunity for international scientists interested in acquiring knowledge and practical skills in all facets of working with cereal rusts. The program trained 15 rust pathologists and wheat scientists from Ethiopia, Kenya, Pakistan, Nepal, Bhutan, Georgia, and Kyrgyzstan, ranging from promising young scientists selected by the USDA as Borlaug Fellows to principal and senior scientists in their respective countries. Many of these trainees have become vital partners in the global surveillance network for cereal rusts.
Working in collaboration with CDL and international scientists, Firpo has been closely involved in global surveillance of the stem rust pathogen, spurred by monitoring the movements of, and detecting, new variants in the Ug99 race group. Since 2009, he and the team at the CDL have analyzed 2,500 stem rust samples from 22 countries, described over 35 new races, and identified significant virulence combinations that overcome stem rust resistance genes widely deployed in global wheat varieties. Among the most significant discoveries were the identification of active sexual populations of the stem rust pathogen in Kazakhstan, Georgia, Germany, and Spain that have unprecedented virulence and genetic diversities. More than 320 new virulent types (or races) were identified from these sexual populations. Evolution in these populations will present continued challenges to wheat breeding. Research in race analysis has provided valuable pathogen isolates that are used to evaluate breeding germplasm to select for resistant wheat varieties and to identify novel sources of stem rust resistance.
Written by Bea Ciordia on . Posted in Uncategorized.
The Bangladesh Integrated Pest Management Activity (IPMA) project aims to strengthen the capacity of agricultural stakeholders in Bangladesh by controlling and preventing the spread of current and emerging threats to ensure more efficient, profitable, and environmentally safe agricultural production and productivity.
Objectives
Increase the availability and affordability of integrated pest management measures for the prevention and spread of current and emerging threats
Strengthen the capacity of Bangladesh agricultural stakeholders, such as academia, financial institutions, government, judiciary, media, civil society, the private sector, and value chain actors, to implement integrated pest management measures
Enhance the adoption of integrated pest management by smallholder farmers to increase agricultural production and productivity, while reducing environmental hazards caused by indiscriminate use of pesticides
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.
A CIMMYT researcher and a field worker lay out wheat seed for planting at the center’s headquarters in Texcoco, Mexico. In experimental trials, hundreds or thousands of wheat lines are planted for evaluation, each in small quantities, and so they are carefully laid out and sown by hand. (Photo: CIMMYT)
To help feed a growing world population, wheat scientists have turned to innovative technologies like genomic selection to hasten selection for positive traits — such as high grain yield performance and good grain quality — in varieties that are still undergoing testing. Instead of being shackled by the long duration of traditional breeding cycles, genomic selection allows scientists to make predictions regarding which traits will present when crossing two varieties; allowing breeders greater guidance and lessening potential time lost when crossing varieties that do not display potential for genetic gain. To reap the benefits of genomic selection, it is vital that the predictive models employed are as accurate as possible.
Currently, wheat breeders select characteristics like grain yield performance early in the breeding process, while selecting traits like good grain quality at a later stage in the breeding process.
In an article in the journal G3 Genes, researchers from the International Maize and Wheat Improvement Center (CIMMYT), and partners, led by CIMMYT scientist José Crossa along with Leonardo A. Crespo, Maria Itria Ibba and Alison R. Bentley, endeavored to determine if genomic prediction models could select for both characteristics simultaneously in the breeding process. This would improve selection accuracy in both early and later breeding stages, resulting a reduction in time and expense in delivering improved wheat varieties. They also tested the accuracy of a set of specific mathematical corrections applied to genomic predictions. These correction models identify correlations between genomic predictions and observed breeding values, such as increased yield or grain quality.
Considering two or more traits, like grain yield and good grain quality, is an example of a multi-trait model. The team examined this multi-trait model against a single trait model that improves one specific trait. Overall, the researchers found that prediction performance was highest using the multi-trait model.
However, the team also demonstrated that when breeding programs arrive at their genetic predictions, applying a specific correction method will account for differences between the predicted breeding value and the actual observed breeding value. Current correction models tend to underestimate that difference, which results in breeding programs not running as efficiently as possible.
By partnering selections from different stages in the breeding process and examining the resulting genetic predictions through a more appropriate correction model, the team has shown that breeding programs can use this to their benefit in developing and ultimately releasing improved wheat varieties that meet growing yield needs worldwide and respond to abiotic and biotic stressors.
Agricultural knowledge management framework for innovation (AKM4I) in agri-food systems. (Graphic: CIMMYT)
The key to transforming food production systems globally lies in knowledge management processes, according to a team of researchers from the International Maize and Wheat Improvement Center (CIMMYT).
The challenge is to combine traditional knowledge with state-of-the-art scientific research: to meet regional needs for improvement in farming systems with knowledge networks fostering innovative practices and technologies that increase yields and profits sustainably.
A group of CIMMYT researchers led by Andrea Gardeazábal, Information and Communications Technology for Agriculture Monitoring and Evaluation Manager, recently published a proposal for a new knowledge management framework for agri-food innovation systems: Agricultural Knowledge Management for Innovation (AKM4I).
“We are proposing a knowledge management framework for agricultural innovation that addresses the need for more inclusive and environmentally sustainable food production systems that are able to provide farmers and consumers with affordable and healthy diets within planetary boundaries,” Gardeazábal said.
The AKM4I framework was designed to help agricultural development practitioners understand how farming skills and abilities are developed, tested and disseminated to improve farming systems in real-life conditions.
Following systems theory principles, the model empirically describes how information is created, acquired, stored, analyzed, integrated and shared to advance farming knowledge and produce innovative outcomes that effectively contribute to: collaboratively building local capacities for developing joint problem-solving abilities and integrated-knowledge solutions; empowering farmers with site-specific knowledge; co-creating technology and conducting participatory community-based research; and bridging innovation barriers to drive institutional change.
Knowledge access for systems transformation
Schematic illustration of CIMMYT’s knowledge and technology development networks, or hubs, for sustainable maize and wheat production systems. (Graphic: CIMMYT)
The framework builds on CIMMYT’s learnings from MasAgro, a bilateral project with Mexico that relies on participatory research and knowledge and technology development networks for sustainable maize and wheat production systems.
This CIMMYT project was recently acknowledged with the 2020 Innovative Applications in Analytics Award for developing groundbreaking monitoring, evaluation, accountability and learning (MEAL) systems and tools for publicly funded researchers and field technicians who advise more than 150,000 farmers in Mexico.
“Through the outlined principles and processes, the AKM4I framework can assist in closing the cycle of continually re-creating knowledge, evaluating and iterating upon innovations, building coalitions to democratize knowledge access and utilization, and using MEAL to facilitate course-correction of all stages of knowledge management,” concludes the study.
Denise E. Costich, the recently retired head of the Maize Collection at the Germplasm Bank of the International Maize and Wheat Improvement Center (CIMMYT), sometimes likes to include a Woody Allen quote in her presentations.
“I have no idea what I’m doing,” declares the text over a photo of a befuddled-looking Allen. “But incompetence never stopped me from plunging in with enthusiasm.”
This is perhaps Costich’s tongue-in-cheek way of acknowledging the unusual trajectory that led her to the Germplasm Bank and her zeal for new and interesting challenges. But it is in no way an accurate reflection of the skill, knowledge and humane managerial style she brought to the job.
“CIMMYT requires individuals with a broad set of experiences,” says Tom Payne, head of the Wheat Collection at CIMMYT’s Germplasm Bank. Though she was not trained as a crop scientist, and despite having never worked in a genebank before, Costich’s rich set of professional and life experiences made her an ideal person for the job.
From Ithaca and back again
Born and raised in Westbury, NY, Costich spent much of her childhood on a tree nursery. Her grandfather was the manager, her father became the sales director and eventually her sister also went into the horticulture business. While her experiences on the nursery contributed to an early interest in plants and ecology, the business aspect of the nursery eluded her. “I just can’t sell things. I’m terrible,” Costich says. “But I really do like to study them.”
This studiousness took her to Cornell University in Ithaca, NY, where she initially declared as a wildlife biology major. Her notion of what it meant to “study things” was influenced by her early heroes, primatologists and field biologists Dian Fossey and Jane Goodall. It involved travel. Fieldwork in faraway places. So, when the opportunity arose at the end of her sophomore year to travel to Kenya with Friends World College, Costich didn’t hesitate.
Costich eventually spent four years in Kenya, studying baboons. When she finally returned to Ithaca, she knew two things. Fieldwork was absolutely her thing, and she wanted to pursue a doctorate.
A chance conversation with her housemates in her last semester led to a post-graduation fieldwork stint in the Brazilian Amazon under the supervision of the legendary tropical and conservation biologist, Thomas Lovejoy. But instead of a dissertation topic, she stumbled across a parasite, a case of leishmaniasis and the realization that the rainforest was not the work environment for her.
Unexpected influences and outcomes continued to mark Costich’s career throughout her graduate studies at the University of Iowa. She found her plant not in the field, but while reading a dusty review paper as an exchange student at the University of Wisconsin. Her study of Ecballium elaterium (a wild species in the Cucurbitaceae, or squash, family) did not take her back to the tropics — where most of her peers were working and where she expected to be headed as a grad student — but rather to Spain where, incidentally, she first learned Spanish.
Several years after defending, Costich landed a tenure-track position in the Biology Department at The College of New Jersey. She continued to publish on Ecballium elaterium. Her career appeared to be settling into a predictable, recognizable academic trajectory — one with no obvious intersection with CIMMYT.
Then Costich saw an ad in the Ecological Society of America bulletin for a managing editor position for all of the Society’s journals. Her husband, a fellow biology Ph.D., had been working as an academic journal editor for several years. When Costich saw the ad she immediately drove over to her husband’s office. “I slapped the thing on his desk and said, ‘Here’s your job!’” she recalls.
Costich was right. Soon after, she was on her way back to Ithaca — where the Society’s offices were located — with a family that now included three children. While it was the right move for her family, it came at the cost of her budding academic career. In Ithaca, she soon found herself stuck in the role of itinerant postdoc.
Denise Costich in Spain in 1986, doing fieldwork on Ecballium elaterium with her daughter Mara.
An amazing turn of events
Costich admits that, especially the beginning, the return to Ithaca was tough, even depressing. Her recollections of these years can sound a bit like a game of musical chairs played with research laboratories. As one post-doc or research project wound down, she’d find herself scanning the campus for her next perch. She became very adept at it. “In ten years, I never missed a paycheck,” Costich says.
The turn of the millennium found Costich scanning the horizon yet again. As the days wound down at her latest post, a maize geneticist moved into the lab next door. What started as hallway jokes about Costich jumping ship and joining the maize lab soon turned into an interview, then a job offer.
The job introduced her to nearly everyone at Cornell working in maize genetics. Costich soon found herself managing the Buckler Lab’s work on maize population genetics. Meanwhile, she dabbled in side projects on Tripsacum, a perennial grass genus that is closely related to maize, and managed a major project on switchgrass. At the end of her postdoc, Buckler set to work trying to create a permanent position for her. Once again, Costich’s trajectory was beginning to take a stable, predictable form.
Then CIMMYT scientist Sarah Hearne showed up. “I’d heard through the grapevine — or maybe through the corn field — that the position of manager of the Maize Collection of CIMMYT’s Germplasm Bank was open… and that they were having a hard time trying to find a person for the position,” Costich recalls. She had met Hearne previously and personally knew and had worked with Suketoshi Taba, the pioneering longtime director of the germplasm bank. Naturally the topic emerged as she and Hearne caught up in Ithaca.
Hearne admitted that the search hadn’t yet been successful. “But I know the perfect person for the job,” she added.
“Yeah, who’s that?” Costich asked, not getting the setup.
Denise Costich, the maize collection manager at CIMMYT’s Maize and Wheat Germplasm Bank, shows one of the genebank’s more than 28,000 accessions of maize. (Photo: Luis Salazar/Crop Trust)
A stranger in a strangely familiar land
Costich was not a little surprised by the suggestion. She had never worked at a germplasm bank before. She was finally finding some stability at Cornell.
At the same time, her early dreams of exploring new places through her work, especially the tropics, beckoned. Her youngest son was nearly college-aged. Against the advice of some who had watched her work so hard to establish herself at Cornell, she took the plunge.
By the time she reached the CIMMYT campus in Texcoco, Costich had crisscrossed a good part of the globe, picking up Spanish here, management skills there, a deep knowledge of maize and its biological and cultural evolution yonder. During this life journey, she developed a deep humanism that is all her own.
It all seemed like happenstance, perhaps, until she reached Mexico and — suddenly, counterintuitively — found herself in the field she was perfectly adapted for. “It turned out that being a germplasm bank manager was the perfect job for me, and I didn’t even know it!” Costich says. “I ended up using everything I learned in my entire career.”
That isn’t to say that it was easy, especially at first. Taba, her predecessor, had occupied the post for decades, was a trained crop scientist, and had grown the bank from a regionally-focused collection with 12,000 accessions to the preeminent maize germplasm bank globally with 28,000 accessions, a state-of-the-art storage facility, and a slew of pioneering practices.
Not only had Taba left enormous shoes to fill, during his tenure — as is common in the expansionary phase of many projects — it had been difficult for the bank to keep a full accounting and understanding of all the new material that had been added. According to germplasm bank coordinator Cristian Zavala, by the time Costich joined CIMMYT “we knew very little about the material in our vaults.”
“Taba was primarily a breeder,” Costich says. “I actually think this oscillation between a focus on breeding and a focus on conservation and curation is good for the bank.”
Visiting a newly-built community seed reserve in Chanchimil, Todos Santos Cuchumatanes, Huehuetenango, Guatemala, in 2016. From left to right: Mario Fuentes (collaborator), a member of the community seed reserve staff, Denise Costich, Carolina Camacho (CIMMYT), Miriam Yaneth Ramos (Buena Milpa) and Esvin López (local collaborator).
Visiting one of the oldest community seed reserves in the region, Quilinco, Huehuetenango, Guatemala, in 2016. From left to right: Pedro Bello (UC Davis), Esvin López (local collaborator), Denise Costich, José Luis Galicia (Buena Milpa), Ariel Rivers (CIMMYT) and Miriam Yaneth Ramos (Buena Milpa).
Costich with the winners of the Second Harvest Fair and Largest Mature Ear of Jala Maize Contest in Coapa, in Mexico’s Nayarit state.
Costich (left) measures ears of corn for the Second Harvest Fair and Largest Mature Ear of Jala Maize Contest in Coapa, in Mexico’s Nayarit state in 2019.
Costich (center) shares some comments from the stage at the Second Harvest Fair and Largest Mature Ear of Jala Maize Contest in Coapa, in Mexico’s Nayarit state. To her left is Angel Perez, a participating farmer from La Cofradía, and to her right, Rafael Mier, Director of the Fundación Tortillas de Maíz Mexicana.
A bank for farmers
However, according to Zavala, because of the limited knowledge of much material they were working with, many in the bank’s rank-and-file didn’t fully understand the importance of their work. Morale was mixed. Moreover, despite an assumption that her new job would see her working closely with local smallholders, Costich found that the institution was poorly known by everyday farmers in its host country. Where it was known, associate scientist on innovation and social inclusion, Carolina Camacho, notes, there was an assumption that CIMMYT only worked with hybrid varieties of maize and not the native landraces many smallholders in Mexico depend on.
These became the principal axes of Costich’s work at the bank: curation of backlogged material, staff development, and community outreach.
Thus, when Costich realized that records were being kept in a combination of paper and rudimentary digital formats, she sent Zavala, a promising young research assistant at the time, to an internship at the USDA’s Maize Germplasm Bank Collection in Ames, Iowa, to workshops at CGIAR germplasm banks in Colombia (CIAT) and Ethiopia (ILRI), and to meetings on specialized topics in Germany and Portugal.
Zavala had never left the country before, spoke little English, and remembers being “rebellious” at work. “I needed more responsibility,” he says. “Dr. Denise saw that and helped me grow.” Upon returning from an early trip, Zavala helped implement up-to-date traceability and data management processes, including migrating the genebank’s data onto the USDA’s GRIN-Global platform.
But as Payne points out, Costich’s tenure was never about simple bean — or, in this case, grain — counting. “She sees a more human aspect of the importance of the collections,” he says. The main tasks she set for the bank came to be subsumed into the overarching goal of a fuller understanding of the contents of the bank’s vaults, one that encompassed both their biological and sociocultural importance.
When Costich came across a collection of maize landraces from Morelos state assembled by Ángel Kato in the mid 1960s that conserved the name of the farmer who had donated each sample, she worked with Camacho and graduate student Denisse McLean-Rodriguez to design a study involving the donor families and their communities. McLean-Rodriguez, Camacho and Costich set out to compare the effects of ex-situ versus in-situ landrace conservation in both genetic and socioeconomic terms.
Similarly, when a colleague at INIFAP invited Costich to be a judge at a yearly contest for largest ear of Jala landrace maize in Mexico’s Nayarit state, they soon began discussing how they could contribute more than just their participation as judges to the community. Starting in 2016 Costich was a co-lead on a study of the landrace’s genetic diversity as well as an initiative to rematriate Jala seeds conserved at CIMMYT for over 60 years.
Costich and members of the Maize Collection team hosting Pedro Bello from UC Davis (center, glasses) at the CIMMYT Germplasm Bank in Texcoco, Mexico, for a workshop on seed longevity and conservation techniques.
A genebank is not an island
Genebanks are bulwarks against genetic erosion. But, as Camacho explains, this mission can be understood in both very narrow and very broad senses. The narrow sense focuses on genetic processes per se: the loss of alleles. The broad sense includes the loss of cultural practices and knowledge built and sustained around the cultivation of a given landrace. Through the initiatives the bank has undertaken during her tenure, Costich has tried to demonstrate, both scientifically and in practice, how germplasm collections such as CIMMYT’s can complement, reinforce, and be enriched by the work of smallholders — de facto germplasm conservators in their own right — while contributing to the difficult task of combating genetic erosion in the broad sense.
One gets the sense that in Costich’s view this isn’t about a one-way process of big institutions “helping” smallholders. Rather it’s about collaboration among all the participants in an interdependent web of conservation. As she argued at her recent exit seminar, Costich views germplasm banks as one link in a chain of food security backups that begins at the farm level.
Indeed, Costich’s most recent initiative demonstrated how innovations intended for one link in the chain can travel upwards and find applications at bigger institutions.
Costich recently led an initiative with community seed banks in the Cuchumatanes mountain range of Guatemala to study the use of DryChain technology in post-harvest storage of maize. This experiment showed the enormous benefits that incorporating such technologies could yield for energy-insecure or low-tech family and community seed reserves.
Ultimately, however, the study led to a second experiment at CIMMYT’s tropical-climate station at Agua Fría in Mexico. With advice from collaborators at UC Davis and an industry partner (Dry Chain America), the seed conditioning team retrofitted an old drying cabinet at the station to dry maize without using heat, but rather by forcing air to circulate through sacks of drying beads. Under the direction of Filippo Guzzon, a postdoc and seed biologist working with Costich, the long-term viability of seeds dried using the accelerated technique versus traditional, slower techniques was tested. The study showed no loss in long-term viability using the accelerated drying technique.
Denise Costich, CIMMYT director general Martin Kropff, and the Maize Collection team confer certificates of participation to two visiting interns, Jiang Li (to the left of Kropff), a doctoral student from CAAS, Beijing, China, and Afeez Saka Opeyemi (to the right of Costich), a staff member of the IITA Germplasm Bank in Nigeria.
Costich and the Maize Collection team at the 2018 CIMMYT Christmas party. Filippo Guzzon, seated to the right of Costich, had just been offered a postdoc with the team.
Costich and the Maize Collection team at the 2018 CIMMYT Christmas party.
A very busy retirement
At her exit seminar, Costich was presented a plaque in appreciation of her service at CIMMYT by Kevin Pixley, director of the genetic resources program. Terence Molnar, maize breeder with the Genetic Resources Team, has succeeded Costich as the Maize Germplasm Bank Head.
For some of her close colleagues, however, Costich’s departure is not the end of the road. “This is not a forever goodbye,” Guzzon says. “I will continue to be in touch with my cuatita,” says Camacho, who has also left CIMMYT.
For her part, Costich echoes that this is not a forever goodbye at all. Not to her friends and colleagues, and certainly not to her work. At a socially-distanced, maize-based farewell lunch Costich held just days before her departure, she was still busy weaving social connections and furthering collaborations among maize fanatics of all stripes — from chefs and designers to scientists and policy advocates.
She is already considering taking a part time position at her old lab at Cornell and a return to Tripsacum research. At the same time, she will be a visiting scientist at Mexico’s National Center for Genetic Resources (CNRG), where officially she will be heading up part of an international switchgrass study. Costich is hoping to leverage her tenure at CIMMYT by getting involved in a push to help improve the Mexican national system for plant genetic resources. Additionally, she has recently accepted an invitation from Seed Savers Exchange to join their board and she is looking forward to volunteering her time and expertise to various seed-saving initiatives within that organization and their many collaborators.
Asked what she’s looking forward to tackling in her retirement that isn’t work related, Costich betrays her deep allegiance to the plant world. “I don’t know,” she says, “I’m thinking of starting a big vegetable garden.”
Cover photo: Denise Costich stands for a photo during the inauguration of the CIMMYT Genebank museum in 2019. (Photo: Alfonso Cortés/CIMMYT)
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.
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)
Fall armyworm continues to cause havoc in Africa. Farmers in Somalia have not been spared since this unwelcome guest showed up in the country over three years ago. As part of the mitigation measures, the Somali Agriculture Technical Group (SATG) in partnership with the International Maize and Wheat Improvement Center (CIMMYT) and the International Committee of the Red Cross (ICRC) recently conducted online trainings on fall armyworm management for sustainable crop protection. The online trainings, targeting national agriculture stakeholders in the country, took place on August 25 and September 30, 2020, with nearly 250 participants attending both webinars.
“This is the first of our efforts to reach out to our partners in Somalia, especially the Somali Agriculture Technical Group and the national agricultural research system, to increase the awareness on the integrated pest management approaches that can help combat this highly destructive pest,” said B.M. Prasanna, Director of CIMMYT’s Global Maize Program and the CGIAR Research Program on Maize (MAIZE).
“This training was designed to help participants to gain a better understanding about fall armyworm, how to identify it, how to monitor and scout for it, how to effectively implement a management strategy that is environmentally and ecologically benign, in order to protect the food security and livelihoods of farmers and their families,” Prasanna said.
An integrated pest management strategy for sustainable control of fall armyworm should consider various interventions, including regular scouting and monitoring of the pest in the fields, host plant resistance, biological and biorational control, agroecological management, and use of environmentally safer pesticides and good agronomic practices tailored for the socio-cultural and economic contexts of the farmers. Ultimately, the purpose of a functional integrated pest management approach is to suppress pest population by applying techniques that minimize human and environmental harm, while protecting the crops from economic damage.
“I am happy to see the expertise from high levels of research at CIMMYT, icipe, IITA, universities, SATG and the humanitarian sector coming together to tackle and solve problems linked to food production and consumption. I believe that such important trainings have great value for Somalia, and should be further strengthened and encouraged,” said Abdalla Togola from the ICRC.
B.M. Prasanna, Director of CIMMYT Global Maize Program and the CGIAR Research Program MAIZE, presents at the online training on integrated pest management-based fall armyworm control. (Photo: Joshua Masinde/CIMMYT)
Hussein Haji, the Executive Director of Somali Agriculture Technical Group speaks at the fall armyworm online training on integrated pest management-based fall armyworm control. (Photo: Joshua Masinde/CIMMYT)
Professor Dan McGrath of Oregon State University, USA, delivering a training on integrated pest management-based fall armyworm control. (Photo: Joshua Masinde/CIMMYT)
John Karonga, an agronomist at the International Committee of the Red Cross (ICRC) speaks at the online training on integrated pest management-based fall armyworm control. (Photo: Joshua Masinde/CIMMYT)
Hussein Haji, the Executive Director of SATG was optimistic that the training would go a long way to empower farmers in Somalia, through their cooperatives, and could lead to better ways of tackling challenges such as fall armyworm, already made worse by other stresses like drought and desert locusts.
“Through our extension workers, we hope this information will trickle down to our cooperatives, who produce mainly maize and sorghum seed in Somalia,” he added.
This comes on the back of a partnership between the ICRC and SATG to implement activities intended to improve food production among rural communities in six regions of Somalia. The partnership would enhance quality seed production with a focus on maize and sorghum, the major staple crops in the country.
Besides Prasanna, the key resource persons included Dan McGrath (Professor Emeritus, Oregon State University, USA), Joseph Huesing (CIMMYT Consultant on integrated pest management) and Georg Goergen (Entomologist, International Institute of Tropical Agriculture), Frederic Baudron (CIMMYT Systems Agronomist), Anani Bruce (CIMMYT Entomologist), Yoseph Beyene (CIMMYT Regional Breeding Coordinator for Africa) and Saliou Niassy (Head of Agricultural Technology Transfer Unit, International Center of Insect Physiology and Ecology).
The fall armyworm, a voracious caterpillar officially reported for the first time in Africa in Nigeria in 2016, remains a serious pest with devastating consequences on millions of farmers’ food and livelihood security. The pest has spread quickly throughout sub-Saharan Africa, primarily attacking maize and sorghum, two main staple crops in the region. The Food and Agriculture Organization of the United Nations (FAO) estimates up to 18 million tons of maize are lost to the pest annually, at an estimated economic loss of $4.6 billion.
To reduce the losses, experts have been recommending a toolbox of integrated pest management (IPM) practices to minimize the damage on smallholder farmers’ fields. Scientists at CIMMYT are also working intensively to develop improved maize varieties with native genetic resistance to this devastating insect pest.
Cover photo: Kowthar Abdirahman Afyare studies agriculture at the Somali National University. (Photo: AMISOM Public Information)
