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Theme: Environmental health and biodiversity

The world needs better management of water, soil, nutrients, and biodiversity in crop, livestock, and fisheries systems, coupled with higher-order landscape considerations as well as circular economy and agroecological approaches.

CIMMYT and CGIAR use modern digital tools to bring together state-of-the-art Earth system observation and big data analysis to inform co-design of global solutions and national policies.

Our maize and wheat genebanks preserve the legacy of biodiversity, while breeders and researchers look at ways to reduce the environmental footprint of agriculture.

Ultimately, our work helps stay within planetary boundaries and limit water use, nutrient use, pollution, undesirable land use change, and biodiversity loss.

New publications: Genome-wide breeding to curtail wheat blast

A recent publication in the journal Frontiers of Plant Science provides results of the first-ever study to test genomic selection in breeding for resistance to wheat blast, a deadly disease caused by the fungus Magnaporthe oryzae that is spreading from its origin in Brazil to threaten wheat crops in South Asia and sub-Saharan Africa.

Genomic selection identifies individual plants based on the information from molecular markers, DNA signposts for genes of interest, that are distributed densely throughout the wheat genome. For wheat blast, the results can help predict which wheat lines hold promise as providers of blast resistance for future crosses and those that can be advanced to the next generation after selection.

In this study, scientists from the International Maize and Wheat Improvement Center (CIMMYT) and partners evaluated genomic selection by combining genotypic data with extensive and precise field data on wheat blast responses for three sets of genetically diverse wheat lines and varieties, more than 700 in all, grown by partners at locations in Bangladesh and Bolivia over several crop cycles.

The study also compared the use of a small number of molecular markers linked to the 2NS translocation, a chromosome segment from the grass species Aegilops ventricosa that was introduced into wheat in the 1980s and is a strong and stable source of blast resistance, with predictions using thousands of genome-wide markers. The outcome confirms that, in environments where wheat blast resistance is determined by the 2NS translocation, genotyping using one-to-few markers tagging the translocation is enough to predict the blast response of wheat lines.

Finally, the authors found that selection based on a few wheat blast-associated molecular markers retained 89% of lines that were also selected using field performance data, and discarded 92% of those that were discarded based on field performance data. Thus, both marker-assisted selection and genomic selection offer viable alternatives to the slower and more expensive field screening of many thousands of wheat lines in hot-spot locations for the disease, particularly at early stages of breeding, and can speed the development of blast-resistant wheat varieties.

Read the full study:
Genomic Selection for Wheat Blast in a Diversity Panel, Breeding Panel and Full-Sibs Panel

The research was conducted by scientists from the International Maize and Wheat Improvement Center (CIMMYT), the Bangladesh Wheat and Maize Research Institute (BWMRI), the Instituto Nacional de Innovación Agropecuaria y Forestal (INIAF) of Bolivia, the Borlaug Institute for South Asia (BISA) and the Indian Council of Agricultural Research (ICAR) in India, the Swedish University of Agricultural Sciences (Alnarp), and Kansas State University in the USA. Funding for the study was provided by the Bill & Melinda Gates Foundation, the Foreign and Commonwealth Development Office of the United Kingdom, the U.S. Agency for International Development (USAID), the CGIAR Research Program on Wheat (WHEAT), the Indian Council of Agricultural Research (ICAR), the Swedish Research Council, and the Australian Centre for International Agricultural Research (ACIAR).

Cover photo: A researcher from Bangladesh shows blast infected wheat spikes and explains how the disease directly attacks the grain. (Photo: Chris Knight/Cornell University)

How interactions among hidden enemies and drought effects grain yield and disease severity in bread wheat

In nature, plants are simultaneously exposed to a complex system of biotic and abiotic stresses that limit crop yield. The cereal cyst nematode Heterodera filipjevi and dryland crown rot, caused by Fusarium, are important diseases facing cereal production around the world that cause significant yield loss. Yield loss accelerates when those diseases coexist with other abiotic stresses, such as drought.

Hexaploid bread wheat (Triticum aestivum L.) is an essential staple food for a large part of the world’s population, covering around 20% of daily caloric intake in the human diet, with global production at about 670.8 million tons per year, produced over 215.4 million hectares of land worldwide. Therefore, the program studying soil-borne pathogens at the International Maize and Wheat Improvement Center (CIMMYT)’s Turkey office initiated a study to investigate the effect of soil borne diseases (H. filipjevi and Fusarium culmorum) individually and in combination with drought on some morphological and physiological traits in wheat germplasm with different genetic tolerances to the three studied factors.

In this study, yield components included thousand kernel weight, spike weight, seed per spike and total grain yield. Morphological parameters, including plant height, final plant number (seedling emergence), relative water content, leaf chlorophyll content, H. filipjevi cyst number and presence of crown rot, were studied under greenhouse conditions in Turkey.

The main findings of the study showed that the interaction among water stress, F. culmorum and H. filipjevi increased the damage on the wheat parameters studied when compared with each stress applied alone. One of the most significant damages was seen in high seedling mortality under the three combined stresses (56% seedling death rate), which indicates the damage on wheat yield might occur at the seedling stage rather than later stages. This reduces plant density per area, which was ultimately responsible for low grain yield produced. The known dryland disease, crown rot, caused by F. culmorum, was significantly pronounced under water-stressed conditions.

In all studied parameters, the lowest damage was found among the resistant cultivars to biotic or abiotic stresses. This underscores the importance of wheat breeding programs to develop resistant germplasm, and reminds farmers to replace their old, susceptible varieties with new, resistant ones.

Based on our intensive experience in the CWANA region, most wheat growers basically do not recognize soil borne pathogens as a problem. In fact, most of them do not know that what nematode or soil fungal species are in their fields affecting yield. The term “hidden enemy” perfectly applies to the problems in the region and beyond. Integrated pest management (IPM) is, however, not practiced in the entire region and soil borne pathogen-induced yield losses are simply accepted.

We can conclude from this study that yield reduction in wheat due to soil borne pathogens could be lessened by improving and understanding the concept of IPM in the region where the practice of winter mono-culturing of wheat is the norm. Management of cereal soil-borne pathogens, especially cereal cyst nematode and crown rot, could involve an integrated approach that includes crop rotation, genetic resistance, crop nutrition and appropriate water supply.

Cover photo: Four different test crops show different stresses: T1V8 = Drought, T2V8 = Drought and Nematodes, T3V8 = Drought and fungus, T4V8 = Drought and nematode and fungus together. (Credit: CIMMYT)

CIMMYT trains next generation of scientists to tackle soil-borne pathogens

Two new students have graduated from the International Maize and Wheat Improvement Center’s (CIMMYT’s) Soil-Borne Pathogens program. The two new graduates, Khawla Mehalaine and Salah-Eddine Laasli, were supervised by CIMMYT senior scientist Abdelfattah Dababat.

He leads the Soil-Borne Pathogens program, which focuses on identifying the main soil-borne pathogens associated with cereals and developing an integrated pest management approach to combat them. The research team is particularly interested in finding novel sources of resistance against these pathogens.

Over the last two decades, CIMMYT scientists leading the Soil-Borne Pathogens program have trained tens of students which constitute the next generation of top researchers on this topic. Through this program, CIMMYT has also organized workshops and courses in North Africa, including a symposium on cereal nematodes held in Agadir, Morocco, in 2017.

Since soil-borne pathogens are exacerbated by water stress conditions, researchers have identified the Central and West Asia and North Africa regions as priority areas, due to their vulnerability to drought.

On March 1, 2021, Syngenta, in collaboration with CIMMYT and other partners, led the first One Earth Soil and Root Health Forum, an event which examined the importance of root and soil health to food security, climate resilience and livelihoods. The event also created a community for action on root and soil health.

Khawla Mehalaine celebrates graduating from her PhD. (Photo: handout)
Khawla Mehalaine celebrates graduating from her PhD. (Photo: handout)

Nematodes in Algeria

Mehalaine holds an engineering degree in agronomy and a master’s degree in plant protection from the Higher National School of Agronomy (ENSA) in Algeria. She successfully defended her PhD dissertation “Studies of cereal cyst nematodes of the genus Heterodera in the regions of northern Algeria” in June 2021, graduating from ENSA with honors.

She studied the behavior of four durum wheat varieties against cereal cyst nematodes through field surveys, molecular identification at species levels, and by evaluating the yield components of these wheat varieties.

She was promoted by ENSA professor Hammach M. and supervised by Dababat from CIMMYT, and professors Mustafa Imren and Göksel Özer from Abant Izzet Baysal University in Turkey.

“Completing my doctorate was a truly enriching experience and a challenging but rewarding journey,” Mehalaine said. “It was a collective effort and I am extremely grateful to Dr Abdelfattah Dababat for sharing his scientific skills, for his patience and support, and for all the opportunities I was given to further my research. Thanks to him, I got to know the world of nematodes. Special thanks to CIMMYT for funding the molecular study part.”

Salah-Eddine Laasli on his graduation day. (Photo: handout)
Salah-Eddine Laasli on his graduation day. (Photo: handout)

Root-lesion nematode and crown rot fungi

Laasli graduated with an International Master of Agronomic and Environmental Nematology (IMANEMA) from Ghent University, in collaboration with CIMMYT, the National Institute of Agricultural Research in Morocco and the Faculty of Agriculture at Abant Izzet Baysal University in Turkey.

His master thesis, entitled “Interaction of Root-Lesion Nematode (Pratylenchus thornei) and Crown Rot fungi (Fusarium culmorum) associated with wheat resistance under simulated field conditions,” was promoted by Wim Bert, a professor at the University of Ghent, and Dababat. The project was also supervised by Imren and Özer.

Laasli evaluated the host status of 150 spring wheat lines to both P. thornei and F. culmorum, and estimated the damage caused by the disease complex involving both pathogens at different infection scenarios. He found several lines that possessed multiple resistance to both diseases tested — which could be powerful sources of resistance for breeding program worldwide.

Cover photo: Irrigated wheat field. (Photo: S. Sukumaran/CIMMYT)

Bringing wild wheat’s untapped diversity into elite lines

A collaboration involving 15 international institutes across eight countries has optimized efforts to introduce beneficial traits from wild wheat accessions in genebanks into existing wheat varieties.

The findings, published in Nature Food, extend many potential benefits to national breeding programs, including improved wheat varieties better equipped to thrive in changing environmental conditions. This research was led by Sukhwinder Singh of the International Maize and Wheat Improvement Center (CIMMYT) as part of the Seeds of Discovery project.

Since the advent of modern crop improvement practices, there has been a bottleneck of genetic diversity, because many national wheat breeding programs use the same varieties in their crossing program as their “elite” source. This practice decreases genetic diversity, putting more areas of wheat at risk to pathogens and environmental stressors, now being exacerbated by a changing climate. As the global population grows, shocks to the world’s wheat supply result in more widespread dire consequences.

The research team hypothesized that many wheat accessions in genebanks — groups of related plant material from a single species collected at one time from a specific location — feature useful traits for national breeding programs to employ in their efforts to diversify their breeding programs.

“Genebanks hold many diverse accessions of wheat landraces and wild species with beneficial traits, but until recently the entire scope of diversity has never been explored and thousands of accessions have been sitting on the shelves. Our research targets beneficial traits in these varieties through genome mapping and then we can deliver them to breeding programs around the world,” Singh said.

Currently adopted approaches to introduce external beneficial genes into breeding programs’ elite cultivars take a substantial amount of time and money. “Breeding wheat from a national perspective is a race against pathogens and other abiotic threats,” said Deepmala Sehgal, co-author and wheat geneticist in the Global Wheat program at CIMMYT. “Any decrease in the time to test and release a variety has a huge positive impact on breeding programs.”

Deepmala Sehgal shows LTP lines currently being used in CIMMYT trait pipelines at the experimental station in Toluca, Mexico, for introgression of novel exotic-specific alleles into newly developed lines. (Photo: CIMMYT)
Deepmala Sehgal shows LTP lines currently being used in CIMMYT trait pipelines at the experimental station in Toluca, Mexico, for introgression of novel exotic-specific alleles into newly developed lines. (Photo: CIMMYT)

Taking into genetic biodiversity

The findings build from research undertaken through the Seeds of Discovery project, which genetically characterized nearly 80,000 samples of wheat from the seed banks of CIMMYT and the International Center for Agricultural Research in the Dry Areas (ICARDA).

First, the team undertook a large meta-survey of genetic resources from wild wheat varieties held in genebanks to create a catalog of improved traits.

“Our genetic mapping,” Singh said, “identifies beneficial traits so breeding programs don’t have to go looking through the proverbial needle in the haystack. Because of the collaborative effort of the research team, we could examine a far greater number of genomes than a single breeding program could.”

Next, the team developed a strategic three-way crossing method among 366 genebank accessions and the best historical elite varieties to reduce the time between the original introduction and deployment of an improved variety.

Sukhwinder Singh (second from left) selects best performing pre-breeding lines in India. (Photo: CIMMYT)
Sukhwinder Singh (second from left) selects best performing pre-breeding lines in India. (Photo: CIMMYT)

Worldwide impact

National breeding programs can use the diverse array of germplasm for making new crosses or can evaluate the germplasm in yield trials in their own environments.

The diverse new germplasm is being tested in major wheat producing areas, including India, Kenya, Mexico and Pakistan. In Mexico, many of the lines showed increased resistance to abiotic stresses; many lines tested in Pakistan exhibited increased disease resistance; and in India, many tested lines are now part of the national cultivar release system. Overall, national breeding programs have adopted 95 lines for their targeted breeding programs and seven lines are currently undergoing varietal trials.

“This is the first effort of its kind where large-scale pre-breeding efforts have not only enhanced the understanding of exotic genome footprints in bread wheat but also provided practical solutions to breeders,” Sehgal said. “This work has also delivered pre-breeding lines to trait pipelines within national breeding programs.”

Currently, many of these lines are being used in trait pipelines at CIMMYT to introduce these novel genomic regions into advanced elite lines. Researchers are collaborating with physiologists in CIMMYT’s global wheat program to dissect any underlying physiological mechanisms associated with the research team’s findings.

“Our investigation is a major leap forward in bringing genebank variation to the national breeding programs,” Singh explained. “Most significantly, this study sheds light on the importance of international collaborations to bring out successful products and new methods and knowledge to identify useful contributions of exotic in elite lines.”

Read the full article:
Direct introgression of untapped diversity into elite wheat lines

Cover photo: A researcher holds a plant of Aegilops neglecta, a wild wheat relative. Approximately every 20 years, CIMMYT regenerates wheat wild relatives in greenhouses, to have enough healthy and viable seed for distribution when necessary. (Photo: Rocío Quiroz/CIMMYT)

Singh receives lifetime award for wheat breeding successes

Ravi Singh, head of global wheat improvement at the International Maize and Wheat Improvement Center (CIMMYT), received the 2021 Borlaug Global Rust Initiative (BGRI) Lifetime Achievement Award for his contribution to protecting wheat from new races of some of agriculture’s oldest and most devastating diseases.

Read more: https://www.world-grain.com/articles/16099-singh-receives-lifetime-award-for-wheat-breeding-successes

New CSISA Infographic highlights the impact of the CIMMYT’s Soil Intelligence System (SIS)

In agriculture, good soil management is a pillar of productive systems that can sustainably produce sufficient and healthy food for the world’s growing population.

Soil properties, however, vary widely across geography. To understand the productive capacity of our soils, we need high-quality data. Soil Intelligence System (SIS) is an initiative to develop comprehensive soil information at scale under the Cereal Systems Initiative for South Asia (CSISA) project in India. SIS is led by the International Maize and Wheat Improvement Centre (CIMMYT) in collaboration with ISRIC – World Soil Information, International Food Policy Research Institute (IFPRI), and numerous local partners on the ground.

Funded by the Gates Foundation, the initiative launched in 2019 helps rationalize the costs of generating high-quality soils data while building accessible geo-spatial information systems based on advanced geo-statistics. SIS is currently operational in the States of Andhra Pradesh, Bihar and Odisha where the project partners collaborate with state government and state agricultural universities help produce robust soil health information.

Farmers are the primary beneficiaries of this initiative, as they get reliable soil health management recommendations to increase yields and profits sustainably while state partners, extension and agricultural development institutions and private sector benefit primarily by expanding their understanding for agricultural interventions.

Modern Soil Intelligence System Impact

CIMMYT’s SIS Project lead Balwinder Singh said, “The Soil Intelligence Systems initiative under CSISA is an important step towards the sustainable intensification of agriculture in South Asia. SIS has helped create comprehensive soil information – digital soil maps – for the states of Andhra Pradesh, Bihar and Odisha. The data generated through SIS is helping stakeholders to make precise agronomy decisions at scale that are sustainable.”

Since its launch in December 2019, a wider network and multi-institutional alliances have been built for soil health management and the application of big data in addressing agricultural challenges. In the three states the infrastructure and capacity of partners have been strengthened to leverage soil information for decision-making in agriculture by devising new soil health management recommendations. For example, in the state of Andhra Pradesh, based on SIS data and outreach, State Fertilizer and Micronutrient Policy (SFMP) recommendations were created. Similarly, soil health management zones have been established to strengthen the fertilizer distribution markets enabling farmers with access and informed choices.

“Soil Intelligence System delivers interoperable information services that are readily usable by emerging digital agricultural decision support systems in India”, noted Kempen Senior Soil Scientist at ISRIC.

The three-part infographic highlights the impact of SIS initiative in the select three States and emphasizes the importance of SIS in other parts of the country as well.

CIMMYT, AGG wheat experts share latest discoveries at BGRI Technical Workshop

Dave Hodson, International Maize and Wheat Improvement Center (CIMMYT) senior scientist delivered a large-scale overview of the current global wheat rust situation and the state of disease surveillance systems. He underscored the importance of comprehensive early warning systems and promising new detection tools that help to raise awareness and improve control. A new assessment of the early warning system for rust In Ethiopia showed a real impact on farmers’ interest, awareness, and farming practices to control the disease, as well as high-level policy changes.

Alison Bentley, CIMMYT Global Wheat Program director, described cutting-edge tools and methods by CIMMYT and, in particular, the Accelerating Genetic Gains in Maize and Wheat for Improved Livelihoods (AGG) project to increase wheat productivity in the face of changing climates. In addition to the new approaches on the supply side, she argued, we also need increased research on the demand side to better understand why farmers will choose a new variety, the role of markets and gender, and how we can scale up these systems. Bentley emphasized the criticality of supporting public and private sector efforts to get more improved germplasm into farmers’ fields in less time.

Philomin Juliana, CIMMYT Global Wheat Program associate scientist highlighted the pivotal role that data plays in breeding decisions and line advancements in CIMMYT’s wheat breeding program. This has been facilitated by improvements in how data sets, like genomic estimated breeding values (GEBVs), are shared with breeders. “CIMMYT has adopted a holistic, data-driven selection approach” that leverages phenotypic data, genomic-estimated breeding values (GEBVs) and selection indices, Juliana explained.

Managing stresses the key to better wheat varieties for all

In an interview with The Land, Alison Bentley, director of CIMMYT’s Global Wheat Program and the CGIAR Research Program on Wheat (WHEAT), emphasized the importance of developing drought-tolerant wheat varieties to see better yields in tough seasons.

Read more: https://www.theland.com.au/story/7492717/managing-stresses-the-key-to-better-wheat-varieties-for-all/?cs=4937

Ravi Singh earns Lifetime Achievement award from BGRI

CIMMYT distinguished scientist Ravi Singh conducts research on a wheat field while. (Photo: BGRI)
CIMMYT distinguished scientist Ravi Singh conducts research on a wheat field while. (Photo: BGRI)

World-renowned plant breeder Ravi Singh, whose elite wheat varieties reduced the risk of a global pandemic and now feed hundreds of millions of people around the world, has been announced as the 2021 Borlaug Global Rust Initiative (BGRI) Lifetime Achievement Award recipient.

Singh, distinguished scientist and head of Global Wheat Improvement at the International Maize and Wheat Improvement Center (CIMMYT), endowed hundreds of modern wheat varieties with durable resistance to fungal pathogens that cause leaf rust, stem rust, stripe rust and other diseases during his career. His scientific efforts protect wheat from new races of some of agriculture’s oldest and most devastating diseases, safeguard the livelihoods of smallholder farmers in the most vulnerable areas in the world, and enhance food security for the billions of people whose daily nutrition depends on wheat consumption.

“Ravi’s innovations as a scientific leader not only made the Cornell University-led Borlaug Global Rust Initiative possible, but his breeding innovations are chiefly responsible for the BGRI’s great success,” said Ronnie Coffman, vice chair of the BGRI and international professor of global development at Cornell’s College of Agriculture and Life Sciences. “Perhaps more than any other individual, Ravi has furthered Norman Borlaug’s and the BGRI’s goal that we maintain the global wheat scientific community and continue the crucial task of working together across international borders for wheat security.”

In the early 2000s, when a highly virulent rust race discovered in East Africa threatened most of the world’s wheat, Singh took a key leadership role in the formation of a global scientific coalition to combat the threat. Along with Borlaug, Coffman and other scientists, he served as a panel member on the pivotal report alerting the international community to the Ug99 outbreak and its potential impacts to global food security. That sounding of the alarm spurred the creation of the BGRI and the collaborative international effort to stop Ug99 before it could take hold on a global scale.

As a scientific objective leader for the BGRI’s Durable Rust Resistance in Wheat and Delivering Genetic Gain in Wheat projects, Singh led efforts to generate and share a series of elite wheat lines featuring durable resistance to all three rusts. The results since 2008 include resistance to the 12 races of the Ug99 lineage and new, high-temperature-tolerant races of stripe rust fungus that had been evolving and spreading worldwide since the beginning of the 21st century.

“Thanks to Ravi Singh’s vision and applied science, the dire global threat of Ug99 and other rusts has been averted, fulfilling Dr. Borlaug’s fervent wishes to sustain wheat productivity growth, and contributing to the economic and environmental benefits from reduced fungicide use,” Coffman said. “Ravi’s innovative research team at CIMMYT offered crucial global resources to stop the spread of Ug99 and the avert the human catastrophe that would have resulted.”

An innovative wheat breeder known for his inexhaustible knowledge and attention to genetic detail, Singh helped establish the practice of “pyramiding” multiple rust-resistance genes into a single variety to confer immunity. This practice of adding complex resistance in a way that makes it difficult for evolving pathogens to overcome new varieties of wheat now forms the backbone of rust resistance breeding at CIMMYT and other national programs.

Ravi Singh (center) with Norman Borlaug (left) and Hans Braun in the wheat fields at CIMMYT’s experimental station in Ciudad Obregón, in Mexico’s Sonora state. (Photo: CIMMYT)
Ravi Singh (center) with Norman Borlaug (left) and Hans Braun in the wheat fields at CIMMYT’s experimental station in Ciudad Obregón, in Mexico’s Sonora state. (Photo: CIMMYT)

The global champion for durable resistance

Ravi joined CIMMYT in 1983 and was tasked by his supervisor, mentor and friend, the late World Food Prize Winner Sanjaya Rajaram, to develop wheat lines with durable resistance, said Hans Braun, former director of CIMMYT’s Global Wheat Program.

“Ravi did this painstaking work — to combine recessive resistance genes — for two decades as a rust geneticist and, as leader of CIMMYT’s Global Spring Wheat Program, he transferred them at large scale into elite lines that are now grown worldwide,” Braun said. “Thanks to Ravi and his colleagues, there has been no major rust epidemic in the Global South for years, a cornerstone for global wheat security.”

Alison Bentley, Director of CIMMYT’s Global Wheat Program, said that “Building on Ravi’s exceptional work throughout his career, deployment of durable rust resistance in widely adapted wheat germplasm continues to be a foundation of CIMMYT’s wheat breeding strategy.”

Revered for his determination and work ethic throughout his career, Singh has contributed to the development of 649 wheat varieties released in 48 countries, working closely with scientists at national wheat programs in the Global South. Those varieties today are sown on approximately 30 million hectares annually in nearly all wheat growing countries of southern and West Asia, Africa and Latin America. Of these varieties, 224 were developed directly under his leadership and are grown on an estimated 10 million hectares each year.

In his career Singh has authored 328 refereed journal articles and reviews, 32 book chapters and extension publications, and more than 80 symposia presentations. He is regularly ranked in the top 1% of cited researchers. The CIMMYT team that Singh leads identified and designated 22 genes in wheat for resistance or tolerance to stem rust, leaf rust, stripe rust, powdery mildew, barley yellow dwarf virus, spot blotch, and wheat blast, as well as characterizing various other important wheat genome locations contributing to durable resistance in wheat.

Singh’s impact as a plant breeder and steward of genetic resources over the past four decades has been extraordinary, according to Braun: “Ravi Singh can definitely be called the global champion for durable resistance.”

This piece by Matt Hayes was originally posted on the BGRI website.

World Food Day 2021: The future of food is in our hands

As the calendar turns to October 16, the International Maize and Wheat Improvement Center (CIMMYT) celebrates World Food Day. This year’s theme is “Our actions are our future.”

Our lives depend on agri-food systems.

They cover the journey of food (for example, cereals, vegetables, fish, fruits and livestock) from farm to table — including when it is grown, harvested, processed, packaged, transported, distributed, traded, bought, prepared, eaten and disposed of. It also encompasses non-food products (for example forestry, animal rearing, use of feedstock, biomass to produce biofuels, and fibers) that constitute livelihoods, and all the people, as well as the activities, investments and choices that play a part in getting us these food and agricultural products.

The food we choose and the way we produce, prepare, cook and store it make us an integral and active part of the way in which an agri-food system works.

A sustainable agri-food system is one in which a variety of sufficient, nutritious and safe foods is available at an affordable price to everyone, and nobody is hungry or suffers from any form of malnutrition. The shelves are stocked at the local market or food store, but less food is wasted and the food supply chain is more resilient to shocks such as extreme weather, price spikes or pandemics, all while limiting, rather than worsening, environmental degradation or climate change. In fact, sustainable agri-food systems deliver food security and nutrition for all, without compromising the economic, social and environmental bases, for generations to come. They lead to better production, better nutrition, a better environment and a better life for all.

Let’s fix the system

The contradictions could not be starker — millions of people are hungry or undernourished, while large numbers are chronically overweight due to a poor diet. Smallholder farmers produce more than one-third of the world’s food, yet are some of the worst affected by poverty, as agriculture continues to be an unpredictable sector. Agri-food systems are major contributors to climate change, which in turn threatens food production in some of the world’s poorest areas. Rampant food loss and waste, side by side with people relying on food banks or emergency food aid.

The evidence is there for all to see — there has never been a more urgent need to transform the way the world produces and consumes food.

This year, for World Food Day, we bring you four stories about CIMMYT’s work to support sustainable agri-food systems.

Better production

CGIAR centers present methodology for transforming resource-constrained, polluting and vulnerable farming into inclusive, sustainable and resilient food systems that deliver healthy and affordable diets for all within planetary boundaries.

New integrated methodology supports inclusive and resilient global food systems transformation

Better nutrition

CIMMYT scientists expect to sharply ramp up new wheat varieties enriched with zinc that can boost the essential mineral for millions of poor people with deficient diets. Newly-developed high-zinc wheat is expected to make up at least 80% of varieties distributed worldwide over the next ten years, up from about 9% currently.

New zinc-fortified wheat set for global expansion to combat malnutrition

A woman makes roti, an unleavened flatbread made with wheat flour and eaten as a staple food, at her home in the Dinajpur district of Bangladesh. (Photo: S. Mojumder/Drik/CIMMYT)

Better environment

Understanding the relationship between climate change and plant health is key to conserving biodiversity and boosting food production today and for future generations.

Protecting plants will protect people and the planet

Durum wheat field landscape at CIMMYT's experimental station in Toluca, Mexico. (Photo: Alfonso Cortés/CIMMYT)
Durum wheat field landscape at CIMMYT’s experimental station in Toluca, Mexico. (Photo: Alfonso Cortés/CIMMYT)

Better life

Assessing value chain development’s potential and limitations for strengthening the livelihoods of the rural poor, a new book draws conclusions applicable across the development field.

Taking stock of value chain development

A researcher from the International Maize and Wheat Improvement Center (CIMMYT) demonstrates the use of a farming app in the field. (Photo: C. De Bode/CGIAR)
A researcher from the International Maize and Wheat Improvement Center (CIMMYT) demonstrates the use of a farming app in the field. (Photo: C. De Bode/CGIAR)

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Taming wheat blast

As wheat blast continues to infect crops in  countries around the world, researchers are seeking ways to stop its spread. The disease — caused by the Magnaporthe oryzae pathotype Triticum — can dramatically reduce crop yields, and hinder food and economic security in the regions in which it has taken hold.

Researchers from the International Maize and Wheat Improvement Center (CIMMYT) and other international institutions looked into the potential for wheat blast to spread, and surveys existing tactics used to combat it. According to them, a combination of methods — including using and promoting resistant varieties, using fungicides, and deploying strategic agricultural practices — has the best chance to stem the disease.

The disease was originally identified in Brazil in 1985. Since then, it has spread to several other countries in South America, including Argentina, Bolivia and Paraguay. During the 1990s, wheat blast impacted as many as three million hectares in the region. It continues to pose a threat.

Through international grain trade, wheat blast was introduced to Bangladesh in 2016. The disease has impacted around 15,000 hectares of land in the country and reduced average yields by as much as 51% in infected fields.

Because the fungus’ spores can travel on the wind, it could spread to neighboring countries, such as China, India, Nepal and Pakistan — countries in which wheat provides food and jobs for billions of people. The disease can also spread to other locales via international trade, as was the case in Bangladesh.

“The disease, in the first three decades, was spreading slowly, but in the last four or five years its pace has picked up and made two intercontinental jumps,” said Pawan Singh, CIMMYT’s head of wheat pathology, and one of the authors of the recent paper.

In the last four decades, wheat blast has appeared in South America, Asia an Africa. (Video: Alfonso Cortés/CIMMYT)

The good fight

Infected seeds are the most likely vector when it comes to the disease spreading over long distances, like onto other continents. As such, one of the key wheat blast mitigation strategies is in the hands of the world’s governments. The paper recommends quarantining potentially infected grain and seeds before they enter a new jurisdiction.

Governments can also create wheat “holidays”, which functionally ban cultivation of wheat in farms near regions where the disease has taken hold. Ideally, this would keep infectable crops out of the reach of wheat blast’s airborne and wind-flung spores. In 2017, India banned wheat cultivation within five kilometers of Bangladesh’s border, for instance. The paper also recommends that other crops — such as legumes and oilseed — that cannot be infected by the wheat blast pathogen be grown in these areas instead, to protect the farmers’ livelihoods.

Other tactics involve partnerships between researchers and agricultural workers. For instance, early warning systems for wheat blast prediction have been developed and are being implemented in Bangladesh and Brazil. Using weather data, these systems alert farmers when the conditions are ideal for a wheat blast outbreak.

Researchers are also hunting for wheat varieties that are resistant to the disease. Currently, no varieties are fully immune, but a few do show promise and can partially resist the ailment depending upon the disease pressure. Many of these resistant varieties have the CIMMYT genotype Milan in their pedigree.

“But the resistance is still limited. It is still quite narrow, basically one single gene,” Xinyao He, one of the co-authors of the paper said, adding that identifying new resistant genes and incorporating them into breeding programs could help reduce wheat blast’s impact.

Wheat spikes damaged by wheat blast. (Photo: Xinyao He/CIMMYT)
Wheat spikes damaged by wheat blast. (Photo: Xinyao He/CIMMYT)

The more the merrier

Other methods outlined in the paper directly involve farmers. However, some of these might be more economically or practically feasible than others, particularly for small-scale farmers in developing countries. Wheat blast thrives in warm, humid climates, so farmers can adjust their planting date so the wheat flowers when the weather is drier and cooler. This method is relatively easy and low-cost.

The research also recommends that farmers rotate crops, alternating between wheat and other plants wheat blast cannot infect, so the disease will not carry over from one year to the next. Farmers should also destroy or remove crop residues, which may contain wheat blast spores. Adding various minerals to the soil, such as silicon, magnesium, and calcium, can also help the plants fend off the fungus. Another option is induced resistance, applying chemicals to the plants such as jasmonic acid and ethylene that trigger its natural resistance, much like a vaccine, Singh said.

Currently, fungicide use, including the treatment of seeds with the compounds, is common practice to protect crops from wheat blast. While this has proven to be somewhat effective, it adds additional costs which can be hard for small-scale farmers to swallow. Furthermore, the pathogen evolves to survive these fungicides. As the fungus changes, it can also gain the ability to overcome resistant crop varieties. The paper notes that rotating fungicides or developing new ones — as well as identifying and deploying more resistant genes within the wheat — can help address this issue.

However, combining some of these efforts in tandem could have a marked benefit in the fight against wheat blast. For instance, according to Singh, using resistant wheat varieties, fungicides, and quarantine measures together could be a time-, labor-, and cost-effective way for small-scale farmers in developing nations to safeguard their crops and livelihoods.

“Multiple approaches need to be taken to manage wheat blast,” he said.

Climate-smart strategy for weed management proves to be extremely effective

Rice-wheat cropping rotations are the major agri-food system of the Indo-Gangetic Plains of South Asia, occupying the region known as the “food basket” of India. The continuous rice-wheat farming system is deceptively productive, however, under conventional management practices.

Over-exploitation of resources leaves little doubt that this system is unsustainable, evidenced by the rapid decline in soil and water resources, and environmental quality. Furthermore, continuous cultivation of the same two crops over the last five decades has allowed certain weed species to adapt and proliferate. This adversely affects resource-use efficiency and crop productivity, and has proven to negatively influence wheat production in the Western Indo-Gangetic Plains under conventional wheat management systems.

Studies suggest weed infestations could reduce wheat yields by 50-100% across the South Asian Indo-Gangetic Plains. Globally, yield losses from weeds reach 40%, which is more than the effects of diseases, insects, and pests combined.

Herbicides are not just expensive and environmentally hazardous, but this method of chemical control is becoming less reliable as some weeds become resistant to an increasing number common herbicides. Considering the food security implications of weed overgrowth, weed management is becoming increasingly important in future cropping systems.

How can weeds be managed sustainably?

Climate-smart agriculture-based management practices are becoming a viable and sustainable alternative to conventional rice-wheat cropping systems across South Asia, leading to better resource conservation and yield stability. In addition to zero-tillage and crop residue retention, crop diversification, precise water and nutrient management, and timing of interventions are all important indicators of climate-smart agriculture.

In a recently published 8-year study, scientists observed weed density and diversity under six different management scenarios with varying conditions. Conditions ranged from conventional, tillage-based rice-wheat system with flood irrigation (scenario one), to zero-tillage-based maize-wheat-mung bean systems with subsurface drip irrigation (scenario 6). Each scenario increased in their climate-smart agriculture characteristics all the way to fully climate-smart systems.

At the end of 8 years, scenario six had the lowest weed density, saw the most abundant species decrease dramatically, and seven weed species vanish entirely.  Scenario one, with conventional rice-wheat systems with tillage and flooding, experienced the highest weed density and infestation. This study highlights the potential of climate-smart agriculture as a promising solution for weed suppression in northwestern India.

Read the full study: Climate-smart agriculture practices influence weed density and diversity in cereal-based agri-food systems of western Indo-Gangetic plains

Cover image: Farmer weeding in a maize field in India. (Photo: M. Defreese/CIMMYT)

A new tool to strengthen the fight against fall armyworm in Asia

Together with the United States Agency for International Development (USAID) and Feed the Future, the International Maize and Wheat Improvement Center (CIMMYT) and the CGIAR Research Program on Maize (MAIZE) are pleased to announce the release of “Fall Armyworm in Asia: A Guide for Integrated Pest Management.”

The publication builds on intensive, science-based responses to fall armyworm in Africa and Asia.

Fall armyworm in Asia: A guide for integrated pest management“I have encountered few pests as alarming as the fall armyworm,” wrote USAID Chief Scientist Rob Bertram in the guide’s Foreword. “This publication … offers to a broad range of public and private stakeholders — including national plant protection, research and extension professionals — evidence-based approaches to sustainably manage fall armyworm,” Bertram adds.

“Partners from a wide array of national and international institutions have contributed to the mammoth task of formulating various chapters in the guide,” said B.M. Prasanna, director of CIMMYT’s Global Maize Program and of MAIZE. “While the publication is focused on Asia, it provides an updated understanding of various components of fall armyworm integrated pest management that could also benefit stakeholders in Africa.”

In January 2018, CIMMYT and USAID published a similar guide on integrated pest management of fall armyworm in Africa, which reached a large number of stakeholders globally and is widely cited. Prasanna spearheaded the development and publication of both guides.

The current publication also follows CIMMYT’s announcement of three fall armyworm-tolerant elite maize hybrids for sub-Saharan Africa.