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Tag: pest and disease resistance

Building global capacity to combat wheat blast

Written by Julian Bañuelos-Uribe on . Posted in News.

Researchers and experts from 15 countries convened in Zambia, between 4-15 March 2024, for an international training on wheat blast disease screening, surveillance, and management.

Wheat blast, caused by pathogen Magnaporthe oryzae pathotype triticum, is threatening global wheat production especially in warmer and humid regions. The disease was first observed in Parana state of Brazil in 1985 and subsequently spread to Bolivia, Paraguay, and Argentina. Outside of South America, wheat blast incidences were recorded for the first time in Bangladesh in 2016 and in Zambian wheat fields in 2018.

To mitigate the impact of this potential plant pandemic, the Zambia Agriculture Research Institute (ZARI), in collaboration with CIMMYT and other partners, organized a comprehensive training for building research capacity and raising awareness within the local and international community, especially in at-risk countries.

“This collaborative effort, supported by various international partners and funders, underscores the importance of global cooperation in addressing agricultural challenges such as wheat blast. The objective of the training was to empower researchers with knowledge and tools for enhanced wheat production resilience in regions vulnerable to this destructive disease,” said Pawan Kumar Singh, principal scientist and project leader at CIMMYT. Singh collaborated with Batiseba Tembo, wheat breeder at ZARI-Zambia, to coordinate and lead the training program.

Thirty-eight wheat scientists, researchers, professors, policymakers, and extension agents from countries including Bangladesh, Brazil, Ethiopia, India, Kenya, Mexico, Nepal, South Africa, Sweden, Tanzania, United Kingdom, Uruguay, Zambia, and Zimbabwe convened at the Mt. Makulu Central Research Station in Chilanga, Zambia.

“Wheat blast is a devastating disease that requires concerted efforts to effectively manage it and halt further spread. The disease is new to Africa, so developing capacity amongst country partners before the disease spreads more widely is critical,” said Tembo.

Participants at the International Training on Wheat Blast Screening and Surveillance. (Photo: CIMMYT)

Highlights from the training: discussions, lab exercises, and field visits

During the training, participants engaged in lectures, laboratory exercises, and field visits. There were insightful discussions on key topics including the fundamentals of wheat blast epidemiology, disease identification, molecular detection of the wheat blast pathogen, isolation and preservation techniques for the pathogen, disease scoring methods, disease management strategies, and field surveillance and monitoring.

The course also provided practical experience in disease evaluation at the Precision Phenotyping Platform (PPP) screening nursery located in Chilanga research station. This involved characterization of a diverse range of wheat germplasm with the aim of releasing resistant varieties in countries vulnerable to wheat blast. Additionally, participants undertook field visits to farmers’ fields, conducting surveillance of wheat blast-infected areas. They collected samples and recorded survey data using electronic open data kit (ODK) capture tools.

Participants listen to a lecture by B.N. Verma, director of Zambia Seed Co., on the history of wheat production in Zambia. (Photo: CIMMYT)

“The killer disease needs to be understood and managed utilizing multi-faceted approaches to limit the expansion and damages it can cause to global wheat production. The Bangladesh Wheat and Maize Research Institute (BWMRI) is willing to share all the strategies it deployed to mitigate the effect of wheat blast,” said Golam Faruq, BWMRI’s director general.

Participants visited seed farms to gain practical insights into seed production processes and quality assurance measures. These visits provided first-hand knowledge of seed selection, breeding techniques, and management practices crucial for developing resistant wheat varieties. Participants also visited research sites and laboratories to observe advanced research methodologies and technologies related to wheat blast management. These visits exposed them to cutting-edge techniques in disease diagnosis, molecular analysis, and germplasm screening, enhancing their understanding of effective disease surveillance and control strategies.

Field visit. (Photo: CIMMYT)

“The training and knowledge sharing event was a significant first step in developing understanding and capacity to deal with wheat blast for partners from several African countries. It was wonderful to see the efforts made to ensure gender diversity among participants,” said Professor Diane Saunders from the John Innes Centre, UK.

CIMMYT and China join forces to tackle wheat disease in Africa

Written by Julian Bañuelos-Uribe on . Posted in News.

While wheat acreage has been increasing across the whole of Africa, the sub-Saharan countries account for a significant proportion of the total growth and yield, equaling an area of approximately 3.1 million hectares and a production of more than 9 million tons. However, in recent years, Fusarium head blight (FHB) or head scab has become a major disease in the region, causing significant reductions in yield and quality due to the lack of resistant varieties and management tools.

In China, a successful wheat shuttle breeding program by the Chinese Academy of Agricultural Sciences (CAAS) and CIMMYT for improving FHB has existed since the 1980s. Additionally, CIMMYT and the Jiangsu Academy of Agricultural Sciences (JAAS) have provided an FHB screening station in Nanjing since 2019. With a wealth of experience in confronting the disease, this ongoing partnership can help to solve the challenges currently faced by farmers in Africa.

To this end, CAAS, JAAS, and CIMMYT organized a training workshop on FHB management for Africa, which took place with financial support from China Aid in Beijing and Nanjing, China, between 10 and 23 April 2024. Twenty participants, 45% of which were women, attended the workshop, with specialists in wheat breeding, pathology, seed quarantine, and other related fields at public institutions in Ethiopia, Zambia, and Lesotho.

“This is the first time China has worked with an international organization to conduct an agricultural training workshop for sub-Saharan Africa,” said Zhonghu He, CIMMYT distinguished scientist and country liaison officer in China.

A hands-on demonstration at the Jiangsu Academy of Agricultural Sciences (JAAS) and CIMMYT Fusarium head blight (FHB) precision phenotyping platform helps scientists in Africa to better understand and fight the wheat disease. (Photo: Liu Xiyan/CAAS)

Practical tools to target FHB

Experts from China and CIMMYT shared their successful experiences of FHB management, including breeding resistant varieties. The trainees benefitted from hands-on experience of FHB identification, disease screening (including inoculum preparation, inoculation, and scoring), mycotoxin quantification techniques, and wheat breeding.

At the end of the workshop, the participants were extremely pleased to observe the impressive progress made in China on wheat FHB both on breeding and disease control, and they expressed strong willingness to contribute to collaboration between Africa, China, and CIMMYT on more wheat breeding and research. Netsanet Bacha Hei from the Ethiopian Institute of Agricultural Research (EIAR) was impressed with the scientific and technical expertise provided in the training and mentioned that sub-Saharan Africa needs similar practical trainings to mitigate the threat of FHB. Similar opinions were echoed by Doreen Malekano Chomba from the Zambian Plant Quarantine and Phytosanitary Service (PQPS), who discussed the need to have an effective in-country surveillance and monitoring to assess and manage FHB in the region.

Participants gather for the opening ceremony of the workshop at the Chinese Academy of Agricultural Sciences (CAAS) in Beijing. (Photo: Li Simin/CAAS)

Xu Zhang, who heads the FHB research program at JAAS, is very appreciative of the collaborative work that has been going on for several decades between CIMMYT and China, highlighting that the workshop represents another step in understanding and managing FHB in sub-Saharan Africa and beyond, Zhang said, JAAS and CIMMYT has grown together through strong partnership.

“This training lays firm groundwork for future China-Africa-CIMMYT collaboration on mitigating the threat of FHB and improving wheat production and food security in sub-Saharan African countries,” said He.

Successful surveillance results in early first detection of Ug99 in South Asia

Written by Julian Bañuelos-Uribe on . Posted in News.

Successful global wheat disease surveillance and monitoring has resulted in early detection of wheat stem rust Ug99 in Nepal. A combination of vigilant field surveys and sampling by Nepal’s National Plant Pathology Research Centre (NPPRC) and National Wheat Research Program (NWRP), supported by rigorous and accurate disease diagnostics at the Global Rust Reference Center (GRRC), Denmark, resulted in confirmed detection of the Ug99 strain named TTKTT. The long running and sustained surveillance efforts undertaken by NPPRC and NWRP, including off-season surveys, proved vital in the detection of Ug99 in Nepal. Confirmed results were obtained from two field samples collected in early November 2023 from off-season summer wheat crops in Dolakha district, Nepal. Repeated experiments and high quality pathotyping and genotyping at GRRC confirmed the results.

“The combination of molecular genotyping of incoming samples, without prior recovery in our laboratory and independent diagnostic assays of recovered stem rust isolates, confirmed the presence of Ug99 and a highly virulent race variant termed TTKTT,” says professor Mogens Hovmøller, leader of the GRRC at Aarhus University in Denmark.

Suraj Baidya (NPPRC) and Roshan Basnet (National Wheat Research Program) undertake field surveys at Dandunghe, Dolakha, Nepal. (Photo: CIMMYT)

Ug99 was first detected in East Africa in 1998/99, and its unique virulence sparked fears that a large proportion of wheat cultivars globally would be at risk from this potentially devastating disease. The international wheat community came together through the Borlaug Global Rust Initiative (BGRI) to address the threats posed by Ug99. The BGRI partners have successfully monitored the evolution and spread of Ug99 and bred hundreds of resistant wheat varieties that are now being grown at scale in priority wheat growing regions. Migration of Ug99 from Africa to other regions, including South Asia, was always seen as likely due to the transboundary nature of the disease and long-distance dispersal of rust spores by wind.

Detection of a Ug99 race in Nepal is not therefore a surprise, but it highlights the effectiveness of the wheat rust surveillance and monitoring systems that have been developed. The disease was present at extremely low levels in the fields in Nepal, and early detection is one of the main factors in preventing disease spread. Other factors also contribute to reduced risk. The wheat on which the Ug99 race TTKTT was detected were fodder crops and cut soon after the surveys were completed, which prevented further buildup of disease. In addition, no wheat is grown in the main season in these areas, with farmers shifting to cultivation of potato (a non-host crop for stem rust).

According to Suraj Baidya, senior scientist and chief of NPPRC, “Extensive follow up surveys in the Dolakha detection area by NPPRC in the 2023/24 main season resulted in no wheat being observed and no detection of stem rust.” Similarly, extensive surveys by NPPRC throughout other wheat growing areas of Nepal in the 2023/24 main season have resulted in no reports of stem rust in the country. To date, extensive surveys in other countries in South Asia (Pakistan, Bangladesh, Bhutan) have not detected stem rust in 2023/24.

Although the current risk of stem rust outbreaks is considered to be low, detection of the Ug99 race TTKTT in Nepal is a clear reminder of the threat posed to wheat production in South Asia by the incursion of virulent stem rust races or other plant diseases of concern. “The spread and risk from transboundary diseases like stem rust is increasing,” says Dave Hodson, leader of the Wheat Disease Early Warning Advisory Systems (DEWAS) project at CIMMYT. “Sustained and increased surveillance efforts are needed across the region and expanded to include other important emerging diseases.” Successful deployment of Ug99 resistant cultivars through the BGRI partners, including CIMMYT, ICARDA and NARS, has decreased vulnerability, but it is important to note that the race TTKTT is a recently evolved variant of Ug99 with additional virulence compared to the original strains. As a result, not all cultivars in South Asia may have effective resistance today. Screening of germplasm and major cultivars from South Asia against TTKTT at the Kenya Agriculture and Livestock Research Organization (KALRO)/CIMMYT international stem rust screening nursery in Kenya is extremely important to get an accurate picture of current vulnerability.

The details of the diagnostic confirmation of Ug99 in Nepal are available at the GRRC website (see GRRC lab report)

Work on wheat disease surveillance and monitoring, plus breeding of resistant varieties is being supported by the DEWAS and AGG projects funded by BMGF and FCDO, UK.

Key partners –

National Plant Pathology Research Centre (NPPRC), Nepal. Contact: Suraj Baidya (suraj_baidya222@yahoo.co.in)

National Wheat Research Program (NWRP), Nepal. Contact: Roshan Basnet

Global Rust Reference Center (GRRC), Aarhus University, Denmark. Contact: Mogens Hovmøller (mogens.hovmoller@agro.au.dk)

Cornell University. Contact: Maricelis Acevedo (ma934@cornell.edu)

CIMMYT. Contact: David Hodson (d.hodson@cgiar.org)

Bargaining for Better: How gender roles in household decision-making can impact crop disease resilience

Written by Julian Bañuelos-Uribe on . Posted in Publications.

‘A better understanding of the links between gender roles in household decision-making and the adoption of technologies can enhance the uptake of innovations in smallholder farming systems,’ concludes a recently published paper by CIMMYT. The paper connects women’s bargaining power in households with the adoption of rust resistant wheat varieties, based on the work of Accelerating Genetic Gains in Maize and Wheat (AGG) in Ethiopia.

“While an emerging body of literature finds positive correlations between women’s influence in household decision-making and socioeconomic, health, and nutritional outcomes, few studies have analyzed the links between intra-household decision-making and the adoption of agricultural technologies,” said Michael Euler, agriculture research economist at CIMMYT.

A case study in Ethiopia

For this study, researchers used a dataset from Ethiopian wheat-producing households.

Ethiopia is the second-largest wheat producer in Africa, with an aggregate grain production of 5.5 million metric tons and 4-5 million farmers engaged in cultivation. The Ethiopian Highlands are a hot spot for wheat rust. With recurrent epidemics in the last decade, the emergence of new strains of wheat rust increased production risks. On the positive side, farmers seem to be responsive to the management of rust diseases. Rust-resistant bread wheat varieties, released since 2010, have been widely adopted by smallholder farmers across Ethiopia.

The CIMMYT study surveyed 1,088 wheat-producing households in Ethiopia to analyze the links between women’s role in household decision-making concerning crop production and the adoption and turnover rates of rust-resistant wheat varieties. Female and male members from the same households responded separately, which facilitated capturing individual perceptions and the intra-household dynamics in decision-making.

Farmer Shumuna Bedeso weeds her wheat field. (Photo: Peter Lowe/CIMMYT)

Intra-household decision-making arrangements and wheat varietal choice

Overall, the study reveals a positive association between women’s role in decision-making regarding the selection of wheat seed and the adoption of rust-resistant wheat varieties and wheat varietal turnover. Findings may be related to differences in risk aversion between women and men farmers. While women farmers may tend to advocate for the adoption of rust resistant varieties to avoid potential financial difficulties that arise from purchase of fungicide in the growing season, men farmers may be more inclined to adopt high yielding varieties and use fungicides to combat rust within the season.

Spouses may agree or have different opinions regarding their decision-making roles. Spousal agreement on the woman having a role in making crop variety decisions is associated with higher adoption rates compared to spousal agreement that the woman has no role. Joint decision-making with mutually uncontested spousal roles may yield better outcomes due to larger combined exposure to information, as well as spousal discussion and reflection on potential implications of the varietal choice decision.

Conclusion: It is about negotiation, contestation and consensus

Household decisions, including the decision to adopt agricultural technologies often result from negotiation, contestation, and consensus between wife and husband. This process is shaped by diverging interests, motivations and objectives, while its results are determined by different levels of individual bargaining power. “Our findings indicate that women’s ownership of agricultural land and household assets is strongly associated with their active role in household decisions on wheat varietal choice, and with spousal agreement,” said Moti Jaleta, senior agricultural economist at CIMMYT. The dynamics in intra-household decision-making are likely to influence households’ adoption of agricultural technologies.

Disregarding the dynamics in decision-making implies that households are unilateral decision-makers, a scenario which probably does not hold true considering the level of spousal disagreement regarding their roles and influence in choosing crop varieties. A deeper understanding of the connections between gender dynamics in household decision-making and adoption choices can enhance the efficiency of public extension systems, increase the adoption rates of modern innovations, improve agricultural productivity, and enhance livelihoods in smallholder agriculture.

Read the complete paper here.

East African wheat breeding pipeline and E&SSA network

Written by Julian Bañuelos-Uribe on . Posted in Blogs.

Healthy wheat and wheat affected by Ug99 stem rust in farmer’s field, Kenya. (Photo: CIMMYT)

The East African wheat breeding pipeline aims to improve wheat varieties and contribute to regional food security by ensuring a stable and resilient wheat supply. In 2022, CIMMYT, in partnership with the Kenya Agriculture and Livestock Research Organization (KALRO) established a Joint Breeding Program in Njoro, a town southwest of the Rift Valley in Kenya. This was one of the first integrated breeding pipelines between CGIAR and National Agricultural Research and Extension Systems (NARES) partners.

Over the last three decades, genetic trials of over 77 varieties have been conducted in several regions. In East Africa, an expanded testing network that spans over multiple research institutes in Kenya and Ethiopia has been established for Stage 1 and Stage 2 trials in network countries. This makes the pipeline a powerful driver of positive impacts, rapidly enhancing both farm productivity and production in target regions. In Kenya specifically, a genetic gain trial was conducted at two sites in 2023 with the Stage 1 trials evaluated across eight locations. These are being distributed to NARES partners to establish correlations between the breeding site in Kenya and the Target Population of Environments (TPEs) in the E&SSA regions. This breeding pipeline demarcates the population improvement from product development. Other areas in the trials include the enhancement of genetic diversity to build resilience, adaptability, and quality enhancement to meet market and consumer demands.

The trial will continue in 2024 and 2025 to establish a baseline for genetic gains and to enable the assessment of the breeding pipeline’s progress in the coming years. The first cohort of pipeline materials (250 crosses) has been advanced to F2 generation and will be ready for distribution to E&SSA partners in 2025.

Accelerated breeding

The anticipation is that accelerated breeding techniques will be implemented in Kenya by incorporating a three-year rapid generation bulk advancement (RGBA) scheme aimed at diminishing the time necessary for variety development and release. This collaborative effort encompasses various activities, including joint crossing block, generation advancement, yield testing, and population improvement. The three-year RGBA scheme, coupled with data-driven selection utilizing advanced data analytics (GEBV, SI) and genomic selection approaches, is expected to play a pivotal role in facilitating informed breeding decisions in the East African region.

3-year RGBA scheme. (Photo: Sridhar Bhavani)

Varietal improvement

The project aims to develop and release improved wheat varieties that are well adapted to the East African agroecological conditions. The Kenyan environment closely mirrors wheat-growing conditions in Ethiopia, Tanzania, Uganda, Rwanda, and Burundi, and spillover impacts to sub-Saharan countries such as Zambia and Zimbabwe. This strategic alignment with local conditions and close cooperation with NARES partner organizations has proven to be very effective in addressing critical gaps, including high-yield potential, disease resistance, and climate resilience, and aligns with CIMMYT’s overall wheat strategy for Africa.

Enhanced disease resistance

Kenya stands out as a hotspot for rust diseases, showcasing notable diversity in stem rust variants (ug99) and yellow rust. The virulence spectrums of these diseases differ from those found in Mexico, posing challenges to effective breeding strategies. It is expected that the breeding pipeline will effectively tackle these challenges as well as those associated with fusarium, Septoria, and wheat blast, which are on the rise in African environments.

Climate adaptation

The East African wheat breeding pipeline is committed to breeding wheat varieties that can thrive in changing climatic conditions, including heat and drought tolerance, and expanding testing in marginal rainfed environments experiencing heat and drought stress.

Through the support of our partners and funders from the Bill and Melinda Gates Foundation, Foundation for Food and Agriculture Research (FFAR), and Foreign, Commonwealth and Development Office FCDO, the following achievements can be reported:

Regional collaboration and cooperation

For over four decades, the enduring collaboration with KALRO has yielded significant successes including the operation of the largest phenotyping platform for stem rust and various diseases. The Mexico-Kenya shuttle breeding program, incorporating Ug99 resistance, has successfully countered the threat of stem rust by releasing over 200 varieties in targeted regions and advancing the East African wheat breeding pipeline. The plan is to replicate these accomplishments in other target regions through the E&SSA network. To address limitations in KALRO’s breeding program and to conduct standardized trials, a strategic partnership with a private seed company Agventure Cereal Growers Association has been established. This collaboration will facilitate yield testing at multiple sites in Kenya to identify lines with superior performance for the East African region. So far, lines exhibiting high yield potential of up to 8 tons/ha, even under rain-fed environments, have been identified. The collaborative efforts are already making a noticeable impact, as evidenced by reports indicating increased adoption of zero-tillage practices among farmers. This shift has proven beneficial, especially during years marked by heat and drought challenges, resulting in higher returns for these farmers.

Increased capacity of national programs

From 1-13 October 2023, the AGGMW project held a training program on “Enhancing Wheat Disease Early Warning Systems, Germplasm Evaluation, Selection, and Tools for Improving Wheat Breeding Pipelines”. The course which brought together 33 participants from over 13 countries was held at the KALRO station in Njoro- Kenya. The comprehensive program covered a wide range of crucial subjects in the field of wheat breeding and research. Topics included breeding methodologies, experimental design, data collection, statistical analysis, and advanced techniques such as genomic selection. Participants also engaged in practical hands-on data analysis, explored rust pathology, and delved into early warning systems. Moreover, they had the opportunity for direct evaluation and selection of breeding materials. The course aimed to equip participants with a diverse skill set and knowledge base to enhance their contributions to the field of wheat breeding and research.

Other initiatives supporting the breeding pipeline include CGIAR programs, Accelerated Breeding and Crops to End Hunger. This multi-faceted approach within the breeding pipeline underpins the importance of fostering regional collaboration, knowledge sharing, and strategic investments in enhancing wheat production and addressing critical challenges in the region.