Alison Bentley (right) and Martin Jones inspect wheat in a glasshouse. (Photo: Toby Smith/Gloknos)
In November 2020, Alison Bentley will be joining the International Maize and Wheat Improvement Center (CIMMYT) as the new program director of the Global Wheat Program. She will be succeeding Hans Braun, who has steered the program for the last 16 years.
Bentley is thrilled to join CIMMYT and excited about the opportunity to harness science and breeding to improve livelihoods. She believes in a collective vision for equitable food supply and in science-led solutions to deliver impact.
âIt really is an exciting time for wheat research: the international community has worked together to produce sequence and genomic resources, new biological and physiological insights, a wealth of germplasm and tools for accelerating breeding. This provides an unparalleled foundation for accelerating genetic gains and connecting ideas to determine how we can practically apply these tools and technologies with partners to deliver value-added outputs,â she said.
Bentley has worked on wheat â wheat genetics, wheat genetic resources and wheat pre-breeding â her entire career. She is the UKâs representative on the International Wheat Initiative Scientific Committee, and is a committee member for the Genetics Society, the UK Plant Sciences Federation, the Society of Experimental Botany, and the Editorial Board of Heredity.
Bentley obtained her PhD from the University of Sydney, Australia, in 2007. She then joined the National Institute of Agricultural Botany (NIAB) in the UK, where she progressed from Senior Research Scientist (2007) to Program Leader for Trait Genetics (2013), and Director of Genetics and Breeding (since 2016).
Currently, Bentley is involved in international research projects in Ethiopia, The Gambia, Ghana, India and Pakistan. She leads a number of UK-India projects with partners including Punjab Agricultural University, the Indian National Institute of Plant Genome Research and the University of Cambridge, studying variation and developing wheat and other cereal germplasm with enhanced resource use efficiency.
Wheat crop losses due to heat and drought affect food availability and increase the costs for billions of consumers around the world. The Alliance for Wheat Adaptation to Heat and Drought (AHEAD) is an international network that hosts initiatives and projects dedicated to addressing scientific gaps and builds synergies to support the development of new wheat varieties that are resilient to heat and drought.
CIMMYT Country Representative in Pakistan Dr Muhammad Imtiaz briefed National Food Security Minister Fakhr Imam on the potential strategy to increase use of high-yielding, climate resilient and rust-resistant seed varieties; closing the yield gap by timely sowing and optimal use thereby formulating and applying the right policy; and ensuring good support price in place.
CIMMYT country representative Muhammad Imtiaz briefed National Food Security and Research Minister Syed Fakhar Imam on the Wheat Productivity Enhancement Programme (WPEP) and Agricultural Innovation Programme for Pakistan (AIP) and how these interventions had a positive impact on the countryâs productivity.
A new project, Accelerating Genetic Gains in Maize and Wheat for Improved Livelihoods (AGG), seeks to achieve these results by speeding up genetic gains in maize and wheat breeding to deliver improved, stress resilient, nutritious seed to smallholders in 13 countries in sub-Saharan Africa (SSA) and four in South Asia. The 5-year AGG project is funded by the Bill & Melinda Gates Foundation, the UK Department for International Development (DFID) and the U.S. Agency for International Development (USAID).
The maize component of the project brings together diverse partners, including the International Maize and Wheat Improvement Center (CIMMYT) and the International Institute of Tropical Agriculture (IITA) as co-implementers; national agricultural research systems (NARS); and small and medium-sized (SME) seed companies.
It was the site where International Maize and Wheat Improvement Center (CIMMYT) scientist Norman Borlaug famously received news of his 1970 Nobel Peace Prize win. Now, Toluca station will become CIMMYTâs new testing site for rapid generation advancement and speed breeding in wheat â a method that accelerates generation advancement of crops and shortens the breeding cycle using tools like continuous lighting and temperature control.
Recent progress of the 2-hectare rapid generation advancement screenhouse under construction at Toluca station. (Photo: Suchismita Modal/CIMMYT)
The Toluca wheat experimental station is one of CIMMYTâs five experimental stations in Mexico, located in a picturesque town on the outskirts of Mexicoâs fifth largest city, Toluca, about 60 kilometers southwest of Mexico City. The station was strategically chosen for its cool, humid conditions in summer. These conditions have made it an ideal location for studying wheat resistance to deadly diseases including yellow rust and Septoria tritici blotch.
Since its formal establishment in 1970, Toluca has played a key role in CIMMYTâs wheat breeding program. The site is also of significant historical importance due to its origins as a testing ground for Borlaugâs shuttle breeding concept in the 1940s, along with Ciudad ObregĂłn in the Sonora state of northern Mexico. The breeding method allowed breeders to plant at two locations to advance generations and half the breeding cycle of crops.
Applying this unorthodox breeding method, Borlaug was able to advance wheat generations twice as fast as standard breeding programs. Planting in contrasting environments and day lengths â from the cool temperatures and high rainfall of Toluca to the desert heat of Ciudad ObregĂłn â also allowed Borlaug and his colleagues to develop varieties that were more broadly adaptable to a variety of conditions. His shuttle breeding program was so successful that it provided the foundations of the Green Revolution.
Toluca was also the site where the first sexual propagation of the destructive plant pathogen Phytophtora infestans was reported. The deadly pathogen is best known for causing the potato late blight disease that triggered the Irish potato famine.
Early photo of Toluca station. (Photo: Fernando Delgado/CIMMYT)
New life for the historic station
More than 50 years since its establishment, the station will once again host cutting-edge innovation in wheat research, as the testing ground for a new speed breeding program led by wheat scientists and breeders from Accelerating Genetic Gains in Maize and Wheat (AGG).
Funded by the Bill & Melinda Gates Foundation, the UK Department for International Development (DFID), the U.S. Agency for International Development (USAID) and the Foundation for Food and Agriculture Research (FFAR), AGG aims to accelerate the development and delivery of more productive, climate-resilient, gender-responsive, market-demanded, and nutritious maize and wheat varieties.
While most breeding programs typically take between 7-8 years before plants are ready for yield testing, shuttle breeding has allowed CIMMYT to cut the length of its breeding programs in half, to just 4 years to yield testing. Now, AGG wheat breeders are looking to shorten the breeding cycle further, through rapid generation advancement and speed breeding.
Speed breeding room at Toluca station. The Heliospectra lights support the faster growth of plants. (Photo: Suchismita Mondal/CIMMYT)
âThe AGG team will use a low-cost operation, in-field screenhouse, spanning 2 hectares, to grow up to 4 generations of wheat per year and develop new germplasm ready for yield testing within just 2 years,â said Ravi Singh, CIMMYT distinguished scientist and head of wheat improvement. âThis should not only save on cost but also help accelerate the genetic gain due to a significant reduction in time required to recycle best parents.â
Construction of the new rapid generation advancement and speed breeding facilities is made possible by support from the Bill and Melinda Gates Foundation and DFID through Delivering Genetic Gain in Wheat (DGGW), a 4-year project led by Cornell University, which ends this year. It is expected to be complete by September.
Rapid generation advancement screenhouse under construction at Toluca station in October 2019. (Photo: Alison Doody/CIMMYT)
Wheat fields at Toluca station. (Photo: Fernando Delgado/CIMMYT)
Early photo of Toluca station. (Photo: Fernando Delgado/CIMMYT)
Wheat fields at Toluca station. Nevado de Toluca features in the background. (Photo: Fernando Delgado/CIMMYT)
Early landscape of wheat fields at Toluca station (Photo: Fernando Delgado/CIMMYT)
Rapid generation advancement screenhouse under construction at Toluca station in October 2019. (Photo: Alison Doody/CIMMYT)
Recent progress of the rapid generation advancement screenhouse under construction at Toluca station. (Photo: Suchismita Modal/CIMMYT)
Speed breeding room at Toluca station. The Heliospectra lights support the faster growth of plants. (Photo: Suchismita Mondal/CIMMYT)
CIMMYT Global Wheat Program Director Hans Braun highlighted the importance of testing the new breeding scheme. âBefore completely adopting the new breeding scheme, we need to learn, optimize and analyze the performance results to make necessary changes,â he said.
If all goes well, Toluca could once again be on the vanguard of wheat research in the near future.
âWe plan to use the speed breeding facility for rapid integration of traits, such as multiple genes for resistance, to newly-released or soon to be released varieties and elite breeding lines,â said CIMMYT Wheat Breeder Suchismita Mondal, who will lead the work in these facilities. We are excited to initiate using the new facilities.â
A new project, Accelerating Genetic Gains in Maize and Wheat for Improved Livelihoods (AGG), seeks to achieve these results by speeding up genetic gains in maize and wheat breeding to deliver improved, stress resilient, nutritious seed to smallholders in 13 countries in sub-Saharan Africa (SSA) and four in South Asia. The 5-year AGG project is funded by the Bill & Melinda Gates Foundation, the UK Department for International Development (DFID) and the U.S. Agency for International Development (USAID).
Striga, an invasive parasitic weed with purple-colored flowers, looks striking and harmless. But, beyond that mark of beauty, is a nutrient-sucking monster that stunts crops such as maize and sorghum, leaving affected farmers counting losses.
Witchweed thrives in poor soils with low rainfall conditions. It is prevalent in farming systems with poor crop management practices and in communities where farmers use minimal or no fertilizer. Once maize begins germinating in Striga-prevalent soil, it stimulates Striga seeds to germinate. Striga then attaches to the roots of the host plant, sapping nutrients from the plant, leading to stunting. The potential yield loss can reach up to 100%. Some farmers attempt to uproot it once they notice it germinating alongside their maize plantation, but this is often too late because damage is done as soon as the parasite attaches to the maize roots. When mature, the weed deposits tens of thousands of tiny seeds into the soil. This makes it very difficult for farmers to get rid of it.
To tackle this challenge, farmers need to apply inorganic fertilizer, which is not always affordable, or animal manure to enrich the soil before planting. They are also advised by researchers and extensionists to practice crop rotation or intercropping with legumes such as beans, soybean or groundnuts that restrict Strigaâs germination. Â In the Assessment of Management Options on Striga Infestation and Maize Grain Yield in Kenya, for example, researchers recommend that Striga control measures include a combination of herbicide-resistant or maize varieties with native genetic resistance intercropped with legumes.
Nevertheless, while a few control measures have been moderately successful, the problem still persists, especially in western Kenya, eastern Uganda and lake zone of Tanzania, where farmers have frequently voiced their frustrations at the ubiquity of this invasive weed.
âWhile crop rotation with crops such as soybean or beans may break the cycle of Striga, its seed can stay in the soil and remain viable for up to 10 years,â says Dan Makumbi, a maize breeder with the International Maize and Wheat Improvement Center (CIMMYT), who is leading research efforts against the witchweed.
A sorghum field infested with Striga in Siaya County. (Photo: Joshua Masinde/CIMMYT)
Norah Kayugi on a Striga-infested farm in Siaya County. (Photo: Joshua Masinde/CIMMYT)
Norah Kayugi holds a bunch of Striga weeds she has uprooted on a farm she works as a casual laborer in Siaya. (Photo: Joshua Masinde/CIMMYT)
A blow to optimal yield potential
Maize is a staple crop that is predominantly cultivated by smallholder farmers in western Kenya and the lake region. It is an important source of food security and livelihoods of millions of people in the region, but constraints such as Striga prevent farmers from obtaining the cropâs ideal potential.
âThe yield loss would have been adequate to cover my familyâs food requirements for a year,â Naliaka said. âFrom two farming seasons, I could harvest a sufficient quantity of maize and sell some surplus to pay my childrenâs school fees. With the Striga menace, all that is but a dream.â
Just like Naliaka, Norah Kayugi, a 40-year-old widowed mother of six children from Siaya County in Kenya, has seen her maize production fall to less than 8 bags of 90kgs per acre. In normal circumstances, they would obtain at least 16 bags of maize per acre. The significant yield loss sets back many affected households in a big way, as they experience food shortage only a few months after harvest. Some divert their reduced incomes for food purchases, possibly leaving other priorities such as health and education of their children unattended.
Kayugi, who has been a farmer since 1997, now takes on casual jobs to supplement her farming in order to support her family, being the sole breadwinner following her husbandâs demise years ago. âI plant vegetables, beans and maize to sustain my family. My one-acre farm yields about 10 bags of 90ks each. But I know for sure that were it not for this weed, the yield potential could reach 30 bags of 90kgs each per acre.â
A young, yet-to-flower Striga weed at the CIMMYT-KALRO Kibos Research Station in Kisumu. (Photo: Joshua Masinde/CIMMYT)
Standing up to multiple farming stresses
These smallholders, like their counterparts elsewhere in sub-Saharan Africa, already face other farming challenges, including climate change-induced droughts, pests such as the fall armyworm, diseases like maize lethal necrosis (MLN), and declining soil fertility, among others. While CIMMYT has registered breakthroughs in developing maize varieties that tolerate such stresses, on-going efforts against Striga are also taking shape, challenges notwithstanding.
The development and deployment of the imazapyr-resistant (IR) maize has been one such instance of effective Striga control. With this method, herbicide-resistant maize seeds are coated with herbicide. The seed germinates and absorbs some of the herbicide used to coat it. The germinating maize stimulates Striga to germinate and as it attaches to the maize root, it is killed before it can cause any damage. Despite its effectiveness, sustaining this technology presented a major challenge to seed companies.
âIt was costly for seed companies, as they needed to establish and sustain the operation of separate seed treatment units dedicated to production of the herbicide-coated maize seed. Once you establish a line to dress the seed with the chemical, you cannot use it to treat any other seeds as the chemical will destroy them,â said Makumbi.
Seed companies â like NASECO in Uganda, Kenya Seed Company in Kenya, Western Seed Company and FreshCo in Kenya, and Meru Agro in Tanzania â obtained financial and technical support from a partnership initiative coordinated by African Agricultural Technology Foundation (AATF) and backed by CIMMYT to scale commercialisation of StrigAwayTM maize in East Africa. The initiative was funded by USAIDâs Feed the Future Partnering for Innovation program through Fintrac and it supported the seed companies to establish seed treatment facilities to handle herbicide resistant maize. This allowed each of the companies to have a fully dedicated facility for herbicide resistant maize seed processing. âRight now, herbicide resistant maize hybrid seed is available on the market in Kenya, Tanzania and Uganda,â Makumbi said.
CIMMYT field technician Carolyne Adhiambo at a maize field experiment showing promise of Striga tolerance or resistance the Kibos Research station in Kisumu. (Photo: Joshua Masinde/CIMMYT)
Native hope
In the past few years, Makumbi and his team, in collaboration with the International Institute for Tropical Agriculture (IITA) and the Kenya Agricultural and Livestock Research Organization (KALRO), have redirected their efforts towards breeding for native genetic resistance to Striga. This means developing seeds which are naturally resistant to Striga, reducing the need for herbicides. The early indication is that there are several parental lines showing potential to tolerate or resist Striga, and these are being used to develop hybrids. The hybrids, which offer multiple benefits for farmers, are under wide scale testing in Kenya.
âIn our tests, we are not only looking at Striga resistance alone but also other important traits such as good yield under optimal conditions, drought stress and low soil fertility, resistance to major foliar diseases including gray leaf spot, Turcicum leaf blight, maize streak virus and ear rots,â Makumbi noted.
As these breeding efforts continue, there is light at the end of the tunnel. The hope of farmers taking back full control of their maize farms from Strigaâs âbewitching waysâ in the near future remains alive.
Sudha Nair is inspired every day by her passion for biology and genetics. The senior scientist at the International Maize and Wheat Improvement Center (CIMMYT) based in Hyderabad, India, works to define and practice the best strategies for applying genomics in agriculture.
âI always knew that science is what I would love to pursue,â said Sudha, an alumnus of both the Indian Agricultural Research Institute (IARI) in New Delhi and the National Institute of Agrobiological Sciences in Japan.
Originally from Kerala, India, Sudha did not expect a career in agriculture. âI studied for engineering after my high school as I was selected for that course before I was selected for the biology stream. It didnât take me even a single moment to decide to leave the course six months later when I was selected for the undergraduate program in agriculture,â Sudha said. âI canât say that it is love for agriculture that forced me to choose the field I am in, but it is the fascination for biological science. I love genetics and I love research; as long as I get to do this as part of my job, I am happy.â
Sudhaâs first experience working with CIMMYT involved her PhD dissertation at IARI, which was a part of research conducted for the Asian Maize Biotechnology Network (AMBIONET), led by CIMMYT. âI had always looked at CIMMYT as an organization doing high quality applied science,â she said.
Starting in 2010 as a consultant for the Drought Tolerant Maize for Africa (DTMA) project, Sudha then interviewed for the position of maize fine-mapping specialist in 2011 and was selected as a scientist. Her career at CIMMYT has now spanned close to a decade.
Her role involves implementation of molecular breeding in the maize breeding program in Asia. This includes discovery, validation and application of molecular markers for prioritized traits, genomic selection, and marker-based quality assurance and quality control in maize breeding â through current and past projects like Heat Tolerant Maize for Asia (HTMA), Climate Resilient Maize for Asia (CRMA) and the CGIAR Research Program on Maize (MAIZE). Apart from this, she is currently involved in the Accelerating Genetic Gains in Maize and Wheat (AGG) project for incorporating elite and stress tolerance genetics from Asia in the elite African maize germplasm.
Sudha has been a part of a number of global maize projects including the Stress Tolerant Maize for Africa (STMA) project, which developed improved maize varieties tolerant to stresses such as drought and diseases, and HarvestPlus in maize, developing nutritionally enriched maize cultivars. She has also played a key role in developing CIMMYTâs second-generation tropicalized haploid inducers using marker-assisted breeding.
Sudha Nair speaking at a Heat Tolerant Maize for Asia (HTMA) annual review and planning meeting. (Photo: Sudha Nair/CIMMYT)
Bringing genetics and breeding together
Sudha is grateful for the role of CIMMYT in increasing acceptance and use of genomics in breeding programs. âWhen I started off as a graduate student, any work related to molecular genetics was called biotechnology, and we were considered as a different âbreedâ, who worked in silos to spend resources on âupstream researchâ, and whose results never saw any breeding applications. Breeding and molecular genetics were like parallel lines that would never meet,â she explained.
âIn course of time, the research communities in applied breeding institutes like CIMMYT have brought about changes in strategies, goals, and more importantly, attitudes, and now all of us work towards one major goal of developing impactful products (varieties) for benefiting resource-constrained farming communities worldwide. All in all, I and my colleagues in the upstream research team in CIMMYT Global Maize Program have an important responsibility of providing core support to the breeding and seed systems teams in developing and delivering impactful products.â
When asked what the most enjoyable part of her work is, Sudha cited the practicality and applicability of her work. âBasically, my job responsibility is to design and implement the best strategies for applying genomics in maize breeding to achieve higher genetic gains,â she explained. âBeing in an organization like CIMMYT, what is most satisfying about the role I am in is the translation of upstream research into tools for improving breeding efficiency and in turn into impactful maize varieties that the farming communities around the world cultivate.â
Wheat fields at the Campo Experimental Norman E. Borlaug (CENEB) near Ciudad ObregĂłn, Sonora, Mexico. (Photo: M. Ellis/CIMMYT)
More than 100 scientists, crop breeders, researchers, and representatives from funding and national government agencies gathered virtually to initiate the wheat component of a groundbreaking and ambitious collaborative new crop breeding project led by the International Maize and Wheat Improvement Center (CIMMYT).
The new project, Accelerating Genetic Gains in Maize and Wheat for Improved Livelihoods, or AGG, brings together partners in the global science community and in national agricultural research and extension systems to accelerate the development of higher-yielding varieties of maize and wheat â two of the world’s most important staple crops.
Funded by the Bill & Melinda Gates Foundation, the U.K. Department for International Development (DFID), the U.S. Agency for International Development (USAID), and the Foundation for Food and Agriculture Research (FFAR), the project specifically focuses on supporting smallholder farmers in low- and middle-income countries. The international team uses innovative methods â such as rapid cycling and molecular breeding approaches â that improve breeding efficiency and precision to produce varieties that are climate-resilient, pest and disease resistant and highly nutritious, targeted to farmersâ specific needs.
The wheat component of AGG builds on breeding and variety adoption work that has its roots with Norman Borlaugâs Nobel Prize winning work developing high yielding and disease resistance dwarf wheat more than 50 years ago. Most recently, AGG builds on Delivering Genetic Gain in Wheat (DGGW), a 4-year project led by Cornell University, which ends this year.
âAGG challenges us to build on this foundation and make it better, faster, equitable and sustainable,â said CIMMYT Interim Deputy Director for Research Kevin Pixley.
At the virtual gathering on July 17, donors and partner representatives from target countries in South Asia joined CIMMYT scientists to describe both the technical objectives of the project and its overall significance.
âThis program is probably the worldâs single most impactful plant breeding program. Its products are used throughout the world on many millions of hectares,â said Gary Atlin from the Bill & Melinda Gates Foundation. âThe AGG project moves this work even farther, with an emphasis on constant technological improvement and an explicit focus on improved capacity and poverty alleviation.â
Alan Tollervey from DFID spoke about the significance of the project in demonstrating the relevance and impact of wheat research.
âThe AGG project helps build a case for funding wheat research based on wheatâs future,â he said.
Nora Lapitan from the USAID Bureau for Resilience and Food Security listed the high expectations AGG brings: increased genetic gains, variety replacement, optimal breeding approaches, and strong collaboration with national agricultural research systems in partner countries.
Indiaâs farmers feed millions of people. (Photo: Dakshinamurthy Vedachalam)
Reconnecting with trusted partners
The virtual meeting allowed agricultural scientists and wheat breeding experts from AGG target countries in South Asia, many of whom have been working collaboratively with CIMMYT for years, to reconnect and learn how the AGG project both challenges them to a new level of collaboration and supports their national wheat production ambitions.
âWith wheat blast and wheat rust problems evolving in Bangladesh, we welcome the partnership with international partners, especially CIMMYT and the funders to help us overcome these challenges,â said Director General of the Bangladesh Wheat and Maize Research Institute Md. Israil Hossain.
Director of the Indian Institute for Wheat and Barley Research Gyanendra P. Singh praised CIMMYTâs role in developing better wheat varieties for farmers in India.
âMost of the recent varieties which have been developed and released by India are recommended for cultivation on over 20 million hectares. They are not only stress tolerant and high yielding but also fortified with nutritional qualities. I appreciate CIMMYTâs support on this,â he said.
Executive Director of the National Agricultural Research Council of Nepal Deepak K. Bhandari said he was impressed with the variety of activities of the project, which would be integral to the development of Nepalâs wheat program.
âNepal envisions increased wheat productivity from 2.84 to 3.5 tons per hectare within five years. I hope this project will help us to achieve this goal. Fast tracking the replacement of seed to more recent varieties will certainly improve productivity and resilience of the wheat sector,â he said.
The National Wheat Coordinator at the National Agricultural Research Center of Pakistan, Atiq Ur-Rehman, told attendees that his government had recently launched a âmega projectâ to reduce poverty and hunger and to respond to climate change through sustainable intensification. He noted that the support of AGG would help the country increase its capacity in âvertical productionâ of wheat through speed breeding. âAGG will help us save 3 to 4 yearsâ in breeding time,â he said.
For CIMMYT Global Wheat Program Director Hans Braun, the gathering was personal as well as professional.
âI have met many of you over the last decades,â he told attendees, mentioning his first CIMMYT trip to see wheat programs in India in 1985. âTogether we have achieved a lot â wheat self-sufficiency for South Asia has been secured now for 50 years. This would not be possible without your close collaboration, your trust and your willingness to share germplasm and information, and I hope this will stay. â
Braun pointed out that in this project, many national partners will gain the tools and capacity to implement their own state of the art breeding strategies such as genomic selection.
âWe are at the beginning of a new era in breeding,â Braun noted. âWe are also initiating a new era of collaboration.â
The wheat component of AGG serves more than 30 million wheat farming households in Bangladesh, Ethiopia, India, Kenya, Nepal and Pakistan. A separate inception meeting for stakeholders in sub-Saharan Africa is planned for next month.
Despite the many benefits of conservation agriculture, uptake by smallholder farmers remains limited. Alongside the struggle to maintain adequate soil cover and limited opportunities for crop diversification, weed management is a major constraint to the widespread adoption of conservation agriculture.
Although all three components of the practice â zero or minimal tillage, permanent soil cover and crop diversification â can reduce weed populations, the effects of these efforts may only become apparent in the medium to long term. As a result, many smallholders are likely to forgo these in favor of hand weeding, cheap herbicides and tillage â which controls weeds in the short term but also brings weed seeds from the seedbank to the soil surface and creates optimum conditions for germination.
In an effort to evaluate the impact of using conservation agriculture practices for weed management, researchers from the International Maize and Wheat Improvement Center (CIMMYT) used data from a long-term trial in the Mexican Highlands to evaluate weed biomass, density and diversity with and without herbicide control.
Results of their study â recently published in Agronomy â show that weed density and biomass were generally much lower in areas where conservation agriculture was practiced, compared to conventional tillage. All three components helped to significantly reduce weed biomass, with an even greater reduction when all three practices were applied together. When herbicides were applied, weed biomass in conservation agriculture was 91% lower in maize and 81% lower in wheat than in conventional tillage.
The authors found that different treatments favored different weed species but did not observe any trend toward increased perennial weeds in conservation agriculture. The data from their study supports claims that if adequate weed control is achieved in the initial years, weed populations in conservation agriculture systems are lower than in conventional tillage ones. Given these weed-controlling effects, the authors posit that these practices are likely to lead to lower herbicide use in the long term â which may be welcome news for smallholders who have reported weed management to be particularly problematic in the initial years after adopting conservation agriculture.
An early warning system to predict and mitigate wheat rust diseases in Ethiopia. 2019. Allen, C., Thurston, W., Meyer, M., Nure, E., Bacha, N., Alemayehu, Y., Stutt, R., Safka, D., Craig, A.P., Derso, E., Burgin, L., Millington, S., Hort, M.C., Hodson, D.P., Gilligan, C.A. In: Environmental Research Letters v. 14, no. 11, art. 115004.
A new project, Accelerating Genetic Gains in Maize and Wheat for Improved Livelihoods (AGG), seeks to achieve these results by speeding up genetic gains in maize and wheat breeding to deliver improved, stress resilient, nutritious seed to smallholders in 13 countries in sub-Saharan Africa (SSA) and four in South Asia. The 5-year AGG project is funded by the Bill & Melinda Gates Foundation, the UK Department for International Development (DFID) and the U.S. Agency for International Development (USAID).
Drought tolerant maize route out of poverty for community-based seed producer, Kenya. (Photo: Anne Wangalachi/CIMMYT)
As plant pests and diseases continue to evolve, with stresses like drought and heat intensifying, a major priority for breeders and partners is developing better stress tolerant and higher yielding varieties faster and more cost effectively.
A new project, Accelerating Genetic Gains in Maize and Wheat for Improved Livelihoods (AGG), seeks to achieve these results by speeding up genetic gains in maize and wheat breeding to deliver improved, stress resilient, nutritious seed to smallholders in 13 countries in sub-Saharan Africa (SSA) and four in South Asia. The 5-year AGG project is funded by the Bill & Melinda Gates Foundation, the UK Department for International Development (DFID), the U.S. Agency for International Development (USAID), and the Foundation for Food and Agriculture Research (FFAR).
The maize component of the project brings together diverse partners, including the International Maize and Wheat Improvement Center (CIMMYT) and the International Institute of Tropical Agriculture (IITA) as co-implementers; national agricultural research systems (NARS); and small and medium-sized (SME) seed companies.
Ambitious targets
At the inception meeting of the maize component of AGG on July 10, 2020, project leaders, partners and funders lauded the ambitious targets that aim to bolster the resilience and better the livelihoods, food and nutritional security of millions of smallholder farmers in SSA. At least 150,000 metric tons of certified seed is expected to be produced, adopted by 10 million households, planted on 6 million hectares by 2024 and benefiting 64 million people.
âWe are developing climate resilient, nutritious, efficient, productive maize varieties for the farming community in sub-Saharan Africa. We will continue to work closely with our partners to develop product profiles, which are centered on the varieties that are really needed,â said CIMMYT Interim Deputy Director for Research Kevin Pixley.
AGG draws a solid foundation from previous projects such as Drought Tolerant Maize for Africa (DTMA), Improved Maize for Africa Soils (IMAS), Water Efficient Maize for Africa (WEMA) and Stress Tolerant Maize for Africa (STMA). Several high-yielding maize varieties that tolerate and/or resist diseases such as maize lethal necrosis (MLN), gray leaf spot (GLS), northern corn leaf blight, maize streak virus (MSV), turcicum leaf blight (TLB) and are drought-tolerant (DT), were developed and released to farmers across SSA. Varieties with nutritional traits such as nitrogen use efficiency (NUE) and quality protein maize (QPM) were also developed in the preceding initiatives.
Drought Tolerant Maize for Africa (DTMA) project monitoring and evaluation takes place in Tanzania. (Photo: Florence Sipalla/CIMMYT)
A matter of âlife or deathâ
âWhen farmers are confronted by aggressive farming challenges, they want products that address those challenges at the earliest opportunity. Waiting for years could mean the difference between life and death,â remarked David Chikoye, the director of Southern Africa Hub at IITA.
A key focus of AGG is to incorporate gender-intentionality – special attention to the needs of women farmers and consumers – from the traits bred into new varieties, through the communication and technology deployment strategies.
âAGG provides an excellent opportunity to reorient our maize breeding, seed scaling and delivery strategies for greater impact on the livelihoods of smallholder farmers, especially women and the disadvantaged communities that are not well reached so far,â said B.M. Prasanna, director of CIMMYT’s Global Maize Program and the CGIAR Research Program on Maize. âOur vision is to accelerate genetic gains to 1.5-2 percent annually across different breeding pipelines in the 13 participating countries in SSA and to reach over 10 million households with improved varieties.â
AGG will strengthen the capacity of partners to achieve and sustain accelerated variety replacement — or turnover — and increase genetic gains in farmersâ fields.
Old vs new
Many improved varieties have been released in the past decade. However, the turnover of old and obsolete varieties with new and improved ones is not happening as quickly as anticipated.
âWe are producing good products and getting them out, but not at the speed that farmers need. How do we make it possible and profitable for seed companies to quickly introduce new hybrids?â posed Gary Atlin, program officer at the Bill & Melinda Gates Foundation. âWe need to move towards a breeding and seed system where we know that we can develop a new product in 4 or 5 years and then get it to the farmers much more quickly. This is a complex problem.â
To enhance AGGâs ability to identify new products that perform well for farmers under their challenging circumstances, on-farm testing will be scaled up significantly.
Guest of honor, Ethiopiaâs Minister of State for Agriculture Mandefro Nigussie, lauded CIMMYTâs support in improving the resilience and productivity of maize and wheat in the country. He observed that this has helped improve maize productivity in Ethiopia from around 2 tons/ha to about 4 tons/ha over the past two decades.
âWe consider such a huge accomplishment as a combination of efforts in germplasm development and breeding efforts of CIMMYT and the Ethiopian national programs. That partnership will flourish further in this new project,â he said.
Farmers in Coahuila are embracing technology by using WhatsApp to exchange experiences and access technical information, especially on sustainable farming practices such as ecological pest management.
This article by Sakshi Saini was originally published on the CCAFS website.Â
A high throughput crop phenotyping platform, the âLeasyscanâ located at ICRISATâs HQ Patancheru, India. Photo: A. Whitbread (ICRISAT)
Ever-increasing emissions of greenhouse gases (GHG) is a global concern due to the association of high atmospheric GHG concentrations with global warming and climate change. A large and growing body of evidence predicts that this would further have a multifaceted impact on the human population, especially the poor and vulnerable groups, further exacerbating their vulnerabilities.
But what about crops? Plants use carbon dioxide (CO2)âone of the most abundant GHGs, for photosynthesis. So shouldnât an increase in atmospheric carbon dioxide aid crops to flourish? A counter-argument to this would be that at the same time there would be changes in other factors such as a change in precipitation rate, frequency and intensity of rains, among others, which might negatively impact crop production. So, how exactly would climatic variations impact the yield and productivity of crops? These are some of the questions that have been a global concern. Many studies have researched this, employing varied approaches such as systems biology, physiology and crop modelling. However, unprecedented changes in climatic conditions still pose uncertainties on the impacts on crops.
Recent research by an interdisciplinary team of scientists from the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), the CGIAR Research Program on Climate Chanage, Agriculture and Food Security (CCAFS)-Africa and CCAFS-Asia aspires to answer some of these questions. As part of this research, they have compiled recent progress made in the physiological and molecular attributes in plants, with special emphasis on legumes under elevated CO2 conditions in a climate change scenario. The study proposes a strategic research framework for crop improvement that integrates genomics, systems biology, physiology and crop modelling approaches to cope with the changing climate. Some of the prime results of the study are as follows:
1. Major physiological and biochemical alterations in legumes triggered by elevated CO2
A range of physiological and biochemical alterations take place in plants exposed to elevated CO2. In the case of legumes, elevated atmospheric CO2 concentrations also affect the nutritional quality and nodulation, causes changes in rhizosphere and Biological Nitrogen Fixation (BNF), among others. Studies have shown that elevated CO2 would stimulate plant growth under nitrogen-sufficient conditions, but under nitrogen-limited conditions, it may have the detrimental effect of reducing plant growth by altering its primary metabolism. The anatomical differences between C3 and C4 plants (plants with C3 and C4 photosynthetic pathways) and their different ways of sequestering carbon (removing carbon dioxide from the atmosphere), have been an area of interest for climate scientists. Elevated CO2 combined with limited nitrogen may also promote biological ageing (senescence) rates as observed in flag leaves of rice and wheat. Studies also show that a higher level of carbon dioxide increases senescence rate in legumes.
2. Impact of elevated carbon-dioxide interaction with other abiotic stresses
As mentioned earlier, CO2 is not the only factor that is impacting plant growth, it is dependent on other environmental factors such as water deficit stress and temperature, among others. Thus, these factors also need to be considered in combination with the atmospheric concentration. Studies have reported that elevated CO2 induced a decrease (of 10%) in evaporation rates in both C3 and C4 plants. This caused an increase in canopy temperature (0.7 °C) coupled with a 19% yield increase in C3 crops. There is evidence that an increase in CO2 has also phased down the effect of oxidative stress. Though, there is limited literature available about the impact of elevated carbon dioxide keeping into consideration the drought and heat responses of various crops.
3. Elevated carbon dioxide and its interaction with biotic stress-altered pathogen aggravation and virulence
The changing climate has affected pest-crop dynamics with more frequent outbreaks and changed the geographical distribution of pests, posing an economic threat to crops. Sometimes, other abiotic stresses like drought could increase fungal virulence as reported in drought-tolerant peanut and Aspergillus interaction. However, a combined interaction is not always additive as both unique and common responses have been observed. Increased CO2Â causes greater photosynthate availability, but reduced foliage quality along with an increased concentration of plant defensive compounds after a pest infestation. This, in turn, affects insect feeding and increases disease incidence and predator parasitism interactions.
4. Molecular interventions for crop improvement under elevated carbon-dioxide
While elevated CO2Â may cause greater photosynthate availability, the interaction of elevated CO2Â with mentioned biotic and abiotic stresses calls for the development of climate change ready crop varieties. Thus, genomics assisted breeding along with other modern approaches can be very powerful tools to develop superior varieties, to de-risk the existing food system. This transformative approach towards the production of plants and crops would be instrumental in sustainably ensuring food security.
An integrated research framework for the future
The discussion and evidence presented illustrate that the effect of elevated CO2 under a changing climate scenario is multifaceted and aggravated by the overlapping interaction of stressors. The notion that CO2 has beneficial effects in terms of increased productivity is now being questioned since the photosynthetic fertilization effect is short term and often not time-tested for major crop species. The IPCC 2018 special report highlights several policy-level approaches that are aimed at limiting greenhouse gas emission. The scientific community needs to be prepared with suitable research outcomes to cope with the effects of elevated atmospheric CO2 levels. In this regard, an integrated framework combining different biological disciplines has been proposed by the team (Fig. 1).
Figure 1:Â A representation of a multifaceted strategy that could be employed to harness cutting edge technologies and greater precision to cope with elevated CO2, and generally with a changing climate.
While significant advances have been made in crop genomics, systems biology and genomics-assisted breeding, the success of trait dissection and trait deployment is very much dependent on the quality and precision of phenotyping. Recent advances in plant phenotyping using high throughput phenotyping tools have revolutionized the uptake of phenotype and allelic information in a more precise and robust way and complemented high throughput genomic resources
In the opinion of the authors of the publication, an integrated research framework that includes genomics/ systems biology and phenomics together with crop modelling would result in faster data-driven advances for understanding the optimal GxExM (genotype x environment x management) scenarios for current and projected climates. Interdisciplinary approaches as has been done through the Climate-Smart Village approach, are key to graduating from a descriptive level to an improved quantitative and process-level understanding of sustainable crop productivity.
