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funder_partner: Technical University of Munich (Technische Universität München)

Wheat blast spread globally under climate change modeled for the first time

Written by Julian Bañuelos-Uribe on . Posted in News, Press releases.

Climate change poses a threat to yields and food security worldwide, with plant diseases as one of the main risks. An international team of researchers, surrounding professor Senthold Asseng from the Technical University of Munich (TUM), has now shown that further spread of the fungal disease wheat blast could reduce global wheat production by 13% until 2050. The result is dramatic for global food security.

With a global cultivation area of 222 million hectares and a harvest volume of 779 million tons, wheat is an essential food crop. Like all plant species, it is also struggling with diseases that are spreading more rapidly compared to a few years ago because of climate change. One of these is wheat blast. In warm and humid regions, the fungus magnaporthe oryzae has become a serious threat to wheat production since it was first observed in 1985. It initially spread from Brazil to neighboring countries. The first cases outside of South America occurred in Bangladesh in 2016 and in Zambia in 2018. Researchers from Germany, Mexico, Bangladesh, the United States, and Brazil have now modeled for the first time how wheat blast will spread in the future.

Wheat fields affected by wheat blast fungal disease in Passo Fundo, Rio Grande do Sul, Brazil. (Photo: Paulo Ernani Peres Ferreira)

Regionally up to 75% of total wheat acreage affected

According to the researchers, South America, southern Africa, and Asia will be the regions most affected by the future spread of the disease. Up to 75% of the area under wheat cultivation in Africa and South America could be at risk in the future. According to the predictions, wheat blast will also continue to spread in countries that were previously only slightly impacted, including Argentina, Zambia, and Bangladesh. The fungus is also penetrating countries that were previously untouched. These include Uruguay, Central America, the southeastern US, East Africa, India, and eastern Australia. According to the model, the risk is low in Europe and East Asia—with the exception of Italy, southern France, Spain, and the warm and humid regions of southeast China. Conversely, where climate change leads to drier conditions with more frequent periods of heat above 35 °C, the risk of wheat blast may also decrease. However, in these cases, heat stress decreases the yield potential.

Wheat fields affected by wheat blast fungal disease in Passo Fundo, Rio Grande do Sul, Brazil. (Photo: Paulo Ernani Peres Ferreira)

Dramatic yield losses call for adapted management

The affected regions are among the areas most severely impacted by the direct consequences of climate change. Food insecurity is already a significant challenge in these areas and the demand for wheat continues to rise, especially in urban areas. In many regions, farmers will have to switch to more robust crops to avoid crop failures and financial losses. In the midwest of Brazil, for example, wheat is increasingly being replaced by maize. Another important strategy against future yield losses is breeding resistant wheat varieties. CIMMYT in collaboration with NARs partners have released several wheat blast-resistant varieties which have been helpful in mitigating the effect of wheat blast. With the right sowing date, wheat blast-promoting conditions can be avoided during the ear emergence phase. Combined with other measures, this has proven to be successful. In more specific terms, this means avoiding early sowing in central Brazil and late sowing in Bangladesh.

First study on yield losses due to wheat blast

Previous studies on yield changes due to climate change mainly considered the direct effects of climate change such as rising temperatures, changing precipitation patterns, and increased CO2 emissions in the atmosphere. Studies on fungal diseases have so far ignored wheat blast. For their study, the researchers focused on the influence of wheat blast on production by combining a simulation model for wheat growth and yield with a newly developed wheat blast model. Environmental conditions such as the weather are thus included in the calculations, as is data on plant growth. In this way, the scientists are modeling the disease pressure in the particularly sensitive phase when the ear matures. The study focused on the influence of wheat blast on production. Other consequences of climate change could further reduce yields.

Read the full article.

Further information:

The study was conducted by researchers from:

  • CIMMYT (Mexico and Bangladesh)
  • Technical University of Munich (Germany)
  • University of Florida (United States)
  • Brazilian Agricultural Research Corporation (Brazil)
  • International Fertilizer Development Center (United States)
  • International Food Policy Research Institute (United States)

Adapting growing seasons to climate change can boost yields of world’s staple crops

Written by Alison Doody on . Posted in Publications.

Rising global temperatures due to climate change are changing the growth cycles of crops worldwide. Recent records from Europe show that wild and cultivated plants are growing earlier and faster due to increased temperatures.

Farmers also influence the timing of crops and tend to grow their crops when weather conditions are more favorable. With these periods shifting due to climate change, sowing calendars are changing over time.

Over thousands of years of domesticating and then breeding crops, humans have also managed to artificially change how crop varieties respond to both temperature and day length, and in turn have been able to expand the area where crop species can be grown. Farmers can now choose varieties that mature at different rates and adapt them to their environment.

Including farmers’ decisions on when to grow crops and which varieties to cultivate are vital ingredients for understanding how climate change is impacting staple crops around the world and how adaptation might offset the negative effects.

In a ground-breaking study, a team of researchers from the Potsdam Institute for Climate Impact Research (PIK), the Technical University of Munich and the International Maize and Wheat Improvement Center (CIMMYT) investigated how farmers’ management decisions affect estimates of future global crop yields under climate change.

“For long time, the parametrization of global crop models regarding crop timing and phenology has been a challenge,” said Sara Minoli, first author of the study. “The publication of global calendars of sowing and harvest have allowed advancements in global-scale crop model and more accurate yield simulations, yet there is a knowledge gap on how crop calendars could evolve under climate change. If we want to study the future of agricultural production, we need models that can simulate not only crop growth, but also farmers’ management decisions.”

Using computer simulations and process-based models, the team projected the sowing and maturity calendars for five staple crops, maize, wheat, rice, sorghum and soybean, adapted to a historical climate period (1986–2005) and two future periods (2060–2079 and 2080–2099). The team then compared the crop growing periods and their corresponding yields under three scenarios: no adaptation, where farmers continue with historical sowing dates and varieties; timely adaptation, where farmers adapt sowing dates and varieties in response to changing climate; and delayed adaptation, where farmers delay changing their sowing dates and varieties by 20 years.

The results of the study, published last year in Nature Communications, revealed that sowing dates driven by temperature will have larger shifts than those driven by precipitation. The researchers found that adaptation could increase crop yields by 12 percent, compared to non-adaptation, with maize and rice showing the highest potential for increased crop yields at 17 percent. This in turn would reduce the negative impacts of climate change and increase the fertilization effect of increased levels of carbon dioxide (CO2) in the atmosphere.

They also found that later-maturing crop varieties will be needed in the future, especially at higher latitudes.

“Our findings indicate that there is space for maintaining and increasing crop productivity, even under the threat of climate change. Unfortunately, shifting sowing dates – a very low-cost measure – is not sufficient, and needs to be complemented by the adaptation of the entire cropping cycle through the use of different cultivars,” said Minoli.

Another important aspect of this study, according to Anton Urfels, CIMMYT systems agronomist and co-author of the study, is that it bridges the GxMxE (Gene-Management-Environment) spectrum by using crop simulations as an interdisciplinary tool to evaluate complex interactions across scientific domains.

“Although the modeled crops do not represent real cultivars, the results provide information for breeders regarding crop growth durations (i.e. the need for longer duration varieties) needed in the future as well as agronomic information regarding planting and harvesting times across key global climatic regimes. More such interdisciplinary studies will be needed to address the complex challenges we face for transitioning our food systems to more sustainable and resilient ones,” said Urfels.

Read the study: Global crop yields can be lifted by timely adaptation of growing periods to climate change

Cover photo: Work underway at the International Maize and Wheat Improvement Center in Zimbabwe (CIMMYT), is seeking to ensure the widespread hunger in the country caused by the 2015/6 drought is not repeated, by breeding a heat and drought tolerant maize variety that can still grow in extreme temperatures. CIMMYT maize breeders used climate models from the CGIAR Research Program on Climate Change, Agriculture and Food Security (CCAFS) to inform breeding decisions. (Photo: L. Sharma/Marchmont Communications)

A generalized wiring diagram for wheat, as proposed by the authors. The diagram depicts the traits most commonly associated with the source (left) and sink (right) strengths and others that impact both the sink and source, largely dependent on growth stage (middle). TGW, thousand grain weight.

Diagram links physiological traits of wheat for yield potential

Written by Rodrigo Ordóñez on . Posted in Press releases.

A generalized wiring diagram for wheat, as proposed by the authors. The diagram depicts the traits most commonly associated with the source (left) and sink (right) strengths and others that impact both the sink and source, largely dependent on growth stage (middle). TGW, thousand grain weight.
A generalized wiring diagram for wheat, as proposed by the authors. The diagram depicts the traits most commonly associated with the source (left) and sink (right) strengths and others that impact both the sink and source, largely dependent on growth stage (middle). TGW, thousand grain weight.

As crop yields are pushed closer to biophysical limits, achieving yield gains becomes increasingly challenging. Traditionally, scientists have worked on the premise that crop yield is a function of photosynthesis (source), the investment of assimilates into reproductive organs (sinks) and the underlying processes that enable and connect the expression of both. Although the original source-and-sink model remains valid, it must embrace more complexity, as scientific understanding improves.

A group of international researchers are proposing a new wiring diagram to show the interrelationships of the physiological traits that impact wheat yield potential, published on Nature Food. By illustrating these linkages, it shows connections among traits that may not have been apparent, which could serve as a decision support tool for crop scientists. The wiring diagram can inform new research hypotheses and breeding decisions, as well as research investment areas.

The diagram can also serve as a platform onto which new empirical data are routinely mapped and new concepts added, thereby creating an ever-richer common point of reference for refining models in the future.

“If routinely updated, the wiring diagram could lead to a paradigm change in the way we approach breeding for yield and targeting translational research,” said Matthew Reynolds, Distinguished Scientist and Head of Wheat Physiology at the International Maize and Wheat Improvement Center (CIMMYT) and lead author of the study. “While focused on yield potential, the tool can be readily adapted to address climate resilience in a range of crops besides wheat.”

Breeding milestone

The new wiring diagram represents a milestone in deterministic plant breeding. It dovetails simpler models with crop simulation models.

It takes into account how source and sink strengths may interact with wheat developmental stages to determine yield. For example, at the time of stem growth, spike growth or effective grain filling.

This diagram can be used to illustrate the relative importance of specific connections among traits in their appropriate phenological context and to highlight major gaps in knowledge. This graphical representation can also serve as a roadmap to prioritize research at other levels of integration, such as metabolomic or gene expression studies. The wiring diagram can be deployed to identify ways for improving elite breeding material and to explore untapped genetic resources for unique traits and alleles.

Yield for climate resilience

The wheat scientific community is hard at work seeking new ways to get higher yields more quickly to help the world cope with population growth, climate change, wars and stable supplies of calories and protein.

“To ensure food and nutritional security in the future, raising yields must be an integral component of making crops more climate-resilient. This new tool can serve as a roadmap to design the necessary strategies to achieve these goals,” said Jeff Gwyn, Program Director of the International Wheat Yield Partnership (IWYP).

— ENDS —

READ THE FULL PUBLICATION:

A wiring-diagram to integrate physiological traits of wheat yield potential

INTERVIEW OPPORTUNITIES:

Matthew Reynolds – Distinguished Scientist and Head of Wheat Physiology at the International Maize and Wheat Improvement Center (CIMMYT)

Gustavo Ariel Slafer – Research Professor at the Catalonian Institution for Research and Advanced Studies (ICREA) and Associate Professor of the University of Lleida

For more information or to arrange interviews, please contact the CIMMYT media team:

Marcia MacNeil and Rodrigo Ordóñez: https://staging.cimmyt.org/media-center/

ACKNOWLEDGEMENTS:

The study is an international collaboration of scientists from the International Maize and Wheat Improvement Center (CIMMYT), the Catalonian Institution for Research and Advanced Studies (ICREA), the Center for Research in Agrotechnology (AGROTECNIO), the University of Lleida, the University of Nottingham, the John Innes Centre, Lancaster University, Technische Universität München, CSIRO Agriculture & Food, and the International Wheat Yield Partnership (IWYP).

ABOUT CIMMYT:

The International Maize and Wheat Improvement Center (CIMMYT) is an international organization focused on non-profit agricultural research and training that empowers farmers through science and innovation to nourish the world in the midst of a climate crisis.

Applying high-quality science and strong partnerships, CIMMYT works to achieve a world with healthier and more prosperous people, free from global food crises and with more resilient agri-food systems. CIMMYT’s research brings enhanced productivity and better profits to farmers, mitigates the effects of the climate crisis, and reduces the environmental impact of agriculture.

CIMMYT is a member of CGIAR, a global research partnership for a food-secure future dedicated to reducing poverty, enhancing food and nutrition security, and improving natural resources.

For more information, visit staging.cimmyt.org.

ABOUT IWYP:

The International Wheat Yield Partnership (IWYP) represents a long-term global endeavor that utilizes a collaborative approach to bring together funding from public and private research organizations from a large number of countries. Over the first five years, the growing list of partners aims to invest up to US$100 million.

For more information, visit https://iwyp.org