Climate change may dramatically reduce wheat production

At least one-quarter of the world's wheat production will be lost to extreme weather from climate change in the coming decades if no adaptation measures are taken, researchers, including one of Indian-origin, have warned.
Researchers have found that wheat yields are projected to decrease by 6 per cent for each degree Celsius the temperature rises if no measures to adapt to extreme weather fluctuations are taken.
Vara Prasad, professor of crop ecophysiology and director of the US Agency for International Development Feed the Future Sustainable Intensification Innovation Lab at Kansas State University, was part of the collaborative team that conducted the research.

Prasad and colleagues said that based on the 2012-2013 wheat harvest of 701 million tonnes worldwide, the resulting temperature increase would result in 42 million tonnes less produced wheat - or a loss of nearly one-quarter of the current wheat production.
"It's pretty severe. The projected effect of climate change on wheat is more than what has been forecast. That's challenging because the world will have to at least double our food supply in the next 30 years if we're going to feed 9.6 billion people," Prasad said.
For the study, researchers systematically tested 30 wheat crop models against field experiments from around the world that were conducted in areas where the average temperature of the growing season ranged from 15 to 32 degrees Celsius.

The models accounted for planting dates, planting rates, temperatures and other crop management factors.

With the models, researchers were able to look at the effects of temperature stresses on wheat and predict future changes based on temperature changes.
Researchers found that the effects from climate change and its increasing temperatures on wheat will be more severe than once projected and are happening sooner than expected.
"Extreme temperature doesn't only mean heat; it also means cold. Simply looking at the average temperature doesn't really show us anything because it's the extremities that are more detrimental to crops," Prasad said.
"Plants can handle gradual changes because they have time to adapt, but an extreme heat wave or cold snap can kill a plant because that adjustment period is often nonexistent," he said.

Researchers also found that increasing temperatures are shortening the time frame that wheat plants have to mature and produce full heads for harvest, resulting in less grain produced from each plant.
Currently, Prasad and colleagues at Kansas State University, in collaboration with the university's Wheat Genetics Resource Center, are using growth chambers and heats tents to quantify the effects of temperature.
The data will help in refining the crop models so that they can be more accurate in predicting wheat responses.
The study is published in the journal Nature Climate Change.