GLOBAL - For the first time, an international consortium of researchers have used a systematic multi-model test to exploit data from field and artificial heating experiments to focus on the responses of wheat to high temperatures.
The consensus from this international multi-model test predicts that global wheat production will drop by six per cent for each degree centigrade of global warming together with increased variability of yield across regions and seasons.
Thirty wheat crop models were compared within the Agricultural Model Inter-comparison and Improvement Project (AgMIP) with two previously unpublished data sets from field experiments in which wheat was exposed to mean temperatures ranging from 15oC to 32oC during the growing season.
The first experiment was the Hot-Serial-Cereal experiment with a wide range of sowing dates and artificial heating treatments. The second experimental set was from the International Maize and Wheat Improvement Centre (CIMMYT) multi-location experiments that were spread across seven temperature environments worldwide.
Many of the individual simulation models predicted wheat yields accurately for typical conditions, however, when effects of higher temperatures were tested, the results of the model simulations were more variable. Nevertheless, by combining results from all models, the ensemble median was consistently more accurate in simulating temperature responses than any single model and reproduced observations well.
Extrapolating the predictions of the multi-model ensemble indicated global wheat production losses of six per cent for each degree centigrade of global warming with increased variability of yield across regions and seasons.
Dr Mikhail Semenov, whose team at Rothamsted Research contributed to this research, said: “Options exist to adapt and mitigate the adverse effects of climate change on global wheat production.
"Breeding for late maturing cultivars with longer grain filling to recapture the temperature-induced loss of biomass and grain yield could be beneficial as long as exposure to heat stress and terminal drought does not become counter-productive. Optimizing this trade-off should be region specific, and crop modelling is a key exploration tool to underpin crop adaptation for a changing climate.”
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