Yield disease control key under climate change

Oilseed rape disease losses are predicted to increase by a further £50M by 2050, under high CO2 emission scenarios. However, such losses, on untreated crops of winter oilseed rape, could be mitigated by effective control of the two main diseases; phoma stem canker and light leaf spot.

Scientists from Rothamsted Research, an institute of BBSRC, SAC and the University of Vienna, have demonstrated that disease control can be aided by new disease forecasting systems.

In research published in the June issue of "Food Security", the scientists used disease and crop models to show that unlike the disease phoma stem canker, which had previously been predicted to become more severe under a range of climate change scenarios, light leaf spot, the disease associated with oilseed rape crops in northern England and Scotland, was predicted to decrease in severity in coming decades.

Economic analysis indicated that this, coupled with increased yields from treated crops where diseases were effectively controlled, would be enough to offset increased losses from canker so that the net UK losses from climate change for untreated oilseed rape would be small.

Dr Neal Evans from Rothamsted Research explained "We weren’t surprised by the outcome of this study since the results reflect what we know about the biology of these two plant pathogens. Phoma stem canker is a global disease which is actually most severe in hot, dry countries such as Australia so one would expect the disease to be favoured by global warming.

In contrast, light leaf spot is favoured by cooler, moist conditions and so would not be expected to fair so well in the future". Professor Bruce Fitt added "These results can be used by industry and government to guide policy for adaptation to climate change, as a contribution to global food security".