Impacts of climate change on phoma stem canker and light leaf spot on UK oilseed rape

To illustrate impacts of climate change on plant disease epidemics, an oilseed rape crop growth model, and weather-based disease forecasting models for phoma stem canker (Leptosphaeria maculans) and light leaf spot (Pyrenopeziza brassicae) were combined with projected UK temperature and rainfall under high and low carbon emissions climate change scenarios for the 2020s and 2050s. It was predicted that, if diseases are controlled, oilseed rape yields will increase, especially in Scotland. However, it was also predicted that phoma stem canker epidemics will not only increase in severity but also spread northwards from England to Scotland by the 2020s and that yield losses will increase to 50% in southern England if diseases are not controlled. There is evidence that the major gene for resistance to L. maculans Rlm6 is temperature-sensitive, since it operated at 15°C but not at 25°C. These results provide a stimulus to develop models to predict effects of climate change on other crop diseases. Such predictions can be used to guide policy and practice in adapting to effects of climate change on food security.