Range and severity of a plant disease increased by global warming

A research team led by Rothamsted Research has used a weather-based model developed to predict the start and severity of epidemics of phoma stem canker, a disease of oilseed rape and other brassicas that causes losses of $900M worldwide, to investigate the consequences of predicted climate change scenarios.

The team of biologists and mathematicians found that warmer winters significantly advanced the date of stem canker appearance in spring and increased the severity of canker before harvest. They also predicted that epidemics will spread north from England to Scotland, where cankers do not currently occur on oilseed rape.

The research was part of programme of work to reduce reliance on use of pesticides in crop protection. “The phoma stem canker forecast model was developed as a tool to help guide fungicide applications timing by farmers and their advisors. We realised we could extend the use of the model by incorporating climate change scenario data to examine how global warming might impact on future epidemics” explained Dr Neal Evans, a Plant Pathologist at Rothamsted Research.

These results provide a stimulus to develop models to predict effects of climate change on other plant diseases, especially in delicately balanced agricultural or natural ecosystems. Such predictions can be used to guide policy and practice in adapting to effects of climate change on food security and wildlife.