Arable Crop Disease Control, Environmental Change and Food Security

Abstract

Crop diseases cause yield losses, yet crop productivity needs to increase by > 70% over the next 35 years to accommodate population growth and changing dietary preferences1. Crop plants and pathogens interact in response to changes in environmental conditions. Recent predictions made by combining climate model data with an oilseed rape growth model and a phoma stem canker model suggest that yield will increase in the UK, especially in Scotland, whereas potential losses from phoma stem canker will be greatest in southern England2. Oilseed rape production in China is threatened by the possible arrival of Leptosphaeria maculans, a more virulent causal agent of phoma stem canker than the existing species Leptosphaeria biglobosa3. A strong correlation found between sulphur dioxide concentration and the ratio of Phaeosphaeria nodorum to Zymoseptoria graminicola in archived wheat samples at Rothamsted Research (1844 to date) suggests that subtle environmental changes can also cause changes in pathogen populations4. Ensuring future food security under environmental change is challenging and will require increased understanding of in planta disease processes. Effector-triggered defence (ETD) operates against extracellular fungal pathogens by R gene-encoded cell surface receptor-like proteins that trigger cell death only after a period of endophytic pathogen growth5. An example of this is resistance in oilseed rape against Pyrenopeziza brassicae that operates by preventing asexual sporulation. Exploiting such understanding and developing strategies to control biotic stressors are important to ensure adequate food supply for the future6.