Septoria tritici is the most significant foliar disease in UK wheat causing between £43M to £53M in yield losses annually; Yellow and brown rust are more sporadic but cause significant losses during high disease years. In all cases control is by fungicide application costing £82M annually. Effective disease management relies on either prophylactic pesticide use or significant manual intervention and time consuming assessment of crop disease indicators.

Indications are that current levels of pesticide use could lead to increased risk of pesticide resistance, if this should occur it is estimated that wheat yields could reduce by up to 20%. To address this……