Impact of tree growth and rain on fungicide efficacy against apple scab

Description

Apple growers apply fungicides every year to control apple scab caused by the fungus Venturia inaequalis. The treatments are repeated at regular intervals based on the risk of infection, the appearance of new leaves, and rain washing off the fungicide. Recommended treatment frequencies are mainly based on empirical criteria that vary considerably among specialists. Yet findings from published studies and other research could greatly improve decision-making on treatment frequencies.

The aim of this project is to determine the combined impact on fungicide efficacy of rain and the appearance of new leaves to more accurately identify how long treatments remain effective. The data generated by this project will be compatible with currently available software i.e., RIMpro and the Agropomme model. The findings will enable more rational use of fungicides during the primary infection period.

Objective(s)

• Quantify the combined impact of rain and the appearance and growth of new leaves on the efficacy of fungicides applied before the infection period