Location: Horticultural Crops Disease and Pest Management Research Unit
Project Number: 2072-22000-045-047-G
Project Type: Grant
Start Date: May 1, 2024
End Date: Oct 31, 2025
Objective:
1. The role of canopy management in UV-C based grape powdery mildew management programs.
2. Understanding fungicide phytotoxicity in wine grapes – The role of sulfur concentration, adjuvants, and the environment.
Approach:
We will refine and adapt field-based UV-C light applications for the control of grape powdery mildew to optimize a low-chemical input disease management regime for arid grape production regions such as eastern Washington and eastern Oregon, as well as Idaho. Specifically, we will explore how canopy management impacts UV-C light efficacy when applied during the critical window for berry infection (immediate pre-bloom to 4 wks post full bloom).
Summer “sulfur burn” is a common concern in wine grape production. It stems from a fear that grapevine foliage and fruit can experience severe phytotoxic burns if sulfur is sprayed during, or just before, periods of high temperatures. This objective will attempt to define what components of a mid-summer sulfur spray – sulfur concentration, sulfur formulation, adjuvant, and environmental conditions – are truly driving the risk of phytotoxicity. The resulting information will be used to update spray recommendations and alleviate potential fears associated with mid-summer fungicide treatments.
