Today, Shane Breeden (plant pathology graduate student and technician for the Horticulture and Plant Pathology Departments) observed downy mildew in our Horticulture Farm research plots for the first time this year (Watkinsville, GA). This indicates that producers should be scouting for it throughout the state. In addition, if you have not already done so, I would consider incorporating highly efficacious materials such as Zampro, Revus, Ridomil Gold MZ (note the pre-harvest interval), etc. in spray programs as we move forward. Downy mildew spores can infect within a few hours when leaves or fruit are wet; dew counts for sufficient wetness. You definitely want to have good protection against this disease as we progress through the remainder of the season. Initial symptoms of downy mildew are “oil” spots on the upper leaf surface with white, fluffy spore formation on the leaf underside. See below for examples from today.

Downy mildew “oil spots”
Downy mildew sporulation on the underside of leaves
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