In a commercial orchard adjacent to an abandoned orchard near Kearneysville. Table 1 . Maryblyt predicted a single infection period on April 24th. With average daily temperatures above 60 F for the remainder of this week, infection risk is high. Blossom blight symptoms from the April 24th infection could be visible by May 6.
Powdery mildew occurs wherever apples are grown.
In some areas of the country it is a major foliar disease. In other areas, it is only a minor problem. Economic loss from mildew varies with climatic conditions, cultivar susceptibility, and orchard or nursery management practices. Apple leaves, blossoms, and fruit can be infected. Infections on leaves first appear as whitish, felt-like patches of fungal mycelium and spores, most commonly on the lower surface.