Dr. Mengjun Hu, University of Maryland, and Kathy Demchak, Penn State University, have written an extensive article on effective strategies for Botrytis and Anthracnose fruit rot control for the 2022 season.
Managing gray mold (Botrytis) on strawberries is increasingly challenging because of fungicide resistance development, plus a new Botrytis species that is less susceptible to fungicides is becoming common in the mid-Atlantic region. Resistance to certain fungicides is also a problem in managing anthracnose fruit rot. This article describes disease management strategies designed to slow further resistance development while also providing specifics for managing our two most common fruit rots.
There are at least four species of Botrytis that can infect strawberries, but only two of them have been commonly found in the region. Botrytis cinerea, the species traditionally infecting strawberries, is present nearly everywhere and affects many horticultural crops. Recently another species, Botrytis fragariae, has also been found and, as its name indicates, is more specific to strawberry plants. It appears to overwinter on strawberry plant tissue and preferentially colonizes blossoms early in the spring, causing them to “turn brown and dry up.” While sometimes only one of these species is present, both can be present at the same time in a field and even in the same blossom. Using certain fungicides selects for resistant strains of either species and also preferentially selects for one species over the other. This means that both species have resistance to multiple fungicide groups, and both species can survive in fungicide-treated fields.
Read the complete research at www.extension.psu.edu.