Symptoms and Disease Cycle Crown rot is caused by the soil-inhabiting fungus Phytophthora cactorum . The pathogen infects the roots of the strawberry through wounds in the root tissue. Symptoms are different, depending on the fruit stage. On immature, green fruit, the infected areas appear dark brown or normal green with a brown edge. On ripe, mature fruit, they can appear either without color change or bleached and ranging in color from light lilac to purple.
Infected fruits are characteristically tough and leathery, having a bitter taste.
When weather conditions are warm and rainfall is abundant, the pathogen releases its spores into the soil. These infested soil particles are dispersed onto the fruits by splashing rain or wind. Disease Management Practices such as mulching, which keeps the fruit off the ground and aids in minimizing rain splash, will help control leather rot. Growers also should plant resistant cultivars, provide good soil drainage, and avoid planting in low spots. Powdery Mildew Powdery mildew occurs on a wide range of hosts and almost everywhere the strawberry is grown.