Floricane leaves are also susceptible, but rarely infected. Cane lesions appear purple under the heavy primocane wax, but turn brown when the wax is rubbed off. In winter, lesions turn silver to gray and become difficult to identify. In the spring, spur blight causes buds near infected nodes to fail or remain inactive. Gray mold , a common and serious disease of raspberries, causes blossom blight and fruit rot.
Gray mold can also infect senescing leaves and canes.
Infection typically begins on young flowers, but quickly spreads to fruit during cool, wet weather. Often immature berries, with latent infections, remain symptomless until the fruit matures. However, when environmental conditions are cool and wet, infected berries may become covered by a mass of gray or brown fungal material. This mass of fungal material gives fruit a moldy appearance. Physical damage, bruising, or wounding causes an increase in the number of fruit infections and post harvest rot.