Most conidia are splashed onto flowers, new leaves, and wounds during blossom and petal fall. If conditions remain humid, germination occurs and twig blight begins. The fungus moves from either flowers or leaves into the stem. Symptoms include red foliar lesions that progress to wilted stems, to dead stems with leaves attached. If a stem is infected at the crown because of winter injury, the entire stem will suddenly wilt and die.
Infected fruits are soft and split easily.
Conidia are released during rainy periods from blossom bud swell thru late August. Cankers are brownish and may encircle the stem. As they progress downward, stems become flattened and turn gray. In the heat of summer these stems wilt. The reddened leaves remain attached.