At first, small dark purple spots up to one-fourth of an inch in diameter appear on the upper side of the leaves. These spots never have light centers as do those of Cercospora leaf spot and they have a more irregular outline. The fungus can also attack other parts of the plant. Some varieties have resistance to leaf scorch. Fungicide applications at repeated intervals should give adequate control.
Red stele is the most serious root disease of strawberries.
It occurs during the late winter and spring. The fungus attacks only strawberries and is spread from one area to another primarily through diseased plants. Infected plants are stunted and wilt in dry weather. The root systems have a rattail appearance with few lateral roots produced. The disease is more disastrous in low, poorly drained fields during cool weather.