This root rot disease has become a serious problem facing strawberry production in the northern two-thirds of the United States. The disease is most destructive in heavy clay soils that are saturated with water during cool weather. Once it becomes established in the field, the red stele fungus can survive in soil up to 13 years. Under favorable conditions of high soil moisture and cool temperature, plants will show typical disease symptoms within 10 days after infection. Symptoms When plants start wilting and dying in the more poorly-drained portions of the strawberry field, the cause is very likely red stele disease.
Infected plants are stunted, lose their shiny green luster, and produce few runners.
Younger leaves often have a metallic bluish-green cast. Older leaves turn prematurely yellow or red. With the first hot, dry weather of early summer, diseased plants wilt rapidly and die. Diseased plants have very few new roots compared to healthy plants that have thick, bushy white roots with many secondary feeder roots. Infected strawberry roots usually appear gray, while the new roots of a healthy plant are yellowish-white.