Return to Diseases

Phytophthora crown and root rot (Phytophthora spp.) is caused by a soilborne, fungus-like water mold. Initially, young leaves wilt; however, disease development is usually rapid, and entire plants collapse within a few days. If individual crowns become infected, only one portion of the plant may die. When diseased plants are pulled, they often break at the soil surface as a result of rotted crowns. Pathogen buildup can occur in poorly drained sites and during wet seasons. Crowns rot and become brown from the upper portion and then spread downward. Roots become affected later in the disease progression. Phytophthora overwinters in plant debris and can persist in soils for many years. Pathogen can build up in poorly drained sites and during wet seasons. Survival structures can develop if infected plants remain in fields. 

Phytophthora crown and root rot.

(Photo: Frank Louws, North Carolina State University)

Management:

• Provide good internal drainage; manage water runoff.
• Use proper sanitation.
• Remove infected plants as soon as symptoms develop.
• Rotate with non-host crops; rotate away from strawberry and solanaceous crops (up to 6 years).
• Begin with clean plant material.
• Use fungicides to suppress disease and reduce spread; fungicides do not cure disease.

Return to Diseases