How to Manage Pests

UC Pest Management Guidelines


Phytophthora Fruit and Crown Rot

Pathogen: Phytophthora capsici and other species

(Reviewed 11/05, updated 6/08)

In this Guideline:


Phytophthora fruit and crown rot is most commonly found on squash and pumpkins, but all cucurbits are susceptible. This disease occurs suddenly in a field and plants wilt and die within a few days of infection. Infected fruit rot quickly. The roots and stems are soft, water-soaked, and brown. A downy growth is often apparent on plant lesions during periods of high humidity.


This disease only occurs where the soil has been moist for an extended period of time. Phytophthora capsici also infects tomatoes and peppers and is found throughout the state.


Good water management is usually sufficient to control this disease. Provide good drainage and avoid excessive soil moisture by extending intervals between irrigations and avoiding long irrigation periods.


[UC Peer Reviewed]

UC IPM Pest Management Guidelines: Cucurbits
UC ANR Publication 3445


R. M. Davis, Plant Pathology, UC Davis
T. A. Turini, UC Cooperative Extension, Imperial County
B. J. Aegerter, UC Cooperative Extension, San Joaquin County
J. J. Stapleton, UC IPM Program, Kearney Agricultural Center, Parlier

Acknowledgment for contributions to Diseases:
W. D. Gubler, Plant Pathology, UC Davis

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