How to Manage Pests

UC Pest Management Guidelines


Water Mold (Fruit Rot)

Pathogens: Pythium ultimum and other species

(Reviewed 12/13, updated 12/13)

In this Guideline:


Water-soaked lesions develop on ripe fruit in contact with wet soil. Within several days, the entire infected fruit turns into a water bag.


Avoid late-season irrigation, especially when threat of rainfall increases. Avoid wetting the top of beds when fruit is ripening. Shorter furrow irrigation runs and higher beds may lessen risk.


[UC Peer Reviewed]

UC IPM Pest Management Guidelines: Tomato
UC ANR Publication 3470


R. M. Davis, Plant Pathology, UC Davis
G. Miyao, UC Cooperative Extension, Solano and Yolo counties
K. V. Subbarao, USDA Agricultural Research Station, Salinas, CA
J. J. Stapleton, UC IPM Program and Kearney Agricultural Center, Parlier
B. J. Aegerter, UC Cooperative Extension, San Joaquin County (powdery mildew on field-grown tomatoes)
Acknowledgments for contributions to Diseases:
B. W. Falk, Plant Pathology, UC Davis

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