How to Manage Pests

Pests in Gardens and Landscapes

Seasonal development and life cycle—Phytophthora root and crown rot

The fungus that causes Phytophthora root and crown rot survives in soil as spores (oospores) for several years. Water, temperature, and soil texture are the major factors affecting the development of root and crown rot. The presence of water is mandatory; soil saturation for as little as 5 to 6 hours can result in infection. Optimum temperature for plant infection is 75° to 92° F. Contaminated seed and transplants or soilborne inoculum are sources of primary infections. Irrigation water often disseminates fungal propagules from infested areas to other parts of the garden. Increased frequency and duration of irrigation favor disease development. Symptoms usually appear following a warm, wet period. The disease is severe in fine-textured soils that drain slowly and in highly compacted soils. The Phytophthora species that attacks peppers and eggplants also affects tomatoes.

Stunting and discoloration of pepper roots

Stunting and discoloration of pepper roots


Statewide IPM Program, Agriculture and Natural Resources, University of California
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