Vegetable Diseases Caused by Phytophthora capsici in Arizona

Phytophthora capsici is responsible for some of the most important diseases of peppers and cucurbits worldwide. The diseases are commonly referred to as Phytophthora blight, Phytophthora crown and root rot, Phytophthora fruit rot, and damping off. P. capsici was first described by Leon H. Leonian on chile pepper in New Mexico in 1922. This pathogen subsequently has caused severe disease epidemics on susceptible vegetables in North, Central and South America, Europe, Asia, and many states across the United States. In Arizona, the disease has become a chronic problem for pepper, squash, and melon production in the southern part of the state. P. capsici can cause extensive losses on peppers and cucurbits under favorable weather conditions during the summer monsoon season.