Not available – first paragraph follows: California pistachio production is a fast-developing industry: over 40,000 acres of trees have been planted in the past 12 years. Although a number of disease and insect problems are known to affect pistachios in California, “epicarp” lesion is considered one of the most serious problems, causing losses of 30 percent or more. Although it is termed “epicarp” (skin) lesion, it also affects the mesocarp (flesh), and the endocarp (shell) of the fruit.

This research was supported in part by the California Pistachio Commission. The authors thank H.R. Teranishi, J. Maranto, and R.H. Beede for their technical assistance. Photographs by J. Hall.