Pear scab (Venturia pirina) has come more prevalent in recent years in the north coastal regions, especially in Mendocino County. A closely related fungus causes apple scab (Venturiu inaequalis) but does not affect pears, although the life cycles, infection requirements, and even control measures for apple and pear scab are remarkably similar. While apple scab research is ample and worldwide in scope, the applicability of some of this research to pear scab California has not been established.

The authors acknowledge the assistance of J. March, Potter Valley pear grower, and P. Montoya in conducting these studies