Occurrence and Incidence of Verticillium Wilt in Chilean Avocado Groves. B. A. Latorre, Adjunct Professor, Departamento de Ciencias Vegetales, Facultad de Agronomía, Pontificia Universidad Católica de Chile, Casilla 114-D, Santiago, Chile. P. T. Allende, Former Student, Departamento de Ciencias Vegetales, Facultad de Agronomía, Pontificia Universidad Católica de Chile, Casilla 114-D, Santiago, Chile. Plant Dis. 67:445-447. Accepted for publication 8 November 1982. Copyright 1983 American Phytopathological Society. DOI: 10.1094/PD-67-445.

Verticillium wilt was found in several new avocado groves in Chile. The disease has been particularly severe on the cultivar Hass grafted on Mexicola avocado rootstocks and planted after susceptible crops, primarily tomato, cabbage, squash, cauliflower, artichoke, or chrysanthemum. It has rarely occurred in orchards established after nonsusceptible crops. Incidence of the disease in seven groves varied from 1.3 to 10.4% of affected trees, with an overall incidence of 2.9%. Symptoms were characterized by sudden collapse of the foliage, death of leaves, and development of dark brown streaks in the sapwood. Trees usually recovered after the initial collapse. The economic loss due to Verticillium wilt was estimated at $942/yr in an 8-yr-old Hass orchard where 10.4% of the trees were infected.