Expansion of Cankers Caused by Leucostoma cincta on Sweet Cherry Trees

Abstract

Wounds made in July 1987 and fresh pruning cuts made monthly from August 1989 to July 1990 on sweet cherry trees were inoculated with Leucostoma cincta. Infection occurred each month, with a higher percentage of wounds becoming infected during the spring and summer than during the winter months. Inoculation with conidia placed directly on wounds or inoculation with pruning shears contaminated with conidia and mycelia resulted in the same incidence and severity of cankers. Canker enlargement was related to increasing monthly temperature. Greatest canker enlargement usually occurred from April through August. The period of least canker enlargement occurred from October through January. The largest cankers resulted from inoculations in July, and the smallest cankers resulted from inoculations in November, December, and January. Canker expansion curves were significantly described by cubic or quadratic equations for inoculation made during 10 of 12 months.