Infection of cold-injured blueberry stems by Botryosphaeria dothidea.

摘要

A blueberry field in Bladen County, NC, USA, was examined biweekly or monthly for the 3 years to determine conditions associated with high plant mortality in young bushes. Plants grew profusely, did not become completely dormant, and 139 of 500 bushes were cold-injured at first frost in Nov. 1992. Cold-injured stems (c. 10-30 cm in length) developed a characteristic dead, hook-shaped tip which persisted throughout the following growing season. In 1993, the incidence of B. dothidea in stems injuredby cold the previous Nov. was 19, 39 and 88% for Mar., May and Jun,, respectively. Widespread infection by B. dothidea following cold injury could account for past observations of field epidemics 1-2 years after planting.