Effects of Environmental Factors and Cultural Practices on Bull's Eye Rot of Pear.

Abstract

Bull's eye rot of pome fruits caused by Neofabraea spp. is characterized by infection occurring in the orchard throughout the growing season whereas rot lesions develop during long-term storage after harvest. Bull's eye rot was observed on pear fruit exposed to natural infection for any of six to nine sequential 1-to-2-week exposure periods during two growing seasons. Highest infection levels were associated with exposure closest to harvest. Over-tree irrigation and late harvest resulted in higher bull's eye rot incidence than under-tree irrigation and early or mid-season harvest. Fruit were inoculated prior to harvest with Neofabraea perennans to determine the effect of environmental factors on the development of bull's eye rot. The effect of temperature was inconsistent; disease was greatest at 10°C in one year of study but greatest at 30°C in the second year. Bull's eye rot developed independently of wetness durations longer than 0.5 h.