Freeze Damage in Six Rabbiteye Blueberry Cultivars

Abstract

Rabbiteye blueberries ( Vaccinium asheiReade) are becoming an increasingly important small fruit crop in the Southeastern United States. Most of this area has relatively mild winters and comparatively few chilling hours (hours below 7°C). Studies have in dicated that 400-500 hours of chilling are usually sufficient for normal floral bud break in rabbiteye blueberries (2, 3, 4, 6). In this region, cold periods are often interrupted by weeks of temperatures above 7°C. After the chilling requirements of blueberries are satisfied, extended periods of warm temperatures (around 20°-25°C) initiate flower-bud growth. Individual flower buds and solitary flowers become more susceptible to cold damage as flower development in creases. Flower buds in Tifblue cultivar in stage 2 as described in a previous study (5) withstood temperatures of -4°C or below. Tifblue flower buds in advanced stages (floral rating of 4 or above) were severely damaged by temperatures of -4°C (5).