Variation Among Highbush Blueberry Cultivars in Susceptibility to Spring Frost

Flower bud injury was assessed in 18 cultivars of highbush blueberry ( Vaccinium corymbosum L.) after two spring frosts. Bud position on shoots was significantly correlated ( P < 0.05) with percent brown ovaries. Significant differences in proportion of brown ovaries were noted among cultivars, but most of the variation was associated with stage of bud development. The least-developed buds were the most hardy. Bloom date was significantly correlated with harvest date across cultivars, although ‘Spartan’ flowered much later than other early ripening cultivars.