SUMMARY
Stem blight, caused by the fungus Botryosphaeria dothidea, is a destructive disease of rabbiteye (Vaccinium ashei Reade) and high-bush (V. corymbosum L.) blueberries in the southeastern United States. The susceptibility of 20 southern highbush, two rabbiteye, and two highbush cultivars were compared using a detached stem assay. Fresh isolates of B. dothidea obtained from infected southern highbush blueberry plants were used as inoculum in this study. Succulent, partially-hardened stems were surface disinfected, rinsed in sterile distilled water, wounded by scraping away a section of bark, and inoculated by covering the wound with a mycelial agar block of B. dothedia and securing with parafilm wrap. The base of each stem was inserted into moistened, sterilized sand in a 150 mm × 25 mm tissue culture tube and incubated at 25°C, 100% RH for 30 days. Lesion length was measured after 15 days incubation. Cultivars with the shortest mean lesion length were classified as relatively resistant and included ‘Pearl River’, ‘Emerald’, ‘Star’, ‘Sharpblue’, ‘Elliott’, ‘Misty’, ‘Bluecrisp’, ‘Darrow’, ‘Southmoon’, ‘Ozarkblue’, ‘Sapphire’, and ‘Brightwell’. Cultivars with the longest lesions at 15 days were classified as relatively susceptible and included ‘Legacy’, ‘Gulf Coast’, ‘Cooper’, ‘Georgiagem’, ‘O'Neal’, ‘Reveille’, ‘Jubilee’, and ‘Magnolia’.
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