ARS | Publication request: Botryosphaeria stem blight of southern blueberries: effect of temperature on infection and lesion development

Submitted to: Phytopathology
Publication Type: Abstract Only
Publication Acceptance Date: June 15, 2012
Publication Date: July 1, 2012
Citation: Smith, B.J., Miller Butler, M.A. 2012. Botryosphaeria stem blight of southern blueberries: effect of temperature on infection and lesion development. Phytopathology. 102:S4.111.

Technical Abstract: Botryosphaeria stem blight is a destructive disease of rabbiteye (Vaccinium ashei) and highbush (V. corymbosum) blueberries in the southeastern United States. Historically this disease has been reported to be caused by the fungus Botryosphaeria dothidea. Recently other species in the Botryosphaeriacea family also have been identified as causal pathogens. The effect of temperature on infection of southern highbush (SHB) and rabbiteye (RE) blueberry cultivars by B. dothidea and other species was compared using a detached stem assay. Succulent, partially-hardened stems were wounded, inoculated with a mycelial block from 14 to 28-day-old cultures of the pathogens, and incubated for 14-22 days at 10, 15, 20, 25, 30, and 35o C. Lesion length was measured, and isolations were made from locations 10 mm above and 10 and 20 mm below the inoculation point on each stem. Main effects due to cultivar, species and temperature showed that stems of the RE cultivar, Climax, and the SHB cultivar, Star; those inoculated with B. dothidea and Diplodia seriata; and those incubated at 30 and 35o C had the greatest average lesion length and the highest recovery percentage of each inoculated species. The effect of temperature and culture medium on the growth and pycnidia production of the three species was also determined. Information gained from this study will be used to more effectively manage Botryosphaeria stem blight on blueberries.