Location: Southern Horticultural ResearchTitle: Botryosphaeria Stem Blight on Blueberries: Effect of Vaccinium Cultivar, Botryosphaeriaceae Species and Temperature
|Miller Butler, Melinda|
Submitted to: Acta Horticulturae
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/1/2016
Publication Date: 11/1/2017
Citation: Smith, B.J. and Miller-Butler, M.A. 2016. Botryosphaeria stem blight on blueberries: effect of Vaccinium cultivar, Botryosphaeriaceae species and temperature. Abstract Book XI International Vaccinium Symposium, University of Florida Gainesville, FL. Page 177.
Technical Abstract: Botryosphaeria stem blight is a destructive disease of blueberries grown in the southern United States. Historically stem blight has been reported to be caused by the fungus Botryosphaeria dothidea. Recently, other genera in the Botryosphaeriaceae family have been identified as causal pathogens of this disease. A detached stem assay was used to compare the effect of temperature on lesion development of one highbush, two southern highbush and two rabbiteye blueberry cultivars following inoculation by isolates of three Botryosphaeriaceae genera. Partially-hardened, terminal stems were wounded, inoculated with an isolate of B. dothidea, Neofusicoccum ribis, or Diplodia seriata, and incubated at 10, 15, 20, 25, 30, and 35oC. Lesions developed fastest on stems of the southern highbush cultivar Star. Stems inoculated with B. dothidea developed lesions at a faster rate than stems inoculated with the other two isolates. Lesion development was faster on stems incubated at higher temperatures than on stems incubated at lower temperatures. The effect of temperature on growth rates of these isolates in culture was also determined by growing each isolate on acid potato dextrose agar in the dark in growth chambers at 10, 15, 20, 25, 30, and 35oC. After 5 days the average colony diameter of each of isolate was least when incubated at 10°C. B. dothidea colony diameter was greatest at the three higher temperatures. D. seriata colony diameter was greatest at 25°C, and N. ribis colony diameter was greatest at 30°C. The optimum growth temperature for each isolate in culture was not the same as the optimum temperature for lesion development for each isolate.