Production of Botrytis cinerea for potential introduction into a vineyard.

Botrytis cinerea was produced in solid-phase fermentation, liquid fermentation and on potato dextrose agar. Stored products were evaluated for grape colonization in grape bioassays and in field trials, and for B. cinerea density using colony forming unit analyses and a nucleic-acid-based method. B. cinerea colony forming unit density was significantly correlated to the probability of successful grape colonization in grape bioassays (p-value=0.0002). Solid fermentation products could be stored longer than liquid fermentation and potato dextrose agar products. There was little difference in the rate of grape colonization in laboratory bioassays among solid-phase fermentation, liquid fermentation and plate culture products. Although the initial B. cinerea colonization rate of field grapes was slightly greater on vines treated with solid-phase fermentation and plate culture products compared to vines treated with product from liquid fermentation, there was no significant difference in final colonization between vines treated with solid-phase fermentation, liquid fermentation and plate culture products and untreated vines.