Although weather plays a large role in determining the most important timings for Botrytis fungicides, sprays at or near veraison consistently appear to be important. Recent research in the Finger Lakes region suggests that applications at bloom and bunch closure can be as important as those at veraison and preharvest if the weather is wet during these earlier periods, although they are not so important if it is dry then. Rovral performance usually is improved by adding oil or a surfactant to the spray mix, although this is not true for Vangard and Elevate. Low-risk vineyards rarely require this treatment. Life Sciences Bulletin No. 138 for GBM risk assessment protocols, or contact the Grape IPM program.
Most insecticides are incompatible with lime.
Check label for incompatibility before tank mixing insecticides with alkaline spray materials. Life Sciences Bulletin No. 118 for information on effects of alkaline hydrolysis on pesticides. Scout vineyards carefully, apply when larval feeding begins, and repeat after 5-7 days. See New York's Food and Life Sciences Bulletin No. 138 for information on treatment guidelines. Finger Lakes growers of Concord and other native grape cultivars should monitor leafhopper populations carefully, as resistance is suspected in isolated vineyards of the region.