Grape IPM in the Northeast
Third Week in August
IPM practices to be implemented
- Grape Berry Moth Risk Assessment protocol: damage threshold is 15 percent damaged clusters, see discussion below.
- continue disease management protocols, if applicable, see discussion below.
- determine when berries reach 8° Brix
Grape Berry Moth Risk Assessment Protocol
Scouting for grape berry moth (also available as a 234k pdf file) damage should be accomplished for high-risk vineyards at this time. There are no further scouting requirements for vineyards classified as low- or intermediate-risk for grape berry moth. Research has shown that there is no risk of further economic damage from grape berry moth in low- and intermediate-risk vineyards if the risk assessment protocol has been followed to this point in the season. The sampling procedure for Grape Berry Moth Risk Assessment is the same as in the third week in July except that the damage threshold at this scouting is an average of 15 percent damaged clusters. Both the interiors and the edges of vineyards should be scouted. For complete information on grape berry moth scouting, consult New York's Food and Life Sciences Bulletin 138, Risk Assessment of Grape Berry Moth and Guidelines for Management of the Eastern Grape Leafhopper (appendix 2) (717k pdf file).
Berries are no longer susceptible to infection by black rot and powdery mildew at 8° Brix, which occurs in the latter part of August in an average year. Varieties that are susceptible to powdery and/or downy mildew should continue to receive an appropriate disease management program to limit foliar infections, which can lead to premature leaf fall in years conducive to disease development.