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Grape IPM in the Northeast

Pea-sized Berries (5 mm)

IPM practices to be implemented

Inoculum available for infection

see discussion below.


 

Postinfection Disease Management Protocol - Concord

Primary inoculum for black rot and powdery mildew is generally expended at this time. The postinfection disease management strategy can be terminated in Concord vineyards if primary infections of black rot and powdery mildew have been prevented (less than 1 percent cluster infection). If primary infection from either of these diseases is present in the vineyard, a protectant schedule should be followed until veraison (color change).

Disease Management Protocol for Vinifera and Highly Susceptible Hybrid Cultivars

The postinfection disease management strategy for Vinifera and French hybrids should be continued to ensure management of powdery mildew, downy mildew, and Botrytis. Berries are susceptible to infection by black rot and powdery mildew from bloom until 8° Brix. Varieties susceptible to powdery mildew and downy mildew can experience premature leaf fall due to severe infections in years conducive to disease development.

Inoculum available for infection

Botrytis Bunch Rot (212k pdf file)
Removal of leaves around clusters on mid- or low-wire, cordon-trained, or cane-pruned vines before bunch closing will reduce Botrytis-caused losses. Leaf removal is easiest in vertical-shoot positioned vineyards with a well-defined fruiting zone. Proper timing of leaf removal is critical and is dependent upon variety. Fruit of some varieties will sunburn if leaf pulling is performed too close to cluster closing. Cooperative Extension offices will assist growers with proper timings for leaf removal. Consult the current edition of New York and Pennsylvania Pest Management Recommendations for Grapes for preventive fungicide timings.