Grape IPM in the Northeast
Postbloom
IPM practices to be implemented
- Grape Berry Moth Risk Assessment protocol, see discussion below.
- Grape Leafhopper, see discussion below.
- continue Disease Management Protocol, see discussion below.
- apply final spray for primary-season protectant disease management protocol
Monitoring required
- weather parameters of temperature, precipitation, leaf wetness, and relative humidity
- Grape Rootworm, see discussion below.
Inoculum available for infection
- Botrytis bunch rot 211k pdf file
- powdery mildew 490k pdf file
- black rot 548k pdf file
- Phomopsis Cane and Leaf Spot 277k pdf file
- downy mildew 300k pdf file
Grape Berry Moth Risk Assessment Protocol
Vineyards in the high- or intermediate-risk categories for grape berry moth (also available as a 234k pdf file) should receive an insecticide application at 10 days postbloom (10 days after 50 percent bloom). Grape berry moth damage has been shown to be concentrated on vineyard edges. Therefore, application of insecticide to only the outside three to six rows can often provide economic management of grape berry moth. This strategy works best with rows running parallel to vineyard edges. Current sprayer technology, however, does not allow for adequate coverage for rows perpendicular to vineyard edges.
Grape Leafhopper
(also available as a 230k
pdf file)
Insecticide applications in vineyards in the high- or intermediate-risk
categories for grape berry moth will also provide management of leafhopper.
In most years this single postbloom application of insecticide is all that
is needed to maintain this pest below economic levels. Vineyards that are
at low risk for grape berry moth damage should be treated with insecticide
at this time only if substantial leaf feeding by adults was found in the
prebloom scouting. If insecticide is applied only for leafhopper in a low-risk
vineyard, the insecticide label should be consulted for rates. Many insecticides
can be applied at greatly reduced rates for management of leafhopper. If
grape berry moth management is also required, the full rate of insecticide
should be used. For specific rate recommendations please consult the current
edition of the New York and Pennsylvania Pest Management Recommendations
for Grapes.
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Postinfection Disease Management Protocol
Weather should continue to be monitored throughout the growing season until veraison (color change). Disease management requirements will differ depending on vineyard site and variety. Good primary-season (bud break through pea-size berries) management of powdery mildew (490k pdf file) and black rot (548k pdf file) will enable Concord growers to discontinue their fungicide program at pea-size berries (mid-July). Growers of highly susceptible varieties, however, must continue disease management for powdery mildew, downy mildew, and Botrytis bunch rot (211k pdf file) much later into the season to limit berry infections (berries become less susceptible to infection by black rot and powdery mildew at 8° Brix) and to limit early defoliation due to severe foliar infections of powdery and/or downy mildew. See IPM Disease Management Protocols for complete information on postinfection disease management protocols.
Grape Rootworm
(also available as a 255k pdf file)
Although rootworm was once one of the worst insect pests of grapes in the
Northeast, it is now considered only an occasional pest because modern insecticides
have provided control of it. Adults feed on grape foliage, producing chainlike
feeding patterns on the leaves. Immature stages feed on the roots and can
cause serious damage and vineyard decline over a period of years if left
untreated. Grape rootworm has appeared in damaging levels in some New York
State vineyards in recent years and may require treatment if widespread
leaf injury by adults is present. Vineyards in the low-risk category for
grape berry moth are the most vulnerable to rootworm problems and should
be monitored for adult feeding in late June or early July. In vineyards
with rootworm infestations, a postbloom insecticide application will control
adults and prevent infestation of roots by the larval stage.