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Crop and Pest Management Guidelines

A Cornell Cooperative Extension Publication
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44003

5.2.4 1-INCH SHOOT GROWTH (when the average shoot length is 1 inch)

Pest(s)

Materials

Rate per Acre

Comments

5.2.4 1-INCH SHOOT GROWTH (when the average shoot length is 1 inch)

Phomopsis cane and leaf spot

This spray may be important if a prolonged rainy period occurs before the next anticipated spray, especially in blocks with a history of Phomopsis development. Phomopsis diseases are most likely to become a problem when the fungus is allowed to build up on dead canes or other infected wood in the vines (e.g., pruning stubs, spurs), especially if weather is wet during critical stages of disease development. Therefore, hedged vineyards are at an elevated risk of incurring economic losses from Phomopsis, although damage can occur in all pruning and training systems. Rachises are highly susceptible when clusters first become visible and infections during this early part of the season are most damaging. Fruit infections can be initiated through the young berry stems as soon as clusters become visible and can continue to occur until fungal spores are depleted, which is approximately the pea-sized berry stage. The maximum rates of the listed products should not be necessary in the very early season IF sprays are thoroughly applied. Although some other active ingredients are registered for control of Phomopsis, the three included in the products listed below (captan, mancozeb, ziram) are the only ones that have consistently provided good control in NY trials. See Table 3.1.2 for varietal susceptibility to this disease.

Captan 4L

1.5-2 qt

or Captan 50WP

2-4 lb

or Captan 80WDG

1.25-2.5 lb

or Captan Gold 4L

1-2 qt

or Captan Gold 80WDG

1.25-2.5 lb

OR

*NYDithane DF

2-4 lb

or Dithane M45

or *Manzate Pro-Stick 75DF

or Penncozeb 75DF

OR

*NYDithane F-45

1.6-3.2 qt

or *NYManzate Max 4F

OR

Ziram 76DF

3-4 lb

Anthracnose

Only a problem on a few specific varieties; see the entry under Anthracnose in Section 3.1, Vineyard Disease Management, for a list of susceptible varieties and weather conditions favoring its development. Only Rally, Inspire Super, Revus Top, Quadris Top, and Pristine are specifically labeled for control of anthracnose and none of them are generally recommended for use this early in the season, since the diseases that they primarily target are not active yet. However, early season control can be important on susceptible varieties, especially when wet. This can be provided by sprays of mancozeb, ziram, or captan that are applied to control Phomopsis and other diseases during the early season. A delayed dormant spray of lime sulfur that is thoroughly applied will also provide some control and can be used to supplement conventional fungicide programs in problem blocks or to substitute for them to some extent when conventional fungicides will not be used (e.g., "organic" production systems).

Powdery mildew

This powdery mildew spray is only appropriate for V. vinifera and other highly susceptible varieties, and may be particularly valuable in vineyard blocks with significant disease the previous year, if weather forecasts call for rain and temperatures persistently above 50°F. Even under favorable environmental conditions, it is much less critical in vineyard blocks where good control of foliar infection was maintained through Labor Day (in the previous season) and/or where the next spray will include a material with eradicative action against young infections (e.g., sulfur, oils, potassium salts). The materials listed below should not be used on sulfur-intolerant varieties (see Table 3.1.2); however, such varieties are unlikely to need treatment this early in the season.

Liquid sulfur 6L

see label, rates vary

OR

Wettable Sulfur (several formulations)

see label, rates vary

OR

Regalia

1-4 qts (see label)

Regalia is a biopesticide that has provided fair to very good control of powdery mildew in NY and PA trials, depending on disease pressure. It is likely to work best on less susceptible varieties or at times of year when pressure is low. Different rates are recommended depending on whether it is used alone or in a tank mix. Because Regalia requires 48 hours to activate plant defenses, applications need to start before infection. This product could be included in an organic spray program or in rotation before or after the critical powdery mildew control window (immediate prebloom and post bloom) to slow the development of resistance to other products. Regalia should not be relied on for powdery mildew control during immediate prebloom and post bloom applications.

OR

ProBlad Verde

18.1-45.7 fl oz

ProBlad Verde is a biopesticide that has provided fair to good control of powdery mildew in NY and PA trials.

ProBlad Verde is OMRI listed and can be included in an organic spray program or in rotation before or after the critical powdery mildew control window (immediate prebloom and post bloom) to slow the development of resistance to other products. It should not be relied on for conventional powdery mildew control during this critical window. No more than 5 applications can be made during the season, and ProBlad Verde may be applied no more than twice before alternating with a product that has a different mode of action.

OR

Howler

2.5-7.5 lbs

OR

Romeo

0.23 lbs

OR

Stargus

0.5-4.0 qts

Stargus has shown to be more effective when tank mixed with Regalia.

KEY FOR SECTION 5.2:

* Federal restricted-use pesticide*NY Restricted-use pesticide in New York State

† Not for use in Nassau/Suffolk Counties.^ Not registered for use in New York State at press time