Crop and Pest Management Guidelines

A Cornell Cooperative Extension Publication

2.4 Using NEWA Resources in a Vineyard Integrated Pest Management (IPM) Strategy

Historically, management practices for vineyard pests in the Eastern United States were based on the calendar or on a growth stage such as bud break, bloom or Veraison using materials with a broad spectrum of activity. This was a straightforward approach to pest management, and for many years, this type of spray program was very effective. However, as the nation became more conscious of pesticide use, the Food Quality Protect Act (FQPA) was introduced in 1996, and broad-spectrum pesticides were either restricted in their usage, were banned completely, or had grapes removed from their labels. As the years have passed, new fungicides and insecticides have come on the market, but with a trend toward less toxic and narrower spectrum pesticides.

With the narrower spectrum pesticides came the need to understand the life cycle of vineyard pests, how individual pesticides worked, resistance management, varietal susceptibility, and economic thresholds (treatment thresholds). A critical component of this was knowledge of the combination of environmental factors that promote insect and disease development in a vineyard. The research faculty and extension staff at Cornell and Penn State Universities have developed this type of knowledge and the challenge became how best to get the information implemented into grower vineyards.

Weather information is also a key component of any vineyard IPM strategy. In and of itself, weather information can help in spray decisions, but when combined into an information database that includes pest developmental models, weather data is transformed into applications that can assist in determining if there is:

  1. A need to spray
  2. A need to tighten up, or extend, spray intervals
  3. A need to change the materials (active ingredient or mode of action) used
  4. A need to add sprays or the opportunity to eliminate them

The best resource available for growers in New York and Pennsylvania to monitor the weather and its effect on grape pests is the Network for Environment and Weather Applications (NEWA). What is NEWA? Available on line at, NEWA provides web-based weather and pest model relevant to vineyards across New York State and Pennsylvania.

Weather, insect and disease models displayed on NEWA provide grape growers and members of the grape industry a wealth of information to assist in making the spray decisions listed above for powdery mildew, black rot, downy mildew, Phomopsis Cane and Leaf Spot and grape berry moth. Each weather station has its own Station Page with links to pest forecasts (Grape diseases, Grapevine downy mildew and Grape berry moth) as well as a wealth of weather information.

This makes NEWA an excellent resource for use in developing, implementing and evaluating a vineyard IPM strategy. Information provided on the NEWA website includes, but is not limited to;

  1. Weather records
    1. Daily summary of weather parameters (i.e., temp, rainfall, leaf wetness, relative humidity)
    2. Hourly recording of weather paramters
    3. Historical weather records
  2. Pest models and forecasts (grapes)
    1. Grape berry moth phenology based Degree Day model
    2. Primay infection events for
      1. Powdery mildew
      2. Black Rot
      3. Phomopsis
    3. Down mildew DMCast model of infection events by grape cultivar
  3. Growing Degree Day (GDD) information (base 50F used for grapes, other base temps available)
  4. National Weather Service forecasts

The weather and pest model information is of greatest value the closer it is to a vineyard. In a perfect world, there would be a weather station for every vineyard block to generate the best pest forecast model results specifically for each vineyard block. The best way to get an idea of where these machines are located in reference to a specific vineyard is to scan the location map on the NEWA Home Page or click on Stations Pages in the main menu to access a list of alphabetized station names.

While there are a large number of weather instruments on the NEWA website, they may not all be located in vineyards. However, the information those instruments provide can be used in vineyards that are in close proximity to get a general idea of the pest and weather conditions.

You can access model information for powdery mildew, black rot, Phomopsis, downy mildew and grape berry moth through the Pest Forecasts found on a specific station page or by using the Pest Forecast drop down menu found in the blue ribbon found near the top of each page of the NEWA site and selecting Grape Forecast models. Used on a regular basis, model information for the various pest models can assist in determining whether the spray interval for these diseases should be tightened or extended. The Grape Diseases forecasts operate like a mini-expert systems with disease management options developed by Wayne Wilcox (Department of Plant Pathology and Plant-Microbe Biology, Cornell University) and Juliet Carroll and Tim Weigle (NYS IPM Program). Being able to choose the current phenological stage of a vineyard, or portion of a vineyard, provides customized results for all the different varieties in a vineyard operation.

The phenology-based degree-day model for grape berry moth found on NEWA was developed as a cooperative effort between research entomologists and extension staff at Cornell, Penn State and Michigan State Universities. This model uses wild grape bloom as a biofix date to start accumulation of degree-days and allows the date of wild grape bloom to be entered for customized results. While the model will provide a default date for wild grape bloom, the ability to enter the actual date wild grape bloom was observed makes the information provided by the model much more valuable.

Using the pest forecast model and weather information found on NEWA a vineyard IPM strategy can be developed that uses resources wisely while managing pest populations to a commercial level. NEWA combines knowledge of the pests' life cycle and how weather conditions affect its development with current and historical weather data to generate infection event and insect development status and predictions or forecasts. Combining the results of models found on NEWA knowledge of pests by individual vineyard blocks, varietal susceptibility, and the materials used for managing the pests provides the basis for implementation a sound vineyard IPM strategy.

Other resources are available online, including:

Network for Environment and Weather Applications

2019 New York and Pennsylvania Pest Management Guidelines for Grapes:

New York State grape IPM insect and disease fact sheet database:

Cornell University Pesticide Management Education Program:

Penn State Pesticide Education Program:

Pesticide Application Technology at Cornell University:

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