Extension & Outreach

Providing growers with information about diseases of vegetable crops and their management is the goal of my program.  I conduct applied (translational) research generating practical results that are relevant for crop production.  Gardeners will find some information at this website useful; I also conduct a Master Gardener class on plant diseases focused on vegetables. See About for additional general information on my program.

•  For gardeners
•  Vegetable and herb disease factsheets and articles
• Resistant vegetable variety tables
• Organic management of vegetable diseases
• Zucchini yellow mosaic virus
• Tomato late blight
• Basil downy mildew
• Strawberry disease images and information

Extension project websites and program involvement

• Vegetable disease factsheets and articles
  Lists of disease resistant vegetable varieties and information about biopesticides (product lists for crops plus efficacy data) are at this website in addition to articles and factsheets prepared for vegetable growers. This website is in the ‘Pest Management’ section of the Cornell Vegetables website.
• Basil downy mildew monitoring website
  Obtaining information about occurrence of this disease at an open website (accessible to anyone) was started by myself the year after it was first seen in several states including NY. The effort progressed to the current website which maps occurrence reports, facilitating seeing where they are, in addition to having a report list, and it is part of the national Ag Pest Monitor Program. The website also has photographs of symptoms, management recommendations for growers (greenhouse and field) and gardeners, a news section, and an alert feature that anyone can use to receive notification of reported occurrences within a distance that they specify from their location.
• Cucurbit Downy Mildew Forecast
  Sentinel plots are maintained at LIHREC to obtain information on downy mildew occurrence in the different cucurbit crop types. When found a report is logged. Long Island growers are kept up-to-date with information from the site about new occurrences of downy mildew in the U.S. and the forecasted risk for Long Island through articles in the Suffolk County weekly agricultural update.
• USAblight.org
  Samples are submitted when late blight is found in tomato and potato on Long Island to assist with tracking this important disease and the genotypes of the causal pathogen. Web content has been prepared for this web site. The Cornell Decision Support System (DSS) has been investigated. During the summer, news articles are routinely written for the Suffolk County weekly agricultural update to inform Long Island growers about late blight occurrence in the U.S. and fungicide application recommendations from the DSS.

List of Extension presentations made by M. T. McGrath

Some recent presentations

• Tips on Managing Vegetable Diseases Accumulated over a Career.  Commercial Vegetable Growers Winter Meeting.  Collegeville, PA.  2/21/24.
• Managing Anthracnose in Tomatoes and Peppers – A Disease that Always Seems to Be There.  2023 Cornell Cooperative Extension Eastern NY Fruit & Vegetable Conference. Albany, NY. 2/22/23.
• Outlook for Powdery and Downy Mildew Control in Vine Crops – Fungicides, Variety Resistance and More!  2023 Cornell Cooperative Extension Eastern NY Fruit & Vegetable Conference. Albany, NY. 2/22/23.
• Effective, economic fungicide program for tomatoes: is it possible??  2023 NYS Vegetable Growers Expo. Tomato Session. Syracuse, NY. 2/6/23.
• Some Love It Wet, Others Dry: The Many Cucurbit Pathogens and Their Management.  2023 NYS Vegetable Growers Expo. Cucurbit Session. Syracuse, NY. 2/6/23.
• Review of Powdery Mildew Management.  Proceedings.  2023 Mid-Atlantic Fruit and Vegetable Convention. Pumpkin Session.  Hershey, PA.  2/2/23.
• What was Learned From Over 20 Years of Evaluating Biofungicides.  Proceedings.  2023 Mid-Atlantic Fruit and Vegetable Convention.  Biocontrol Session.  Hershey, PA.  1/31/23.
• Lessons Learned Over a Career About Vegetable Diseases, Management and Fungicide Resistance.  Proceedings.  2023 Mid-Atlantic Fruit and Vegetable Convention.  General Vegetable Session.  Hershey, PA.  1/31/23.
• Greenhouse Vegetable Disease Management.  2023 Mid-Atlantic Fruit and Vegetable Convention.  Greenhouse Vegetable Session.  Hershey, PA.  1/30/23.
• Effectively Managing Diseases of Vegetables.  Berkshire Grown Workshop Webinar.  1/18/23.
• Tips on Managing Vegetable Diseases Organically. 2023 Long Island Agricultural Forum. Sustainable Session. 1/12/23.
• Recommendations for Managing Important Diseases Based on Research.  2023 Long Island Agricultural Forum.  Vegetable Session.  1/11/23.
• Managing  disease  in high  tunnel  winter  greens.  High Tunnel Winter Greens Workshop Webinar.  1/9/23.
• Everything you Need to Know to Effectively Manage Cucurbit Diseases in 2023.  Proceedings.  Cucurbits Session. New England Vegetable and Fruit Conference.  12/13/22.
• Tips on Managing Vegetable Diseases Organically.  Proceedings.  Great Lakes EXPO.  12/8/22.
• Get a Handle on Managing Powdery and Plectosporium.  Proceedings.  Great Lakes EXPO.  Grand Rapids, MI.  12/7/22.
• Fungicide Resistance Management in Cucurbits (2020) (Proceedings)
• Organic Disease Control in Winter Tunnels (2019) (Proceedings)
• Biopesticides (2018)
• Downy mildew diseases (2018) (article focusing on organic management)
• Disease Management in  Cucurbits (2015)
• Heat Treating Seeds for Disease Management (2016) 
• Crop Rotation for Disease Prevention (2016)

•   Growing Produce

USAblight late blight map

Note: Not all states/regions currently report late blight to the USAblight web site.

NEWA Tomato And Potato Disease Forecasts

For late blight and early blight, and also Septoria leaf spot and anthracnose in tomato. Access them under Pest Forecasts in the menu bar. Fill in requested information to obtain a crop-specific forecast.