ALERT: LATE BLIGHT FOUND IN MASSACHUSETTS
On Thursday, July 11, we received notice that late blight was identified on tomatoes in Franklin County, Massachusetts. Franklin County borders Cheshire County in New Hampshire. The cloudy, rainy conditions that we are having are ideal for spread of spores. Tomato and potato growers should take action. Here are some recommendations for commercial growers and home gardeners.
For commercial growers:
Growers should scout diligently and use protectant fungicides. Some may want to consider switching to late blight-specific fungicides. For a current list of fungicide recommendations, please see the New England Vegetable Guide.
If you suspect late blight in your tomatoes and/or potato crops, please have it checked out. One way to do this quickly is to send digital images to either your county field specialist, Cheryl Smith, or Becky Sideman You can also send or bring samples to the Plant Diagnostic Lab in Durham.
If you have any questions, please get in touch.
For home gardeners:
At this point in the season, if symptoms begin appearing on tomato or potato plants and you are positive it is late blight, follow these steps:
- Remove plants.
- Place in a plastic bag.
- Seal bag and discard in trash OR completely bury plants deep enough underground so plants will decompose and will not re-sprout.
DO NOT put the plants in a compost pile, as spores will still spread from this debris.
Fungicides must be applied BEFORE symptoms appear. Fungicides containing chlorothalonil, or copper formulations are relatively effective for late blight prevention. For organic production, ONLY copper-based formulations are effective.
For more details, images, and management options, watch this video or visit Cornell’s Long Island Horticultural Research & Extension Center.
—Becky Sideman & Cheryl Smith