FARMINGTON — Late blight, the scourge that decimated potato and tomato crops across Maine and the Northeast last summer, has been confirmed at a site in Waldoboro, and other suspected sites along the coast are now being investigated, according to the University of Maine Cooperative Extension Pest Management Office.

Growers should remain vigilant for signs of the disease that thrives in rainy and cool conditions and spreads by wind-borne spores that can travel up to 40 miles.

One way to diminish a plant disease’s impact is to grow resistant varieties. However, none have been available, said Dave Fuller, the agricultural professional with the Extension’s Franklin County office.

Fuller is offering a tour of a demonstration site where he is growing several varieties of potatoes and tomatoes that seed breeders claim have some resistance to late blight.

The “twilight tour” will be at 5 p.m. Thursday, Sept. 9, at Fuller’s farm on Chesterville Hill Road in Chesterville. Call 778-4650 for directions. Those going to the farm are advised to wear appropriate clothing and bring a notebook.

At 4 p.m. Wednesday, Sept. 15, there will be an after-harvest, taste-testing at the Franklin County Cooperative Extension Office at 138 Pleasant St. in Farmington.

 The free, two-session workshop will examine eight varieties of tomatoes and six varieties of potatoes.

 “One of the best defenses against disease is to use resistant varieties,” Fuller said. “The plants can still become infected but they usually survive.”

 “To our surprise, we found there were no resistant varieties to this disease on the market,” he said.

The plantings he is doing are “observation trials” and are not rigorously -controlled tests that involve inoculation with the disease in a lab, he said.

Two of the tomato resistant varieties will be on the market next season, and the trials will give home and market growers a chance to observe how the vegetable grows on the vine and taste it for flavor and texture before trying it themselves.

The harvest from his farm will be donated to the local food pantry, he said.

To search for information on late blight and its symptoms, go to www.extension.maine.edu.

Tour, discuss and taste the outcome of the University of Maine Cooperative Extension’s research and trial garden in Franklin County.

This two-session workshop will address resistance to late blight, flavor and utility of specific tomato and potato varieties.

Session 1: 5 p.m. Thursday, Sept. 9, at the trial site Chesterville Hill Road in Chesterville. Call 778-4650 for directions.

Session 2: A late blight-resistant tasting and discussion will be held a 4 p.m. Wednesday, Sept. 15 at the Franklin County Cooperative Extension, 138 Pleasant Street, Farmington.

Any person with a disability who needs accommodations for this program should call the office at 778-4650 to discuss their needs at least three days in advance.