Amy Hepworth went long tomatoes this year. A farmer in Milton, New York, Hepworth brought new land into production and invested heavily in the crop hoping the effort would help pay for the farm and, in part, help stimulate the local economy. Then came late blight.

Hepworth and her partner Gerry Greco detailed their battle with the air-born fungus when the members of Hepworth’s community supported agriculture (CSA) from Sixth Street Community Center in New York City visited Hepworth Farms two weeks ago. The visit upstate was our first in the long relationship with the organic farm, and as Hepworth and Greco plunged into a discussion on tomato pathology, it seemed the farmers were as excited about the trip as we were.

Early this spring the farmers were already taking every possible precaution to guard against the five other diseases that normally plague the fruit. They bought all new stakes and seed trays and carefully sanitized the seeds in boiling water. Tomato diseases are often borne in the soil, so they chose land that had no disease history, some of which had not been cultivated for a 100 years.

The preparation left Hepworth and Greco feeling confident as they went out to secure growing contracts for the season. Their hope was to generate cash to pay for the farm and employ more workers.

“We are going into fields that don’t have any history of disease, this is our year we don’t have to spray,” Hepworth said of their position in the spring. “We go out and get a lot of contracts for growing, to pay for this. Because we have to employ more people now because the economy is sluggish. Farmers have to pick up, we’re going to kick in some idle land, we’re going to do our part, because we’re the producers, so that is our job. So we go out and get more contracts. Now comes the late blight.”

“Bummer,” someone in the crowd says.

“Yeah,” replies Hepworth.

Late blight is the same air-born fungus that led to the Irish Potato Famine in the 1840s. The disease thrives in the unseasonably cool wet weather we had earlier this summer. The blight turns the leaves and stems brown and a white mildew spreads across the surface. Tomatoes become a brown mush. Like most mildew, high temperatures and dry conditions kill the fungus, so it could never sustain the weeks of soaring temperatures that are typical of Northeastern summers.

Instead there is a pandemic. At the first sign of blight a plant must be pulled and destroyed, and the plants around the blight infestation must be torched. Farmers across the Northeast have lost their tomatoes and the thousands of dollars invested in them.

“So meanwhile, back at the ranch, we’re sitting on 10-15 acres of tomatoes and that means for us that after every rain we have to put copper out there,” Hepworth said. “It was really hard to handle and do, but there was not a lot of choice about it. Now you can say, ‘Well, plant another crop.’ Well at this point, there’s a quarter of a million dollars invested in this ordeal here. We have a lot of things going on here to sustain and support a farm to feed people. So we spray. We sprayed the copper this year. And we have tomatoes. There are many, many organic farmers who do not have tomatoes this year.”

Copper based fungicide is the treatment accepted in organic farming practices and it is one of the few tools to fight blight. According to the Cornell University Cooperative Extension, the state’s agricultural research institution, application of copper is advised only after following other organic practices including using land with no disease history, planting in wide rows and determining disease resistant cultivars. Copper application is strictly controlled because it does not break down in the soil and its accumulation is harmful to soil biology.