Rob Johanson drove down a dirt path along a 5-acre field of potato plants and pointed to a scorched hole in the middle.
Plants surrounding the burned earth were spindly with brown, irregular spots on their leaves from late blight fungus.
Maine farmers have reported late blight -- an airborne, spore-based disease -- in potato and tomato crops. The plant disease, responsible for the Irish potato famine of the 1850s, can destroy a crop and thrives in cool, moist weather.
Johanson's farmhands walked the fields with backpack propane burners destroying diseased plants covered in lesions.
"All this would be in bloom, all purple flowers," Johanson said waving his hand out the window as he drove by. "But the plants have been pretty beat up. We were trying to save them. It spreads from one leaf to the next and, eventually, to the stem, and kills the whole plant.
Martin Draper, a senior plant pathologist at the U.S. Department of Agriculture, said the rate of infection has been "explosive."
The disease has spread to every state in the Northeast and the mid-Atlantic.