Blight spoils tomatoes
February 19. 2013 2:55AM
But a problem in the supply to backyard gardeners seems to have added punch to a fungal assault the likes of which local growers haven’t experienced before.
“It really is a tough year for the growers, and the gardeners too,” said John Efflinger, commercial horticulture educator with the Penn State Cooperative Extension in Lackawanna County. “It’s widespread throughout both (Luzerne and Lackawanna) counties in gardens, and we’ve seen it in both tomatoes and potatoes.”
The culprit, phytophthora infestans, is a fungus that caused the infamous Irish potato famine of the 1840s, but also kills tomatoes. The spores, which can spread in the air for miles in a day, often show up before growers see any signs of the blight, Efflinger said, and can only be combated by destroying infected plants.
Generally dying out in northern winters but surviving in the warmer south, the blight usually makes its annual march north on storm winds, taking most the growing season to get here.
Commercial growers are well aware of the annual campaign and set up fortifications against it. Like most farmers, Lenny Burger, a vegetable grower in Drums, sprays his tomatoes and potatoes regularly with fungicide and follows a “blightcast” organized by Penn State University.
This year, however, an Alabama wholesaler supplied infected seedlings nationwide to big-box retailers, including Wal-Mart, Kmart, Home Depot and Lowe’s. Though the supplier has pulled its remaining supply in 12 states, including Pennsylvania, New York and New Jersey, the blight has slipped through the fungicide barrier into backyard gardens.
The problem is that farmers have few defenses at their disposal beyond nature and timing. Hot, dry weather retards the fungus and natural cycles keep it from striking quickly. Importing it acted as something like a blitzkrieg.
“It’s not coming in a normal pattern; it’s just popping up all over,” Burger said.
“On a good day it (the spores) can move 30 to 40 miles in the air, and that’s why it became such a threat,” Efflinger said. “Typically, what happens is we’ll see some blight late in the season because it has to blow in from the south. But this year, it was trucked up here.”
And once it’s here, nothing short of destroying the crop stops it. “If the weather is right, you’re supposed to go out and put fungicide on your plants so it doesn’t get into your leaves,” Burger said. “If it’s really favorable and you get a lot of these spores around, it’s even hard to get the fungicide to work. When it was last around, farmers sprayed and sprayed.”
Efflinger recommends fungicides with either chlorothalonil or mancozeb. Gardeners should look for blotches on otherwise healthy-looking, green leaves, he said. Turn one over during a time of high humidity and there will be whitish fuzz – the spores. There also might be black “lesion” areas on the stem, he said.
While any unaffected fruit is safe to eat, he said that all infected plants should be destroyed, and even suggested that they be contained in a bag before pulling so that spores don’t escape.
Burger said he hasn’t had any real crop damage, but the increased protection has put a dent in his budget. In typical years he’ll spray a cheaper, older fungicide every other week. This year, he’s sprayed every week, alternating between the cheaper stuff and a newer, more expensive formula. Much more expensive: $66 per pound compared to $5.
“If they weren’t predicting such a heavy problem this year, I probably would have gone with the old standby,” he said.
“There are some farmers that are going to be impacted pretty hard,” Efflinger said. “I could answer that better in October, but right now we’re in the middle of it and we’re trying to fight it and get these crops to harvest. … There’s nothing we can do beyond what we already are.”
The Associated Press contributed to this report.
Rory Sweeney, a Times Leader staff writer, may be reached at 970-7418.