Blight threatens peninsula potatoes

For the third season, a fungal disease known as late blight — the Irish potato famine disease — hit potato growers in the Matanuska-Susitna Valley.

Some of those potatoes currently are being sold on the Kenai Peninsula, according to Tom Jahns, Kenai Peninsula land resources agent for the University of Alaska Fairbanks Cooperative Extension Service.

Although that poses no threat to anyone eating potatoes from plants affected by the disease, the danger is in using them for seed and spreading the fungus to the peninsula, Jahns warned.

“I think it’s worthy of letting people know,” he said.

Late blight affects potatoes and tomatoes and is found most places in the world where the two crops are grown, according to a fact sheet on the disease published by the Cooperative Extensive Service. It kills plants in the field and causes tubers to rot during winter storage. It was first noted in Alaska in 1995, in a commercial field of potatoes grown in the Matanuska-Susitna Valley. In 1998, it appeared again, spread quickly and impacted potatoes and tomatoes. Incidents of it also were reported in Juneau, but not Interior Alaska or the Kenai Peninsula.

“Oftentimes, it’s speculated that the disease came in on tomatoes and is brought home to gardeners that didn’t realize there was a problem,” Jahns said of shipments coming to Alaska.

The disease spreads rapidly by air, with the spores traveling hundreds, if not thousands of miles, he said.

Barb Walker, owner of Wagon Wheel Trading Post in Homer, buys her potatoes from farmers in the Delta Junction area. The possibility of spreading disease is one reason Walker cautions against using store-bought potatoes for seed. Walker’s second reason is that potatoes from the Lower 48 are usually sprayed so they don’t sprout in the stores.

All potatoes being sold as “Alaska Grown” could be affected, according to Jahns, including those sold at the Fred Meyer store, Safeway stores and from the produce truck that has been selling 50-pound sacks of potatoes at the corner of the Sterling Highway and Kalifornsky Beach Road in Soldotna.

“Any Valley potatoes would not be excluded (from the danger),” Jahns said.

However, quality of the potato is not affected, he said.

Agreeing with Jahns, Walker said eating affected potatoes is not hazardous.

“I’m sure we’ve been buying and eating a lot of potatoes from (the Matanuska-Susitna Valley) because that’s probably who sells the most,” she said. “But don’t plant them.”

“I’m trying to get the word out,” Jahns said. “First, don’t buy more potatoes than you can consume within a couple of months from these sources. Second, do not, under any circumstances, use these as seed potatoes for next year.”

For more information on late blight in Alaska, call the Cooperative Extension Service in Soldotna at 262-5824.

The publication, “Late Blight Disease of Potato and Tomato in Alaska,” can be requested from extension personnel or viewed on the Web at http://www.uaf.edu/ces.

Clarion reporter Phil Hermanek contributed to this story.