ONTARIO, Ore.-Oregon State University field trials are showing that sweet potatoes can be grown effectively and with high yields in this region.
But one farmer who has tried growing them here says the market for sweet potatoes in eastern Oregon and southwestern Idaho is sketchy.
The sweet potato trials at OSU's research station near Ontario are in their third season. Yields were disappointing during the first year because of an unusually cool growing season, but they have fared very well the past two seasons, OSU weed scientist Joel Felix said.
The very hot weather in the region the past two summers has been ideal for sweet potatoes, Felix, who is overseeing the trials, said.
"They have been growing like crazy because of the weather we've been having," he said. "They like the hot weather."
Even temperatures that have soared above 100 many times this year don't bother sweet potatoes, he adds.
"They will not wilt or be hassled by that weather," Felix said.
While Irish potatoes need to be cooled off with sprinkler irrigation water when temperatures are that hot, "the sweet potatoes don't like that, " he said. "That is weather sweet potatoes like. Overhead irrigation is not a good friend of sweet potatoes."
Yields in 2012 averaged between 20-35 tons per acre, which is equivalent to what growers in California achieve, Felix says. Because weather conditions this year are similar to last year, he expects the same results in 2013.
While sweet potatoes like hot weather, early or late frosts are a real problem for that crop, Felix said. Farmers in this region would have to wait until the end of May or beginning of June when there is no possibility of a kill frost to plant sweet potatoes and the crop has to be harvested on the day following the first frost.
Oregon farmer Bill Johnson grew several acres of sweet potatoes in 2011 under contract but the processor that purchased them didn't renew the contract the next year.
He said the crop looked good but sweet potatoes aren't easy to harvest and there is some question about yields. However, he said if he grew them differently now using the strategy Felix has developed, "I think ... it would be economically feasible."
The problem right now for farmers in the area who might want to grow the crop is that there is no certain market for them locally. While some local processors are bringing in sweet potatoes from as far away as Florida and North Carolina and turning them into fries, there are no signals they want the crop to be grown locally in large numbers.
"I'm not sure what I'd do with a semi-load full of sweet potatoes. That's the issue," Johnson said. "I'm still not sure there is an opportunity here for us locally."
Officials from three major fry processing companies in the region did not respond to requests to be interviewed for this story.