In early July Marc Bybee, vice president of Nyssa, OR-based Fiesta Farms, was concerned the Treasure Valley of Idaho-Eastern Oregon was looking at a bumper crop of onions. By early September his take on the season had changed.

“We have excellent quality, and in my opinion better than the early onions last year,” Bybee said. “But a large number of fields were hurt by the summer’s record heat and by the yellow spotted iris virus.”

With summer 2013 setting records for heat in the Treasure Valley of Idaho-Eastern Oregon, shippers are seeing somewhat reduced yields and a smaller size profile on their onions.

But Kay Riley, general manager of Snake River Produce in Nyssa, OR, said quality of the Spanish Sweets his operation began packing on Aug. 21 is excellent, and production will be normal this season.

Riley told The Produce News in early September that the region had experienced 70 days with temps exceeding 90F starting June 1, and 13 of those days saw the century mark of 100F.

Hot weather has posed challenges for onion growers in the Treasure Valley. Bob Komoto, sales manager at Ontario Produce in Ontario, OR, described the situation this way. “The temperatures have been above normal. June and July had several 100 degree days in a row,” he told The Produce News. “That put the onions under stress and increased the thrip pressure since higher temperatures result in more reproduction of the thrip. Also, these higher temperatures make it more likely that the iris yellow spot virus will affect the onions.”

Noting that portions of the Treasure Valley have seen reduced onion sizing and some reduction in yields due to record heat this summer, Joe Farmer, general manager for Fort Boise Produce in Parma, ID, said he’s expecting overall good sizing.

“Right now,” he said in early September, “it’s early to say what the yields will be, but we think our growers overall will have good sizes.

Dave Larsen, field operations, said one-third of the company’s fields are under drip irrigation, and he noted that the heat affected a very small percentage of Fort Boise’s crop.

Early September onion crop assessments by Herb Haun, general manager of Haun Packing in Weiser, ID, indicated good quality and size range.

Haun said, “We started shipping Aug. 19, which is about normal timing for us, and we’ll go into storage starting mid-September. The onions look very good, very mature, and we also have a good range of sizes with plenty of jumbos. The colossals are tighter than they have been, though.”

Record heat during the summer accounts for the smaller volumes of colossals, he said, and yields are also affected by the dry, cold spring.

Nunhems USA, part of Bayer CropScience, continues to work with onion growers in the Treasure Valley to commercialize new onion varieties that will meet production challenges and increase production efficiencies.

In early September, Rene Emch, Nunhems’ global product specialist-onions, provided some insights into research currently being conducted in the Treasure Valley. Nunhems is located in Parma, ID, and is part of Bayer CropScience.