Some high-yielding varieties susceptible, researchers find

By MATTHEW WEAVER

Capital Press

Stripe rust hurt the performance of many wheat varieties during this year's Northwest university wheat trials.

In the spring wheat trials in which May and June rains ended suddenly, some trials dried out, researchers found.

"In many of those locations, there was a lot of stripe rust," Washington State University Extension Crop Specialist Stephen Guy said. "That just exacerbates the drying out of the plants."

The performance of WSU's soft white winter wheat variety, Xerpha, which has faced farmer questions about quality, was also hampered by stripe rust in some areas.

"This year, Xerpha was attacked by stripe rust pretty extensively," Guy said.

Xerpha tends to get stripe rust early in the year, before farmers spray their fields. That early damage can hurt its performance, Guy said.

However, he said Xerpha still lives up to its reputation as a high-yielding variety. It was the highest-yielding variety in areas with less than 12 inches of precipitation per year.

Varieties like Chukar, Masami and several numbered lines matched Xerpha's yield in those trials.

"In most of those areas, we did not have high levels of stripe rust," Guy said. "In some other areas where we had high levels, many varieties did not perform very well at all, and Xerpha is one of those."

In intermediate rainfall areas like Anatone, Wash., Xerpha was the highest-yielding variety, with 123 bushels per acre, 20 more than the trial average.

That was another site without stripe rust problems, Guy said.

"It's certainly not going to be a consistent top performer at all these locations because of its stripe rust susceptibility this year," he said.

Oregon State University Extension Cereals Specialist Mike Flowers said stripe rust impacted many of the trial areas throughout his state, particularly those in Umatilla County and LaGrande and on the west side of the state.

Most of the top 10 varieties in Oregon's trials are experimental, Flowers said.

Varieties typically planted in larger acreages, such as Tubbs 06, Xerpha and Goetze, were affected by stripe rust more in the trials than they would be in production fields.

"We do not spray or protect our trials from diseases, because we want to rate those varieties for disease resistances," Flowers said.

Growers should look at a variety's total package, including yield, average performance over several years and disease resistance, Flowers said.

He encourages growers to diversify the varieties they grow to spread their risk.

Flowers advised growers be aware that varieties like Tubbs 06 and Xerpha are moderately susceptible to stripe rust.

If planted in areas where stripe rust could be an problem, farmers should be prepared to spray fungicides, he said.

But stripe rust might not even be an issue next year, Flowers and Guy both said.

"We don't know what the weather's going to be next year, but it will probably be different than this year," Guy said.

Online

WSU Variety Testing Program: http://variety.wsu.edu

SO Variety testing: http://cropandsoil.oregonstate.edu/wheat/varieties.htm