Two-gene variety has less yield loss than previous type
By MATTHEW WEAVER
PULLMAN, Wash. -- A Washington State University wheat breeder will discuss the university's first two-gene Clearfield wheat variety during the upcoming field tour season.
"Historically, farmers always thought Clearfield comes at a yield penalty," WSU's Kulvinder Gill said. "The reason was most of the Clearfield lines were single-gene and they always have some damage, resulting in some yield loss."
Gill began working on the two-gene variety in 2006 at the request of the Washington Grain Commission. The first line from those efforts, winter wheat WA-8143, is ready for release if field tests go smoothly, Gill said.
The Clearfield system allows farmers to spray wheat with Beyond herbicide, which is almost 99 percent effective against jointed goatgrass and other grasses, said Dana Herron, Washington Grain Commission member.
"It kills basically every grass in the field except the wheat," Herron said.
Gill said it is the first two-gene Clearfield variety from a public breeding program in the Pacific Northwest.
"It gives farmers a lot more options to spray (Beyond) a little bit more," he said.
With WA-8143, tests have shown minimal damage, if any, Gill said.
Gill has been working on a fast track with the variety, beginning with field trials in 2009. Field evaluations began in 2011.
Because of the quick development and unusual cold, wet weather last year, it's not certain how the variety will perform in drier weather, making this year's data "super critical," Gill said.
"We've made some mistakes in the past by releasing varieties too early," Herron said. "We want to make sure all the data is well-documented and it truly is an improvement. The devil is always in the details. We don't want any surprises when it gets out into the field."
If field evaluations are satisfactory to researchers and stakeholders, Gill hopes to request full release this year.
The variety was one of the few high-yielding varieties across climatic zones, Gill said.
The variety also has good resistance to stripe rust and snow mold, Gill said.
Herron said the variety has great application in the dryland regions.
"The commission actually gave Kulvinder Gill a challenge to come up with a two-gene variety," Herron said. "He said he could do it in two years; he actually did it in 18 months. I applaud his efforts."
Beyond herbicide attacks an enzyme that develops protein in plants. Wheat has three copies of the enzyme's genes.
In a single-gene Clearfield variety, the herbicide can still damage the other two copies of the enzyme. In two-gene varieties, only one gene is damaged, Gill said.
"Ideally, we can go with three genes," he said.
No research has yet been done to develop a three-gene variety, he said. "I think two-gene is good enough at this point that we don't see a significant yield drag."
There is some damage on the leaf, but the plant recovers, Gill said.
"But that doesn't mean we don't go for three genes at some point," he said.