Posted: Tuesday, January 08, 2013 9:32 AM
By MATTHEW WEAVER
The relatively warm winter the Pacific Northwest is experiencing will open the door to more stripe rust this year, a Washington plant pathologist says.
"So far we have not had very good weather yet," said Xianming Chen, USDA Agricultural Research Service plant pathologist in Pullman, Wash. "That's why we see the rust prediction is still a severe level. But it's good it's not extremely severe."
Chen predicts wheat varieties that are highly susceptible to stripe rust will see yield losses of about 41 percent.
That's lower than last year's forecast of 47 percent yield losses. More than 60 percent loss is considered extremely severe, according to Chen.
Rust resistant winter wheat varieties like Xerpha or Tubbs 06 may see half the loss of a susceptible variety, Chen said.
Some spring wheat varieties are also highly susceptible. In tests, Chen said, the Washington State University soft white spring wheat variety Babe showed more rust than expected.
During the last two years, there hasn't been much fall stripe rust infection, due to the dry Septembers, Chen said.
He said a more severe rust outbreak is still possible if spring and summer conditions are wet and cool like 2010, when a severe rust outbreak occurred.
Farmers need to think about the rust resistance of the spring wheat variety they plant, Chen said.
When he makes his next forecast in early March, he will consider whether they should make a fungicide application along with their herbicide. At that point, farmers will also need to start looking in their fields for signs of stripe rust, he said.