03/22/07 PNW stripe rust forecast for 07

Farm and Ranch March 22, 2007 Forecast models for stripe rust in the Pacific Northwest for this year predict only a light to moderate level of the disease. Xianming Chen, ARS research plant pathologist at Pullman, says that on a disease severity scale of "0", no rust, to "9" or 99 percent rust the model has come up with a disease severity value of "6" for 2007. Chen says this prediction is much lower than those for the last five years and is equivalent to those for 2000 and 2001. The reason; Chen: "It is mainly due to the cold weather in the winter time. So that cold winter time reduces the rust survival." Chen says there was probably less rust inoculum around going into winter as well. Chen: "Because last year the stripe rust was not very severe, the inoculum before winter was also was low." Chen says a field survey March 16th found no stripe rust in the Walla Walla and Horse Heaven Hills areas in southeastern Washington, where the disease usually shows up first in the eastern Pacific Northwest. He says since stripe rust has not been reported in the major wheat growing areas of the eastern PNW, and is expected to occur late, early applications of fungicides mixed with herbicides is not recommended. Chen says growers in central and southeastern areas in Washington and adjacent regions in Oregon may start to check their winter wheat fields for stripe rust in mid to late April. Growers in eastern Washington and northern Idaho may check their fields beginning in mid May. I'm Bob Hoff and that's the Northwest Farm and Ranch Report on the Northwest Ag Information Network.