05/21/07 Stripe rust update

Farm and Ranch May 21, 2007 Stripe rust has begun showing up in disease monitoring and wheat breeding nurseries in the Palouse region That's the latest stripe rust update from Xianming Chen of the Agricultural Research Service in Pullman. Chen says stripe rust severities in those nurseries is low with some small hot spots of up to 40 percent severity. He says the disease has not been found in commercial fields checked in the area. Chen says stripe rust is generally under control in the Horse Heaven Hills and Connell areas of Washington, the hard red winter wheat region. Most fields of Finley and Buchanan have been sprayed. Chen does say irrigated growers should check their fields about four weeks after the first fungicide application and if rust starts redeveloping a second application should be considered. Chen says the observations so far fit scientists' prediction of light to moderate stripe rust this year. He says cultivars with moderate to high levels of high temperature, adult plant resistance should not have a problem and even cultivars without that adult resistance that have been resistant in recent years should also not have a stripe rust problem. For growers with winter or spring cultivars that were susceptible in 2005 Chen says check your fields for stripe rust and consider using fungicides if the rust develops to 5 to 10 percent severities and prevalence. He notes that in the Palouse region wheat fields still produce dew on plants at night and early morning which allows rust infection. Chen says current temperatures are favorable for stripe rust development but if it stays dry development will slow until the next rain. I'm Bob Hoff and that's the Northwest Farm and Ranch Report on the Northwest Ag Information Network.