Effect of Stripe Rust on Winter Wheat in Southwest Kansas.
Curtis Thompson and Alan Schlegel. Kansas State Univ, Southwest Res. Ext. Center, 4500 E. Mary St, Garden City, KS 67846-9132
Wheat stripe rust has been infesting Kansas wheat since 2001 at an increasing frequency and intensity compared to previous years. Fungicide applications can be costly, however, may be required to maintain wheat yield, quality, and profitability. These experiments evaluate wheat variety response to various fungicide treatments. Experiments were conducted near Wright-Ford County, Garden City-SWREC, Hugoton-Stevens County, Ashland-Clark County, and Coldwater, Comanche County, KS. All fungicide treatments were applied with a back pack sprayer to wheat in the boot to early heading stage. Tilt at 4 oz/a increased wheat yield by 20 bu/a and test weight by 4 lb/bu in the Ford Co. experiment which was heavily infested with stripe rust during spring of 2001. Fungicide treated wheat yielded 9 bu/a more than untreated wheat when averaged over varieties at the Comanche, Clark, and Steven’s County sites during 2005. However, only a 0.6 lb/bu increase in test weight was observed. A stripe rust resistant variety, Tam 111, was the highest yielding variety and had excellent test weight. In experiments at SWREC near Garden City in 2005, fungicide application reduced stripe rust infestation on Jagger, Stanton and Thunderbolt. However, fungicide had little or no affect on grain yield or test weight. Stripe rust can be very devastating to a wheat crop, making properly applied fungicides very valuable to maintaining wheat yield and quality. Wheat variety selection remains to be one of the most important management decisions a producer can make to minimize the effect of stripe rust on wheat.