Submitted to: Wheat Newsletter
Publication Type: Other
Publication Acceptance Date: March 1, 1996
Publication Date: N/A
Technical Abstract: Stem rust was light in the U.S. in 1995 with minimal yield losses. Winter survival of stem rust north of Texas was less than normal, and dry weather in late winter and early summer limited stem rust increase in the Great Plains. As in recent years, Pgt-TPMK (48%) and Pgt-QCCJ (27%) were the most common races in the U.S. Spring wheat varieties in the northern plains are resistant to both races. Wheat leaf rust overwintered more abundantly than in 1994 in Kansas, but an early April freeze in western Kansas set back the epidemic. In spite of that, leaf rust caused 5% yield loss in Kansas. Leaf rust losses in winter wheat ranged from 2% to 5% in the Pacific Northwest, the Southeast, and the Midwest. Losses were limited to 0.2% or less in spring wheat due to effective resistance to prevailing races. The leaf rust population in the U.S. was more diverse than in previous years with 14 new races identified in 1995. Race MBR-10 was most common in 1995 as it was in 1994. Virulence to Lr-16, a resistance gene found in several new hard red wheat varieties, increased in 1995, appearing in several new races. Two new races were found attacking Jagger, a new wheat variety expected to become predominant in Kansas. Wheat stripe rust caused little damage on winter wheat in the southern plains in 1995. Severe stripe rust developed in plots of susceptible wheat in the Pacific Northwest, but losses in commercial fields were minimal because of effective adult plant resistance in commonly grown varieties.