Writer: Joe Bryant (806) 746-6101, j-bryant1@tamu.edu
Contacts: Dr. David Worrall (817) 552-9941; Dr. Mark Lazar (806) 359-5401
BUSHLAND–Strides in developing resistance to the multiple stresses that annually confront the wheat crops of Texas and neighboring states were showcased here at a recent Panhandle Ag Day tour in May.
The wheat breeding nurseries and test plots of the Texas Agricultural Experiment Station were a featured stop at the spring field day on the grounds of the USDA-Agricultural Research Service station here.
“The High Plains annually produces over 50 percent of the Texas wheat crop, up to 70 million bushels,” said Dr. David Worrall, Experiment Station wheat breeder at Vernon.
“This area has an unpredictable climate, which can subject crops to a wide array of physical and biological stresses, often simultaneously,” Worrall said. “We are committed to continuing the successful history of wheat improvement at this station by addressing resistance to these stresses.”
The most recently released variety from this project is TAM 110, released in 1996. Its main feature is resistance to greenbug, including biotypes E, I and K. No other U.S. wheat variety possesses resistance to these biotypes. It possesses most of the other characteristics of TAM 107, including good drought resistance, early maturity and excellent winterhardiness.
Its main weaknesses are lack of resistance to leaf rust and to Russian wheat aphid, so it is recommended only for dryland or limited irrigation production on the High Plains. Producers must be prepared to spray TAM 110 in event of an outbreak of Russian wheat aphid, the scientist said.
Breeding lines currently in advanced stages of testing include high forage-producing, beardless lines, additional drought-resistant lines with superior baking quality, and drought-resistant lines with moderate stature.
Wheat varieties for this area require high yield potential, heat resistance and resistance to wheat streak mosaic virus and related viruses.
“For irrigated production, lodging resistance and leaf-rust resistance are important.” Worrall said. “For dryland production, moderate stature–as opposed to true semi-dwarf– and exceptional drought resistance are important. Compatibility with various grazing strategies and improved processing quality are other important objectives, the research scientist said.
The 1996 crop year was extremely drouthy.
“Dryland production was greatly reduced, and in dryland trials at Bushland and Washburn, top yields were about 10-15 bushels an acre,” reported Dr. Mark Lazar, Experiment Station wheat breeder at Amarillo.
The top three dryland varieties were TAM 107, TAM 105 and Agripro Hybrid 7510. Varieties yielding less than nine bushels an acre included Ogalalla, TAM 300, Tomahawk, TAM 201, Rowdy, Pecos , Agripro Hybrid 7510, Sturdy, Jagger, 2180, 2163 and Hickok.
“Though all varieties released for the High Plains have excellent winter hardiness, no known varieties possess resistance to the late spring freezes that have characterized several recent growing seasons, including 1997,” Worrall said. “The best defense against these occasional disasters is later planting, such as October, and using more than one variety, with differing maturities.”
Spring freezes affected the irrigated nursery yield at Bushland in 1996, even though this was October-planted. But the reductions weren’t as severe as for earlier-planted wheat.
Top irrigated yields exceeded 90 bushels an acre, although 24 inches of irrigation were required due to the drought. The top- yielding varieties in the irrigated nursery were Agripro Hybrid 7510, Ogalalla, TAM 105, Agripro Hybrid 7501, 2137 and TAM 200.
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