'Avalanche' Hard White Winter Wheat
	Avalanche Breeder Seed Headrow Isolation (left) Yuma, Arizona April 2000	Avalanche (left) and Akron (right) Grain Color

'Avalanche' hard white winter wheat was developed by the Colorado Agricultural Experiment Station and released to seed producers in September 2001. Avalanche was selected from the cross KS87H325/'Rio Blanco' made in 1988 at Hays, KS. KS87H325, an unreleased experimental line from the Kansas State University-Hays wheat breeding program, has the pedigree RL6005/RL6008//'Larned'/3/'Cheney'/Larned/4/'Bennett' sib/5/'TAM 107'. RL6005 and RL6008 are Canadian lines where Lr16 and Lr17, respectively, were backcrossed into a 'Thatcher' background.

Avalanche is an awned, white-glumed, medium maturity, semidwarf hard white winter wheat. Avalanche is medium maturing (142 days to heading from Jan. 1), about 4 days later than TAM 107, similar to 'Akron', and 4 days earlier than 'Prowers 99'. Plant height of Avalanche is medium-short (29.8 inches), 1 inch taller than TAM 107 and 3 inches shorter than Prowers 99. The straw strength of Avalanche is good, similar to TAM 107 and Akron but superior to Prowers 99.

Selection History

Avalanche was selected as an F4:5 line in 1993 and, following preliminary yield testing in Kansas in 1994, was given the experimental designation CO940611. Hand sorting of F4:9 bulk seed samples for white kernel color was done in 1997. For generation of breeder seed, 300 heads were selected at random from preliminary seed increases in 1999. Breeder seed of Avalanche originated from a composite of 262 F11:12 head-rows selected in 2000 based on agronomic uniformity and purity of white kernel color.

Yield Performance

Avalanche was tested in Colorado Dryland Variety Performance Trials from 1998-2001. Averaged over 35 trial locations between 1998-2001, Avalanche (50.8 bu/a) yielded less than Alliance (52.2 bu/a), similar to Akron (51.0 bu/a), and greater than TAM 107 (48.7 bu/a). In comparison with other hard white winter wheat cultivars available in Colorado, Avalanche has yielded less than 'Trego' (51.6 versus 49.5 bu/a; 25 locations, 1999-2001) but greater than both 'Lakin' (41.1 versus 38.9 bu/a; 15 locations, 2000-2001) and 'Nuplains' (41.1 versus 37.6 bu/a; 15 locations, 2000-2001).

Disease and Insect Resistance

On the basis of field evaluations in Colorado and cooperative evaluations through the USDA Regional Testing Program, Avalanche is resistant to stem rust (caused by Puccinia graminis Pers.:Pers. f. sp. tritici Eriks & E. Henn.), moderately susceptible to leaf rust (caused by Puccinia triticina Eriks.; syn Puccinia recondita Roberge ex Desmaz.), and moderately susceptible to both wheat streak mosaic virus and Barley yellow dwarf virus. Avalanche is susceptible to the Great Plains biotype of Hessian fly [Mayetiola destructor (Say)], greenbug [Schizaphis graminum (Rondani)], and Russian wheat aphid [Diuraphis noxia (Mordvilko)].

End-Use Quality Characteristics

Milling and bread baking characteristics of Avalanche were determined from composite grain samples from eight subregional production zones (1) from the 1999 and 2000 USDA Southern Regional Performance Nurseries and from the 1999 and 2000 Colorado Dryland Variety Performance Trials. Relative to the broadly adapted check cultivar TAM 107, Avalanche had higher test weight (60.8 versus 58.7 lb/bu), kernel weight (30.1 versus 29.6 g/1000 kernels), and flour yield (67.9 versus 66.4 %) with similar flour protein (11.7 versus 11.9 %) and ash contents (.44 versus .42 %). In bread baking tests, Avalanche had better crumb grain and texture scores (3.7 versus 3.1 score; 0-unacceptable to 6-excellent scale) and slightly lower bake water absorption (62.2 versus 63.0 %) than TAM 107. Mixograph mixing time, Mixograph tolerance score, and loaf volume were similar for Avalanche and TAM 107.

Development Team

Scott D. Haley, James S. Quick, T. Joe Martin, Jerry J. Johnson, John A. Stromberger, Sally R. Clayshulte, Bruce L. Clifford, Frank B. Peairs, and Jeff B. Rudolph

Affiliations

• S.D. Haley, J.S. Quick, J.A. Stromberger, S.R. Clayshulte, B.L. Clifford, and J.J. Johnson, Soil and Crop Sciences Dep., Colorado State Univ., Fort Collins, CO 80523
• T.J. Martin, Kansas State Univ. Ag. Res. Center-Hays, Hays, KS 67601
• F.B. Peairs, and J.B. Rudolph, Bioagricultural Sciences and Pest Management Dep., Colorado State Univ., Fort Collins, CO 80523

References and Notes

1. Peterson, C.J. 1992. Similarities among test sites based on cultivar performance in the hard red winter wheat region. Crop Sci. 32:907-912.

Breeder seed of Avalanche will be maintained by the Colorado Agricultural Experiment Station. Avalanche is protected by the U.S. Plant Variety Protection Act (PVPA).

Acknowledgements

Avalanche was developed with financial support from Colorado Agric. Exp. Stn. Projects 795 and 646 and the Colorado Wheat Administrative Committee.