Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/9/2002
Publication Date: 12/1/2002
Citation: KHALIL, I., CARVER, B.F., KRENZER, E.G., MACKOWN, C.T., HORN, G.W., RAYAS-DUARTE, P. 2002. GENETIC TRENDS IN WINTER WHEAT GRAIN QUALITY WITH DUAL-PURPOSE AND GRAIN-ONLY MANAGEMENT SYSTEMS. CROP SCIENCE. v. 42. p. 1112-1116.
Interpretive Summary: Wheat is the primary winter forage grazed in the southern Great Plains (SGP). About 20 million acres of winter wheat are planted yearly. As much as 80% of the total wheat acreage is grazed and nearly 8 million acres of the grazed wheat is harvested for grain each year. Often the end-use quality of grain harvested from a dual-purpose (forage plus grain) crop is perceived as inferior to a grain-only crop. We evaluated this perception and determined if long-term genetic changes in grain quality traits are equally expressed with dual-purpose and grain-only management systems as commonly practiced in the SGP. Traits measured were kernel hardness, grain protein, flour yield, mixing time and tolerance, large-kernel fraction, kernel weight, and kernel diameter of 12 hard red winter wheat cultivars spanning nearly 80 yr of genetic improvement. Comparisons of traits between the two management systems indicated a high level of consistency. With exception of smaller kernel weight with dual-purpose management, we detected no detrimental effect of the dual-purpose management system on cultivar performance, or on cultivar differences associated with breeding, for several characteristics commonly used to estimate bread wheat quality. These results will be useful to grain buyers, millers, wheat breeders, and agronomists seeking to improve winter wheat grazing, cropping, and marketing opportunities for farmers in the SGP.
Technical Abstract: Hard red winter wheat (Triticum aestivum L.) grain harvested from a dual-purpose (forage plus grain) crop is believed to have inferior end-use quality compared to a grain-only crop. A study was conducted for 4 yr at the wheat Pasture Research Center near Marshall, OK to evaluate this perception and determined if long-term genetic changes in grain quality are equally expressed under two management systems commonly practiced in the southern Great Plains. Grain-only and dual-purpose management systems were used, each featuring whole-plot treatments of a foliar fungicide and split-plot treatments of 12 hard red winter (HRW) wheat cultivars spanning nearly 80 yr of genetic improvement. Dual-purpose experiments were grazed from November through late February or early March of each year. The effect of fungicide treatment was not significant. Cultivar x system interactions were generally absent, and the correlation between management systems varied from r = 0.74 to 0.99 (P < 0.01), indicating a high level of consistency in quality between systems. Kernel weight in the dual-purpose system did not reach the same level as in the grain-only system for some cultivars, though kernel diameter was not negatively affected. Grain protein and dough strength, measured by mixing time and tolerance, were unaffected by management system. Significant genetic progress was observed in both systems for only the physical quality attributes (kernel weight and diameter, and percent large kernels). With exception of kernel weight, we detected no detrimental effect of the dual-purpose management system on cultivar performance, or on cultivar differences associated with breeding, for several characteristics commonly used to estimate bread wheat quality.