Effect of Awn Suppression on Grain Yield and Agronomic Traits in Hard Red Winter Wheat
- Roger A. Weyhrich,
- Brett F. Carver and
- Edward L. Smith
Producers in the southern Great Plains who utilize wheat for grain, hay, or late-season grazing would benefit from awnless hard red winter (HRW) wheat cultivars if yield potential is maintained relative to awned cultivars. The influence of awn suppression in contemporary cultivars in the southern Great Plains is unknown. Our objective was to determine the genetic effect of awn suppression on grain yield and agronomic traits measured in several HRW backgrounds and Oklahoma production environments. Experimental materials were derived by two methods from the same source populations: ‘TAM 107’*2/‘McNair 1003’, ‘Mustang’*2/McNair 1003, and ‘Century’*2/ McNair 1003. Bulk populations of lines were derived randomly from either homozygous awned or awnletted (spikes with one to three tip awns) F2 plants in each cross. The six bulk populations were evaluated in 11 environments. In a separate experiment, 78 pairs of awned and awnletted F3-derived sib lines (26 pairs per cross) were evaluated in four environments. No differences in grain yield were detected between awned and awnletted bulk populations from Mustang or Century, but a significant decrease in yield was found for the awnletted TAM 107 population. Significant decreases in test weight were associated with the awnletted character in all backgrounds. The Century-awnletted population had longer spikes, greater spike harvest index, and more kernels per spike than the Century-awned bulk. In 69% of the sib-pair comparisons, the awnletted sib did not differ significantly from the awned sib in grain yield. Where significant differences occurred, the awned sib was always higher yielding. It may be possible to develop awnletted lines with acceptable yield performance in the Great Plains, but close attention must be given to test weight to maintain current expectations of awned cultivars.
Copyright © 1994.