Agronomic Characterization of ‘Yogo’ Hard Red Winter Wheat Plant Height Isolines

In spite of the success of semidwarf wheats (Triticum aestivum L.) throughout the world, there are currently no adapted semidwarf hard red winter wheat cultivars with sufficient winterhardiness being grown in Montana and the Northern Great Plains. Studies were initiated to determine the suitability of short stature winter wheats for Montana. Selected agronomic traits were evaluated in 20 ‘Yogo’ winter wheat isogenic height lines and the recurrent parent, Yogo, representing three plant height phenotypes: dwarf, semidwarf, and tall. Yogo is a hard red winter wheat cultivar adapted to harsh winters and low rainfall. Significant differences (P < 0.01) among plant height phenotypes were observed for percent emergence, emergence rate, coleoptile length, test weight, and grain yield. Percent emergence, emergence rate, and coleoptile length were all positively associated with plant height, with linear coefficients of determination of 0.79,0.76, and 0.65, respectively. Grain yield was negatively correlated with plant height (r² = 0.77). Average grain yields over four Montana locations were 1486,1287, and 996 kg ha⁻¹ for the dwarf, semidwarf, and tall plant height phenotypes, respectively. There were no significant differences among phenotypes for crown depth. No winter-kill was observed among isolines at any location, including one at which other winter wheats had differential winter injury ranging from 30 to 100% winter survival. Backcrossing of the rht, and rht2 semidwarfing genes into the Yogo genetic background resulted in no apparent effect on winterhardiness. In spite of short coleoptiles and poor field emergence, short stature winter wheat appears well suited to Montana and the Northern Great Plains dryland wheat growing areas, particularly in areas with a high production potential.