Using IMI-Resistant and Susceptible Wheat Cultivar Blends to Simulate Winter Damage.

Occasionally, winter wheat in the Great Plains experiences winter damage. When this occurs, farmers must determine the level of damage, its effects on grain yield, and whether they should destroy the crop or leave for eventual harvest. This research was conducted to help answer these questions. Two wheat cultivars, “TAM 110” and “Above” were mixed in three blends, 1:1, 2:1, 1:2, plus controls and treated with the herbicide, imazamox, at two times during the growing season to simulate winter damage. The imazamox treatment was used to kill the susceptible cultivar, TAM 110, leaving different stand levels. Four replications were used in a randomized complete block design with a split-plot arrangement of the imazamox treatment. The whole-plot treatment was the imazamox treatment and sub-plot was the cultivar blends. There were no yield differences among the five cultivar blend and no chemical control treatments. Also, there were no yield differences among the control treatments and the 1TAM110:1Above and 1TAM110:2Above cultivar blends treated with imazamox in the fall. The 1TAM110:1Above and 2TAM110:1Above blends treated in the spring with imazamox yielded within 85% and 73% of the controls, respectively. This demonstrates wheat’s ability to compensate for stand loss during the growing season.