Effect of Varro Tank Mixes on Weed Control in Spring Wheat

Objective:       

To evaluate the efficacy and crop safety of Varro tank mixes in spring wheat.

Materials and Methods:

Varro was applied in combination with standard broadleaf herbicides to evaluate weed control and crop safety in spring wheat relative to that obtained with Huskie Complete and Wolverine Advanced. The experimental design was a randomized complete block with three replications.  Egan spring wheat was planted on April 22, on 7.5 inch row spacings, to a depth of two inches. Common lambsquarters, canola, wild oats and wild buckwheat were planted in the center of each plot on April 28. Herbicide treatments were applied using a CO₂ backpack sprayer with Teejet XR11002 nozzles in 20 GPA of water. Treatments were applied on May 18 when the wheat was at the four-leaf stage and the weeds were at the two to three leaf stage.

Results:            

Initial crop injury ranged from 13.3 to 23.3% for Huskie Complete and for treatments containing Varro, while Wolverine Advanced had only 3.3% injury. As the season progressed crop injury declined for all treatments and ranged 0 to 8.3 percent. Wild oats and canola were the primary weeds present, with lower densities of wild buckwheat and common lambsquarters. By July 1, weed control was 100% for all of the treatments except for Wolverine Advanced, which had 90% control for wild oats. Herbicide use improved yields by about 68% compared to the check, but there were no yield differences among the herbicides tested.

Summary:           

The Varro tank mixes produced more crop injury than Wolverine Advanced.  However, this early injury did not appear to impact yield.  Wild oat control was excellent regardless of the tank mix partner.