Research Objective
An in-crop application of Viper® ADV without a pre-seed tank mix provided sufficient control of glyphosate-resistant canola volunteers and maximized yields at the three dryland sites. Layering pre-seed herbicide tank mixes with an in-crop application of Viper® ADV was extremely beneficial at Outlook under irrigation.
At Yorkton and Melfort, the flush of volunteers was late, and the overall volunteer population was low at Indian Head; therefore, an in-crop Viper® ADV herbicide application without any additional pre-seed herbicides was adequate, providing over 85% control of glyphosate-resistant volunteers at these locations.
At Outlook, canola volunteers were heavy, with earlier and multiple flushes. Using pre-seed tank mixes alone provided 60% control of glyphosate-resistant volunteers and increased soybean yields by 36% compared to the control. However, when layering pre-seed tank mixes with an in-crop application of Viper® ADV, volunteers were controlled up to 90% and soybean yields were up to 68%. Differences were observed among the pre-seed tank mixes, but product efficacy was inconsistent so that no conclusions can be drawn about specific tank mixes.