A NOVEL APPLICATION OF THE HERBICIDE ETHOFUMESATE TO INCREASE AND PROLONG THE EFFECTIVENESS OF GLYPHOSATE RESISTANT TECHNOLOGY IN SUGARBEET

(WYO-427-08)

Glyphosate resistant sugarbeet represents the most significant technological advance in sugarbeet weed management since the introduction of selective herbicides. Unavailability of currently used postemergence herbicides, hesitance to use preemergence herbicides, and reluctance to use tillage for weed control in the glyphosate resistant sugarbeet crop could potentially result in near total reliance on a single herbicide for weed management in the glyphosate resistant sugarbeet crop. Reliance on a single herbicide will almost surely lead to glyphosate resistant weeds, and by the time glyphosate resistant weeds appear in Wyoming sugarbeet fields, growers will have few acceptable management options. It is therefore imperative that this technology be utilized prudently, and proactive management strategies put in place in order to prolong the utility of the technology well into the future. We propose a novel use of a herbicide currently registered for weed control in sugarbeet in order to increase the effectiveness and prolong the utility of glyphosate resistant technology in sugarbeet. Ethofumesate is widely used as a preemergence herbicide on conventional sugarbeet acres in Wyoming and the US. The use rate of ethofumesate required to achieve adequate weed control often results in injury to the sugarbeet crop. Previous research has demonstrated that preemergence application of ethofumesate can increase uptake of subsequently applied herbicides. The goal of this research project is to determine whether ethofumesate can be applied to glyphosate resistant sugarbeet at a rate low enough to minimize crop injury, but still provide an economic weed control benefit by increasing uptake, and therefore increasing the efficacy, of subsequently applied glyphosate. If the findings of this research support our hypothesis, weed management programs will be more likely to include multiple herbicide modes of action for proactive resistance management, and provide better management of difficult to control weeds while reducing crop injury potential.

USDA CRIS Project Information Link: 0213038