Newest research for improving sugarbeet management was on display June 23 at the University of Idaho Snake River Pest Management Research Tour in Kimberly, Idaho.
The tour led off with presentations about various pest management practices for beets and several other crops.
Kochia weeds found growing in two beet fields in Eastern Oregon and Southwestern Idaho last year were resistant to glyphosate, the active ingredient in the popular weed killer Roundup. Weeds don’t mutate to develop resistance to an herbicide like glyphosate. Instead the glyphosate allows a very small population of the weeds that are naturally resistant to thrive because it kills off their competition.
That’s why growers must use other herbicides in addition to Roundup. The use of multiple chemistries will control resistant weeds. Crop rotation is also an important tool, because it allows growers to use different chemistries.
Growers cannot rely on glyphosate alone to control weeds, UI Extension weed scientist Don Morishita said.
Researchers are determining how widespread the resistant weeds are and developing ways to help beet growers in the region deal with them.
That includes field trials designed to show growers the benefit of using multiple herbicides, in addition to Roundup, to prevent or control the development of glyphosate-resistant weeds.
A beet field trial at Kimberly is examining weed control with pre-ethofumesate and post-glyphosate tank mixtures. Ten different tank mixtures are being compared against the untreated control. Results from the trial will be completed by mid-November.