Applying weed controls in the spring can be tricky, said Bob Scott, weed scientist with the University of Arkansas Cooperative Extension Service.
Many Arkansas wheat growers who would normally apply herbicides in the fall had to shift the activity to spring due to wet weather, late planted wheat and late emerging ryegrass.
Scott said cold spring temperatures can be trouble.
“When it gets cold, many enzyme-inhibiting herbicides, such as Osprey, don’t work as well. It’s better to wait until temperatures are above 55 degrees for two or three days before and after application.”
Osprey’s label warns that injury may occur if nitrogen fertilizer is applied within 14 days of an Osprey application, Scott said. Osprey at the full rate is effective on larger ryegrass and does a fair job on bluegrass, many broadleaves and vetch in late January and early February. It can be tank-mixed with Harmony Extra for garlic.
Axial or Hoelon is a good option for spring ryegrass control if the ryegrass isn’t Hoelon-resistant. Use the full labeled rate of either herbicide for best results, Scott recommended, but don’t tank-mix broadleaf herbicide with Hoelon.
Wild buckwheat and vetch will cause major harvest problems. Harmony Extra is the industry standard for garlic and onion and many of these other broadleaves.