By Harold Watters, Ohio State University Extension agronomist
With the crappy spring, we missed proper burndown timing, pre-emergent herbicide application and now are working on missing the proper timing for post applications. Consider adding a second component to that glyphosate application when you do post your corn or soybeans. The idea is to have a second method of attack on those weeds that may be resistant, have grown a little larger than planned or you have had problems with in the past.
The Ohio, Indiana & Illinois Weed Control Guide is a great resource for getting management tips on how best to apply herbicides. See the recommendation tables to choose potential partners for those post applications. The Guide is available on-line from Mark Loux on his Weed Management website: https://u.osu.edu/osuweeds/. Know also what is appropriate for the herbicide technologies Enlist, Extend or LibertyLink if you are using them.
Don’t forget about drift. The spring burndown season was more than a little scary, and hopefully we will be into post spray season soon, so there is still potential for drift onto sensitive crops. Here from the Weed Control Guide are some tips on how to reduce the chances for drift.
Off-target movement of herbicides
Spray drift is the downwind movement of spray particles from the application site to non-target areas. The extent of spray drift increases as:
(1) the size of spray droplets decreases,
(2) the height above the ground from which the droplets are released increases, and
(3) wind speed increases.
Drift can be minimized by following these guidelines:
- Spray when wind speed is low.
- Use the maximum nozzle orifice size without distorting spray pattern.
- Reduce spray pressure to the lowest setting without distorting spray pattern.
- Using nozzles that minimize drift, such as Air Induction, Turbo Teejet, or Flat Fan DriftGuard nozzles. Or the ones recommended for the new dicamba and 2,4-D products – always read the label.
- Use drift control agents when permitted by the label.
- Follow label precautions for drift reduction measures.