Herbicides work best when used correctly. To get the best return on investment from your pasture weed spraying, experts with Corteva Agriscience offer six tips.
1. Identify the Weed Problem and Determine if You Have White Clover You Want to Keep.
Your best choice of herbicides, application rates and timing vary by target weed species and whether you have nontarget white clover.
For broadleaf weed control, DuraCor® herbicide is the product of choice. It controls more than 140 broadleaf weed species and provides soil residual activity to control new germinations for several weeks after application. But DuraCor also controls several legumes that might be desirable in a pasture. NovaGraz™ herbicide preserves white clover and annual lespedeza – and all their benefits. As a nonresidual herbicide, NovaGraz is an excellent choice where extended weed control is not desired.
2. Use a Calibrated Sprayer or a Professional Applicator.
Proper calibration avoids both the waste and expense of overapplication, and it prevents reduced control from underapplication. Get your money’s worth. Don’t guess. Calibrate.
3. Spray at the Right Time With the Right Rate.
Annual weeds in pastures are generally most susceptible early in the season when they’re small and actively growing and when soil moisture is adequate. Using DuraCor will provide longer soil residual activity than any other pasture herbicide and will control weeds that germinate for several weeks after spraying. After that, competition and soil shading from a healthy grass cover often provide season-long control.
4. Recognize That Drought-stressed or Mature Weeds Will Be More Difficult to Control.
Effectiveness may be reduced if weeds don’t have adequate moisture and aren’t rapidly growing when you spray. In a dry year, spraying early will improve results and help your grass capture scarce moisture. Weed-free pastures always recover faster from drought. The key is to spray early when conditions are acceptable. For late applications or less favorable conditions, you’ll need to increase the application rate for satisfactory control.
5. Follow Label Directions for Application and Mixing.
For ground broadcast, apply the recommended rate of herbicide in 10 to 20 gallons of total spray mixture per acre. Use the recommended rate of an agricultural surfactant to thoroughly wet the foliage; NovaGraz™ herbicide, for example, requires methylated seed oil (MSO) as a surfactant. Consider a drift control additive to reduce drift and improve deposition.
6. Remember Soil Residual Activity and Plant Residue.
Although DuraCor® herbicide can provide weed control for several weeks in permanent grass pasture, it should not be used on cropland or on land to be rotated to crops. Most broadleaf crops are more sensitive to residual activity than weeds. Those crops may be affected if planted within two years, or longer, of spraying.
Don’t plant a broadleaf crop until an adequately sensitive field bioassay shows the crop will not be harmed. Cereals and corn, however, can be planted one year after treatment. Remember grasses treated with any soil residual herbicide may carry herbicide residue that can be transferred to the soil by hay or by livestock manure or urine.
Contact your local Premier agronomist for more localized recommendations to customize your pasture improvement.
**This article was provided by Corteva Agriscience.
