As rangeland and pastures green up, check the following tips on pasture weed control, courtesy of Dow AgroSciences range and pasture scientists.
1) Identify what’s reducing your stands. Lack of rain, poor fertility, overstocking or other factors can contribute to overgrazing. And that can open previously healthy grass stands to broadleaf weeds and other undesirable plants. For long-term restoration, start by adjusting your grazing management plan to match available forage.
2) Identify the weed – then what will control it. Herbicides are often the most effective and efficient option to set your pasture on the road to recovery. Which herbicides you choose, and the recommended application rates, will vary by weed species and timing. For many weeds, a broad-spectrum herbicide with residual control will be the most cost-effective. If woody plants are also present, or are the dominant species, consider products labeled for brush control. Some products offer weed and brush control, or you can tankmix to reach the desired control spectrum. Once you’ve established what species you want to target, contact your applicator, ag chemical dealer or company specialist for a specific product and timing recommendation.
3) Use a calibrated sprayer to prevent waste, over-application expenses or reduced results from under-application. For more information on sprayer calibration, check your sprayer’s equipment manual.
4) Spray the right rate at the right time. Annual weeds in pastures are generally most susceptible early in the season, when they’re about 2” tall and actively growing, and when soil moisture is adequate. The lowest labeled rates will be effective then. A broad-spectrum herbicide with residual control at higher labeled rates will control weeds that germinate after spraying. Contact herbicides, such as 2,4-D, are effective only on emerged weeds and won’t effectively control weeds that sprout after application. Treat weeds while they are actively growing, but before flowering and seed production. Keep in mind that you’ll need to increase herbicide rates as the plants advance in their life cycle.
5) Consider mowing – not spraying – drought-stressed or mature weeds. Weeds without adequate moisture that aren’t actively growing will be difficult to control with herbicides. Don’t spray unless you’re willing to accept less control. Mowing biennial and perennial plants will set them up for fall treatment when they generate regrowth.
6) Follow label directions for application and mixing. For ground broadcast, apply the recommended herbicide rate in 10-20 gallons of total spray mixture per acre. For brush control, use at least 20 gallons/acre to ensure thorough coverage. For either weeds or brush, use the recommended rate of an ag surfactant to thoroughly wet the foliage. Consider a drift-control additive to reduce drift and improve deposition.
7) Use herbicides with good soil residual activity carefully. They shouldn’t be used on cropland or land to be rotated to crops. Herbicide-treated grasses may, for a time, carry a residue that can be transferred to the soil by hay, livestock manure or urine. Be sure to read and observe all label precautions. For more information on rangeland and pasture weed control, weed identification, species-specific rate and timing recommendations, and more, visit www.RangeAndPasture.com.