Maximizing Pre-Emergence Weed Control

Growers need to build a complete herbicide program that utilizes residual and contact herbicides throughout the season. This is best achieved by starting with a burndown program, followed by a pre-application chasing the planter. Finally, wrap up with a post-emergence application and include a residual herbicide in every application. Once herbicides are chosen, it is time to evaluate the adjuvant(s) recommended or required by the herbicide labels. Adjuvants are designed to help herbicides achieve maximum efficacy. Without adjuvants, weed control is compromised which can cost up to half of the crop’s yield potential by allowing weeds to take the vital nutrients and water needed to maximize yield.

It is important for pre-emergence herbicides to hold in the upper part of the soil profile in order to maximize weed seed–herbicide contact. If a soil-applied herbicide moves through the soil profile below the weed seed germination zone, weed control is compromised, thus forcing an additional herbicide application. In order to maximize residual herbicide performance, Helena recommends adding the adjuvant Grounded^® to every application, unless excluded by a tank mix partner. Grounded has three distinct modes of action, allowing herbicides to achieve maximum efficacy. Check out this demo to see how Grounded reduces leaching of herbicides through sandy soils..

In addition to aiding herbicides in holding in the upper soil profile, a minimum rate of 1% v/v (4 qt/100 gal) of Grounded will aid in drift control and deposition of the herbicides. As an oil-based adjuvant, Grounded reduces driftable fines, helping your herbicides stay on target and providing deposition through the canopy when used in a post-emergence application. Putting all of the herbicides on target ensures the lethal dose for the target weeds is delivered.

Lastly, the addition of Grounded in certain tank mixes, such as k-salt glyphosates and atrazine or other flowable herbicides, greatly improves compatibility. The emulsifier in Grounded not only helps compatibility, but it also keeps the spray solution homogenous, allowing for trouble-free applications. At some point, every grower has experienced a sprayer that is out of commission due to a compatibility issue. A clogged-up sprayer on the turn-row wastes time and money, as well as potentially missing an application when there is a break in the weather to allow spraying.

– Michael M. Kenty, Ph.D., Product Specialist