Start Clean, Stay Clean to Help Control Resistant Weeds

Strategies for controlling herbicide-resistant weeds with a preplant foundation of burndown and residual herbicide.

Resistant Weeds

Herbicide-resistant weeds are an increasing threat in the Mid-South. Weed science experts recommend a “start clean, stay clean” approach that overlays contact plus residual herbicides to control weeds while they are small and reduce weed seed production.

Spring Weed Control by Crop

Weather and workload allowing, it’s best to stay ahead of weeds with a preplant foundation of burndown and residual herbicide. DuPont Pioneer agronomy research manager Dan Poston says timely planting is key to maximizing soybean yield, which means thinking carefully about how herbicide choices affect the preplant interval. Tank mixtures that contain DuPont LeadOff® herbicide combat resistant weeds with contact plus residual control and two active ingredients, rimsulfuron and thifensulfuron. If preplant interval allows, apply LeadOff® to help control chickweed, henbit, marestail and annual bluegrass.

LeadOff® (1.5 ounces per acre) gives flexibility to plant corn immediately after application or plant soybeans and cotton 30 days after application.

Soybeans

Whatever preemergence program is chosen for soybeans, consider these points:

  1. Start clean. Tank-mix LeadOff® with an effective contact herbicide such as Gramoxone.
  2. Use rainfall for activation or start a postemergence program earlier than normal, within label constraints.
  3. Apply a postemergence herbicide containing fomesafen/metolachlor or fomesafen approximately 21 days after planting, plus glyphosate for Roundup Ready soybeans or Liberty for LibertyLink soybeans.

Burndown and Preplant for Soybeans

Trivence® herbicide (6.0 to 10.0 ounces per acre) is for effective burndown plus residual control of many challenging weeds, including Palmer amaranth, marestail, waterhemp, giant ragweed, morningglory and lambsquarters. With three modes of action, the flexible formulation is an effective tool for growers who have glyphosate- and ALS-resistant weeds in their soybean fields. It can be applied preplant and up to three days after planting.

Trivence® moves quickly through the target weed, reaching leaves, roots and shoots for consistent control. Long-lasting residual keeps fields clean after planting, allowing more uniform soybean emergence and better stand establishment. Trivence® performs well even under cool, wet conditions and mixes with a variety of herbicides. See the Trivence® label (PDF) for tank-mixing guidelines.

When selecting a DuPont preplant/preemergence program for soybeans, pay special attention to rotational crop requirements associated with chlorimuron ethyl, especially for rice and on high pH soils. This is also important with postemergence herbicides containing fomesafen, which help control Palmer amaranth.

Corn

LeadOff® herbicide can be used up to corn planting for a healthy, vigorous start. Some herbicides typically mixed with LeadOff® earlier in the season might not be suitable for an application immediately before or after planting, however. Some options available at or near corn planting include:

  • LeadOff® plus Gramoxone SL or glyphosate gives more complete burndown.
  • Add a low rate of atrazine with LeadOff® for enhanced residual control.

For corn at V2 or V3 through V6, use a combination of contact plus residual products that include DuPont™ Realm® Q, Resolve® Q or Steadfast® Q herbicides. The “Q” stands for “safened”, meaning these herbicides can be applied to more hybrids with more adjuvants under more conditions.

DuPont LeadOff® and Trivence® herbicides are not available in all states. See your local DuPont retailer or representative for details and availability.

 

Roundup Ready (Monsanto); Liberty, LibertyLink (Bayer); Gramoxone (Syngenta).

 

The information provided on this website is for reference only. Always refer to the product labels for complete details and directions for use.