Post-Emergence-Only Treatments May Leave Lingering Weeds
Rows of corn from a field treated with only a post-emergence application of Acuron® and Roundup PowerMAX® herbicide show thinner stalks and weaker pollination from early season weed damage.
When planning a corn herbicide program, you may consider only applying post-emergence treatments. While these treatments may be effective in reducing weed pressure later in the season, allowing weeds to grow unchecked for several weeks early in the season can still result in unnecessary levels of damage and yield loss.
Trials this summer at the Rend Lake, IL, Grow More™ Experience site demonstrate the risk to fields that have made post-emergence-only herbicide applications, even with products as effective as Acuron® corn herbicide. Combined with Roundup PowerMAX® herbicide, post-emergence applications of Acuron did clear corn fields of weeds. However, weeks of unaddressed weed pressure resulted in thinner corn stalks and weaker pollination long after the treatments were made.
Ears of corn from plants in a field treated with a post-emergence-only application of Acuron showed effects of early-season weed pressure. These ears have lost kernels at their ends.
Corn ears from the trial fields suffered too, with the tips of ears lacking corn kernels. While this may not seem like a large loss when viewed ear-by-ear, the total effect can result in large yield losses for growers. In a field with 30,000 corn plants per acre, a loss of just 3 kernels per ear equals a loss of 1 bushel of corn per acre.
To defend against weeds in corn and prevent yield loss, our recommendation is a burndown application of Gramoxone® SL 2.0 herbicide followed by:
- A preemergence application of Acuron or Acuron Flexi at the full labeled rate. OR
- A 2-pass application of Acuron or Acuron Flexi with half the rate applied preemergence, followed by the remaining rate post-emergence, plus glyphosate for an additional site of action (SOA). A foundation rate of Acuron or Acuron Flexi can also be followed by Halex® GT herbicide plus either an atrazine or dicamba brand for an additional SOA.
Both Acuron brands provide burndown and residual control of tough weeds, and effective weed control can lead to higher yield potential. Trials show Acuron delivers 5-15* more bushels than other corn herbicides. With the commodity market we’re in right now, every bushel counts. In addition to higher potential yields, clean fields mean cleaner grain and less chance of being docked at the elevator for weed seed.
Contact your Syngenta sales representative for help identifying the right weed management plan for your area.
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