Published on Friday, November 5, 2021
The Enlist™ system provides farmers the opportunity to utilize 2,4-D choline, Liberty®, and glyphosate. Beck’s Practical Farm Research (PFR)® data shows that utilizing multiple, effective SOAs in the pre-emerge resulted in less waterhemp for the post-emergence application to control. In 2021, Beck’s PFR set out to determine how the pre-emergence application impacted the post-emergence application and, conversely, how the post-emergence application impacted the preemergence application in Enlist E3® soybeans. The study was designed to evaluate various programs in the Enlist system targeting heavy, medium, and low waterhemp pressure.
Averaged across the six post-emergence options, Fierce® MTZ and Authority® Elite resulted in the greatest waterhemp control. Though Valor® XLT is a two SOA herbicide, many waterhemp populations are resistant to Group 2 herbicides, resulting in reduced control. Boundary® contains metribuzin and Dual II Magnum®, resulting in effective waterhemp control. However, metribuzin residual longevity may not last as long as the other actives within Fierce MTZ and Authority Elite. Though Verdict® has two SOAs, a 5 oz. rate of Verdict resulted in very low residual value and averaged 81% control. Even in an area of low weed pressure, the pre-emerge application sets up the post-emergence application for success.
Selecting the proper post-emergence application, like Enlist One® + Liberty®, resulted in effective control across many of the medium and low weed pressure scenarios. The success of the post-emerge trip was impacted by the pre-emerge application. When we used a pre-emerge designed for heavy weed pressure, waterhemp control never fell below 96%. When a program was selected based on medium weed pressure, waterhemp control ranged from 80 to 96%, depending on what post-emergence application was applied. If we selected a low weed pressure program, waterhemp control ranged from 69 to 90%. The lower ratings can be explained by the heavy waterhemp pressure within these plots, showcasing why it is critical to select the proper pre-emerge herbicide program for your weed spectrum and weed pressure.
LIBERTY®, ENLIST ONE® + GLYPHOSATE, OR ENLIST ONE + LIBERTY?
Beck’s PFR data shows that when it comes to waterhemp control, Enlist One® + Liberty® can provide the most effective control in the Enlist™ system. However, we saw a reduction in grass control with Enlist One + Liberty. Across all six pre-emerge herbicides, Enlist One + Liberty waterhemp control never fell below 83%. Compared to Liberty alone, waterhemp control fell as low as 69%, and compared to Enlist One + glyphosate, control fell as low as 78%. Averaged across all treatments, Liberty resulted in 87% control, Enlist One + glyphosate, 89% control, and Enlist One + Liberty, 93% control. Therefore, in heavy waterhemp situations, Enlist One should always be tank-mixed with Liberty. Enlist One + Liberty will provide two effective SOAs on glyphosate-resistant waterhemp, reducing selection pressure on both Enlist One and Liberty. We can be successful with either Liberty or Enlist One + glyphosate when the proper preemerge is utilized.
If we used a pre-emerge designed for heavy weed pressure, waterhemp control never fell below 96%. If we selected a program based upon medium weed pressure, waterhemp control ranged from 80 to 96% depending on what postemergence application was applied. If we selected a low weed pressure program, waterhemp control ranged from 69 to 90%. The lower ratings can be explained by the heavy waterhemp pressure in these plots. Across all six preemerge herbicides, Enlist One + Liberty waterhemp control never fell below 83%, compared to Liberty where control fell as low as 69% or Enlist One + glyphosate in which waterhemp control fell as low as 78%. If Warrant was added to Enlist One + Liberty, waterhemp control never fell below 89%.
Author: Jim Schwartz
Categories: Agronomy, Agronomy Talk
Tags: soybeans, Agronomy, Herbicide, weed management, enlist