Published on Friday, November 12, 2021
SPRAY COVERAGE (1-YEAR DATA)
Applying Enlist One® + glyphosate at 10 gal./A. never resulted in greater than 70% (waterhemp) and 75% (fall panicum) control. However, by upping our spray volume from 10 to 15 gal./A., waterhemp control increased by 17%, and fall panicum control increased by 20%. Why did two systemic herbicides, Enlist One and glyphosate, have such a large response to carrier rate? Even though complete coverage is not as crucial, the herbicide must still reach each plant. Putting the Power in the Pre™ generally leads to reduced weed pressure and greater control; therefore, a pre-emerge was withheld from these demonstration plots to ensure enough vegetation was present at the time of the post-emerge treatment. When increasing from 15 to 20 gal./A., we saw less response with Enlist One + glyphosate vs. Enlist One + Liberty®. When Enlist One + glyphosate was applied at 20 gal./A. (compared to 15 gal./A.), waterhemp control only increased by 3% and fall panicum control by 1%. Note that in heavy vegetation scenarios, 20 gal./A. may still be needed with Enlist One + glyphosate.
Compared to a Turbo TeeJet Induction™ (TTI) nozzle, applying Enlist One® + glyphosate with a TeeJet® Air Induction Extended Range (AIXR) nozzle increased waterhemp control by 3% when averaged across 10, 15, and 20 gal./A. carrier rates. However, spraying Enlist One + Liberty® increased waterhemp control by 7.4% when an AIXR nozzle was used instead of a TTI nozzle. The difference between a TTI nozzle vs. an AIXR nozzle was never greater than 8% when utilizing Enlist One + glyphosate. However, when Enlist One + Liberty was applied, an AIXR nozzle had up to a 12% advantage over a TTI nozzle. This showcased how nozzle selection was less impactful with Enlist One + glyphosate compared to Enlist One + Liberty. However, in thicker vegetation, canopy penetration is difficult, giving the AIXR a slight advantage even when applying two systemic herbicides. Carrier rate played a large role with the Enlist One + glyphosate applicaton. Once again, the greater amount of water could penetrate the canopy and reach the smaller weeds; thus, Enlist One + glyphosate should be applied in a minimum of 15 gal./A.
Just like with Liberty®, Enlist One® + glyphosate was impacted by carrier rate due to the thick vegetation. By upping our spray volume from 10 to 15 gal./A., waterhemp control increased by 17%, and fall panicum control increased by 20%. Enlist One + glyphosate compared to Enlist One + Liberty: we did not see a large increase at 20 gal./A. vs. 15 gal./A. and nozzle selection did not play as large of a role when applying. Averaged across 10, 15, and 20 gal./A., utilizing an AIXR nozzle only increased waterhemp control by 3% by 28 DAT compared to a TTI nozzle.
Author: Jim Schwartz
Categories: Agronomy, Agronomy Talk
Tags: Agronomy, Herbicide, weed management, enlist