UGA County Extension Agents assist Corteva with Forage Demonstrations

Dr. Lisa Baxter, Greg Pittman (Jackson County), Shane Kornberg (Whitfield County), and Jonathon Stickland (Meriwether County)

Introduction: Three counties were selected to host demonstration sites this spring to illustrate the performance of a new herbicide, NovaGraz, from Corteva Agriscience. NovaGraz can be used to control broadleaf weeds while protecting the white clover component of grass-white clover mixtures. This product contains both 2,4-D and Florpyrauxifen-Benzyl.

Methods: These demonstrations took place in Jackson, Whitfield, and Meriwether counties in Georgia. Herbicides were applied in early April with a CO2 backpack research sprayer at each location. This sprayer was set to deliver the spray volume at 20 gallons per acre using TeeJet AIXR11002 nozzles. Treatments are listed in the table below.

Plots were evaluated at project initiation and at 30 days after application. The evaluation included ratings of percent groundcover and injury to the white clover.

Results: Figure 1 illustrates the change in percent groundcover following herbicide application. In the top of the figure, you can see that the species composition was similar among all plots prior to herbicide application. The species composition did not change in the unsprayed control after 30 days. All herbicide treatments reduced broadleaf weeds (light brown color in figure 1) within 30 days, but did not reduce grass weeds (dark brown color in figure 1). This was expected since neither chemical has activity on grasses. More white clover was sustained under the NovaGraz treatments than the DuraCor (dark blue color in figure 1). As you can see in figure 2, the percent clover injury was almost 100% in the DuraCor treated plots compared to less than 20% in both NovaGraz treatments. The fescue component increased in all plots treated with herbicide, to compensate for the loss of white clover and broadleaf weeds.

Figure 1. Percent coverage of fescue, white clover, broadleaf weeds, and grass weeds of plots treated with herbicide. Ratings were conducted at project initiation and 30 days after.

Figure 2. Percent injury to the white clover in plots treated with herbicide. Ratings were conducted at 30 days after project initiation.

Acknowledgments: Thank you to the producers and farms that hosted these demonstrations. These included Joel Davis (J&J Farms in Jefferson, GA), Gerald Brown (Brown Angus Farms), Chris Farrell (Farrell Farms in Greenville, GA). More information on NovaGraz may be found here: https://www.corteva.us/products-and-solutions/pasture-management/novagraz.html