Journal of NACAA

Teff Grass Production and Tolerance to Post-emergence Herbicides

ISSN 2158-9429

Volume 15, Issue 1 - June 2022

Editor: Linda Chalker-Scott

Abstract

There is limited information on the impact of labeled post-emergence herbicides on teff grass (Eragrostis tef [Zuccagni] Trotter) production. The purpose of this study was to evaluate the tolerance of ‘Tiffany’ teff grass to labeled forage post-emergence herbicides. The study was conducted in the fall of 2021 at the Henry H. Leveck Animal Research Farm at Mississippi State University. The experimental design was a randomized complete block with a split-plot arrangement with three replications. The main plots were two growth stages (leaf stages 4 and 6), and the subplots were 15 herbicide treatments (Check, Chapparal, Permit, Milestone, Crossbow, Redeem R+P, Duracor, Pasturegard, Weedmaster, Remedy, Grazon P+D, Grazon Next, Velpar). Teff grass was planted at a rate of 10 lb PLS ac-1 in 6’ x 10’ plots. Nitrogen was applied at 50 lb N ac-1 using urea ammonium sulfate (33-0-0-18S). Herbicide treatments were applied with a CO2 backpack sprayer calibrated to deliver 20-gal ac-1 output at 60 psi. Plots were rated for chemical injury, lodging, GCC, NDVI, and LAI at 7 and 14 DAT. Plots were harvested at 14-d post-application and samples were analyzed for CP, ADF, NDF, IVTDMD, WSC, and starch using a Foss DS2500 NIR instrument and the 2021 grass hay equation from the NIRS Forage and Feed Testing Consortium. There was a significant difference in yield between growth stages (P<0.0001), with leaf stage 6 yielding 56% more than leaf stage 4. Herbicide application impacted seasonal biomass (P = 0.0003) and Velpar had a 67% yield decline compared to check. Leaf stage 6 had a 33% increase in LAI and a higher GCC of 7% than leaf stage 4. Nutritional values were influenced by the growth stage with leaf stage 6 producing greater ADF and NDF and leaf stage 4 having greater CP, starch, and IVTDMD.

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