Effect of Preemergence Herbicides on Hybrid Bermudagrass Divot Resistance and Recovery

Abstract

<jats:p>Divoting is a common occurrence on golf courses and athletic fields. Research was conducted at the University of Tennessee Center for Athletic Field Safety (Knoxville, TN) during 2012–13 evaluating the effects of preemergence (PRE) herbicide applications on hybrid bermudagrass [<jats:italic>C. dactylon</jats:italic> (L.) Pers. × <jats:italic>C. transvaalensis</jats:italic> Burtt-Davy, cv. Tifway] divot resistance and recovery. Plots were subjected to the factorial combination of seven herbicide treatments (indaziflam at 35 and 52.5 g·ha<jats:sup>−1</jats:sup>; prodiamine at 840 g·ha<jats:sup>−1</jats:sup>; pendimethalin at 3360 g·ha<jats:sup>−1</jats:sup>; dithiopyr at 560 g·ha<jats:sup>−1</jats:sup>; oxadiazon at 3360 g·ha<jats:sup>−1</jats:sup>; non-treated control) and three divot timings [1, 2, and 3 months after herbicide treatment (MAT)]. Rates were based on label recommendations for preemergence crabgrass (<jats:italic>Digitaria</jats:italic> spp.) control. Herbicides were applied on 15 Mar. 2012 and 2013. Divots were generated using a weighted pendulum apparatus designed to impart 531 J of impact energy to the turf sward with a golf club. Divot resistance was quantified by measuring divot volume at each timing while divot recovery was quantified by measuring turf cover in the divot scar using digital image analysis. All herbicide-treated plots produced divots with volumes ≤ the non-treated control. In 2013, volumes were greater for divots produced 1 MAT (215 cm<jats:sup>3</jats:sup>) than those created 2 MAT (191 cm<jats:sup>3</jats:sup>) or 3 MAT (157 cm<jats:sup>3</jats:sup>). No differences in divot recovery were detected as a result of herbicide treatment in either year. Under the conditions of this study, applications of PRE herbicides at labeled rates did not affect divot resistance or recovery.</jats:p><jats:p>Chemical names: N-[(1R,2S)-2,3-dihydro-2,6-dimethyl-1H-inden-1-yl]-6-(1-fluoroethyl)-1,3,5-triazine-2,4-diamine (indaziflam), 2,4 dinitro-N3,N3-dipropyl-6-(trifluoromethyl)-1,3-benzenediamine (prodiamine), N-(1-ethylpropyl)-3,4-dimethyl-2,6-dinitrobenzenamine (pendimethalin), S,S-dimethyl 2-(difluoromethyl)-4-(2-methylpropyl)-6-(trifluoromethyl)-3,5-pyridinedicarbothioate (dithiopyr), 3-[2,4-dichloro-5-(1-methylethoxy)phenyl]-5-(1,1-dimethylethyl)-1,3,4-oxadiazol-2-(3H)-one (oxadiazon)</jats:p>