Fraise mowing can improve herbicidal control of bermudagrass

Abstract

AbstractHerbicide control options for bermudagrass [Cynodon dactylon (L.) Pers or C. dactylon x C. transvaalensis Burtt‐Davy] include non‐selective herbicides such as glyphosate (N‐[phosphonomethyl] glycine), as well as selective graminicides such as fenoxaprop (Fenoxaprop‐P‐ethy) and fluazifop (Fluazifop‐P‐butyl). Regardless of the herbicide used, effective bermudagrass control can only be achieved with repeated applications. Fraise mowing has been recently introduced into the turfgrass industry and these machines can remove thatch and growing points down to a depth of 5.0 cm. Our hypothesis was that if a high percentage of the growing points of a bermudagrass stand were physically removed with fraise mowing, the remaining growing points would be more easily controlled with various herbicides. Six trials were conducted over two seasons to determine if fraise mowing and herbicides could be used in combination to improve bermudagrass control. Treatments included various combinations and timings of glyphosate (2.74 kg a.i. ha−1) and fluazifop (0.42 kg a.i. ha−1), applied to plots that were fraise mowed to a depth of 3.75 cm or not fraise mowed. Fraise mowing alone physically removed a significant amount of the bermudagrass growing points and provided partial bermudagrass control. A combination of fraise mowing and herbicide generally improved bermudagrass control over the herbicides alone. Herbicides applied after fraise mowing generally provided better bermudagrass control in comparison to applying herbicides prior to fraise mowing. Aggressive fraise mowing appears to be a tool that can improve bermudagrass control and could shorten the overall time window needed to remove existing bermudagrass from a site.