Herbicide tolerance in 11 grass species for minimal‐to‐no‐mow golf course rough

Abstract

Research was conducted to determine the tolerance of 11 grass species used in minimal-to-no-mow turf areas to three postemergence herbicides applied at one-and twofold the maximum label rates in 2018 and 2019. Grasses were transplanted into field plots in West Lafayette, IN, in 2018 and 2019, allowed time to establish (∼1−2 mo), and then either treated with one application of quinclorac, sethoxydim, and topramezone at two rates or not treated. All 11 grass species had acceptable tolerance (≤20% injury) to quinclorac applied at 0.845 kg acid equivalent (a.e.) ha -1 . Quinclorac at 1.69 kg a.e. ha -1 produced moderate injury (≥21% injury) on only little bluestem [Schizachyrium scoparium (Michx.) Nash.], prairie dropseed [Sporobolus heterolepis (A. Gray) A. Gray], and switchgrass (Panicum virgatum L.). Strong creeping red fescue (Festuca rubra L. ssp. rubra Gaudin), which had ≤5% injury from all three herbicides, exhibited the greatest tolerance among grass species tested.With the exception of strong creeping red fescue, sethoxydim significantly injured all other grass species. Injury from topramezone varied among grass species and herbicide rates. Grasses tolerant (≤20% injury) to topramezone at both rates were big bluestem (Andropogon gerardii Vitman), broomsedge bluestem (Andropogon virginicus L.), indiangrass [Sorghastrum nutants (L.) Nash], strong creeping red fescue, and tall fescue [Festuca arundinacea Schreb.; syn. Schedonorus arundinaceus (Schreb.) Dumort., nom. cons.]. Tolerance among species was variable to quinclorac, sethoxydim, and topramezone, and thus turf managers should first identify desired grass species prior to herbicide application. INTRODUCTIONGolf course turf surrounding the putting green, tee, and fairway of each hole is called "rough" (Beard & Beard, 2005).Golf courses typically have two different rough areas: a primary rough, which is mown between 3.8 and 10.2 cm and causes moderate difficulty in golfer strokes, and a secondary Abbreviations: a.e., acid equivalent; DAA, days after application.This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

Tolerance of little bluestem to ACCase‐inhibiting herbicides in Pennsylvania

“…These findings are similar to those of Patton et al. (2021) in which sethoxydim caused >30% injury to little bluestem plants. Practitioners should be aware that applications of the ACCase‐inhibiting herbicides sethoxydim, fluazifop, and quizalofop can be detrimental to little bluestem when used to control grass weeds in mixed little bluestem/fine fescue rough.…”

“…In Pennsylvania, perennial and annual grass weeds invade fine fescue/little bluestem rough, and golf course managers occasionally use postemergence herbicides as control options (Landschoot, 2018). ACCase‐inhibiting herbicides control a variety of grass weeds, but relatively few studies have examined the effects of these herbicides on little bluestem (Patton et al., 2021).…”

Tolerance of fine fescues to indaziflam formulations in minimal‐to‐no mow golf course rough

“…Strong creeping red fescue (Festuca rubra L. ssp. rubra Gaudin)-a fine fescue-is among the cool-season perennial grass species most tolerant of postemergence herbicides for grass weed control in minimal-to-no mow areas (Patton et al, 2021). However, further information on preemergence weed control options for minimal-to-now mow rough areas would benefit golf course superintendents and potentially help mitigate herbicide resistance (Brosnan et al, 2020).…”