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.

Core Ideas Trinexapac‐ethyl (TE) is a common plant growth regulator used in turfgrass systems. The effects of TE on herbicide efficacy to control smooth crabgrass were unknown. Mixing TE with postemergence herbicides did not affect smooth crabgrass control.

Renovation is an opportune time for golf courses to address annual bluegrass (Poa annua L.) weed populations. Dazomet (tetrahydro-3,5-dimethyl-2H-1,3,5-thiadiazine-2-thione) is an effective fumigant, but without a tarp cover, it is only effective at the highest labeled rates. Fraise mowing cultivation could be used to help remove surface material and allow practitioners to effectively fumigate at lower rates. In Summer 2018 and Summer 2019, two cool-season fairway renovation experiments were conducted in East Lansing, MI. The objective of these experiments was to assess annual bluegrass control and creeping bentgrass establishment following dazomet applications to fraise mowed surfaces. In the first experiment (fraise mowing surface disturbance experiment), dazomet was applied at a fixed rate (294 kg·ha−1) to fraise mowed plots at varying levels of surface disturbance (0%, 15%, 50%, and 100%) to a depth of 1.9 cm. In the second experiment (dazomet rate experiment), fraise mowing removed 100% of surface material at a depth of 1.9 cm and dazomet was applied at five rates (0, 294, 588, 147 + 147, and 294 + 294 kg·ha−1). Both experiments were conducted on two soils (sand topdressed vs. native) and evaluated two methods of fumigant incorporation (solid-tine cultivation vs. tillage). Five days after treatments were applied, plots were seeded with ‘Pure Select’ creeping bentgrass (Agrostis stolonifera L.). The level of fraise mowing surface disturbance had no effect on annual bluegrass emergence, and creeping bentgrass cover was poorest in native soils at the highest levels of surface disturbance. In the dazomet rate experiment, dazomet applied twice at 294 kg·ha−1 provided the most consistent control of annual bluegrass. With the exception to single applications of 294 in 2018, all dazomet treatments allowed for greater creeping bentgrass establishment than the nontreated control. Fraise mowing cultivation may simplify the removal of surface material from large areas; however, even when combined with dazomet applied at the highest rates, it fails to provide complete annual bluegrass control.

Two desirable traits consistent in emerging creeping bentgrass (Agrostis stolonifera L.) cultivars are increased canopy density and fine leaf texture. Although the former is often associated with reduced incorporation of applied materials into the turf system, the effects of the latter have not yet been characterized. Some practitioners believe these boundaries can be overcome by topdressing with a dried sand, which they propose settles differently than conventional moist sand. In 2018, two topdressing studies were conducted to evaluate incorporation of moist and dried topdressing sands when applied to six creeping bentgrass cultivars of varying textures into vertically mowed and uncultivated systems. Cultivars were topdressed with dried sand or with moist sand and then incorporated with one of two brushing systems. Across trials, neither brush consistently outperformed the other. A larger proportion of applied topdressing sand was retained by the vertically mowed system and was unaffected by the moisture content of sand. Less sand was retained by uncultivated systems, and the distribution of both sands changed significantly. For moist sands, finer‐textured cultivars, in general, corresponded with greater removal of coarse fractions and a greater retention of fine fractions. Therefore, we provide supporting evidence that topdressing into vertically mowed systems, regardless of sand moisture content, results in enhanced sand incorporation. When topdressing uncultivated, fine‐textured bentgrass putting green systems, however, practitioners could benefit from topdressing with dried sands.

The addition of synthetic fibers to natural grass athletic fields forms a hybrid turf system, and this system claims to increase traffic tolerance and playability. The objectives of this research were to evaluate the physical effects of simulated traffic on two hybrid, carpet-based mat systems (Eclipse and Hero) with Kentucky bluegrass (Poa pratensis L.), compared to a non-hybrid control (100% Kentucky bluegrass). Field research was conducted in 2018 at Michigan State University (MSU), Iowa State University (ISU) and the University of Tennessee (UT) to evaluate the percent green cover, surface hardness, and shear resistance under 25 simulated traffic events (STE).Percent green cover across all treatments was reduced after 25 STE. After 25 STE the hybrid systems had greater percent green cover (Eclipse 49% and Hero 48%) than the non-hybrid control (33%) at the ISU location. Surface hardness values differed between treatments on many rating dates. The hybrid systems reported higher surface hardness values, but these values were never above 100 Gmax. These results indicate that the Eclipse and Hero systems can offer a safe and stable surface even if turfgrass cover is reduced.