Turf managers commonly use sulfonylurea herbicides for turfgrass weed control. The objective of this research was to provide herbicide tolerance and efficacy information for seven sulfonylurea herbicides and another herbicide on several turf and grassy weed species. Annual ryegrass (Lolium multiflorum Lam.), Kentucky bluegrass (Poa pratensis L.), creeping bentgrass (Agrostis stolonifera L.), perennial ryegrass (Lolium perenne L.), tall fescue (Festuca arundinacea Schreb.), bermudagrass (Cynodon dactylon L.), and zoysiagrassgrass (Zoysiagrass japonica Steud.) were treated with two rates of eight herbicides. Kentucky bluegrass and creeping bentgrass were the most tolerant of the cool‐season species, but injury in some cases was severe. Herbicide applications to bermudagrass resulted in temporary discoloration for some treatments, but never resulted in kill. At label rates, sulfonylurea herbicides may eliminate several grass species from creeping bentgrass, Kentucky bluegrass, bermudagrass, and zoysiagrass.

Core Ideas Early fall Proxy (ethephon) applications effectively suppress Meyer zoysiagrass seedheads in spring. Apply Proxy in late‐September when days are approximately 12 hours long to suppress zoysiagrass seedheads. Tank‐mixtures of Proxy with large patch fungicides reduce application labor and equipment costs. ‘Meyer’ zoysiagrass (Zoysia japonica Steud.) is used on golf courses throughout the transitional climatic zone because of its aesthetic and functional quality and tolerance to abiotic stresses. However, a key problem with Meyer zoysiagrass is that it produces seedheads in the spring that reduce aesthetics and increase golf course maintenance costs. The objective of this experiment was to quantify the efficacy of Proxy (ethephon) on Meyer zoysiagrass seedhead suppression at three locations when applied in fall before winter dormancy and in spring prior to seedhead production. The early fall application timing of Proxy provided > 90% suppression of zoysiagrass seedheads with < 10% injury. Late fall and spring Proxy applications provided little seedhead suppression. The early fall application timing that successfully suppressed Meyer zoysiagrass seedheads in our experiment was applied from 23 to 29 September across locations to 100% green zoysiagrass; on dates with a photoperiod of 11.9 to 12.1 h; and following the accumulation of < 14 cooling degree days (20°C base temperature). This research provides turf managers insight on how to best suppress Meyer zoysiagrass seedhead production.

The benefits of composted yard waste applied as a mulch were demonstrated in a field study at two locations and supporting greenhouse research. Compost was applied to eroded roadside slopes of about 12° and 27° to determine the influence on soil displacement and establishment and/or enhancement of permanent roadside vegetation. Treatments consisted of compost rates of 5 cm and planted with asiastic jasmine (Trachelopermum asiaticum), 5 and 10 cm, seeded with 110 or 220 kg·ha–1 80:20 bahiagrass (Paspalum notatum Flugge): bermudagrass (Cynodon dactylon L.) seed mix by weight, straw erosion control mats, and bahiagrass sod. Compost treatments effectively controlled soil displacement regardless of compost rate or seeding with turfgrass at both locations. Effects on roadside vegetation and visual quality varied with location. Asiatic jasmine did not establish at either site. Compost mulch applications increased total vegetation, turfgrass density, and quality at the site with 27° slope and 4% initial soil organic matter content, but resulted in a decline in cover at the site with a 12° slope and <1% organic matter content. Compost mulch can effectively prevent soil displacement from roadside slopes, but may not promote establishment or enhancement of permanent vegetative cover.

This fact sheet gives a brief overview of a two-year project conducted by researchers of the University of Florida's Institute of Food and Agricultural Sciences (UF/IFAS) as part of contract WO#7 with the Florida Department of Transportation (FDOT). This document is ENH 872, one of a series of the Environmental Horticulture Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Original publication date October 1, 2002. https://edis.ifas.ufl.edu/ep133