Selective Torpedograss (Panicum repens) Control in Bermudagrass (Cynodonspp.) Turf

Abstract

Torpedograss has invaded fine turfgrasses in the Southern U.S. due to its tolerance to most commonly used turfgrass herbicides. Research was conducted to determine torpedograss and ‘Tifway’ bermudagrass tolerance to quinclorac and tank-mix combinations with other turf herbicides. Quinclorac rates in excess of 2.2 kg ai/ha were required for control (≥ 80%) of torpedograss. Sequential applications were more effective than single applications. Generally, sequential applications made 3 wk after the initial were more effective than delaying sequential applications until 4 wk after the initial application. Tifway bermudagrass injury from quinclorac applied at 4.5 kg/ha, or at 2.2 kg/ha followed by a sequential application of 1.1 or 2.2 kg/ha, was observed at 4 to 10 wk; however, turf recovered thereafter. Sequential applications of quinclorac plus imazaquin (1.1 + 0.6 kg/ha) increased torpedograss control (approximate 35%) as compared to quinclorac plus MSMA (1.1 + 1.1 kg/ha) but also decreased turf quality versus quinclorac applied alone or in combination with MSMA. Quinclorac applied at 2.2 kg/ha followed by 1.1 kg/ha applied 3 or 6 wk after the initial controlled torpedograss best with least reduction in bermudagrass quality. Quinclorac is the first herbicide reported to selectively control torpedograss in bermudagrass turf.

Influence of temperature levels and planting time on the sprouting of rhizome‐bud and biomass production of torpedograss (Panicum repens L.) in Okinawa island, southern Japan

“…It is one of the serious weeds characterized by its highly regenerative rhizomes, colonizing the crop fields and creating hazards to the farmers, causing great economic losses every year in the tropical and subtropical regions (Holm et al 1977; Peng 1984). Torpedograss is also a severe problem in golf courses in Florida, Texas, Hawaii, Europe, tropical Africa and tropical Asia (McCarty et al 1993; Hossain et al 1999). The weed produced approximately 3.2 kg m −2 of biomass within 1 year, which was caused by a severe competition with crops both above ground and underground in Okinawa, Japan (Hossain 1999).…”

Influence of Cultural Practices on Torpedograss Competition with Two Warm-Season Lawn Grasses

“…L.) and zoysiagrass ( Zoysia japonica Steud.) can be achieved using selective, post‐emergence herbicides such as quinclorac or trifloxysulfuron (1,3,20,21,24). However, no selective post‐emergence herbicides have been documented for the control of torpedograss in centipedegrass [ Eremochloa ophiuroides (Munro) Hack.]…”

“…L.) and zoysiagrass (Zoysia japonica Steud.) can be achieved using selective, post-emergence herbicides such as quinclorac or trifloxysulfuron (1, 3,20,21,24 Herbicides can be an effective means for reducing weed infestations; however, increasing turfgrass vigor through implementation of cultural practices is considered an important component of any comprehensive weed control program (6,27). In a review of cultural management in turfgrass, Busey (2003) concluded optimal mowing heights and fertility reduce weed colonization and promote grass monocultures.…”

Effect of standing water and shoot removal plus standing water regimes on growth, regrowth and biomass production of torpedograss (Panicum repens L.)

“…Approximately 3.2 kg m −2 of torpedograss biomass is produced in 1 year and this causes severe competition with the crops both above ground and underground (Hossain et al 1999a). This weed is a big problem in golf courses in Florida, Texas, Hawaii, southern Europe, Tropical Africa and Tropical Asia (McCarty et al 1993; Hossain et al 1999b). Torpedograss has been considered for use as pasture, and it may be used for soil erosion control (Holm et al 1977; Hossain 1999).…”