Bearded Sprangletop Control in Turfgrass Sod Production

Abstract

Bearded sprangletop [Leptochloa fascicularis (Lam.) Gray] is a problem in turfgrass sod production because it is hard to control with commonly used turfgrass herbicides and can easily contaminate a sod production field, making the turf undesirable for sale to homeowners for use in lawn establishment. Studies were conducted from 2004 to 2007 along the upper Texas Gulf Coast turfgrass sod production areas to determine the most effective postemergence herbicides for control of bearded sprangletop. In one 2‐year study, bearded sprangletop control with fenoxaprop applied once and MSMA at 3.3 kg/ha applied twice, 7 to 10 days apart, varied from 17 to 77 % and 43 to 78%, respectively. Zoysiagrass (Zoysia japonica Steud.) turf injury was greatest with ethofumesate (12 to 50%). Fenoxaprop, MSMA plus trifloxysulfuron, and two applications of MSMA injured zoysiagrass at least 15% in one year but caused 4% or less injury in another year. In another two‐year study, nicosulfuron alone at 0.07 kg/ha controlled bearded sprangletop at least 97% while fenoxaprop alone controlled bearded sprangletop 98% in one year but did not control sprangletop the following year. A combination of nicosulfuron plus fenoxaprop plus MSMA controlled bearded sprangletop at least 96% in one year but controlled only 67% the next. Zoysiagrass (Bouteloua dactyloides Nutt.) injury was greatest with ethofumesate (50%) while fenoxaprop injury was 22%. All other herbicides caused 7% or less zoysiagrass injury. Buffalograss injury was greater than 60% with ethofumesate and nicosulfuron plus fenoxaprop plus MSMA while injury was 20% with MSMA and nicosulfuron. In conclusion, nicosulfuron alone at 0.07 kg/ha provided the most consistent control of bearded sprangletop in turfgrass sod production and caused no injury to zoysiagrass and 20% injury to buffalograss.

Nicosulfuron Absorption, Translocation, and Metabolism in Annual Bluegrass and Four Turfgrass Species

“…Bermudagrass and zoysiagrass appeared tolerant to labeled rates of nicosulfuron (35 to 70 g ha 21 ) in corn, pastures, and hayfields. Similar tolerance levels of these species have been previously reported (Grichar 2011;McElroy 2009), but injury of cool-season turfgrasses has received limited attention. Tall fescue had intermediate tolerance to nicosulfuron over the 4-wk period, and was less susceptible to shoot mass reduction than creeping bentgrass.…”

“…Recently, researchers have evaluated efficacy of nicosulfuron for POST weed control in warm and cool-season turfgrasses. Grichar (2011) noted that sequential nicosulfuron application at 70 g ha 21 provided 97% control of bearded sprangletop [Leptochloa fascicularis (Lam.) Gray] with no injury to 'Empire' zoysiagrass.…”