Control of green and false-green kyllinga (Kyllinga brevifolia and Kyllinga gracillima) in golf course fairways and roughs

Herbicides commonly used to control Cyperus spp. are not completely effective against Kyllinga spp. Field trials were conducted on North Carolina golf courses to evaluate green and falsegreen kyllinga control at fairway and rough golf course mowing heights. Treatments included single and sequential applications of bentazon (1.12 kg ai/ha), halosulfuron (0.07 kg/ha), MSMA (2.24 kg/ ha), and trifloxysulfuron (0.03 kg/ha); imazaquin (0.56 kg/ha) with and without MSMA; and two rates of sulfentrazone (0.42 and 0.56 kg/ha). Green or false-green kyllinga control was equivalent at fairway and rough mowing heights. Halosulfuron applied sequentially, imazaquin with and without MSMA, and trifloxysulfuron applied singly or sequentially, controlled green and false-green kyllinga 89 to 99% 10 wk after initial treatment (WAIT). However, Kyllinga spp. control decreased over the course of the study regardless of herbicide treatment. By one year after treatment (YAIT), bentazon or MSMA alone controlled green or false-green kyllinga 50% or less. No difference was observed in green or false-green kyllinga control between imazaquin vs. imazaquin plus MSMA, sulfentrazone 0.42 vs. 0.56 kg/ha, or trifloxysulfuron one vs. two applications at any rating date. Green kyllinga was seemingly more difficult to control than false-green kyllinga. Sequential applications of bentazon and MSMA, single applications of halosulfuron, sulfentrazone applied at 0.42 and 0.56 kg/ha, and single and sequential applications of trifloxysulfuron controlled false-green kyllinga at least 10% greater than green kyllinga at I YAIT Further research is needed to assess the potential variation among Cyperus and Kyllinga spp. response to herbicides. Nomenclature: Bentazon, halosulfuron, imazaquin, monosodium methanearsonate (MSMA), sulfentrazone, trifloxysulfuron; bermudagrass, Cynodon spp.; false-green kyllinga, Kyllinga gracillima L.; green kyllinga, Kyllinga brevifolia Rottb. #(3) KYLBR. Additional index words: Mowing height, turfgrass management. Abbreviations: WAIT, weeks after initial treatment; YAIT, year after initial treatment.