Effects of Herbicides on Bermudagrass (Cynodonspp.) Sprig Establishment

Abstract

Bermudagrass [Cynodon dactylon(L.) Pers. ♯ CYNDA ‘Vamont’, ‘Midiron’, andCynodon dactylonXCynodon transvaalensisBurlt-Davy ♯ CYNTR ‘Tifway’] cultivars were tolerant to oxadiazon [2-tert-butyl-4(2,4-dichloro-5-isopropoxyphenyl)-Δ2-1, 3,4-oxadiazolin-5-one] applied at rates up to 4.5 kg ai/ha during sprig establishment. The rate of shoot growth from sprigs after oxadiazon treatment was excellent and provided adequate ground cover within 3 months. Oxadiazon applications adversely affected root development of the Midiron cultivar as measured by the force required to uproot the sod. Root development of Vamont and Tifway after oxadiazon application was equal to that of untreated bermudagrass. Oxadiazon plus bensulide [O,O-diisopropyl phosphorodithioateS-ester withN-(2-mercaptoethyl)benzenesulfonamide] was inhibitory to both root and shoot growth of all cultivars. Metribuzin [4-amino-6-tert-butyl-3-(methylthio)-as-triazin-5(4H)-one] applications at 3 and 5 weeks after sprigging caused severe root injury to Vamont and Midiron bermudagrass.