Effects of Herbicides on Bermudagrass (Cynodon spp.) Sprig Establishment

Bermudagrass [Cynodon dactylon (L.) Pers. ♯ CYNDA ‘Vamont’, ‘Midiron’, and Cynodon dactylon X Cynodon transvaalensis Burlt-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 phosphorodithioate S-ester with N-(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.