Published online by Cambridge University Press: 12 June 2017
Oxadiazon [2-tert-butyl-4(2,4-dichloro-5-isopropoxyphenyl)-Δ2-1,3,4-oxadiazolin-5-one] applied to bermudagrasses [Cynodon dactylon (L.) Pers.] at 4.5 kg ai/ha/yr in September reduced turf quality more than when treatments were applied anytime from April through August. The quality of ‘Tifway’ was reduced more than ‘Tifgreen’, ‘Tifdwarf’, or ‘Ormond’, and Ormond was reduced less than the other cultivars 3 weeks following oxadiazon treatment. Turf cover at the end of the growing season was not reduced with annual oxadiazon application at 4.5 kg/ha, whereas the cover was less in all plots treated with 13.5 kg/ha after four and five annual treatments. When compared with respective untreated cultivars, the cover of Tifway was reduced more from 13.5 kg/ha rate of oxadiazon than the other cultivars. Bermudagrass growth was retarded in the spring following oxadiazon applied the previous year.