Differential Bahiagrass (Paspalum notatum) Cultivar Response to Atrazine

Abstract

‘Wilmington’ and ‘Pensacola’ cultivars of bahiagrass (Paspalum notatumFlügge) were found to exhibit a differential level of tolerance to certain triazine herbicides. Pensacola was more susceptible to postemergence treatments of atrazine [2 - chloro - 4 - (ethylamino) - 6 - (isopropylamino) -s- triazine], simazine [2 - chloro - 4,6 - bis (ethylamino) -s-triazine], and cyanazine {2 - [ [4 - chloro - 6 - (ethylamino) -s - triazin - 2 - yl] amino] - 2 - methylpropionitrile} than Wilmington. Injury to Pensacola was noted as early as 2 weeks after the application of 2.4 kg/ha atrazine and cyanazine, whereas similar injury to Wilmington was not observed until later than 4 weeks after the treatment date. Results of14C-atrazine treatments indicated that Wilmington bahiagrass accumulated approximately twice as much14C-atrazine: peptide conjugate as the Pensacola cultivar.