SOD REGROWTH OF ST AUGUSTINEGRASS AFTER PREEMERGENCE HERBICIDE APPLICATION

St. Augustinegrass [Stenotaphrum secundatum (Walt.) Kuntze] sod produc tion involves stolen regeneration from strips left from the previous h arvest. Field studies were conducted to evaluate stolen regrowth and r ooting following preemergence application of herbicides. Herbicides ev aluated were atrazine hyl-N-(1-methylethyl)-1,3,5-triazine-2,4-diamine ], dithiopyr [S,S-dimethyl yl)-6-(trifluoromethyl)-3,5-pyridinecarboth ioate], isoxaben thylpropyl)-5-isoxazolyl]-2,6-dimethoxybenzamide], me tolachlor thylphenyl)-N-(2-methoxy-1-methylethyl)acetamide], oxadiazon 5-(1,1-dimethylethyl)-1,3,4-oxadiazol-2-(3H)-one], pendimethalin -eth ylpropyl)-3,4-dimethyl-2,6-dinitrobenzenamine] and the combination of metolachlor plus atrazine. Acceptable 'Floratam' St. Augustinegrass co lor was noted following all treatments. Twelve to 24% of the stolons w ere unrooted 4 to 8 mo after application following treatment with OS k g a.i. ha(-1) dithiopyr. Five to 22% of the stolons were unrooted 8 mo after treatment with isoxahen at 1.1 kg ha(-1) and pendimethalin at 2 .2 kg ha(-1). Data collected after 8 mo showed stolen rooting to be si milar to the untreated for all treatments. Turfgrass density was unaff ected or slightly improved (approximate to 25%) by herbicide treatment and was highest with oxadiazon, metolachlor, and metolachlor plus atr azine treatments. Neither turfgrass tensile strength nor root dry weig ht was reduced 14 mo after treatment with any of the herbicides evalua ted. Although shortterm (2 to 4 mo) negative effects followed dithiopy r, isoxaben, and pendimethalin treatments, long-term (greater than or equal to 8 mo) effects were transient.