Abstract
Two-year field studies were conducted in young citrus groves at three locations in Florida using bromacil, diuron, norflurazon, oryzalin, oxyfluorfen, simazine, and thiazopyr preemergence herbicides to determine their effectiveness when used individually or in combinations. Herbicides were applied every 120 days with visual ratings taken at 30-day intervals during a 2-year period. Weed control ratings were highest for winter applications for all herbicides. Combinations which included norflurazon or bromacil provided the highest level of weed control. Chemical names used: Bromacil, 5-bromo-6- methyl-3-(1-methylpropyl)-2,4(1H,3H) pyrimidinedione; diuron, N-(3,4-dichlorophenyl)-N,N-dimethylurea; norflurazon, 4-chloro- 5-(methylamino)-2-(3-(trifluoromethyl)phenyl)-3(2H)-pyridazinone; oryzalin, 4-(dipropylamino)-3,5-dinitrobenzenesulfonaminde; oxyfluorfen, 2-chloro-1-(3-ethoxy-4-nitrophenoxy)-4- trifluoromethyl)benzene; simazine, 6-chloro-N,N'-diethyl-triazine- 1,3,5-triazine-2,4-diamine; thiazopyr, methyl 2-(difluoromethyl)- 5-(4,5-dihydro-2-thiazolyl)-4-(2-methylpropyl)-6-(trifluoromethyl)- 3-pyridinecarboxylate.
