A field experiment was conducted in Araras in 1979/80 with the purpose to study the effects of mixture of napropamide and simazine on the control of mono and dicotyledons weeds in two years old coffee trees. The experiment was in randomised blocks with nine treatments and four repplications. The treatments were the following: napropamide at 2.00 and 3.00 kg/ha; simazine at 0.50 and 0.75 kg/ha; and tank mixtures of 2.00 kg/ha of napropamide with 0.50 and 0.75 kg/ha of simazine; and 3.00 kg/ha of napropamide also with 0.50 and 0.75 kg/ha of simazine. A treatment without herbicide was also included in the experiment. A weed count was done 45 days after the aplication of the herbicides, and every 15 days until the 90th day, visual observations were done to detect the percentage of weed infestations. At that time it was also done on the fitotoxicity symptoms caused by herbicides on the coffee trees. The most frequent weeds present in the trial were, Digitaria horizontalis Willd. Eleusine indica (L .) Gaertn, Amaranthus viridis L. and Bidens pilosa L. As it was expected, the mixtures were much more effective than those alone. The mixtures were rather effective in the control of mono and dycotyledons which were present in the experiment. Al treatments with 0.75 kg/ha of simazine presented light symptoms of fitotoxicity, limited to some leaves of the coffee trees, till last observation.
Napropamide - simazine; mono + dicotyledons; new coffee trees