Seletividade e eficiência de herbicidas em cereais de inverno

Abstract

An experiment was carried-out with the objective of evaluating the selectivity and efficacy of herbicides applied for weed control on winter cereals. The experiment was conducted under field conditions at the field station of Embrapa, in Passo Fundo, RS, during the 2005 growing season. The soil of the station is a loam Oxisol. The evaluated crops were wheat, barley, rye and triticale. Black oats, oats, turnipseed and vetch were sown in order to act as volunteer crops interfering with those crops. The tested herbicides were bentazon, metsulfuron-methyl, dichlofop-methyl clodinafop-propargyl, 2,4-D, 2,4-D + picloran, 2,4-D + glyphosate (as sequential application) and iodosulfuron-methyl. The pre-emergence treatments were applied in 23/06/2005, one day before sowing the crops. The post-emergence treatments were applied in 27/07/2005 at the 3-5 leave weed stage. The results indicated that the treatments were selective to wheat, triticale and rye while barley was the species more sensible to them especially to iodosulfuron-methyl. Black oats, oats, and ryegrass responded differently to the treatments according to the tested rate while turnipseed and vetch are efficiently controlled by iodosulfuron-methyl, 2,4-D and 2,4- D + picloram.