Efficiency of alachlor/diuron mixture on weed control in irrigated cotton

Abstract

In order to investigate the efficiency of alachlor/diuron doses (tank mixture) against weeds and their effect on irrigated annual cotton a field trial was placed in Pombal, PB, Brazil, in 1990. The alachlor/diuron doses (expressed in kg/ha of active ingredient) were: (0,6 + 1,0), (1,2 + 1,0), (1,8 + 1,0), (1,2 + 1,8), (1,2 + 1,2), (0,6 + 1,2) all in pre-emergence, control with cultivation and control without cultivation. The experiment was set out in a randomized complete block with five replications. The results showed that: 1) the herbicide mixtures were selective to cotton plants and effective on controlling weeds for a period superior to 60 days after emerging, 2) the herbicide treatments did not affect consistently phenological cotton plant characteristics. The component production and intrinsic fiber characteristics and 3) the highest mean value of "number of bolls" and yield were obtained by the alachlor/diuron dose (1,2 + 1,2) which did not differ from the others treatments except for the lowest dose (0,6 + 1,0) and control without cultivation.