The Effect of Different Soil Disturbance Methods and Weeds Control on Cotton (Gossypium hirsutum) Yield

To evaluate the effect of combined use of mechanical methods (different soil disturbance methods) and chemical weed control on cotton yield, a split plot experiment based on randomized complete block design was conducted at the city of Boshruyeh in 2012. Experiment factors were soil disturbance method as Main-plots with three levels, including conventional tillage, no-till system and conservation tillage; and different methods of weed control at 5 levels (the herbicide trifloxysulfuron sodium at 10, 15 and 20 g ha-1, as well as no weeding and hand hoeing) as sub-plots with four replications. The results showed that there were significant differences between the various methods of soil disturbance, so that the cotton yield, monopodial branch length, number of monopodial and sympodial branches, plant height and number of bolls in conservation and no-tillage systems were greater than conventional system. Application of 20 g ha-1 of trifloxysulfuron sodium led to the greatest value in all measured traits. The interaction effect of soil disturbance and weed control method was significant on the number and length of monopodial branches. The greatest number of monopodial branches were obtained from the conservation tillage (2.59) and hand weeding (2.31). The longest monopodial branches were observed in conservation tillage (15.79 cm) and hand weeding (15.23 cm) treatments.