عنوان مقاله [English]
Background and objectives
Weeds are one of the most important factors reducing sugarcane yield in Khuzestan province. Sugarcane has a vegetative stage susceptible to weed competition, which is about 3 to 6 weeks from the time of planting in a warm and humid season. Therefore, the control of weeds in the early part of the growing season before the canopy closure of sugarcane and covering more than half the rows of planting is very critical. In order to investigate the effect of combination of mechanized weeding and application of three herbicides including indaziflam, 2,4-D+MCPA+metribuzin, on weed control and sugarcane yield, a field experiment was conducted in ratoon2 field in 2017-2018 growing season in Sugarcane Plantation and Industry Company Dehkhoda, Khuzestan, Iran.
Materials and Methods
The experimental design was split plot based on randomized complete block design with three replications. Mechanical weeding at three levels (sweep cultivator, rotavator, and no cultivation) was considered as main plots. Herbicide application was considered as sub plots at three levels [indaziflam (50 ml ai ha-1), 2,4-D+MCPA+metribuzin (675 ml ai ha-1+1050 g ai ha-1) and no herbicide application (as weedy control)]. A weed free check was included for comparison. Herbicide applications were made using backpack sprayer with TeeJet 11004 flat fan nozzle calibrated to deliver 250 L ha-1 at pressure of 2.5 atm. Sugarcane cultivar was CP-614. Weed sampling was carried out 60 days after treatment. Single stem weight, cane yield, final sugar yield, brix, pol, sugar purity and recoverable sugar were measured at the end of growing season and after sugarcane harvest.
The results showed that mechanical weeding treatments leading to reduction weed dry weight. So that, weed control was more effective in rotavator treatment than cultivator. Maximum reduction weed dry weight (52.47%) was seen in integrated rotavator and indaziflam treatment. The results of the quantitative traits of sugarcane showed that using mechanized weeding and herbicide application, caused to increase weight of single stem and yield of cane compared to the control. The greatest single stem weight was observed in cultivator treatment plus 2,4-D+MCPA+metribuzin (1.65 Kg m-2), rotavator+2,4-D+MCPA+metribuzin (1.63 Kg m-2) and indaziflam (1.61 Kg m-2). The final sugar yield (9.79 t ha-1) in indaziflam treatment was greater than other treatments (exception of weed free treatment). However, the measured values of Brix, pol, sugar purity and recoverable sugar did not differ significantly between among treatments.
Results showed that the use of mechanized weeding combined with herbicide applications would have an effective role in improving sugarcane yield and inhibition of sugarcane weeds.