Evaluation the effect of different irrigation systems and weed control treatments on quantitative and qualitative yield of sugarcane (Saccharum officinarum) and weeds biomass

In order to investigate the effect of different irrigation systems and weed control treatments on quantitative and qualitative yield of sugarcane and weeds biomass, an experiment was conducted as split plot based on randomized complete block design (RCBD) with three replications in 2020 at Sugarcane Development Research and Training Institute of Khuzestan, Iran. The five irrigation systems included surface drip irrigation (I0), two types of subsurface drip irrigation with a discharge rate of 2.3 and 3.6 L/h and emitter spacing of 50 and 60 cm (I1 and I2 respectively), Low Energy Precision Application (LEPA) sprinkler irrigation (I3), and the conventional  furrow irrigation method (I4) as the main plot, and weed treatments included no weed control throughout the season, (W0), weed control throughout the season (W1), and use of cultivator (W2). The highest and lowest mean cane yield (167 and 117 ton/ha, respectively) and sugar yield (18.24, 12.40 ton/ha, respectively) were observed in I3 and I4 irrigations, respectively. Mean cane and sugar yield in W0 were significantly lower than W1 and W2 treatments (with a difference of 18.34% and 18.78% for cane yield and 17.84% and 18.85% for sugar yield, respectively). Qualitative traits including Brix, syrup sucrose percentage and syrup purity percentage were not affected by irrigation systems and weed control treatments. The total dry matter of weeds for I0, I1, I2, I3 and I4 Irrigation treatments were 90, 78, 47, 43 and 173 g/m2 under W0 treatment and 30, 23, 16, 15 and 40 g/m2 under W2 treatment, respectively. In the condition of the study area, results indicated that adoption of LEPA sprinkler or subsurface drip irrigation system together with the use of cultivator in the first ratoon leads to irrigation water saving and reduces weeds competition in sugarcane fields.