Optimization of herbicide dose for post-emergence weed control in sugarcane plantation using magnetic spraying

Abstract

Experiments were conducted to appraise the combination of magnetic spraying and herbicide reduced rate for optimizing weed control in sugarcane. The herbicides, 2,4-D (diamine salt) plus Gesapax combi (ametryn + atrazine) were applied post-emergence using a magnetic sprayer at the recommended rates, along with rates 90%, 80%, 70%, 60% and 50% of the recommended rates. These treatments were compared with applications using a knapsack sprayer and a knapsack sprayer with a boom and assessed at 10, 20, 30 and 40 days after spraying (DAS). Four parameter log-logistic models were used to develop dose-response curves and the dose required to obtain 70% and 90% weed control (ED70 and ED90 ). The treatments significantly reduced the weed density at all assessment periods in comparison to that of the weedy check. The ED70 and ED90 values were significantly different between weed types and experimental sites. There was no significant phytotoxic effect on sugarcane due to any rate of herbicide and method of application. In conclusion, the magnetic sprayer could effectively control broadleaf weeds and grasses up to 30 DAS in sugarcane when the dose was reduced by 30% without compromising herbicide efficacy and weed control.