Eco-friendly polymer dispensers for controlled release of agrochemicals

Polymer matrices loaded with agrochemicals are used as controlled release dispensers in pest control. Release kinetics of gossyplure pheromone from polyvinyl chloride (PVC) dispensers for the control of the pink bollworm pest of cotton crop was studied. The dispenser formulation was altered by changing the concentration of the plasticiser, dimethyl phthalate (DMP) and fixing the concentration of gossyplure pheromone. A solvent trap system was designed and fabricated to collect the pheromone released from the dispenser at definite intervals of time. The amount of pheromone released was analysed for quantitative estimation using high performance liquid chromatography (HPLC). The dispensers were found to release gossyplure at a constant rate for a period beyond 30 days of exposure. The release rates were found to increase with increase in the concentration of the plasticizer. Field evaluations for number of insect catches per trap were performed to estimate the effectiveness of the dispensers. The dispensers functioned effectively In controlling the pest up to the full crop period i.e. more than 3 months.