DEPOSITION STUDIES OF A HAND-HELD AIR-ASSISTED ELECTROSTATIC SPRAYER

Laboratory experiments were carried out to determine spray distributio n pattern and deposition characteristics of an air-assisted, electrost atic, spinning disc sprayer at various conditions. Spray distribution patterns were obtained with the aid of a patternator. Fluorometric ana lysis quantified tracer deposit on different levels of the soybean pla nts. Parameters studied were disc rotational speed, liquid flow rate, fan speed, tilt angle between disc plane and air stream direction. Whe n electrode voltage was maintained at 2.5 kV the results indicated tha t the ratio of deposition density of air-assisted and non air-assisted application at top, middle, and bottom levels were 1.38, 1.37, and 1. 5 fold, respectively. Mean deposition on plant target increased 1.44 f old due to air assistance. The leaf underside deposition occupied 27% of the total deposition. It increased 7% over that of the electrostati c unit because of air assistance. The optimum tilt angle between disc plane and air stream direction was found to be 105 degrees.