Abstract

Effective pest control can be achieved, if pesticides are properly applied at correct rate, at right time and on the target by appropriate equipment. The spray with conventional sprayer does not reach the bottom of the plant canopy and also the upper and lower side of leaves in required quantity. In view of this a new air sleeve boom sprayer was designed, developed and its performance was evaluated in the laboratory and field trials. The working principle of the sprayer was totally based on the replacement of air within the canopy with spray laden air. A laboratory set up was developed and tested on actual plant canopy of cotton crop at four experimental variables viz, air velocity (12, 20 and 26 m/s), air sleeve angle (-150, 00, 150 and 300), nozzle angle (250, 350 and 450) and height of boom (50 cm and 70 cm). In the study, special emphasis was given to determine the effective droplet density and droplet size for the control of pests. The deposition of droplet was made at top, middle and bottom position of the plant and on upper and lower leaf surfaces. The results indicated that the recommended levels of droplet density and size were obtained at an air velocity of 26 m/s, air sleeve angle 300, nozzle angle 350 and height of boom 70 cm during lab experiment. The deposition indices during field trials were also calculated at these selected levels of variables. The value of regression coefficient was calculated in laboratory experiments to determine the effect of air velocity, air sleeve angle, nozzle angle and height of boom and to confirm field experiments.

Keywords: Deposition Index, Droplet density, Droplet size, Sleeve boom.