&lt;p&gt;The control of pest can be achieved effectively if pesticides are properly applied at the correct rate, at right time and on the target by appropriate equipment. In field crops like cotton the pest attacks on the lower side of the leaves and mostly at the time of boll formation. The sprays with conventional sprayer do not enter at the bottom position of the plant canopy and on the upper and lower side of the leaves. In view of this a new air sleeve boom sprayer was designed, developed and its performance was evaluated both in the laboratory and the field. The principle of the working of the sprayer was totally based on the replacement of air within the canopy with spray laden air.&lt;br /&gt;
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A laboratory set up was developed and performance was evaluated on actual plant canopy of cotton crop at four experimental variables viz: air velocity (12,20 and 26 m/s), air sleeve angle (-15&amp;deg; ,0&amp;deg;, 15&amp;deg; and 30&amp;deg; ), nozzle angle (25&amp;deg;,35&amp;deg;and 45&amp;deg; ) and height of boom (50 cm and 70 cm). In the study the emphasis was given to determine the effective droplet density and droplet size for the control of pest. The deposition of droplet was taken at top, middle and bottom position of the plant and on upper and lower leaf surface.&lt;br /&gt;
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It was observed that the recommended value of droplet density and droplet size was obtained at air velocity of 26 m/s, air sleeve angle 30&amp;deg;, nozzle angle 35&amp;deg; and height of boom 70 cm. The deposition index was also calculated at these selected levels of variables.&lt;br /&gt;
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A prototype was developed for the field evaluation in the cotton crop. A hydraulic system was mounted on the prototype to facilitate the adjustment of height evaluation of air sleeve boom was conducted at optimum levels of the variables i.e. air velocity 26 m/s, air sleeve 30&amp;deg;, nozzle angle 35&amp;deg; and height of boom 70 cm obtained during laboratory experiment. The obtained droplet density and droplet size was found within the recommended range at top, middle and bottom position of the plant and on upper leaf surface as well as on the top position of the plant and lower leaf surface. The air velocity and air sleeve angle was observed more effective as compared to nozzle angle and height of boom. The value of regression coefficient indicated that the results of field experiment confirmed the results of laboratory experiment conducted to determine the effect of air velocity, air sleeve angle, nozzle angle and height of boom.&lt;/p&gt;
