Design, development and evaluation of a tractor mounted air blast sprayer for coconut and arecanut

A tractor mounted air blast sprayer was designed and developed to reduce the drudgery involved in the manual spraying of pesticide by climbing coconut tree. The sprayer mounted on a small tractor, prime mover, is operated by the power taken from its power take off (PTO). In this study, the influence of two important parameters viz., blower speed (2250 and 3000 rpm) and tractor speed (1.5 and 2.5 km h-1) at different heights on the spray characteristics such as volume mean diameter (VMD), droplet density, and spray deposition were collected and analysed. The tractor speed of 1.5 kmh-1 and blower speed of 3000 rpm was observed at recommended VMD between 100-200 & mu;m at a height above 21 m. Hence, the tractor speed of 1.5 kmh-1 and blower speed of 3000 rpm was selected for field evaluation. The mean height of the coconut tree in the tested field was 24 m. The mean droplet size and deposition were observed at 124 & mu;m and 7.2 & mu;l cm-2, respectively at 24 m height. The effective field capacity, field efficiency, and fuel consumption were 0.524 ha.h-1, 73.72%, and 4.67 l h-1, respectively.