Development and evaluation of tractor operated coconut tree sprayer

Abstract

A tractor-operated tall tree sprayer for coconut was developed. The unit consists of telescopic (60 mm and 37 mm) G.I. pipes which can extend from 8 m to 14 m high by winding a cable. The spray fluid from the chemical tank is sucked by the tractor PTO-driven high pressure pump and delivered to the spray guns through pressure relief and by pass valves. At the top of the 37 mm G.I. pipe, two spray guns are hinged so that they can be moved up and down by a rope operated from the ground level. Rotary and oscillatory movements of the spray guns, and up and down movement of the telescopic pipe enable one to reach the desired target in the canopy. The spray pattern could be adjusted to either jet or mist cone to suit the requirement. The best angle of inclination for maximum height of reach was optimized as 75° to horizontal when the height of reach was 6.92 meter from the tip of the nozzle. It was reduced to 5.10 m when two spray guns were used simultaneously. In one hour 35 coconut trees could be easily sprayed depending on the height of the tree and area of spread of the canopy. For easy transport, the unit is kept in a horizontal position. The same can be erected vertically by winding a cable. The sprayer can also be used for spraying tall orchard trees and field crops.