Abstract

A tractor operated target actuated sprayer was developed and evaluated to reduce the off target application of chemical and thereby reduce soil and environmental pollution. From the observations, it is concluded that educator model IV was found to be the best connector with mixing chamber for the chemical and carrier liquid. The range of pressures adopted for chemical and carrier liquid produced droplets with volume median diameter (VMD) and numeric median diameter (NMD) ranging between 101 and 200 µ and VMD/NMD ratio of 1.09 and 1.29 which is classified as fine spray. The analysis of variance for optimum amount of chemical delivered as influenced by concentration of chemical, width of simulation plate, height of sensor above the plant canopy and forward speed of operation indicated that the selected variables and their interactions significantly affected the amount of chemical delivered. The mean comparison tests indicated that the minimum amount of chemical delivered (499 µl) was achieved at a chemical concentration of 25%, 100 mm width of simulation plate, 3.5 km h^-1 forward speed and sensor height of 300 mm above the plant canopy.

Key words: Off target spraying, target actuated sprayer, spray droplet size, spray deposition.