Effect of Operating Parameters on Performance of Target Actuated Sprayer

Chemical pesticides have played and will continue to play a major role in the rapid advancement of agricultural production. In crop spraying, off target application resulting in air and soil pollution has to be reduced. Hence an attempt has been made to develop a target actuated sprayer to reduce the off target application of chemical and thereby soil and environmental pollution. The different parameters taken for this study are concentration of the spray, width of plant canopy, height of the sensor from the canopy and forward speed of operations. Optimization test were also conducted by using different connectors namely 'T' joint, 'Y' joint, non-return valves and with four models of eductors. From the observations, it is concluded that eductor 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 VMD and NMD ranging between 101 to 200 mu and VMD/NMD ratio of 1.09 to 1.29 which is classified as fine spray. The amount of chemical delivered decreased with the increase in forward speed and height of sensor and with decrease in chemical concentration while it increased with increase in simulation plate width. 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 ill) was achieved at a chemical concentration of 25 percent, 100 mm width of simulation plate, 3.5 km h(-1) forward speed and sensor height of 300 mm above the plant canopy. A prediction model on the amount of chemical delivered was developed based on multiple linear regression analysis (q = -707.1769461 + 70.08855205C + 16.13430133W - 809.1538611S). The analysis of variance of lag time indicated that the selected variables and their interactions significantly affected the amount of chemical delivered at one percent level. The minimum lag time of 1 ms was observed for the combination of 100 mm width of simulation plate forward speed of 3.5 km h(-1) and sensor height of 300 mm above the plant canopy.