Abstract

                                An experimental pulsed spray device was developed and studies were conducted on targeted spraying and spray application rate. The discharge of carrier fluid and chemical were measured at different set of pressures by using two types of hollow cone nozzles viz BAN nozzle and NMD hollow cone nozzle. Carrier fluid pressure was maintained from 0.05 to 0.2 MPa and the chemical tank pressure was varied from 0.05 to 0.3 MPa. The important characteristics of pulsed spray system were evaluated at different pressures and it was found that, at pressure 1 MPa the VMD was medium spray and at pressure 0.15 to 0.4 MPa VMD was fine spray. It is noticed that the applied volume per unit area is uniform when the pressure is within 0.15 to 0.4 MPa. The results showed that the quantity of chemical applied per pulse varied between 0.4 to 1.2 ml per pulse for different operating pressures and target widths. From the prediction equation, the quantity of chemical applied over the plant was calculated as 2.6 ml when the area of the plant is 78 cm2 . Hence the application rate of chemical was estimated as 0.33 ml/cm 2.

Key words : Spot application; Pulsed spray, Discharge rate.