Performance of different nozzles for tractor mounted sprayers

A spray patternator was fabricated for the selection of a suitable nozzle, its height above the plant canopy and spacing between the nozzles for a tractor mounted sprayer to have uniform distribution of pesticide on the cotton crop. Experiments were conducted with three nozzles i.e. Triple Action Nozzle (TAN), Bi-Action Nozzle (BAN) and Hollow Cone Nozzle (HCN) at four different pressures of 2.5, 3.0, 3.5 and 4.0 kg/cm², three spray heights of 40, 50 and 60 cm, and spacing of 40, 45 and 50 cm between nozzles. It was found that with the increase in pressure from 2.5 to 4.0 kg/cm², maximum swath, spray angle and discharge rate increased for all the three types of nozzles. At all working pressures, the triple action nozzle covered larger width but discharge was more than that required for cotton crop. The average discharge rate for Bi-Action Nozzle varied from 369.4 to 477.3 ml/min and swath width increased from 78 to 87cm with the increase in pressure from 2.5 to 4.0 kg/cm². The minimum coefficient of variation in spray distribution was obtained at a working pressure of 3.5 kg/cm². For Hollow Cone Nozzle the swath width was smaller as compared to triple action and bi-action nozzles and the average discharge rate increased from 474.5 to 606.2 ml/min as the working pressure increased from 2.5 to 4.0 kg/cm². At the pressure of 3.5 kg/cm², the nozzle heights of 40 and 50 cm gave better coefficient of variations as 60.56 and 61.76 per cent, respectively. The swath width was more at nozzle height of 50 cm than that of 40 cm. Similarly, the nozzle spacing of 45 cm gave better Coefficient of Variation (10.18%) as compared to other spacing.