Spray Distribution Pattern of Different Sprayers on Cotton using Droplet Analyzer

The spraying performance of commercial sprayers viz. knapsack sprayer, power operated sprayer, self propelled sprayer, aero blast sprayer and air assisted sprayer were compared based on droplet size (NMD, VMD, UC), density of droplets and volume of spray deposition. Droplets were collected on glossy paper strips of 7.5 X 2.5 cm size from upper and lower portion of leaf at top, middle and bottom canopies of cotton plants and were analyzed using a droplet analyzer with ‘USB digital scale’ software. Spray deposition decreased from top portion to bottom portion of the plant for all types of sprayers. Uniformity coefficient (UC) was least for air assisted sprayer (1.8) which meant that air assisted sprayer gave the most uniform droplet size among the sprayers under study. Underside of the leaves of any plant canopy received relatively more number of drops when air-assistance was provided with the sprayer, but without air-assistance under side of leaves remained almost unsprayed.