Field Evaluation of Manual Spraying Technology against White Flies on Cotton Crop in South-West Punjab

With advancement of spray technology and sprayers used on farmer's field spray amount will vary significantly from each sprayer in terms of droplet size which ultimately determines its efficacy. Therefore, it is required to standardize and validate the efficient spray technology for enhancing the effectiveness of pesticides in cotton. Tractor operated gun sprayer is an un-recommended technology with non uniform spraying and VMD, NMD and UC were found to be 164.89 μm, 51.05 μ, 3.23 respectively. The droplets also didn't reach the upper lower side of the leaves where the white flies reside. The cost/h for electrostatic sprayer may be high but it improves the deposition efficiency and also the spatial distribution of deposited droplets throughout the plant canopy, particularly under leaf application where pests usually hide and reside thereby increasing the bio-efficacy. The droplet sizes i.e. VMD, NMD and UC for electrostatic sprayer were found to be 45.95 μm, 21.06 μm and 2.18 respectively. Battery operated knapsack sprayer is time consuming and tedious having VMD, NMD and UC of 176.12μm, 48.12μm and 3.66 respectively.