author(s)
Fouzia Bari, Malik Mukhtar Ahmad, Asma Sherwani and Ashraf Alam Wani

abstract
Droplet size is the diameter of an individual spray droplet. Nozzles are specially designed to make the liquid into fine droplets. The present experiment entitled “Determining the influence of nozzle on droplet spectrum and pesticide deposition in cabbage against Pieris brassicae (Linn.)” was undertaken at RCRQA (Research centre for residue and quality analysis) Laboratory of the Division of Entomology, Shalimar during the year 2014-15. In this experiment effectiveness of different sizes of droplets produced by hollow cone nozzle and full cone nozzle in controlling cabbage butterfly was evaluated keeping in view the pesticide deposition and droplet spectrum of insecticides produced by nozzles. Persistent toxicity, relative residual toxicity, LC_50, LT₅₀ value and order of relative efficacy of three insecticides namely Dichlorvos 76 EC, Malathion 50 EC and Quinalphos 25 EC at three different concentrations were calculated and compared. It was found that Volume Median Diameter produced by hollow cone nozzle was smaller than the full cone nozzle. Hollow cone nozzle produced uniform spectra of droplets as is evident from the relative span and ratio between VMD and NMD of 1.38 and 1.25 as compared to full cone 1.47 and 1.60. Among all the treatment best result was observed in hollow cone nozzle.