Division of Plant Protection, Faculty of Agriculture, Annamalai University, Tamil Nadu
In the event of controlled droplet application approach in ULV spray, the need for studying the effect of spray droplets of various sizes on spray deposit, insect mortality and resistance to removal by rain was felt, As a first step a simple equipment assembly to regulate the droplet size was constructed. Using this, the effect of particle size on the above criteria was studied. Results indicated that droplets of larger dia-mension would result in higher deposit which was susceptible for easy removal by rain. Mortality data on Spodoptera and Crocidolomia suggest that finer droplets were quicker to cause initial mortality and the total morality obtained was also more among finer droplets.
