New chemigation droplet generator for foliar pesticide application

A new droplet generation system for chemigation of foliar pesticides removes water from the irrigation pipeline, increases water pressure with a pump, injects oil-pesticide into the water stream, increases dispersion velocity in small tubes with high velocity in order to break up oil-pesticide droplets, and finally injects the water-oil dispersion back into the irrigation pipeline. Droplet breakup research was reviewed, and a model was developed to predict oil-pesticide maximum droplet size. Two equations were required: one for droplets in the inertial subrange scale, and one for droplets at the large eddy scale. The model was evaluated against 5 data sets in the literature and compared to 3 existing models. For the new model, maximum relative error and average root mean square deviation for maximum droplet size were 40- and 17-%, respectively.