Gan-Mor, S., Institute of Agricultural Engineering, Agricultural Research Organization, Volcani Center, P.O. Box 6, Bet Dagan 50250, Israel
Hetzroni, A., Institute of Agricultural Engineering, Agricultural Research Organization, Volcani Center, P.O. Box 6, Bet Dagan 50250, Israel
Elad, Y., Institute of Plant Protection, Israel
Ronen, B., Institute of Agricultural Engineering, Israel
Mizrach, A., Institute of Agricultural Engineering, Agricultural Research Organization, Volcani Center, P.O. Box 6, Bet Dagan 50250, Israel

A technology for on-site production of physical control agents was developed to facilitate economical manufacturing of pest-control emulsions using selected plant-based cooking oils as the base constituents; these oils are nontoxic to humans and not harmful to the environment. Cooking oil emulsions generally perform as physical control agents, they comply with the world trend toward minimal tolerance of toxic residues, not particularly in agricultural produce, and they are intended for immediate application. Emulsion stability was addressed mainly by reducing the oil droplet size. Reducing emulsion droplet size consumes energy; therefore, a compact, inexpensive, energy-efficient, continuous mechanical emulsifier was developed to enable on-site continuous emulsification. Cooking oils are generally inexpensive and easy to conserve, so on-site emulsion production is potentially inexpensive for growers. Energy consumption and droplet diameter of emulsions produced by this emulsifier were compared with emulsions produced by ultrasonic oscillator technology. Energy consumption of the mechanical system increased from 1.9 to 10.2 J mL -1 as rotational speed increased from 2000 to 5000 rpm and the average droplet diameter (D32) decreased from 7.5 to 4.1 μm, whereas the ultrasonic energy required to produce 1 mL of oil-in-water emulsion increased from approximately 10 to 50 J while average droplet diameter (D 32) decreased from approximately 6 to 2.6 μm. The ultrasonic system produced smaller droplet sizes but presently can only operate on batches in the laboratory. Energy consumption of the mechanical system was lower and since the droplet sizes were fine for the required storage duration and the system could operate continuously, it was favored for on-site operation. © 2012 American Society of Agricultural and Biological Engineers.