Application of Air Jets with a Vortex to Improve Penetration of Air-Borne Insecticide Sprays into Dense Foliage of Citrus Trees

摘要

Air blast sprayers are widely used for the application of insecticides to deciduous fruit trees. In citrus plantations, with their dense foliage, penetration of the spray and good coverage of both sides of the leaves is difficult to obtain. Attempts have been made to improve penetration of the air blast by rotating or oscillating the air outlets. These attempts to stir the foliage by mechanically moving the air outlets have been only partly successful, because they entail a further loss of air speed from outlet to target. It was considered that a swirling air jet issuing from a stationary 'swirl generator' would improve penetration, without having the drawbacks of these mechanical methods. In order to obtain the information required for further experimentation and developmental studies, the basic properties of such a swirling air jet were investigated. (Author)