On the Spraying Characteristics of Agrichemicals by a Sprinkler

Study on the spraying agrichemicals by a sprinkler system for citrus groves (I)

Abstract

To determine the adequate sprinkler system for spraying agrichemicals in citrus groves, the characteristics of the spraying droplet were investigated experimentally. The outline of this study is as follows.
The highest loci of the spraying droplet by the MI type sprinkler with a 27?? nozzle angle was 5-6 in above the ground's surface in case of riser height of 2 m. Therefore, the droplets, especially small ones were easily influenced by wind velocity. The adhesion of the chemical solution was less on the backside of the leaves because of the secondary splash on the leaves or branches was weaker by reason of the small, vertical and slow velocity of the droplets.
As a result of experimenting on the adhesion at different sections on the crown, a sufficient amount of adhesion was obtained at the leaves at the top or middle section of the crown, but it was inferior on the reverse side of the leaves, especially at the skirt or inside of the crown. It was clarified that the adhesion rate for the droplet sprayed with a sprinkler at an angle of 20°-30°was superior to that of 60°-90°.
A sprinkler which can be spray droplets having a diameter from 1.5 to 4.0 mm with a lower angle must be required for increasing the adhesion rate at the skirt and inside of the crown.
As only 15% of the sprayed agrichemical solution adheres to the crown, integrated and comprehensive investigations are required to improve the adhesion efficiency by considering the following factors such as the type and arrangement of the sprinkler, sprinkling method, and reformation of the tree shape.