Influence of Surface Tension of Water on Droplet Size Produced by Flat Jet Nozzles

Abstract

The aim of the study was to check if the quality of water which was taken from different sources (used for plant protection treatments) influences the droplet size generated by agricultural nozzles. The experiment was done in the laboratory of the University of Life Sciences in Lublin (UP Lublin), and water from 3 different sources was used, demineralized water was used as reference water. There were two treatements of adjuvant (Superam 10AL): with and without adjuvant. The water quality was assessed on the basis of the change of surface tension. The surface tension was measured with a drop Shape Analizer DSA30 device. The Flat Fan, one of the agricultural nozzles widely used by farmers, was used in the study. The measurement was done with spraying pressure of the following values: 2 bar, 3 bar and 4 bar with three repetitions. The droplet size was measured with a laser diffractometer HELOS/R - Sympatec. The results show that using the adjuvant changed the surface tension for all the types of the water sources. However, this change was higher for the water from the farm well (source B) and the tap water from UP Lublin building (source C). This change in the surface tension alters in turn the drops size (Volume Median Diameter) depending on the average results of the spray patteren, but only when using 3-bar pressure.