Electrostatic Charging of Aerial Spray Over Cotton

Abstract

Electrostatically charged aerial spray studies were carried out over cotton fields. The study was planned and structured to obtain needed engineering information regarding the role and domain of applicability of this technology/methodology for aerial application. Spray deposition measured directly and separately from the top and bottom surface of cotton leaves was used to quantitatively evaluate three charging protocols: (1) bipolar, (2) alternating polarity, and (3) no-charge. The bipolar spray charging protocol gave significantly higher deposits on the cotton leaves than the no-charge or alternating polarity protocol. Mean deposit levels were 4.3 times higher with bipolar charged spray (Q/M = 2.64 mC/kg) compared to no-charge spray (Q/M = 0 mC/kg). Bipolar charging also showed a 3.0-fold increase in deposit over the alternating polarity protocol (Q/M = 2.64 mC/kg @ 0.29 Hz). Bipolar charging was also demonstrated to be effective in increasing plant canopy penetration and exhibiting a leaf wrap-around effect.