Disposition and Dissipation of Droplets Applied Aerially Using Penetrator®

Deposition of low-volume sprays into a cotton canopy can be improved by adding Penetrator® (West Helena, AK). A spray volume of 9.34 1/ha with Penetrator at 0.59 1/ha gave an increase of about 64% over water alone. Changing the spray volume to 28.07 1/ha gave the largest increase, and a comparable increase was seen when Penetrator was added at this spray volume. Penetrator rates as low as 0.30 1/ha in a spray volume of 9.34 1/ha increased the area of coverage by approximately 37%. Dissipation of droplets from an altitude of 6.1 m showed a straight-line relationship with water alone. When Penetrator was added at 0.59 1/ha in a spray volume of 18.7 1/ha, the rate of droplet dissipation was less than for water alone. Correlation coefficients of height by droplet density or height by area covered for Penetrator were 0.59 and 0.44, respectively. Compared to water alone at nearly the same conditions, the correlation coefficients were 0.89 and 0.83, respectively. Thus, Penetrator may aid in protecting the droplets from evaporation.