THE EFFECTS OF SURFACTANTS ON ADHESION SPREADING AND RETENTION OF HERBICIDE DROPLET ON THE SURFACE OF THE LEAVES AND SEEDS

Abstract

Droplet adhesion, spreading, and retention on leaf and seed surfaces are studied in the presence of surfactants for successful formulation of a herbicide whereby efficient coverage, less wastage, and environment protection are achieved. Cationic, anionic, and nonionic surfactants, e.g., HTAB, SDBS, and tergitol, were added to water and the static contact angle of water droplet was measured on cauliflower, cabbage, spinach leaves, French bean, wheat, and Bengal gram seeds. Droplet adhesion, spreading, and retention were analysed in terms of static contact angle and physical properties of the system. The presence of a small quantity (0.1 wt.%) of tergitol in water increased the adhesion, spreading, and retention of droplet on all leaf and seed surfaces tested. Tergitol, a nonionic surfactant, is likely to be adsorbed more than the ionic surfactants HTAB and SDBS at the water/leaf (or seed)/air interface since plant leaves and seeds are nonionic in nature. The addition of 0.1% wt. of tergitol to a common herbicide, derosal, increases the adhesion, spreading, and retention of derosal on leaf and seed surfaces, consequently, efficient coverage and minimum wastage are attained.

Keywords:

• Herbicide
• Surfactants
• Droplet adhesion
• Spreading
• Retention

ACKNOWLEDGMENTS

Authors acknowledge Dr. S. P. Sinha of IARI, Karnal center for discussion and supplying the sample material for experiments.