Abstract
Foliar wettability of rice plants for aqueous solutions of nonionic surfactants was studied and compared with that of cabbage and soybean plants. Rice leaves were found highly water-repellent having large contact angles over 130° and their wettability was affected by the addition of surfactants most among all the plants examined. The effectiveness of surfactants in enhancing retention of dye solutions in leaves was related to their effectiveness in decreasing surface tension. The surfactants gave the highest retention at their optimum concentrations, which appeared to correspond to their critical micelle concentrations; POE lauryl ether at 0.01%, POE nonylphenyl ether at 0.1% and POE sorbitan monolaurate at 0.5 to 1.0%w/v. It is therefore suggested that rice plants belong to the species with lower wettability and that they need wetting agents to improve foliar wettability.
