The Reversal of Some Effects of a Surfactant on Pesticide Deposits on Foliage by Different Methods of Application

Extract

The influence of surface active agents (surfactants) such as “wetters”, “spreaders” and “stickers” on the deposition of pesticides on foliage is not always readily predictable. The results are influenced by the physical state of the pesticide (solution, emulsion, suspension), its chemical properties, the concentration of borh pesticide and surfactant, the nature of the plant surface, and the mode of application. Kearns (1) has particularly emphasized that the plant surface must be considered when a formulation of a pesticide is produced, and that there can he no general prescription satisfactory for a wide range of crops. For instance, a fungicide formulation that was excellent for banana, the leaves of which are difficult to wet, produced poor results on coffee, a crop relatively easy to treat. Our results now show that opposing results may also be obtained with the same pesticide, same surfactant and same crop, when two different methods of application are used.