Surfactants Up to Table of Contents Ahead to 2. Surfactants Most adjuvants contain one or more chemical compounds known as surfactants.
Surfactants have the physical characteristics of both oil and water.
Surfactants, or surfac e- act ing agents, are a broad category of adjuvants that facilitate and enhance the absorbing, emulsifying, dispersing, spreading, sticking, wetting or penetrating properties of pesticides. Because of the high surface tension of water, spray mixture droplets can maintain their roundness and sit on the leaf hairs or waxy surface without much of the herbicide actually contacting the leaf. See figure 1. The pesticide mixture then becomes susceptible to degradation by sunlight or by gravity that can cause herbicide run-off from the leaf surface. Anionic surfactants are mostly used with acids or salts.