The following surfactants were prepared at various concentrations in distilled water, with and without 3% W/V technical or formulated 2,2-dichloropropionic acid (dalapon): anionic—Vatsol OT (sodium dioctylsulfosuccinate), sodium lauryl sulfate; nonionic—Dynawet (chemistry undisclosed), X-77 (alkylarylpolyoxyethylene glycols, free fatty acids and isopropanol), Tween 20 (polyoxyethylene sorbitan monolaurate), Tween 80 (polyoxyethylene sorbitan monooleate), T-1947 (polyoxyethylene polyoxypropylene polyols). Contact angles on paraffin coated plexiglas and corn leaf surfaces correlated well with surface tension measurements. With solutions having surface tensions of 31 dynes/cm or less, leaf wetting was complete. Although surfactants differed considerably in their influence on surface tension and wetting, all markedly enhanced herbicidal activity, increasingly with rate. The superiority of Vatsol OT as a surface tension reducer and wetting agent was confirmed. Vatsol OT alone was toxic to corn at 0.5% concentration and higher; T-1947 and sodium lauryl sulfate produced early injury symptoms at 5.0% but caused no lasting effect; all other surfactants were nontoxic at all concentrations used. Minimum surface tensions and contact angles occurred at 0.1–0.5% concentration for all surfactants. However, maximum herbicidal activity was observed at ten times these levels or greater. Thus above 0.1–0.5% surfactant concentration herbicidal enhancement was not correlated with surface tension lowering, contact angle, observed wettability or initial toxicity of the surfactants. This confirms the view that herbicide-surfactant-plant surface interactions, more specific than mere increased wetting, are a part of total surfactant action.