ANTITRANSPIRANTS RESEARCH AND ITS POSSIBLE APPLICATION IN HYDROLOGY

Research on antitranspirants may have application in increasing the yield of water from watersheds by reducing transpirational losses from vegetation under certain environmental conditions. There are three broad groups of antitranspirants: (1) reflecting materials that decrease the heat load on the leaf. (2) film‐forming materials that hinder the escape of water vapor from the leaf, and (3) stomata‐closing materials that increase stomatal resistance. Antitranspirants are most effective in decreasing transpiration when other resistances in the passage of water to the roots, through the plant, and to the atmosphere are not great, when there is good coverage of the stomatal bearing leaf surfaces (except for reflecting materials), when new foliar growth following treatment is minimal, and when optimum concentrations and application rates are used. Copyright 1969 by the American Geophysical Union.