Relative Wax Solubility And Phytotoxicity of Oil to Green Foxtail [Setaria Viridis (L.) Beauv.]

Experiments were conducted to determine the relative wax solubility and phytotoxicity of various oils as influenced by emulsifier. Alkane-esterified fatty acids from vegetable oil were more soluble than once-refined vegetable oil or petroleum oil in green foxtail epicuticular leaf wax. Emulsifiers varied in their influence on an oil’s solubility in the epicuticular wax. Green foxtail leaf-cell membrane permeability, as determined by electrolyte leakage from leaf disks, was increased by treating the leaves with methyl-esterified fatty acids of vegetable oil, but not by once-refined vegetable oil. Electrolyte leakage was increased by linseed oil fatty acid ethyl or butyl esters, but not by cottonseed or sunflower oil fatty acid ethyl or butyl esters. Emulsifiers with oils varied in their enhancement of electrolyte leakage from green foxtail leaves compared to oils alone. Green foxtail injury from oils correlated positively with electrolyte leakage from leaf disks, but did not correlate with relative wax solubility.