The fungicidal properties of certain spray-fluids, X. Glyceride oils. (With two text-figures.)

Abstract

Summary1. The fungicidal action of vegetable oils on the conidial stage of the hop powdery mildew, Sphaerotheca Humuli (DC), Burr., is a property common to glyceride oils. When applied with 0·25 per cent. Agral I, the various samples of vegetable and animal oils examined, with the exception of castor oil, proved fungicidal at a concentration of 0·5–1·0 per cent.2. The fungicidal action of glyceride oils is associated with the glyceride structure and, in the presence of Agral I, is unaffected by the presence of those impurities of the oil which are removed by refinement.3. Glycerol, at 4 per cent., is not completely fungicidal and, under the conditions of the experiments, causes leaf injury; oleic acid, at 1 per cent. is phytocidal; triolein, prepared by synthesis from glycerol and oleic acid, is fungicidal at 0·5 per cent. and causes no injury to the leaves.4. The fungicidal properties of glyceride oils are affected by the type of emulsification used and the stable emulsions produced by the twosolution oleic acid method are less effective than the unstable emulsions obtained by agitation with dilute Agral I solutions.