Diol esters—A family of potential plant growth regulators

Abstract

Rice bran wax was found to contain 1, 3-propane diol mono- and diesters of palmitic, stearic, oleic and linolenic acids. The unsaturated esters (especially diesters) are found to be eminently active in the biological growth of rice and wheat seedlings in laboratory tests and under field conditions. They are able to induce appreciable increase in root length, fresh and dry weight, chlorophyll content and rate of photosynthesis in seedlings/plants and also yield of rice grains in the field. An extract of alfalfa revealed the presence of another family of diol esters, namely, 2-methyl 1, 4-butane diol esters of unsaturated acids which are at least as good as the 1, 3-propane diol esters in the plant growth regulating activities. Therefore, the plant growth regulating effect of alfalfa extract attributed to triacontanol could be due to the presence of diol esters as well. The natural occurrence of hitherto unreported diol esters and more importantly their plant growth regulating activities are now described.