The disclosure describes compositions and methods for improved delivery of plant growth regulators comprising contacting a plant with a composition comprising an effective amount of a plant growth regulator and an effective delivery enhancing amount of compound having the structural formula ##STR1## wherein R' is H or a lower alkyl group having 1-4 carbon atoms, m is 3-7, n is 0-17 and R is --CH.sub.3, ##STR2## where R" is H or halogen, with the proviso that if m is 3 and R is CH.sub.3, then n is 5-17.