Abstract: Provided are compositions and methods of improving a plant growth factor. The compositions and methods contain combinations of plant growth regulators such as plant growth retardants and inhibitors of ethylene biosynthesis or action. The ethylene inhibitors comprise substituted oxime-ethers having the general formula: ##STR1## where R1 and R2 independently of one another are C1-C6-alkyl, n is 2 or 3 and R3 is hydrogen or C1-C6-alkyl. Specific inhibitors of ethylene biosynthesis or action include: {?(isopropylidene)-amino!oxy}-acetic acid-2-(methoxy)-2-oxoethyl ester, {?(isopropylidene)-amino!oxy}-acetic acid-2-(hexyloxy)-2-oxoethyl ester, {{cyclohexylidene)-amino!oxy}-acetic acid-2-(isopropyloxy)-2-oxyethyl ester (methoxy)-2-oxoethyl ester, ?((isopropylidene)-amino!oxy acetic acid, aminooxyacetic acid, aminoethoxyvinylglycine, rhizobitoxine, silver ions (e.g. silver thiosulfate), and 2,5-norbornadiene.

Abstract: Provided herein is a plant growth regulator formulation comprising a plant growth regulator dispersed in polyvinyl alcohol ("PVA") particles having a mean diameter greater than 1 micron. The present invention also includes an emulsion containing an aqueous dispersion of PVA encapsulated plant growth regulator particles wherein said particles have a mean diameter greater than 1 micron. The above formulations are useful in methods of improving a plant growth factor in a plant.