Cytokinin is a group of plant regulators that promote cell division, leaf expansion and retard leaf aging.
Cytokinin biostimulants are applied to growing crops (field crops, vegetable crops, small fruits, vines and tree fruit), young trees, ornamentals, and golf courses to increase fruit size, yield, blossoms, branching, healthy appearance, and other desirable growth effects.
Cytokinin is comprised of four naturally occurring cytokinins derived from aqueous extract of seaweed meal -- zeatin [6-(4-hydroxy-3-methylbut-trans- 2-enylamino)-purine], N -methylaminopurine, N -dimethylaminopurine, and 6 6 N -isopentenylaminopurine -- and synthetic cytokinin -- kinetin [6- 6 (furfurylamino)purine].
Cytokinins (i.e. naturally occurring) in aqueous extracts of seaweed meal, are derived from the following algae: Laminaria digitata, Laminaria hyperborea, Fucus serratus and Ascophyllum nodosum. Several, if not all of these species of algal species are consumed by man and/or livestock. The extracts from these plant species (e.g. the naturally occurring Cytokinins) are exempt from the requirements of tolerances when used as plant regulators in or on many raw agricultural commodities (40 CFR 180.1042).