Abstract: An expeditious synthesis of gibberellin A5 (GA5) esters is presented, from which GA5 may be prepared. The synthesis offers an inexpensive route of few steps to these compounds, starting from gibberellin A3 (GA3) esters in the presence of a metal hydride.

Abstract: An expeditious synthesis of gibberellin A5 (GA5) esters is presented, from which GA5 may be prepared. The synthesis offers an inexpensive route of few steps to these compounds, starting from gibberellin A3 (GA3) esters in the presence of a metal hydride.

Abstract: Non steroidal mimetics or analogues of brassinosteroids such as brassinolide include two bicyclic subunits each having a vicinal diol group and a polar unit and linked by a linking moiety such that the vicinal diol groups and polar unit are closely superimposable on corresponding functional groups in the brassinosteroid.

Abstract: Non steroidal mimetics or analogues of brassinosteroids such as brassinolide include two bicyclic subunits each having a vicinal diol group and a polar unit and linked by a linking moiety such that the vicinal diol groups and polar unit are closely superimposable on corresponding functional groups in the brassinosteroid.

Abstract: Disclosed are compositions and methods for promoting plant growth. The compounds are cyclopropyl-, cyclobutyl-, and cyclopentyl-substituted brassinosteroids having high growth promoting ability. They may be used alone or in combination with other plant growth regulating agents.

Abstract: Disclosed are compositions and methods for promoting plant growth. The compounds are cyclopropyl- and cyclobutyl-substituted brassinosteroids having high growth promoting ability. They may be used alone or in combination with other plant growth regulating agents.

Abstract: A method is provided for treating plants or plant tissues (including cuttings, roots, bulbs, corns, tubers, rhizomes and seeds) in order to induce a desired tissue morphology and/or a desired physiological state by applying to the plant an amount of a C-16,17-dihydro gibberellin or C-16,17-dihydro gibberellin precursor effective to produce an at least partial inhibition of the formation of effector gibberellins in said plant.Effects obtainable include dwarfing, stem and shoot and/or root (radicle) growth retardation, flowering, improved fruit quality, inhibiting fruit ripening, improving fruit set, controlling weed growth, inducing male sterility, retarded bud break and tillering.

Abstract: The flowering of broad-leaved trees particularly fruit trees is promoted by applying a selected rapidly metabolizable gibberellin. Use of the method of the invention can promote return flowering and prevent biennial bearing.

Abstract: The flowering of broad-leaved trees, particularly fruit trees, is promoted by applying as a foliar treatment, a selected rapidly metabolisable gibberellin chosen from among gibberllin A.sub.4, C-3 epi-gibberellin A.sub.4, gibberellin A.sub.1, and salts and esters thereof. Use of the method of invention can promote return flowering and prevent biennial bearing.

Abstract: The formation of strobili is promoted in trees of the family Pinaceae by applying an auxin and one or more gibberellins selected from gibberellin A.sub.3, gibberellin A.sub.4, gibberellin A.sub.5, giberellin A.sub.7, gibberellin A.sub.9 and gibberellin A.sub.14. A preferred treatment comprises applying gibberellin A.sub.9 and an auxin and compositions comprising these substances are also disclosed.