Gibberellin A_4/7 enhanced flowering in <i>Pinus</i><i>caribaea</i> var. <i>hondurensis</i>

Abstract

Gibberellin A 4/7 was applied to field-grown grafts of sexually mature poor and good flowering clones of Pinuscaribaea Morelet var. hondurensis. Barr. &amp; Golf. Continuous applications of gibberellin A 4/7 over a 6-week period significantly enhanced seed-cone production in poor flowering clones but had no effect on good flowering clones. Poor flowering clones also showed slight decreases in pollen-cone production with gibberellin A 4/7 , while clones that normally flowered well did not. Gibberellin A 4/7 increased final shoot lengths in the lower (male) and upper (female) crown region of both poor and good flowering clones. A series of timed gibberellin A 4/7 applications suggested that a single treatment near the onset of reproductive bud development may be used to enhance seed-cone production.