Plant hormones are used to control several stages of development and dormancy of
seeds. The objective of this research was to evaluate the effects of abscisic acid (ABA) and its
interaction with gibberellic acid (AG3) on the germination of seeds of three cultivars of lucern
named Crioula, Xai-32 and 5454.The seeds were imbibed in solutions with five concentrations of
ABA (zero, 10, 50, 100 and 200mol), for 24 hours, rinsed or not after ABA treatment, and
transfered to germination boxes lined with filter paper moistened with distilled water and maintained
in germination chamber in the light or in the darkness. In another experiment the seeds were
germinated in plastic boxes lined with filter paper moistened with solutions of ABA (50mol),
AG3 (1mmol), ABA + AG3 and distilled water (control). The ABA (24h) delayed the germination
as the ABA concentration increased. The seeds maintained in ABA (50mol) presented very low
germination, and the interaction ABA + AG3 was not sufficient to overcome the action of the
inhibitor.