To determine the viability of peanut seeds by means of the tetrazolium (TZ) test, the methodology in use nowadays is that by which the seeds, after imbibition in water, have their tegument removed and are then immersed in bulk in the TZ solution. This technique hinders the contact between the tissues of the internal surfaces of the seed cotyledons and the TZ solution because the previous period of water imbibition is not long enough to separate the cotyledons. Thus, the access of the TZ solution to the inner surfaces of the cotyledons and to the embryonic axis between them is very difficult or even impossible. Based on the assumption that this procedure tends to yield results which do not correlate well with seedling emergence in the field, a new technique was attempted by which the seeds, after imbibition, in addition to having their tegument removed, were manually separated in their cotyledons, with the embryonic axis remaining attached to one of them, and the two cotyledons of the same seed were then immersed in the TZ solution in an individual cell of a PVC tray. The assumption was found to be correct : the alternative technique, probably because it resulted in more clearly defined images of the tissues located inside the cotyledons internal surfaces, allowed, in comparison with the results of the conventional technique, more precise predictions of the seeds germination performance in the field.
Arachis hypogaea; seed viability determination; seedling emergence
