ALLELOPATHIC POTENTIAL OF LEAF AND FRUIT EXTRACTS OF Pityrocarpa moniliformis IN GERMINATION OF Mimosa caesalpiniifolia SEEDS

Abstract

Abstract: An allelopathy has been defined as a chemical interaction between species, through metabolites called allelochemicals. The objective of this study was to evaluate the allelopathic potential of the aqueous extracts of leaves and fruits of Pityrocarpa moniliformis (Benth.) Luckow & R. W. Jobson on seed germination and initial growth of Mimosa caesalpiniifolia Benth. seedlings. The leaves and fruit extracts of P. moniliformis were obtained by immersion in distilled water for 24 h, obtaining as concentrations of 0 (distilled water), 25, 50, 75 and 100 g.L-1. The seeding was performed on paper towel and as seeds kept to germinate at 25 ° C with photoperiod of 12 h. The variables evaluated were: percentage of germination, germination speed index, length of root and aerial part seedlings. Germination of M. caesalpiniifolia seeds was not influenced by the extracts of P. moniliformis, but its velocity was reduced. The leaf extract reduced root length as the concentration increased to 57.0 g.L-1, while fruit extracts reduced the concentration to 68.0 g.L-1. The extract of leaves led to an increase on length of aerial part seedlings, whereas the extract of the fruits proposed the reduction up to concentration of 61.5 g.L-1. The aqueous extracts of fruits and leaves of P. moniliformis do not affect the germination of M. caesalpiniifolia seeds, however, there is negative allelopathic effect on speed and initial growth of M. caesalpiniifolia seedlings. KEYWORDS: Allelochemicals, Forest seeds, Heterotoxicity, Vigor.