Predação e germinação de sementes de babaçu (Attalea vitrivir Zona, Arecaceae)

Abstract

Seed predation is a natural phenomenon can occur pre-or post-dispersal, both representing a significant reduction in reproductive potential of the host plant, could eliminate most of the seeds, which compromises the reproduction of the specie. For a better understanding of plants reproduction, information on the germination of seeds are important for contributing to the understanding of the successful establishment of species in the field. As there is little knowledge about predation and germination of Attalea vitrivir Zona, this study aimed to evaluate the predation and germination of this species in the Area de Proteção Ambiental do Rio Pandeiros (APA-Pandeiros) in northern Minas Gerais. It was observed, monthly fruit production in 60 plants in the period June 2009 to September 2010 and were conducted two parallel experiments. The first in the specie’s natural environment and the second under artificial conditions in a greenhouse. The experiment in the natural environment consisted of 800 fruits, 400 scarified and 400 intact (control), left on the field for eight months for assessment of predation and germination. In the greenhouse, was used 360 fruits, 180 scarified and 180 intact, which were planted individually in black bags of seedlings. The results showed that the fructification of A. vitrivir is continuous occurring during the observation period. The morphology of the fruit was not associated with the germination and predation rate. Scarification of the fruits had no effect on germination, but there was preference for oviposition in scarified fruits by Pachymerus cardo. Seed predation by this insect occurred only post dispersal. In natural environment, the predation rate was relatively low, reaching 14.60%, with no differences in time. The occurrence of severals developmental stages of P. cardo during the 8 months of exposure of the fruits in the natural environment suggests possible diapause of this insect. None of the fruit in natural environment germinated during the 8 months of exposure. In the greenhouse, the germination reached 33.05% after five months