Caracterização física de frutos e sementes, morfologia da plântula e secagem de semente de cumaru (Dipteryx odorata (AUBL.) Willd.).

Abstract

The present research describes the biometric characteristics of fruits and seeds, quantify the emergency and evaluate the vigor of cumaru {Dipteryx odorata) originated from three localities in the state of Pará: Ananindeua, Belém and Belterra. Mass, length, width and thickness of fruits and seeds, as well as seed moisture, the percentage of emergency, germination, abnormal seedlings and dead seeds were determined. Sowing was carried out on a substrate of sand and sawdust (1:1), in four replication of 25 seeds. Vigor was tested by the emergency speed index (ESI), length of the parts of seedlings and weight of dry mass. The biometrical parameters varied among the different provenances. Fruits and seeds form Belterra showed the least variation, probably because they were originated from a single tree. Seed moisture was of 51.6% (Belterra), 37.9% (Belém) and 46% (Ananindeua). The emergency began on the 5e (Belterra), 8e (Ananindeua) and 9e day (Belém). The abnormal percentages of germination, emergency, seedlings and dead seeds did not differ among the proveniences. The vigor test the sample of Belterra got the higher IVE and the weight of dry mass, being most vigorous. The emergency is not influenced by the measure of the seeds. The ESI and dry mass weight are the most sensitive parameters for detecting differences in provenances.

The objective was to describe the morphological characteristics of the germination and of the seedling of Cumaru {Dipteryx odorata). Ten seeds were sown per pot, in 13 pots, one pot was examined every two days, totaling 26 days of experiment. Sowing was carried out on a substrato containing sand and sawdust (1:1), in four replications of 25 seeds each. The diameter of the epicotyl, and the length of the epicotyl and of the root were measured at ali stages. Germination was fast and uniform, starting on the 4th day with the radicle emergence, with formation of seedlings from the 12th day. The morphology of germination and seedling growth are similar, providing subsidies for the recognition of seedlings in the soil on the forest, taxonomic and ecological studies on the species.

This study was conducted to verify the effect of drying on the germination and vigor of Dipteryx odorata seeds. Drying was carried out during 28 days, in an environment with average temperature and relative humidity of the air of 27.9° C and 80.54%. Seeds were sowed on a substrato containing sand and sawdust (1:1), in four replications of 25 seeds. The effect of drying in the germination and vigor was evaluated through the humidity degree, percentages of seedlings emergence, germination, dead seeds, abnormal seedlings, emergence speed index, seedlings length and seedling dry mass. The tonka bean seed, for the humidity factor, probably behaves in intermediate storage. In general, the drying up 7.3% of water content affects the quality of seed, which is more pronounced from 5.8%.