GROWING UP COMPARISON AMONG Virola surinamensis (Rol.) Warb PROVENANCES

SUMMARY

Exploration of Virola surinamensis or virola during last decades is causing its local exhaustion, specially on floodplain and swamp forests. At this way. source of genetical material can be affected for future improvement programs and commercial plantation to the specie and for its perpetuation. This work compares precocious growing up of virola from Amazon estuary provenances to be used for improvement and conservation programs.

Provenance trials were established on tcoaraci (Betém-Pará), Igarapé-açu (Bragantina regíon-Pará) and Breves (Marajó Island | in upper-land areas. Virola seeds were collected on Marajó Island, Municipality of Anajás (Mapuá and Jurará rivers). Portel and Melgaço (Preto and Laguna rivers) and on Gurupá Island (Murupucus and Baquiá rivers), with 10 seddlings/mother tree.

Belém and Breves occur in regions of Afi climate, no dry season, and drier month with precipttancs equal or upper to 60 mm. while Igarapé-açu presents monsson climate with high annual pluvial rainy and dry season with montly precipitance average lower than 60 mm.

Higher growing rates to 6 and 12 months plantation were obtained in Icoaraci and Breves, and in Igarapé-açu was observed high mortality during the dry season for progenies from Anajás, where the climate does not present defined dry season. Preto, Laguna, Baquiá and Murupucus provenances were the ones with fast growing and less mortality rate. On this region, plus-trees had been remaining plants from intense exploration process, wich removed big diameter trees. Data obtained at the present indicate virola susceptibility to extensive dry periods during its inicial development and the possibility to adapt on upper-lands areas.