Produção da água de fumaça e seu efeito sobre a germinação de sementes de espécies florestais da Amazônia

Abstract

Smoke produced by burning plant material dissolved in water, has been widely studied for its effect on stimulating the germination and growth of wild and cultivated species. Being an exploratory study of Amazonian forest species, this study aimed to: identify raw materials easily acquired in the Amazon for the production of smoke water and study its effect over the germination of forest species with different ecophysiological characteristics and economic value. Ten kinds of raw materials were tested for the production of smoke water, derived from leaves, wood and forest residues, besides germination paper. The water effectiveness was evaluated in biodrills with tomato seeds in different dilutions. Six materials presented affirmative action, especially in post-germination events (root length and rate of seedling strength). The stimulatory effect was more pronounced in the dilutions 1:25, 1:50 and 1:100. For the study of forest species, the smoke water produced with wood imbauba (Cecropia palmata Willd.) and germination paper were selected. Considering the rate of germination and mean germination time, the species Bertholletia excelsa Humb. & Bonpl., Bellucia grossularioides (L.) Triana, Enterolobium schomburgkii Benth., Cordia goeldiana Hub., Jacaranda copaia (Aubl.) D. Don. e Ochroma pyramidale (Cav. ex Lam.) Urb. were stimulated by smoke. Cariniana micrantha Ducke, Tabebuia serratifolia (G. Don) Nichols and Schizolobium amazonicum Huber ex Ducke were indifferent and the species Swietenia macrophylla King was inhibited. The smoke increased the speed process in species with prolonged germination (B. excelsa and B. grossularioides) and significantly increased germination in plots with low strength (C. goeldiana, O. pyramidale and J. copaia). A more detailed study was conducted with J. copaia, species with difficulties to spread due positive photoblastism positive and short seed longevity. The smoke was not able to eliminate the need for light and constant temperature (25 °C) for seed germination, but was effective in reducing the germination time of seeds from 31 to 22 days. Keeping the seeds soaked in smoke water for 70 days in the dark, achieved an increase in speed of germination for both seed soaked at 25 °C and the thermo-period of 10 °C (20-30 °C). The work envisages the application of smoke water in the forest sector, because it is an affordable product for producers.