Seedling emergence and establishment of Guazuma ulmifolia Lam. submitted to different pre-germination treatments/Emergencia e estabelecimento de plantulas de Guazuma ulmifolia Lam. em funcao de diferentes tratamentos pre-germinativos

• Published in: Ciência florestal 2016-07, p.763
• Main Authors: da Silva, Diellen Librelon, da Luz, Giovana Rodrigues, Veloso, Maria das Dores Magalhaes, Fernandes, Geraldo Wilson, Nunes, Yule Roberta Ferreira
• Format: Article
• Language: Spanish
• ISSN: 1980-5098

This study tested the influence of mechanical and thermal scarification methods on emergence and establishment of Guazuma ulmifolia seedlings. Seeds were subjected to pre- germination treatments of (1) mechanical scarification (sandpaper), and (2) thermal scarification (hot water), in addition to the control treatment (3) from which the seeds were left intact. The thermal scarification treatment differed from the other treatments featuring the largest number of seedling emergence (70%). The seeds treated with sandpaper achieved the lowest emergence percentage not differing from the control treatment. For the germination speed index no significant difference between treatments has been verified and the emergence peak was between the 13rd and 15th days of incubation in all treatments. In the establishment, the seedlings growth (height, diameter and number of leaves and nodes) presented differences between the treatments. It was observed further development of seedlings after their seeds go through thermal scarification. Therefore, scarification with hot water is the most appropriate method for breaking the dormancy of seeds of Guazuma ulmifolia, providing more vigorous seedlings. Keywords: dormancy; germination behavior; establishment. Este trabalho testou a influencia de metodos de escarificacao termica e mecanica na emergencia e estabelecimento de plantulas de Guazuma ulmifolia. As sementes foram submetidas aos tratamentos pre-germinativos de (1) escarificacao mecanica (lixa), e (2) escarificacao termica (agua quente), alem do tratamento-controle (3) no qual as sementes foram deixadas intactas. O tratamento feito com escarificacao termica diferiu dos demais tratamentos, apresentando o maior numero de plantulas emergidas. As sementes tratadas com lixa obtiveram a menor porcentagem de emergencia, nao diferindo do tratamento-controle. Para o indice de velocidade de germinacao nao foi verificada diferenca significativa entre os tratamentos e o pico de emergencia de plantulas foi entre o 13 e 15 dia de incubacao em todos os tratamentos. Quanto ao estabelecimento, o crescimento (altura, diametro e numero de folhas e de nos) das plantulas diferiu entre os tratamentos pre-germinativos. Observou-se maior crescimento das plantulas apos suas sementes passarem por escarificacao termica. Assim, a escarificacao com agua quente e o metodo mais adequado para quebra da dormencia das sementes de Guazuma ulmifolia, proporcionando plantulas mais vigorosas. Palavras-chave: dor