Caracterização de fatores que afetam a germinação de teca (Tectona grandis): Temperatura e escarificação

Abstract

The slow and irregular seeds germination limits the production of teak seedlings (Tectona grandis). Although practical methods are available, few studies have systematically quantified the effect of heating and scarification to break the dormancy. High temperatures can be reached through a solar collector, simple assembly device that can capture and transform the solar energy into heat energy. This study aimed to evaluate the interaction of "heating" and "scarification" to overcome the dormancy of teak seeds, evaluating the solar collector performance. We evaluated experimentssome experiment in complete factorial design with four levels of the factor "heat" (A1 - solarized, A2 - greenhouse at 80° C (12 h), A3 - greenhouse at 80° C (4 h/3 days), A4 - unheated) and three levels of the factor "scarification" (E1 - physical scarification, E2 - chemical scarification, and E3 and - without scarification), totaling 12 treatments with five replicates of 25 diaspores per plot. The F test at 1% of probability indicated the presence of significant interaction between factor heating and "scarification" and the lower germination result of the fruits that were scarified after heating. The use of high temperatures in the absence of scarification featured the best performing treatments to overcome dormancy. The lower performance associated with higher costs and risks for handling discouraged the chemical scarification use on dormancy break. Alternating temperatures enhanced the germination, and the solar collector proved to be a practical alternative, viable and less costly to overcome dormancy in teak.