Cardinal temperatures for the germination of Erythrina variegata L. seeds

The objective of this study was to determine the optimum germination temperature for seeds of the Erythrina variegata L. The experiments were carried out at the Seed Analysis Laboratory at CCA-UFES (Laboratorio de Analise de Sementes of CCA-UFES) in Alegre-ES. The seeds were placed in plastic seed germination containers (gerbox), with sterilized sand as the substrate. Random samples of 25 seeds each were incubated separately at constant temperature of 12oC, 14oC, 16oC, 18oC, 20oC, 22oC, 24oC, 26oC, 28oC, 30oC, 32oC, 34oC, 36oC, 38oC and 40oC, with 8-hour photoperiod. This procedure was repeated four times to obtain a meaningful result. It was found that E. variegata seeds have a broad range of temperature tolerance with seed germination observed between 14oC and 38oC. Temperatures between 22oC and 36oC seemed most favorable with germination in excess of 67%. Temperatures between 32oC and 34oC produced the optimum average rate and time for germination. The highest percentage of E. variegata seed germination was found to be at the temperature of 34oC.