Influence of light and temperature on the germination of Passiflora incarnata L. seeds

The study aimed to assess the influence of temperature and light on germination of Passiflora incarnata L seeds. The treatments consisted of five temperature conditions (25, 30, 35, 20-30 and 30-20 °C) and two light conditions (constant light and constant darkness). The experimental design was completely randomized in a 2 x 5 factorial arrangement (light x temperature). The seeds were kept in a germination chamber during the period of 30 days. The germinated seeds were counted daily. At the end of the experiment, the percentage of seed germination (PSG), germination speed index (GSI), the germination rate (GR) and relative frequency of germination (RFG) were calculated. The data obtained were subjected to analysis of variance and means were compared by Tukey test at 5% probability. The relative frequency of germination was represented as graphs. It was observed that light has an inhibitory effect on seed germination. The constant temperature of 35 °C and the alternating temperatures of 30/20 °C promoted a higher germination seed index for Passiflora incarnata.