Substrates and Temperatures in the Germination of Hibiscus sabdariffa L. Seeds

Vegetable biodiversity in Brazil accounts for almost 67% of the plants on the planet, which are part of studies with focus on determinants of food security and access to adequate and healthy food, while preserving natural resources. Studies indicate that Hibiscus sabdariffa L. is one of the most studied unconventional food crops because of its nutraceutical quality as antioxidant and prevention of hypertension and cancer. Although relevant, substrate and temperature information for seedling production of this species are scarce. Thus, the aim of this study was to evaluate the best substrate and temperature for the vigor and germination test of H. sabdariffa seeds of the Talo Roxo and Rubra varieties. The experiment was laid out in a randomized complete design, in a 7 × 5 factorial arrangement, consisting of the combinations of seven substrates (paper towel, filter paper, vermiculite, between sand, on sand, plantmax® and compost) with five temperatures (20, 25, 30, 35 and 20-30 °C), with four replicates with 50 seeds each. The following variables were evaluated- germination, germination speed index, seedling length and dry mass. For germination and vigor tests of Hibiscus sabdariffa var. Talo Roxo seeds the paper roll substrate is recommended at temperatures of 25 or 35 °C and for var. Rubra seeds, plantmax® at 25 °C and plantmax® and vermiculite at temperatures of 25 or 20-30 °C, respectively.