Seedling emergence of Caryocar brasiliense according to mother plant and gibberellic acid use

Abstract

Caryocar brasiliense is one of the most promising native fruit trees from the Brazilian Savannah, in the Goiás State, Brazil, concerning commercial production. However, the low and irregular germination of its seeds can be an obstacle for producing it on a large scale. Aiming at evaluating the emergence of Caryocar brasiliense seeds and the initial growth of seedlings from 16 plants, ten months after harvesting, with and without gibberellic acid (GA₃), two field trials were carried out. The first one included a randomized split-plot blocks design, with mother plants in the plots, and an immersion treatment for 48 hours, in pure water and in a solution of 500 mg L^-1 of GA₃, in subplots. Every seven days, emergence final percentage, average time and speed index were evaluated. The second field trial used a completely randomized design, with different numbers of replications, according with the number of seedlings from the first experiment. For emergence percentage, speed index and average time, treatments presented a significant effect, with a significant interaction between genotype and treatment, for emergence percentage and speed index, to overcome dormancy. It was observed that the use of 500 mg L^-1 of gibberellic acid may minimize dormancy in Caryocar brasiliense seeds and that the field growth of mother plants was linear and continuous over time.