The propagation of Caryocar brasiliense (pequizeiro) is still little known. This study aimed to evaluate different osmotic conditions with polyethylene glycol (PEG) in the imbibition process and in the germination of pequi seeds, in addition to verifying the electrical conductivity to evaluate the viability of these seeds. The experiment was conducted with freshly dispersed pyrenes and with pyrenes stored for 90 days. The electrical conductivity of the aqueous solution was measured every six hours for up to 48 hours, using five replications with 20 seeds. The extracted seeds were placed in PEG solutions with osmotic potentials: 0.0; −1.0; −2.0; −3.0; −4.0 MPa, monitored at intervals of 12 hours to 60 hours, plus additional treatment with dry seeds without any type of imbibition. The design was completely randomized with four replications of 25 seeds for germination and four replications of ten seeds for monitoring water content during imbibition. Germination percentage, germination speed index (GSI), percentage of dead and live seeds at 40 days were evaluated. In seeds with longer storage time, the electrical conductivity was higher. Treatments that were not submitted to PEG showed higher GSI, lower mortality percentage and higher germination percentage with 40% and 37%, respectively. The electrical conductivity test was adequate.

No abstract

The immersion of seeds in gibberellic acid solutions can promote dormancy breaking. Storage can be dynamic in seed longevity. The objective of this work was to evaluate different concentrations of gibberellic acid applied to seeds isolated from two storage times on the emergence of C. brasiliense tree seedlings grown in tubes. There were two experiments with different planting and storage times. The seeds were extracted from the endocarp. In both, a randomized block design was used with the following seven treatments: 0, 50, 100, 500, 1000 and 2000 mg L−1 of GA3 and dry seeds without pre-soaking, with five replications of 20 seeds. The seeds were treated with fungicide and sown in tubes containing substrate. After 60 days, evaluations and transplantation were carried out. In the experiment with older pyrenes (seeds stored for seven months), there was high seed mortality (96.54%) and a small emergence rate (3.45%). On the other hand, when new pyrenes were used, the percentage of dead seeds was 32.71% and emergence was 62.28%. GA3 did not stimulate germination or the diameter of C. brasiliense tree seedlings, except for stem length. The 2000 concentration provided a greater stem length and greater leaf area compared to dry seeds.