Avaliação da qualidade de sementes de dendezeiro (Elaeis Guineensis Jacq.) produzidas pela EMBRAPA Amazônia Ocidental

Abstract

This trial addresses two chapters: 1) heat-treatment (HT) and germination of oil palm seeds and 2) tetrazolium test (TZ) in embryos of oil palm seeds. The first chapter aimed to evaluate the best HT period for the seeds germination of six oil palm varieties produced by Embrapa. The water content of all seeds was adjusted to 18 ± 0.5%, dry basis, and these remained in the heat-treatment at a temperature of 39 ± 1 °C and relative humidity around 80% for 40, 50, 60 and 80 days. The statistical design was complete randomized block in a 6 x 4 factorial design, with four replications of 500 seeds. The results were submitted to analysis of variance, mean separation test and regression. It was observed significant effect of cultivar, HT period and the interaction between genotype x HT period. The minimum HT period for maximum germination ranged from 45 days for BRS C2328 (69.95%) to 80 days for BRS C2528 (84.28%). For BRS C7201 was not observed significant effect of HT period for seed germination, estimated as 82.15%. It is possible to reduce the HT period to reach the maximum germination for seeds of the cultivars evaluated. In the second chapter four experiments were established in order to standardize the TZ for oil palm seeds: 1 - identify vigor and viability in embryos of seeds, to evaluating temperatures of imbibitions on water (30 and 40° C), tetrazolium (30, 35 and 40° C) and concentrations of salt (0.075, 0.1 and 0.5%); 2 - to evaluate methods of preparation of the seed (kernels and embryos) and substrates for imbibitions (germitest paper and plastic cups); 3 - evaluate different temperatures combinations of embryos imbibitions in water and tetrazolium (30, 35 and 40° C) and different concentrations of salt (0.075, 0.1 and 0.5%) and 4 - to correlate viability by TZ with germination. In all trials the time of embryos imbibition in water was 16 hours and 4 hours for tetrazolium. The results showed that the TZ can be used to evaluate the vigor and viability of oil palm seeds, provided that the embryos are removed, packed in moistened germitest paper, at 30 to 35° C as temperatures of imbibition in water, and 40° C for tetrazolium at a concentration of 0.075%