Armazenabilidade de pirênios de Byrsonima Crassifolia (l.) Kunt muricizeiro, em função de diferentes metódos de superacão de dormência

Abstract

The use of fast and efficient methods for determining seed moisture can help in the preservation of forest species, because moisture is one of the factors that most influence on the deterioration of forest seeds. The objective is to investigate whether the moisture content can influence the storage and/or submission to germination tests, also to test the mechanisms of dormancy, duration and efficient methods that facilitate the germination in species of pyrenes. The experiment was conducted in three stages: first stage was tested the method of stove at 105 ± 3 °C for 24 hours, with five repetitions and containers with 5 grams of wet seeds. Second stage, the method of intermittent drying in the stove at 40 °C for 30 minutes until stabilize the weight, repeated by 15 times. Third stage method of stove at 105 ± 3 °C for 24 hours, with five repetitions and containers with 5 grams of dried seeds. Byrsonima crassifolia presents characteristics of orthodox species, with high humidity after the beneficiation, but to be subjected to drying procedures reached low water levels, however, remained within normal limits. The wet basis of the pyrenes of Byrsonima crassifolia found was of 49.71% of moisture and in the dry basis reached 6.3% of moisture, this way can be inferred that the seeds tested are suitable for storage and / or submission to germination tests. After the humidity test was conducted the germination test with the pyrenes of Byrsonima crassifolia, considering the storage time of 0, 60, 120 and 180 days and the methods of overcoming dormancy, being: chemical scarification with sulfuric acid (H2SO4 ) concentrated by 20 and 40 minutes; gibberellic acid concentration 500mg L-1 (GA3) for 24 and 48 hours; mechanical scarification with sandpaper number 80 for 30 seconds; sandpaper number 80 for 30 seconds more immersion in water for 24 and 48 hours respectively and the control. The objective is to evaluate the germination percentage (% G) and germination speed index (GSI) of pyrenes of Byrsonima crassifolia, in each planting period. Byrsonima crassifolia, has better results at 120 days of storage and the most efficient methods were chemical scarification, superior results were evidenced with H2SO4 40 minutes GA3 48 hours, however the storage and all methods of overcoming dormancy presented results, the most satisfactory was to the 120 days.