Viability and vigor of Acacia mangium Willd. seeds at different storage conditions
Deterioration; Longevity; Physiological Quality.
The primary challenge seed storage is to maintain the physiological quality obtained from harvesting to sowing. The main environmental factors that affect seed quality during this period are the temperature and relative humidity. The objective of this research was to evaluate the viability and vigor of Acacia mangium seeds during the deterioration process in relation to different storage environments. To this end, the seeds were stored in high density polyethylene waterproof bags (20 microns) under three conditions: freezer (T = -20 ± 3ºC; RH = 49 ± 10%), refrigerator (T = 6 ± 5ºC; RH = 52 ± 15%) and laboratory environment (T = 28 ± 2ºC; RH = 54 ± 16%), with assessments conducted every three months over 15 months, considering the periods from 0 (no storage), 90, 180, 270, 360 and 450 days. For each evaluation period were made the following determinations and tests: moisture content (%), weight of thousand seeds (g), germination (%), first germination count (%), germination speed index (IVG), average germination time (days), emergency (%), length (cm) and dry weight (mg) of seedlings. The experimental design was completely randomized, arranged in a split plot, the main portion of the environment (3 levels) and the subplots, the storage periods (6 levels). Four replications of 100 seeds for each treatment were used. For the three storage conditions, the seeds presented a significant reduction in germination percentage and vigor tests during the 450 days of storage. To date, the most suitable condition for conservation of A. mangium seeds, with less loss of physiological quality is the refrigerator environment.