Abstract
The main goal of this study was to evaluate the physical and physiological quality of soybean seeds, cultivar BRS Tracajá, harvested in savanna (cerrado) area of the State of Roraima according to size and storage. The seeds were cleaned and manually classified by size, using three sieves with round holes with dimensions: 5.5; 6.0 and 6.5 mm, subsequently disposed in proper paper bags and stored during six months under conditions of temperature (23 °C) and air relative humidity (60%) at Embrapa Roraima's seed laboratory. The seed quality was evaluated in the beginning of storage and after 2; 4 and 6 months of storage according to the thousand seeds weight test, germination, first germination count, electrical conductivity, field seedling emergence, speed of seedling emergence in the field, seedling dry weight and dry weight per seedling. The results show that the size influences physical and physiological quality of seeds from cultivar BRS Tracajá during storage. Seeds of higher sizes from cultivar Tracajá (6.5 mm) present higher value in the thousand seeds weight test. The highest percentages of germination and vigor through seeds electrical conductivity test, concerning seeds of BRS Tracajá cultivar, during storage, were obtained among seeds of larger sizes (6.0 and 6.5 mm). Seeds with larger sizes from BRS Tracajá (6.0 and 6.5 mm) showed during storage, the highest percentage of field seedling emergence and the seeds with smaller sizes (5.5 mm), the smallest rates of field speed of seedling emergence.
Key words
Glycine max; Germination; Seeds vigour