THE DEGREE OF MOISTURE IN THE HARVEST AND THE DRYING SYSTEM ARE DETERMINANT FOR THE RICE SEED VIGOR

Abstract

The degree of moisture in the harvest and the drying system can be decisive in the quality of the seeds produced. In this work, we tried to evaluate whether the drying system and the degree of moisture in the harvest interfere in the physiological quality of the seeds of rice cultivars. The experiment was carried out in a completely randomized design in a triple factorial scheme. Seeds from six cultivars produced in Alto Vale do Itajaí / SC in the 2016/17 harvest were used with a moisture content of 17% or more and less than 17% in the harvest. The seeds were submitted to stationary and intermittent drying systems. Tests of germination, viability, vigor by accelerated aging and cold were carried out. The seeds harvested with moisture content ≥ 17% showed greater vigor. The cultivar proved to be a factor of great relevance in the sensitivity to thermal and mechanical damage. The drying system did not affect the viability of the seeds, except for the cultivar SCS122 Miura, which was sensitive to thermal and mechanical damage. Stationary drying compromised physiological quality due to the time of exposure to temperature. It is concluded that the use of intermittent drying in seeds of the evaluated cultivars, harvested with humidity level ≥ 17% allows the maintenance of the physiological quality produced in the field.