Study on some aspects of seed vigor for sesame 1

The selection of high quality sesame seed lots is essential to obtain high productivity in the field. This assessment of the physiological potential of the seeds can be obtained by the vigor tests, as they are able to detect more subtle differences in the quality of the seed lots and are fast, when compared to the germination test. However, there are no standardized vigor tests for sesame cultivation. Thus, the objective of this study was to adapt the methodologies for the testing of electrical conductivity, accelerated aging and potassium leaching, in order to evaluate the quality of sesame seeds. For the electrical conductivity test, the seeds were submitted to imbibition periods of 4; 8; 12 and 16 hours, and a number of combinations of seeds/volume of water. For the potassium leaching test, the effects of immersion periods and a number of combinations of seeds/volume of water were evaluated. In the electrical conductivity test, it was demonstrated that the imbibition period of 4 hours and the combination of 25/75 mL of water and 50/75 mL of water is efficient to distinguish the physiological quality of sesame seeds. For the accelerated aging test, the aging periods of 48 hours by the traditional method or 72 and 96 hours with the saturated solution allow the separation of sesame cultivars in different levels of vigor. For the potassium leaching test, a combination of 25/25 mL and 60 or 90 minutes of imbibition is adequate to evaluate seed physiological potential.