The aim of this study was to determine the conditions of the potassium leaching test for evaluating rice seed vigor. Five seed lots of the IRGA 424 variety and five seed lots of the Puita Inta CL variety were tested, and results compared with those from germination tests, first germination count, cold test (without soil), electrical conductivity and seedling germination in the field. The amount of potassium leachate was determined using a flame photometer, after 30, 60, 90, 120, 150 and 180 minutes of immersing 50 seeds in distilled and deionised water at volumes of 20 and 50 mL at 25 ºC. The combination of 50 pure seeds submerged in 50 mL of distilled and deionized water at 25 ºC for 60 minutes was the most efficient procedure for classifying the physiological quality of rice seed lots.
Oryza sativa L; seed quality; seed testing; vigor testing
