Radicle emergence test method for estimating sorghum seeds quality: A tropics practices

Abstract

The radicle emergence (RE) test is often considered over the standard germination test to quickly evaluate the seed lots of various crops and determine their relative vigor and potential field performance. We investigated RE method and determined whether it could predict sorghum seed quality. The radicle sprout was first recorded at 12 h after germinating, and the radicle length was between 1 and 2 mm at 24 h, and finally, the radicle length of more than 2 mm was identified between 30 h and 39 h. The study found a strong correlation between RE counts and Vigor index (VI) (P < 0.001) in sorghum seeds. The regression of these RE with VI revealed highly significant coefficients of determination (R2 = 0.8541, P < 0.001). The regression showed 85 % of variation in VI could be expressed by RE. The study found a positive correlation between vigor index and germination percentage, with an equation y = 0.2312x + 77.25 indicating an increase in vigor index. This equation can be used for predicting germination percentage in tropical regions. The study found a VI of 25 % and a RE of 80 % were found to be crucial for germination. In summary, our investigations led to the recognition of the RE test method for sorghum seed, which was established at a temperature of 28 °C after a period of 36 h. The RE method has been demonstrated to predict the vigor index and germination percentage of sorghum seed lots and might be used for rapid seed quality testing.