Development of a Non-destructive Method of Evaluating the Steely Grain Rate in Hulless Barley (Hordeum vulgare var. nudum) Using the Transmittance of Grains

Steely grain rate is an important index for grain quality of hulless barley. The steely grain rate is evaluated by the ratio of the mealy and translucent areas in the endosperm on the cross-section of the grain. In this study, focusing on the difference in the transmittance between mealy and translucent endosperms, the non-destructive evaluation of steely grain rate using the brightness, an investigator of the transmittance, was developed, and then the accuracy of the method was validated. Ten sample sets of three cultivars collected in different years and fields with different split applications were prepared as calibration and validation sample sets. The regression line between the steely grain rate of the grain and the brightness adjusted by background had a significantly high coefficient of determination (R2) of 0.8709 (p