2008 Volume 77 Issue 2 Pages 133-141
From the regional trials in Tochigi prefecture for dozens of years, we examined the factors causing variation of rice quality (appearance) and their regional difference in Tochigi prefecture. Sowing time, heading time, maturing time, basal dressing, culm length, lodging, panicle blast, brown rice weight, thousand-kernel weight and duration of sunshine hours were factors causing the regional difference. The factors causing a change in quality varied with the regions. In some regions, quality was improved when sowing time was delayed or maturing time was hastened. In some regions, normally stable and high quality cultivars became unstable. A certain range of lodging and brown rice weight, was necessary to obtain high quality rice, and the quality became unstable out of this range. We found similarity in rice quality in some adjacent regions.
