Abstract
Hull cracked grain (HC) is one of grain damages in malting barley. We evaluated the easiness of occurrence of HC by early seeding and shading tratment during the stern shooting stage using 26 Japanese malting barley cultivars. These cultivars were seeded around November 10 and 50% shaded with cheesecloth for about 30 days before heading (from the middle of March to the middle of April). The same experiment was repeated for three years. The frequency of the occurrence of HC was increased by combined treatment of early seeding and plant shading from 5.9% to 31.4%, on the average. There was a significant genotype × year interaction in the percentage of occurrence of HC, and the occurrence of HC varied with the year. Therefore, it is necessary to examine the frequency of HC occurrence for several years to evaluate the tolerance to HC. The occurrence of HC was suggested to be affected by sunshine hours during the stem shooting stage. Among 26 cultivars, Kinuyutaka and Kyushu Nijo 16 produced HC at low frequencies in all three years, and they are favorable parents for breeding the HC-tolerant varieties.
