Abstract
The cultivar differences in the effects of early-sowing (late October) and late-sowing (mid December) on the yield and quality of naked barley (Hordeum vulgare var. nudum) were investigated using three cultivars (Manenboshi, Haruhimeboshi and Hinodehadaka). In early-sowing in which the plants grow in a short-day condition, the number of days from sowing to heading was increased and the yield was increased due to a vigorous initial growth and the large number of grains per unit area. However, the spike number and the number of grains per spike were decreased especially in Hinodehadaka and Haruhimeboshi due to the overluxuriant growth and cold injury in warm winter or late frost year. The total nitrogen content at anthesis in early-sowing increased resulting in increased steel-grain rate and reduced pearled grain whiteness. In late-sowing in which the plants grow in a long-day condition, the number of days from sowing to heading was decreased and the yield was decreased due to the small number of grain per unit area. These trends were marked in years with a cold winter or warm spring. Late-sowing increased grain protein content, steel-grain rate and decreased pearled grain whiteness. In addition, in late-sowing, rain in ripening period reduced the volume weight and grade of grain.
