Barley varieties and its cultivation in east part of Tibet plateau.

Barley husbandry was investigated in the east part of Tibet plateau where the Tibetans are cultivating local varieties as their staple food. Barley lines collected there were grown in Japan to examine the heading date, yield component and so on. Almost all varieties cultivated were naked six-rowed barley. The nakedness seemed to have been selected by Tibetans, as it is a favorable trait for milling. They cultivated barley at small fields on the riverside and mountain slopes by hand using cows for plowing. Organic fertilizer was commonly used as basal dressing. Seeding time ranged from the middle of March to the beginning of April, and harvesting period was in August. These times differed according to the altitude. The harvested barley was dried, and then thrashed by human trampling or using a simple instrument. The heading time of the barley lines varied over a period of nearly one month when grown in Japan. The plants collected at 2900∼3100m tended to head later than those collected at a lower of higher place. The genetic differentiation may have derived from the difference in the climate and crop husbandry in each altitude zone. The kernel weight of collected lines belonged to the biggest grain size group in the naked six-rowed barley varieties of the world. Some proposals for the yield improvement in the explored area are presented.