Abstract
Varietal trial of alfalfa was made on 55 varieties collected from main alfalfa growing regions of the world to select varieties adapted to the warmer region of Japan. The seeds were sown in fall of 1962 and 63, and 5 clippings were made in each season as a rule. After three years test, following results were obtained : In varieties of sativa group, including Spanish, Italian, Australian, Argentina and American common alfalfa, the stands persisted fairly well throughout the test period, while, in varieties of media group, severe standloss was observed in the summer of the second and third harvest year. The correlation between standloss and yield decrease was significantly high. Generally yield level of sativa group ranked moderate or somewhat low in the early part of the test period, but increased later. A fairly large number of varieties of media group, including Du Puits and several Flemish type and some of German and American varieties, were highly productive in the first harvest year, but their yield was decreased after the summer growth depletion of the second harvest year. Thus the yield order was gradually reversed between sativa and media group and in the third harvest year, all varieties of top yield class belonged to sativa group. Plants attacked by anthracnose were frequently found in varieties of media group, which might be one of the reasons of summer standloss of this group. It was evident that sativa group showed better adaptation in the warmer region of Japan. Among the tested varieties, four Italian varieties introduced from Lodi in North Italy, were excellent in both yield and persistency.
