抄録
1. An experiment was designed to investigate growth and yield of alfalfa grown at densities of 2500 plants/m2-A, 625 plants/m2-B, 169 plants/m2-C, and 36plants/m2-D. 2. In 1965 (the seeding year), untill the early flowering stage (the first cutting stage), dry matter yields per unit area were higher in the order A, B, C, D. After the first cutting, this order continued, though the differences between densities gradually decreased. At the second cutting, D yielded the least, there were no significant differences in yield among the other three densities. In 1966 and 1967, there were no significant differences among densities in annual total dry matter yield per unit area. 3. At each harvest except the first harvest in the seeding year, the linear relationship was found between log. dry weight per plant and log. density, and its regression coefficient was approximately 1. 4. The reduction in the number of plants was related to densities, and the percentage of surviving plant numbers to the initial densities at the final harvent of this experiment was 7% for A, 20% for B, 48% for C, and 83% for D. 5. Alfalfa swards ranging in initial density from 169 to 2500 plants per sq. meter were individual plants showing skew frequency distridution of plant weight, except in the early stage of growth in the seeding year.
