スギ・クローン間の競争

This study was made on the effects of the inter-clone competition to the growth of Sugi tree. Three clones used were Kumotooshi, Boka and Senbon. The tree arrangement was shown in Fig. 1. Bo(Ku) shows a Kumotooshi tree surrounded by Boka trees, Ku(Se) shows a Senbon tree surrounded by Kumotooshi trees, and so on. Measurements were made only with the surrounded trees. Measured trees of each combination were 12, separated in two plots.
The planting was made in March 1964. Heights and basal diameters were measued in July 1964, and in winters of 1964, 1965 and 1966. Trees were felled in Dec. 1967. Heights, breast height diameters, numbers of branches, width of crowns and weights of leaves, branches and trunks were measured. The results were as follows.
1. In the same clone combination, Kumotooshi showed the best growth, and Boka was the next.
2. In the whole combination, the sequence of growth amount was as follows.
Se(Ku) > Bo(Ku) > Ku(Ku)
Se(Bo) > Bo(Bo)
Se(Se) > Bo(Se) >Ku(Se)
3. The reason why Bo(Bo) and Ku(Bo) show almost even growth may be either by the characteristics of the clone or by the shortage of tree age.
4. It seems that competition affected much more to the tree diameter and weights of trunks, branches and leaves among the measured characters.