Shoot and root growth of containerized and bare-root cuttings of Cryptomeria japonica during two years after planting. [Japanese]

摘要

We investigated the shoot and root growth of the containerized cuttings of Cryptomeria japonica during two years after planting by comparing with those of bare-root cuttings. Initial tree height and root mass at planting were smaller for the containerized cuttings compared to the bare-root cuttings. There was no difference in stem elongation during the first two growing season between the two cutting, resulting in smaller tree height of the containerized cuttings. Increase of root mass also smaller in the containerized cutting, there was no evidence to support the superiority of the containerized cutting. The top-root ratios of both cutting types once decreased, suggesting the 'planting shock' associated with severe water stress. However, rapid recovery of the top-root ratio in the containerized cuttings suggested their earlier recovery from water stress. Despite of a possible advantage of the containerized cuttings in terms of their rapid recovery from the planting shock, the other growth analyses demonstrated no evidence that this advantage could lead the fast stem elongation to exceed the growth of the bare-root cuttings. We concluded these results that it is difficult to expect the contribution of the containerized cutting to non- or less-frequent weeding treatment for the laborsaving in silviculture work.