2021 Volume 103 Issue 2 Pages 105-116
About 10 years have passed since the practical production of container-grown conifer species began in Japan. In order to investigate the whole method of raising plants (seedlings/cuttings) in multi-cavity containers and clarify the current standard cultivation method and problems, we conducted a questionnaire survey on container cultivation methods for Cryptomeria japonica, Chamaecyparis obtusa, and Larix spp., targeting containerized plant producers nationwide. The cultivation method that producers employed was almost the same as the official manuals issued by the related organizations. As a result of analyzing the relationship between the production scale of containerized plants and production style, the introduction of production infrastructure for labor saving and efficient production and the expertise of bare-root plant production or long experiences of containerized plant production seemed to contribute to mass production of containerized plants. A problem with the production of containerized plants was a poor yield ratio due to substandard (e.g. small size, uneven growth, insufficient diameter, poor formation of root ball) plants. These results reveal that it is necessary to establish a method to efficiently produce containerized plants that reach the standard size by the time of shipment and to construct a stable supply and demand system for sustainable production of containerized conifer plants.
