Fine root growth after planting of containerized sugi (Cryptomeria japonica) seedlings stored in dark

Abstract

Storage of seedlings in dark is effective in height growth control of containerized Cryptomeria japonica seedlings. However, influence of the storage in dark on the seedlings isn't fully clarified. In the present study, fine root growth after planting was compared among the one-year-old containerized seedlings stored in dark for 4 weeks or 8 weeks and ones without storage in dark (control). The seedlings were watered twice a week during the storage in dark. The storage in dark made the seedlings need a longer time lag for the root growth after planting. The root growth of the seedlings stored in dark recovered within 28 days after planting. Survival rate of the control seedlings in the planting trial under dry soil condition was higher than ones of the seedlings stored in dark. The difference in the survival rates couldn't be explained by ability of root growth under dry soil condition. We indicated that the storage in dark for height growth control needed to consider the negative effects of the storage.