Finebubbles(FB),aninnovativetechniqueoriginatinginJapan,hasbeenthefocusofmuchattentioninvariousfields. No study has examined the effects of FB in tree species. Therefore, we evaluated that effects of oxygen-ultrafine bubble(UFB) water on the germination and growth of Brassica rapa var. perviridis and Cryptomeria japonica. We found that oxygen-UFB water had no effect on germination. In bottom-watering cultivated B. rapa var. perviridis, significantly more leaves were obtained with oxygen-UFB water than with water(with or without fertilizer), and taller seedlings were obtained with oxygen-UFB water than with water using only fertilizer. In overhead-watering cultivated B. rapa var. perviridis(with fertilizer), more leaves were obtained with oxygen-UFB water than with water, although seedling height was not statistically different between oxygen-UFB water and water. For C. japonica cultivated with sphagnum moss, oxygen UFB-water(with fertilizer)increased seedling height and slightly increased the shoot and root dry weights compared to water.
To clarify the relationship between size at planting and initial growth of containerized seedlings of Cryptomeria japonica, M StAR containerized seedlings were planted in three forest sites of Shizuoka prefecture, Japan. Height and diameter at ground level were measured immediately after planting and 1 - 3 growth seasons later, and the data were analyzed. Height and diameter at planting were not significantly correlated with the height and diameter 2 or 3 growth season later, respectively. Correlation coefficients between height at planting and that of 2 or 3 growth seasons later showed weak relationship, as well as diameter. No significant differences of height and diameter were shown after 3 growth season among standard containerized seedling size presented by Forestry Agency at planting time. Among categories of height-diameter ratio at planting time, no significant differences of height and diameter across all combination of categories after 2 or 3 growth seasons by multiple comparison test. These tendencies were observed at all three planting site where the soil condition, planting density and weeding method were different. From these results of data analysis, size difference of M StAR containerized seedlings during nursery time, proceed to level accompanied with rising tree age. Thus, in the range of height and diameter at ground level of M StAR containerized seedlings intended in this study, division of narrow range of standard size categories was not necessary.