Abstract
Leaf distribution, light environmental condition and dry matter production of 3-year-old 7 columnar type apple strains on Marubakaido (Malus. prunifolia Bork. var. ringo Asami) and 6 normal type apple cultivars on M.9EMLA were examined. Vertical distribution of leaf area and relative photosynthetically active radiation in the canopies of 3 to 6-year-old 7 columnar type apple strains on Marubakaido and ‘Fuji’ on M.9EMLA were also compared. Total leaf area per 3-year-old trees of 7 columnar type strains and 6 normal type cultivars differed individually. Trees of 7 columnar type strains had greater leaf area index per planting space and average leaf area than those of 6 normal type cultivars. The internode length of 1-year-old shoots of 7 columnar type strains was shorter than that of 6 normal type cultivars. Three to 6-year-old trees of 7 columnar type strains showed worse light environmental conditions in the canopies than those of 6 normal type cultivars. It was considered that worse light environmental condition in the canopies of these 7 columnar type strains was due to its characteristically closer distribution of large leaves on the shoots. Total dry matter production per year of 7 columnar type strains was from 212 g to 743 g and that of 6 normal type cultivars was from 429 g to 812 g. It was inferred from these results that the dry matter production protential of columnar type strains would be worse than that of the normal type cultivars because the measured value of dry matter production was almost the same between columnar type strains and normal type cultivars even when the former were grafted onto vigorous Marubakaido rootstock and compared with the latter grafted on dwarfing M.9EMLA.
