カラムナータイプリンゴ \u27タスカン\u27若木樹の生育,果実品質に及ぼすせん定方法および側枝誘引の影響

The effect of pruning method (strong heading-back pruning (60cm heading-back, 30cm heading-back), thinning-out pruning, control) on the growth, fruit quality and dry matter production of the columnar-type apple tree \u27Tuscan\u27 (from 2-7-year-old trees) on \u27Marubakaido\u27 (Malus. prunifolia Bork. var. ringo Asami) rootstock was studied. Moreover, bending the lateral branches to a horizontal position in winter was examined to promote flower bud formation. Heavy heading-back resulted in lower tree height, smaller trunk cross-sectional area amd lower total shoot numbers, length and dry matter production compared with light heading-back, thinning-out. Thererfore, it was concluded that thinning-out pruning had to be mainly carried out for rapid tree canopy expansion. The maximum distribution areas of branches and fruits were gradually shifted to the upper area of the tree canopy. The light penetration decreased at the middle and bottom areas of the tree canopy in proportion to tree age, but there was no difference in terms of the pruning method. Thus it was concluded that pruning had to be done so that sufficient light could reach the middle and bottom areas of the tree canopy. The pruning method did not affect fruit weight, Brix or fruit acidity. Flower bud numbers were increased by bending the lateral branch to a horizontal position in winter, which increased the fruit weight, Brix and fruit acidity. The bending treatment may also reduce the altrenaive flowering habit