Ｙ字形棚整枝と主幹形整枝リンゴ樹‘ふじ’の乾物生産と器官別分配の比較

Abstract

The dry matter production and assimilate partitioning ratio (APR) in each organ of 'Fuji' apple trees on M. 26/Marubakaido (Malus prunifolia var. ringo Asami) trained to a Y-trellis system were compared with those trained to a central leader to make clear the reason of superiority of trees trained to the Y-trellis in yield.1. No significant differences in current shoot length, shoot number, and leaf area index (LAI) were found between trees trained to the two training systems. The yield of the Y-trellis trained trees was 6, 945 kg/10 a, which is 22% higher than that of the central leader trained trees.2. The dry matter production of the Y-trellis trained trees was 2, 417 kg/10 a, or 23% heavier than that of the central leader trained trees. The fruit dry weight in the former was 1, 198 kg/10 a, or 43% heavier than that in the latter; the APR into fruit were 49.5% and 43.1%, respectively. The APR into the current shoot and older wood of the former were lower than those in the latter.3. There were significant positive correlations between the dry matter production and the current shoot length, LAI, and yield. The APR into fruit was positively correlated with the crown density, whereas it was negatively correlated with current shoot and older wood.4. We conclude that more efficient dry matter production and higher assimilate partitioning ratio into fruit of the Y-trellis trained trees gave rise to the superior yield over the central leader trees.