Horticultural Science and Technology 원예과학기술지 ISSN:1226-8763(Print) 2465-8588(Online)

This study was carried out to investigate shoot growth and fruit characteristics in 4-year-old ‘Yumi’ peach (Prunus persica) trees in response to various amounts of side dressing with fused phosphate fertilizer (phosphoric acid 17%, FPF) under soil cultivation. The amount of side dressing of FPF was set at 40% of a year’s supply, i.e., 132 g/tree FPF (P₂O₅ 22.4 g/tree) and 22.4 g/tree for the control, 2× (44.9 g/tree), 4× (89.8 g/tree), and 6× (134.6 g/tree), which were supplied via three-split application at 15-day intervals. Shoot length at the fruit maturing stage decreased by 12–16% with increasing amounts of side dressing of FPF up to 6×. The mineral concentration in leaves did not change significantly with increasing levels of FPF. Available P₂O₅ and Mg contents in soil after fruit harvest were 3.0- and 1.8-fold higher under increasing FPF levels (up to 6×) compared to the control, respectively. Leaf SPAD values at the fruit maturing stage decreased with increasing FPF levels, whereas fruit length and width increased with increasing FPF levels. Fruit weights and hardness increased with increasing (up to 6×) amounts of FPF. Finally, free sugar concentrations increased with increasing FPF levels. Therefore, the application of large quantities of FPF via side dressing during early fruit growth can improve fruit quality in ‘Yumi’ peach under soil cultivation.