Vol. 75 No: 2

Title:
Nitrogen requirements and vegetative growth of pot-lysimeter-grown `Fuji' apple trees fertilized by drip irrigation with three nitrogen rates

Authors:
HEE-MYONG RO and JIN-MYEON PARK

pp: 237-242

Abstract:
A pot-lysimeter experiment was designed to assess the N requirements of 'Fuji'/M.9 apple (Malus domestica Borkh.) trees fertilized by drip irrigation with three N rates during 2.5 growing seasons (July 1996 to October 1998). Nitrogen rates of 17 (low), 34 (medium), and 67 mg l^-1 (high) were chosen for comparison. Low, medium, and high N rates averaged 0.47, 0.89, and 2.18.g N tree^-1 for 1996; 1.07, 2.35, and 4.90 g N tree^-1 for 1997; 3.81, 6.93, and 13.69 g N tree^-1 for 1998. Corresponding N accumulation was 0.37, 0.44, and 0.37 g N tree^-1 for 1996; 0.74, 0.82, and 1.00 g N tree^-1 for 1997; 2.93, 3.99, and 2.62 g N tree^-1 for 1998. Dry mass increased by 360, 442, and 256 g tree^-1, respectively. Soil inorganic N concentration increased with N rate, and considerable N was accumulated for soils receiving 67 mg N l^-1. Average N uptake efficiency decreased with increasing N rates. However, uptake efficiencies of P and K were highest at 34 mg N l^-1. Overall, trees receiving 67 mg N l^-1 had significantly smaller trunk cross-sectional areas below and above the graft union, tree height, numbers of leaves and floral buds, and total leaf areas than the trees receiving the lower N rates. Trees receiving 34 mg N l^-1 had greater dry mass, contents of N, P and K, and numbers of floral buds and shoots than trees receiving 17 mg N l^-1. Based on tree vigour, budgets for N, P, and K and soil N status, N concentration of 34 mg l^-1 would be adequate for high-density maiden apple trees under the drip-irrigation level of 250 kPa of soil water potential, without over-fertilizing and excessive growth.

Full text: JHSB Subscribers     ISHS members & other users
(PDF 386688 bytes)

Translate:

Go back to previous page