Page 33 - Volume 1, Issue 2, July 2008

Effects of Mg supply on “Colt” cuttings 85
tent of Mg in the plants supplied with 1500
μmol Mg l-1 than in the plants supplied with
150 and 0 μmol Mg l-1. The contents of the
other mineral nutrients also increased with
increasing external supply of Mg (Table 3).
Unit absorption rates
The UAR of Mg followed a cubic equa-
Table 3. The effect of Mg external supply on the relationship between loge- transformed total
amount of Mg, Ca, K, N and P (μmol) in plants and time (days). The equation fitted was (a + bt +ct2 )
where a, b and c were the parameters estimated by the statistical analysis and t time. R2 coeffi-
cients of determination, SED standard error of differences.
0 μmol Mg l-1 150 μmol Mg l-1 1500 μmol Mg l-1
R2 SED a b c a b c a b c
Mg 0.85 0.00013 5.417 0.031 -0.00027 5.417 0.031 -0.00007 5.417 0.031 +0.00016
Ca 0.81 0.00013 6.303 0.066 -0.00044 6.303 0.066 -0.00030 6.303 0.066 -0.00026
K 0.82 0.00012 7.191 0.048 -0.00031 7.191 0.048 -0.00017 7.191 0.048 -0.00011
N 0.82 0.00012 8.332 0.056 -0.00037 8.332 0.056 -0.00023 8.332 0.056 -0.00017
P 0.85 0.00012 4.896 0.069 -0.00043 4.896 0.069 -0.00029 4.896 0.069 -0.00024
Figure 6. The effect of Mg external concentration on the [N] in leaves, stems, new shoots and roots of “Colt”. - 0,
- 150 and - 1500 μmol Mg l-1. The vertical bars are the SEDs.