International Journal of Horticulture, 2017, Vol.7, No. 31, 288-298
290
N absorption (Greenland and Nye, 1959), the results imply that its requirement is less on 110R rootstock for N
absorption.
Table 1 Multiple regression of nutrient absorption index on soil chemical characteristics by Thompson Seedless on different
rootstocks
Nutrient Own root
Dogridge
110R
Regression equation
R
2
Regression equation
R
2
Regression equation
R
2
N
Y = 125.9 +
14.1
X1 -
3.16
X2 –
3.94
X3 - 0.4 X4 –
6.66
X5
0.773** Y = 230.7 + 6.19 X1 - 26
X2 - 54.6 X3 + 4.53 X4 -
1.3 X5
0.162 Y = - 27.88 –
6.56
X1 +
13.4
X2 + 1.13 X3 +
0.23
X4 + 1.69 X5
0.359**
P
Y= 391.2 +
1.31
X1 –
41
X2 +
1.18
X3 – 1.5 X4 –
2.45
X5
0.648** Y = 85.7 – 0.74 X1 – 7.55
X2 + 5.62 X3 – 0.29 X4 –
0.14 X5
0.213 Y = 8.9 –
1.0
X1 +
0.63
X2 -
7.37
X3 + 0.71 X4 +
1.09
X5
0.258*
K
Y= 706.4 +
6.33
X1 -
65.6
X2 -
32.1
X3 –
6.02
X4 –
6.59
X5
0.506** Y = 229.3 +
0.78
X1 –
21.7
X2 -
18.1
X3 – 1. 88
X4 +
0.17
X5
0.607** Y = - 42.8 –
3.66
X1 +
11.58
X2 +
3.86
X3 + 0.06
X4 – 1.21 X5
0.324*
Ca
Y = - 37.9 – 0.13 X1 + 4.77
X2 - 1.12 X3 + 0.05 X4 +
0.5 X5
0.202 Y = -13 + 0.24 X1 +
1.9
X2 +
0.34
X3 +0.06 X4 –
0.12 X5
0.381** Y = 4.85 + 0.16 X1 - 0.43
X2 + 0.3 X3 + 0.08 X4 –
0.05 X5
0.142
Mg
Y= - 11.9 + 0.62 X1 +
2
X2
-
2.69
X3 + 0.07 X4 – 0.03
X5
0.272* Y = - 11.36 + 0.39 X1 +
1.59
X2 +
2.24
X3 + 0.05
X4 – 0.06 X5
0.260* Y = 1.98 – 0.23 X1 + 0.09
X2 + 0.48 X3 – 0.0 X4 +
0.1 X5
0.128
S
Y= 24.5 + 0.27 X1 –
3.21
X2 +
2.5
X3 – 0.03 X4 +
0.35 X5
0.313* Y = 6.63 – 0.17 X1 – 0.39
x2 + 1.33 X3 – 0.12 X4 +
0.1 X5
0.381** Y = 3.43 – 0.38 X1 – 0.2
X2 + 0.78 X3 + 0.02 X4 +
0.1 X5
0.295*
Na
Y = -377.3 +
11.61
X1 +
39.4
X2 +
3.58
X3 + 1.3 X4
+
4.29
X5
0.448** Y = - 18.5 –
0.01
X1 +
1.9
X2 -
2.18
X3 + 0.85 X4 +
0.1 X5
0.266* Y = - 6.74 – 0.26 X1 +
2.96 X2 + 1.95 X3 – 0.22
X4 – 0. 51 X5
0.179
Fe
Y = - 2.31 +
3.23
X1 –
1.78
X2 +
1.46
X3 – 0.27 X4 +
2.72
X5
0.412** Y = 8.74 +
1.91
X1 –
1.98
X2 +
3.44
X3 – 0.15 X4 +
1.4 X5
0.336* Y = 39.6 –
0.44
X1 –
4.55
X2 +
11.6
X3 + 0.37 X4 –
1.25
X5
0.439**
MN Y= 79.9 –
2.13
X1 –
7.82
X2 -
3.9
X3 – 0.85 X4 +
2.1
X5
0.283* Y = - 54.9 –
0.18
X1 +
6.44
X2 +
19.1
X3 + 0.02
X4 + 0.72 X5
0.566** Y = 14.6 +
0.47
X1 –
1.99
X2 +
2.13
X3 + 0.5 X4 –
0.02 X5
0.226*
Zn
Y = - 165.6 +
3.32
X1 +
25
X2 +
2.15
X3 – 1.39 X4 –
0.36 X5
0.752** Y = - 52.2 –
0.72
X1 +
11.2
X2 +
35.1
X3 – 2.2
X4 – 0.59 X5
0.560** Y = - 8.07 –
0.68
X1 +
3.85
X2 +
5.34
X3 – 0.29
X4 –
1.25
X5
0.301*
CU Y = - 29.9 + 0.84 X1 + 4.16
X2 + 1.09 X3 + 0.35 X4 –
0.9 X5
0.105 Y = - 0.26 – 0.0X1 + 0.53
X2 - 0.71 X3 + 0.06 X4 –
0.24 x5
0.082 Y = 11.4 + 0.44 X1 – 1.59
X2 - 0.11 X3 + 0.01 X4 +
0.36 X5
0.134
Note: X1 = Organic Carbon (%); X2 = pH; X3 = EC (dSm
-1
); X4 = CaCO
3
(%); X5 = ESP (%); Coefficients in bold figures are more
than their respective t-stat values
The significant negative relationship of sulphur absorption with soil OC on own root but non-significant one on
other roots (Table 2) indicate that, sulphur absorption by Thompson Seedless root was more independent of soil
OC than other roots. Increasing levels of OC up to 2.06 per cent were associated with reduced sulphur absorption
on own root and steady reduction on 110R, but increased absorption up to 3.3 per cent on Dog Ridge (Table 3).
Thompson Seedless root were more efficient than the other roots in S absorption at all levels of OC, while 110R
was more efficient than Dog Ridge up to 2.0 per cent (Figure 1). Importance of OC in the absorption of S lies in
the fact that 60 per cent of the sulphur taken up by the plants being derived from carbon-bonded sulphur fractions.
Positive response of Dog Ridge roots indicates their dependence on organic carbon for S absorption.
