Agriculture Reference
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tions of N, P and K in leaves compared with N, P and K in leaves in DI treatments. The
higher N, P and K content in leaves of fully irrigated trees was caused by increased
availability of such nutrients in soil under FI. The concentration of nutrients in leaves
decreased with decrease in irrigation regime. However, the amount of N, P and K in
leaves was adequate with both FI and RDI
50
, when compared to the foliar diagnos-
tic chart (2.50-2.93% N, 0.17-0.28% P and 1.63-1.89% K) developed for optimum
'Kinnow' mandarin productivity in North India condition [27]. The suboptimum leaf
nutrient concentration with RDI
0
indicates that withholding irrigation in EFGP is not
suitable for balanced nutrition of 'Kinnow' mandarin plants, which is a prerequisite
for higher productive life of the orchards [14, 27]. The trend of leaf nutrients observed
in this study was reflective of the observations made by [22] in 'Nagpur' mandarin,
which stated that the leaf nutrient composition is affected by water stress in citrus. In
contrast, [25] observed that mineral (N, P, and K) nutrition of 'Clemenules' manda-
rin budded on 'Cleopatra' mandarin in Spain was not affected by water stress which
was imposed by stopping irrigation in both initial fruit growth period and final fruit
growth period. This variation was attributed to the higher nutrients concentration in
soil, better soil water availability due to intermittent rainfall, and higher capability of
the rootstock plant ('Cleopatra' mandarin) for mineral uptake due to its superior root
morphology (higher specific root length and higher root fineness) in the study site as
compared with 'Kinnow' mandarin in the present study.
TABLE 2
Macronutrients (N, P and K) and micronutrients (Fe, Mn, Cu and Zn) content in
leaves of 'Kinnow' mandarin as affected by various regulated deficit irrigation (RDI) and full
irrigation (FI) during 2010 and 2011.
Treatments
Macronutrients (mg kg
-1
soil)
2010
2011
Mean
N
P
N
N
N
K
N
P
K
RDI
0
2.34
c
2.38
c
2.36
c
2.36
c
2.36
c
+1.48
c
+1.82
c
+0.60
a
+2.67
c
RDI
50
2.52
b
2.57
b
2.54
b
2.54
b
2.54
b
+1.71
b
+2.28
b
+0.67
a
+2.96
b
FI
2.69
a
2.71
a
2.70
a
2.70
a
2.70
a
+1.93
a
+3.03
a
+0.72
a
+3.29
a
2010 2011 Mean
Fe Mn Cu Zn Fe Mn Cu Zn Fe Mn Cu Zn
RDI
0
55.6
b
46.2
b
7.2
a
24.2
b
54.4
b
46.0
b
7.0
a
24.0
b
55.0
b
46.1
b
7.1
a
24.1
b
RDI
50
59.7
a
55.6
a
7.6
a
26.3
a
58.8
a
54.2
a
7.3
a
26.0
a
59.3
a
54.9
a
7.5
a
26.2
a
FI 62.6
a
61.5
a
8.2
a
27.1
a
61.3
a
61.0
a
8.0
a
26.9
a
61.9
a
61.3
a
8.1
a
27.0
a
Data in one column followed by different letter are significantly different at
P <
0.05,
as per separation by
Duncan's multiple range test.
RDI
0
= No irrigation at early fruit growth period (EFGP); RDI
50
= Irrigation at 50% crop evapotranspira-
tion at EFGP.
The micronutrient (Fe, Mn, Cu and Zn) concentration in leaves except Cu fol-
lowed the same trend of N and K under different irrigation treatments (Table 2). Over-
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