Agriculture Reference
In-Depth Information
between regions, species, and even genotypes within species (Belanger et al., 2001; Tei et al.,
2002; Ziadi et al., 2008; Yue et al., 2012a,b).
The author studied nitrogen concentration in the shoots and grains of 19 upland rice genotypes
(Table 3.5). Nitrogen concentration in the shoot and N uptake in the shoot (N concentration in the
shoot × shoot dry weight) was significantly influenced by N and genotype treatments (Table 3.5).
However, N concentration in the grain was not influenced either by N or by genotype treatments.
But N uptake in the grain was only influenced by N treatment. Nitrogen concentration in the shoot
varied from 4.8 to 8.9 g kg
−1
with an average value of 6.4 g kg
−1
at low N levels. All the genotypes
showed visual N deficiency symptoms at low N levels. This means that an average N concentration
of 6.4 g kg
−1
in the shoot can be considered as a deficient level in upland rice. At higher N levels, N
concentration in the shoot varied from 5.7 to 12.8 g kg
−1
with an average value of 9.5 g kg
−1
. Visual
N deficiency symptoms were not observed in any genotype at a higher N level. Hence, the average
value of 9.5 g N kg
−1
can be taken as an adequate concentration in the shoots of upland rice at har-
vest. Fageria (2014) reported an adequate concentration for maximum yield of about 8.7 g kg
−1
in the
shoots of upland rice under field conditions at harvest. The slightly higher value of N concentration
in shoots in the present study may be due to the use of different genotypes. Nitrogen concentration
TABLE 3.5
Concentration of N in the Shoot and Grain of Upland Rice Genotypes at Two N Levels
N Concentration in Shoot (g kg
−
1
)
N Concentration in Grain (g kg
−
1
)
Genotype
0 mg N kg
−
1
400 mg N kg
−
1
Across Two N levels
CRO 97505
6.3abc
8.7ab
10.9a
CNAs 8993
6.3abc
7.0ab
11.3a
CNAs 8812
6.9abc
9.2ab
13.3a
CNAs 8938
5.7bc
11.3ab
11.9a
CNAs 8960
6.0bc
10.4ab
12.4a
CNAs 8989
6.3abc
12.8a
11.7a
CNAs 8824
4.9c
9.8ab
12.6a
CNAs 8957
5.4bc
10.8ab
12.8a
CRO 97422
6.7abc
9.8ab
12.5a
CNAs 8817
5.6bc
10.5ab
12.1a
CNAs 8934
8.9a
10.5ab
11.5a
CNAs 9852
7.2abc
10.5ab
11.3a
CNAs 8950
7.6ab
9.1ab
12.6a
CNA 8540
4.8c
9.8ab
12.3a
CNA 8711
6.6abc
10.0ab
12.5a
CNA 8170
5.7bc
8.7ab
11.1a
BRS Primavera
6.0bc
7.2ab
12.5a
BRS Canastra
7.6ab
5.7b
12.1a
BRS Carisma
6.7abc
8.3ab
12.8a
Average
6.4
9.5
12.1
F-test
N level (N)
*
NS
Genotype (G)
**
NS
**
NS
N × G
CV (%)
16
14
Source:
From Fageria, N. K., O. P. Morais, and A. B. Santos. 2010.
J. Plant Nutr
. 33:1696-1711. With permission.
*,**, NS: Significant at the 5% and 1% probability levels and nonsignificant, respectively. Means followed by the same letter
in the same column are not significantly different at the 5% probability level by Tukey's test.
