Agriculture Reference
In-Depth Information
TABLE 7.4
Shoot Dry Weight (g Plant
−
1
) of 15 Dry Bean Genotypes at Different N and Rhizobium
Inoculation Treatments
Genotype
N
0
N
1
N
2
N
3
Average
Aporé
4.45hi
5.59cd
4.18gh
5.44 g
4.91h
Pérola
6.21defg
6.36c
7.57ab
9.27bcd
7.25de
BRSMG Talisma
4.83gh
6.49c
3.79h
3.47h
4.64h
BRS Requinte
6.74cde
6.83c
4.85fgh
10.85b
7.32de
BRS Pontal
3.26i
6.56c
5.72defg
7.98de
5.88g
BRS 9435 Cometa
6.62cdef
6.46c
4.71fgh
9.89bc
6.91ef
BRS Estilo
5.11fgh
6.48c
4.42fgh
6.97efg
5.74g
CNFC 10408
7.47bcd
10.89a
5.53efg
7.14ef
7.75cd
CNFC 10470
6.66cdef
6.38c
3.59h
9.10cd
6.43fg
Diamante Negro
10.47a
10.78a
7.23abcd
12.96a
10.36a
Corrente
6.23defg
4.45d
7.17abcd
6.19fg
6.01g
BRS Valente
5.26efgh
9.13b
5.93cdef
9.54bcd
7.46de
BRS Grafite
8.08bc
10.28ab
8.63a
10.19bc
9.29b
BRS Marfim
8.94ab
10.92a
7.48abc
5.99fg
8.33c
BRS Agreste
6.89cd
5.66cd
6.82bcde
6.28efg
6.41fg
Average
6.48c
7.55b
5.84d
8.08a
F-test
N levels (N)
*
Genotypes (G)
*
N × G
*
CVN (%)
8.54
CVG (%)
7.58
Source:
Adapted from Fageria, N. K. et al. 2014.
Commun. Soil Sci. Plant Anal
. 45:111-125.
*Significant at the 1% probability level. Means in the same column followed by the same letter are not significantly different
at the 5% probability level by Tukey's test. Average values were compared in the same line for significant differences among
N rates. N
0
= 0 mg N kg
−1
(control); N
1
= 0 mg N kg
−1
+ inoculation with rhizobial strains; N
2
= inoculation with rhizobial
strains + 50 mg N kg
−1
; and N
3
= 200 mg N kg
−1
.
produce maximum grain yield either with inoculation with rhizobial strains or with the inoculation
plus addition of a small amount of N. Hence, the addition of N in the inorganic form is essential to
obtain the maximum yield of dry bean.
The N × genotype significant interactions for the maximum root length and root dry weight
were observed, indicating that some genotypes were highly responsive to N treatments while
others were not (Tables 7.6 and 7.7). The maximum root length varied from 11 to 28.33 cm at
0 mg N kg
−1
, 10.33 to 22.67 cm at 0 mg kg
−1
+ inoculation with rhizobia, 11.33 to 24.33 cm at inocu-
lation + 50 mg N kg
−1
, and 12 to 26.67 cm at 200 mg N kg
−1
soil treatment. The average values for
these treatments were 18.2 cm for 0 mg N kg
−1
, 15.31 cm for inoculation treatment, 16.04 cm for
inoculation + 50 mg N kg
−1
, and 18.71 cm for 200 mg N kg
−1.
Across four N levels, the values of root
length varied from 13.33 to 19.66 cm. Variations in the root length of dry bean genotypes have been
reported by Fageria and Moreira (2011) and Fageria (2009).
The root dry weight varied significantly among bean genotypes at different N treatments (Table
7.7). It was significantly higher at 200 mg N kg
−1
soil treatment compared to other N treatments.
The increase in the root dry weight was about 20% at 200 mg N kg
−1
treatment compared to control
treatment. Figures 7.3 and 7.4 show root growth at low and high N rates of two dry bean genotypes.
