Agriculture Reference
In-Depth Information
TABLE 7.6
Maximum Root Length (cm) of 15 Dry Bean Genotypes at Different N and Rhizobium
Inoculation Treatments
Genotype
N
0
N
1
N
2
N
3
Average
Aporé
21.33bcd
13.00cd
17.00bcd
22.33abc
18.41abcd
Pérola
25.33ab
11.67cd
11.33d
23.33ab
17.bcd
BRSMG Talisma
19.67cd
14.00cd
20.33abc
12.00d
16.50cde
BRS Requinte
24.33abc
13.33cd
21.67ab
26.67a
21.50a
BRS Pontal
18.33de
11.67cd
24.33a
14.00vd
17.08bcd
BRS 9435 Cometa
18.33de
17.33abc
12.33d
21.00abcd
17.25bcd
BRS Estilo
21.33bcd
22.67a
17.00bcd
17.67abcd
19.66ab
CNFC 10408
18.67d
21.00ab
11.67d
16.33bcd
16.91bcd
CNFC 10470
13.67ef
17.33abc
11.67d
19.00abcd
15.41def
Diamante Negro
13.33f
21.00ab
15.67bcd
16.67bcd
16.67bcde
Corrente
12.00f
14.00cd
17.33bcd
21.33abc
16.17def
BRS Valente
11.00f
12.33cd
14.33cd
15.67bcd
13.33f
BRS Grafite
28.33a
15.33bcd
14.00cd
19.67abcd
19.33abc
BRS Marfim
13.67ef
10.33d
14.33cd
16.33bcd
13.67ef
BRS Agreste
13.67ef
14.67cd
17.67abcd
18.67abcd
16.16def
Average
18.20a
15.31b
16.04b
18.71a
F-test
N levels (N)
**
Genotypes (G)
**
N × G
**
CVN (%)
17.94
CVG (%)
13.07
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
.
reported that in dry bean, drought avoidance results from root growth and soil water extraction
deep in the profile. N fertilization may increase crop root growth by increasing soil N availability
(Fageria and Moreira, 2011). N also improves the production of lateral roots and root hairs, as well
as increasing the rooting depth and root length density deep in the profile (Hansson and Andren,
1987). Hoad et al. (2001) reported that the surface application of N fertilizer increases root densities
in the surface layers of the soil. Figure 7.1 shows the influence of N and rhizobia treatments on root
growth of a dry bean genotype.
Fageria et al. (2012) studied the influence of N and rhizobia treatments on grain and straw yield of
15 dry bean genotypes under N and rhizobia treatments under field conditions (Tables 7.8 and 7.9).
Grain and straw yields were significantly influenced by N and rhizobium and genotype treatments.
The G × N interaction was also significant for these two traits. Hence, genotype response varied with
the variation in N treatments. In the first year, overall, the grain yield varied from 1011.53 kg ha
−1
produced at control treatment to 3463.53 kg ha
−1
produced at 120 kg N ha
−1
. The increase in grain
yield was 38% with inoculation compared to control treatment. The overall increase in grain yield
was 59% with the addition of 50 kg N ha
−1
+ inoculant. Similarly, the overall increase in grain yield
was 81% with the addition of 120 kg N ha
−1
compared to control treatments. In the second year,
