Agriculture Reference
In-Depth Information
TABLE 3.14
Nitrogen Harvest Index of Dry Bean Genotypes at Two N Levels
Genotype
0 mg N kg
−
1
400 mg N kg
−
1
Pérola
0.82
0.73ab
BRS Valente
0.44
0.53b
CNFM 6911
0.80
0.79ab
CNFR 7552
0.57
0.68ab
BRS Radiante
0.67
0.69ab
Jalo Precoce
0.67
0.75ab
Diamante Negro
0.65
0.71ab
CNFP 7624
0.43
0.78ab
CNFR 7847
0.80
0.85a
CNFR 7866
0.47
0.74ab
CNFR 7865
0.71
0.69ab
CNFM 7875
0.45
0.85a
CNFM 7886
0.44
0.78ab
CNFC 7813
0.47
0.85a
CNFC 7827
0.71
0.85a
CNFC 7806
0.69
0.78ab
CNFP 7677
0.71
0.85a
CNFP`7775
0.70
0.85a
CNFP 7777
0.79
0.88ab
CNFP 7792
0.62
0.72ab
Average
0.63
0.75
F-test
N rate (N)
**
Genotype (G)
**
N × G
**
Source:
From Fageria, N. K., L. C. Melo, and J. P. Oliveira. 2013a.
J. Plant Nutr
. 36:2179-2190.
With permission.
**Significant at the 1% probability level. Within the same column, means followed by the same let-
ter do not differ significantly at the 5% probability level by Tukey's test.
should be used in combination rather than in isolation. The basic principles of conducting green-
house and field experiments are discussed in the succeeding section.
3.7.1 G
reenhouse
or
C
ontrolled
C
ondItIon
e
xperIments
Research is the foundation of technological improvements. The standard of living of a country is
correlated to the use of technology (Fageria, 2005). The low yields of crops in some parts of the
world or countries are the result of actions and interactions of many factors and there are no simple,
easily implementable solutions. A better understanding of the biological, climatic, edaphic, and
management factors through research and the development of production technologies in the appro-
priate sociopolitical-economic climate can help increase crop production in such regions. Further,
in the twenty-first century research, one of the key factors guiding research will be the need to
develop low-cost technology components that do not require a heavy application of purchase inputs
with minimum degradation of natural resources (Fageria, 2005).
In agriculture science, soil fertility and plant nutrition are important subjects whose contribu-
tion in increasing crop yields is well known. Borlaug and Dowswell (1994) reported that as much
as 50% of the increase in crop yields worldwide during the twentieth century was due to the use of
