RA 00015.pdf - OAR@ICRISAT

Plants artificially lodged appeared to increase the
flush of new branches at the nodes above the bent
area; however, there was no significant effect
upon pigeonpea grain yield in either soil.
Setaria planted in the north-south row direction
in the pigeonpea intercropping system gave
significantly higher yields than plantings in the
east-west row direction. In the maize/pigeonpea
intercropping system, the maize yield trend was
similar, but the differences were not significant.
These results are in agreement with results on
wheat (Santhisegaram 1962) and on maize (Dungan
et al. 1955).
Evaluation of Genotypes of Low-growing
Legumes in a Pigeonpea/Cereal Intercrop
System
Several genotypes of low-growing legumes were
tested as a third crop in a pigeonpea/cereal
intercrop system. These low-growing legumes
were planted on broad beds in between the
pigeonpea and cereal rows, thus giving five rows
of crops for 150 cm of space.
In the Alfisols the introduction of mung beans,
cowpeas, black gram, or groundnut had no
significant effect upon the grain yield of the
rapid-growing upright Setaria. There was, however,
a small but significant depression in pigeonpea
grain yield when low-growing legumes were
introduced.
In spite of the slight pigeonpea yield reduction,
the total monetary value was greater in the threecrop
intercrop systems than in the two-crop
(pigeonpea/Setaria) system. There were, however,
large differences in the genotypes used,
especially in cowpeas and groundnuts. The best
cowpea (1152) and groundnut (Robut 33-1)
cultivars in the three-crop combinations produced
total monetary values of Rs 5230/ha,
about 50 percent above that produced in twocrop
systems.
The large differences in yield between genotypes
of low-growing legumes and the differential
effect upon the yield of the other two
intercrops needs further research to evaluate
genotypes and identify crop systems which are
mutually compatible.
Steps Towards Improved Technology
In the development and implementation of improved
technology, there are many facets or
"steps" involved. If one attempted to research
each of the individual phases in combination, the
total number of combinations would become
unmanageably large; also, the effects of many
individual facets have been investigated previously.
For convenience the many steps were
grouped into the following four phases: Variety,
Fertilization, Soil and Crop Management, and
Supplemental Water (where needed).
Sorghum on Alfisols. In 1975, a sorghum
experiment involving comparisons of traditional
vs. improved technology on an Alfisol was
initiated. This experiment was repeated in 1976
with a slight modification in treatments. During
the main crop (rainy) season the rainfall distribution
was adequate and fairly uniform; supplemental
water was not required. Thus, Treatments
9 and 10 were considered as additional
replications of Treatments 4 and 8, respectively,
and only the first three phases can be considered
in interpretation of the main crop yields; however,
Treatments 9 and 10 were considered
separately in the ratoon crop (Table 60). There
was a significant response to improved fertilization.
Improved variety and improved management
as single factors showed an upward trend,
but this was not significant. Sorghum yield in the
1975 experiment showed the same trends. In
comparing yields of improved vs. traditional
levels for these three factors applied individually,
the sum of the increase was 1489 kg/ha; however,
when all three factors were combined (Treatment
8), the increase was 3092 kg/ha-(Table 60).
Figure 77 shows the yield increases of improved
over traditional technology from the
application of the three steps (Variety, Fertilization,
and Soil and Crop Management) singly
and combined. Yield increases from the three
steps combined was double that of the sum of the
increase due to the same three steps applied
singly, thus illustrating the large synergistic effect
of the three steps when applied together in a
system. There was a slight synergistic effect when
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