RA 00015.pdf - OAR@ICRISAT

which ratooning of pigeonpea has been tried,
more research is needed before attempting
conclusions.
Economic analysis of sorghum and maize/
pigeonpea intercrops. In the economic analysis,
we considered total costs of input and the total
value, including sorghum fodder. In the sorghum
trial on Alfisols, the net benefit was by far the
highest with Treatment 8. The next highest
benefit was recorded for Treatment 4, showing
that the traditional variety also responded reasonably
well to improved management and
fertilization. In all treatments with traditional
F Y M fertilization, the net benefits were negative
(Table 60).
The highest rate of return in the
maize/pigeonpea intercrop was for Treatment 8
(Fig 78). 8 The net benefits were highest for
Treatments 8 and 10. Traditional methods
(Treatment 1) showed negative net benefits and
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1000
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1
Variable costs (Rs/ha)
Figure 78. Returns from various steps in improved
technology with a maize/
pigeonpea intercrop on a Vertisol at
ICRISAT Center, 1976-1977. Treatment
numbers (top of bar) are explained
in Table 61.
8 Costs recorded for an application of 10 cm/ha is Rs 590,
which equate Rs 5900/ha-m or about $70/acre-foot. Tank
technology and water application research is under way to
find lower-cost methods of providing supplemental
irrigation.
3
8
4
7
9
10
rates of return, while all the other treatments
showed a positive rate of return (Table 61;
Fig 78).
Weed management in "Steps in Improved Technology"
trial. Weed growth early in the rainy
season is very rapid and if weeds are not removed
on time, serious yield reductions can result. In
Alfisols, which dry rapidly after a rain, hand
weeding can be easily achieved. However, in
Vertisols one may face serious problems when
frequent rains while crops are in the seedling
stage prevent the control of weeds by cultural or
hand-weeding methods. During the past season,
the improved technology treatments received a
minimal amount of herbicides which was very
helpful in reducing weed competition in the early
stage. This was particularly true on the Vertisols,
where with traditional management the average
number of woman days/ha for hand weeding was
48. With improved management, where alachlor
was used at the rate of 0.75 kg/ha and where
effective cultivation was possible in the broad
bed and furrow system, only 10 woman days per
hectare were needed. Thus, the hand weeding
cost/ha was Rs 171/ha more in the traditional
than in the improved management. In the A l -
fisols, the total of two hand weedings required 30
and 56 woman days/ha for improved and traditional
management, respectively; hand weeding
costs in traditional and improved treatments
were Rs 252 and 135 per ha, respectively.
Further investigations on Vertisols are under
way to try to develop an effective low-cost means
of controlling weeds in the early stages under the
wide range of rainfall conditions which occurs
from year to year.
Yield comparisons: random samples vs. entire
plot. In the maize/pigeonpea intercrop experiment
on Vertisols, grain yields were determined
by two methods-random selection of four sub
samples (1.5 by 8 m) vs. harvest of the entire plot.
Although there was some variation between
replicates, within given treatments the two procedures
correlated very closely. The average yield
of all treatments determined by the randomsample
procedure was 44 kg/ha higher than the
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