RA 00015.pdf - OAR@ICRISAT

Table 37. Yield of chickpea following rice at
ICRISAT Center, 1976.
Treatment Dry matter Grain
(kg/ha)
(kg/ha)
Control 1483 1090
Inoculated+150 kg
N/ha 2391 1762
Inoculated 2679 1801
L.S.D. (0.05) 364 278
SE± 161 123
C.V. (%) 7.4 7.9
increased sixfold between the 27th and 61st days,
mainly through growth of already-formed nodules.
Nitrogenase activity over this same period
increased fourfold. Nodules were most active per
unit of nodule tissue at the time of the first assay
(at 17 days) and there was little difference among
fanes. The medium-duration desi cv 850-3/27
formed the largest number of nodules and the
most nodule tissues. From the 17th day on, it had
more than double the number of nodules of the
other cultivars. These nodules also had the
greatest nitrogen-fixing activity (43 µ moles
C 2
H 4
/plant per hour at 61 days) and 850-3/27
was the only cultivar retaining any nitrogenase
activity at 81 days (5 µ moles/plant per hour).
This cutivar also yielded significantly more than
did the other four cultivars.
There was a marked diurnal periodicity in
nitrogenase activity, with activity increasing
rapidly from 0600 hours until about 0900, and
then declining rapidly, with a smaller secondary
peak at 1800 hours. Soil temperature apparently
had little effect on this pattern.
We surveyed the nodulation of 258 entries in
the working collection of chickpea germplasm
used in the breeding program at ICRISAT
Center. Nodule number and weight per plant
varied significantly among lines. A few cultivars
had high nodule numbers per plant at both the
18th and 50th days after planting. Some cultivars
could be identified as having consistently high or
low nodulation. Among cultivars, numbers ranged
from 8 to 97 per plant at 50 days after sowing,
with nodule dry weight ranging from 2 to 105
mg/plant. A survey of 200 germplasm lines
indicated that nodule number per plant was
greater at Hissar; nodules there also remained
active longer.
Nodules at ICRISAT Center were attacked,
apparently by insect grubs. The pest concerned
and the consequences of the damage will be
investigated.
C o m p a r a t i v e G r o w t h a n d
D e v e l o p m e n t
We compared the growth and development of a
number of chickpea cultivars at ICRISAT Center
and at Hissar. As usual, the yields at Hissar
were considerably higher than those at ICRISAT
Center. For example, the cultivar which performed
best of all in our trials at ICRISAT Center,
cv 850-3/27 (which is of medium-duration),
yielded 2029 kg/ha; its yield at Hissar was 3413
kg/ha. Patterns of accumulation of dry matter
during the reproductive phase, in the entire shoot
system as well as in the pods of this cultivar, are
plotted in Figure 37 for the two locations, along
with corresponding climatic data. At ICRISAT
Center, the plants matured 48 days after flowering
began, but at Hissar during the same period
(although there was more accumulation of dry
matter in the shoot system than at ICRISAT
Center), almost no pod formation took place.
During this period the maximum and minimum
temperatures at Hissar were considerably lower
than at ICRISAT Center. At Hissar, the cooler
temperature apparently suppressed pod-set and
consequently favored vegetative growth; as the
temperatures at Hissar rose, both pod development
and the rate of growth of the entire plant
increased. The maturation of the plants at Hissar
took place as the temperature and evaporation
rose to levels higher than those encountered
during the chickpea-growing season at
ICRISAT Center. These and other observations
described below indicate that senescence and
maturation of chickpeas are accelerated by higher
temperatures and/or higher rates of
evaporation.
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