PhD

The efficiency of phosphobacterin culture in increasing the availability
of phosphorus from MRP and the resultant effect on the growth and yield or
banana, cv. Nendran was evaluated by conducting laboratory incubation and
field studies at FSRS, Kottarakkara during 1993-96.
Representative soil samples from the field at FSRS, Kottarakkara were
mixed with MRP, PS, FYM and lime in different combinations and incubated
at 60% WHC for 90 days. There was only a slight variation in the pH of
soil upto 20 days due to the effect of different inputs. After 20 days, the
soil showed a tendency to become slightly acidic reaching a mean value of
only 5.6 from the initial pH of 5.7.
The P solubilising effect was maximum with a combination of PB,
FYM and MRP. At the end of 90 days incubation, out of the 100 ppm P
applied as MRP, a maximum of 19.31 ppm P became available in this
treatment. P solubilised in the unamended soil was only 3.90 ppm and in
the other treatments receiving FYM, lime and MRP either alone or in different
other combinations, the values ranged from 9.2] to 16.73 ppm.
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The application of 3/4 level of the recommended P along with PB,
FYM and mulch has produced a significant positive effect on growth and
yield characters compared to all the other treatments including the treatment
as per package of practices recommendation of the KAU.
The highest bunch yield of 10.68 kg plant-1, which was significantly
superior to the yield in all the other treatments was recorded by plants
supplied with 3/4 level of recommended P as MRP, 10 kg FYM and PB
inoculated with proper mulching. The increase in yield in this treatment
was 7.55% higher than the yield from plants given fertilizers as per the POP
recommendations of the KAU.
The second highest bunch weight of 9.93 kg plant-1 was recorded by
the plants which received the full recommended level of P along with N and
K (POP recommendation). This yield was on par with the yield obtained in
the treatment where only 1/2 the recommended level of P was used along
with PB, FYM and mulch.
The use of FYM and mulching was round to be an essential practice
to obtain the maximum benefit from the use of PB.
It may be concluded from the results of the study that for increasing
the efficiency of utilization of applied P to banana in the acidic laterite soils,
a combined application of MRP and PB along with FYM and mulch is








essential. This package was found to be very effective in increasing the
available- P status or soil, promoting plant growth and increasing the yield
of banana with a lower level of P than what is recommended at present.
For achieving a higher net return from banana cultivation along with
other inputs like FYM and mulch, the use of 3/4 level of P and PB
inoculation may be considered as a viable alternative to the present POP
recommendation.
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