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Vijaya et al. World Journal of Pharmacy and Pharmaceutical Sciences
PLANT GROWTH PROMOTIONAL EFFECT OF DIFFERENT
COMBINATIONS OF VERMICOMPOST, PSB AND RHIZOBIUM ON
SORGHUM
Pudur Girija1
and Dr. T. Vijaya2*
1Rayalaseema University, Kurnool – 518002.
2Professor, Department of Botany, S.V. University, Tirupati – 517502.
ABSTRACT
Biofertilizers are the most advanced biotechnological products
necessary to support developing organic agriculture, green agriculture
and sustainable agriculture. Composting is considered to be one of the
most suitable ways of converting organic wastes into products that are
beneficial for plant growth. The most commonly used bio-inoculants to
supply the nutritional need of the plants are phosphorous soluble
microorganisms (PSM), nitrogen fixers (Azotobacter) and
vermicompost. Vermicompost, Azotobacter and PSB inoculum were
prepared and its effect on plant growth was determined in terms of
plant growth parameters and physiological parameters. The results revealed that inoculation
of vermicompost, Azotobacter and PSB enhanced the shoot length, fresh and dry biomass of
root and shoot, number of leaves compared to control plants. The contents of chlorophyll,
carbohydrates, were also found increased in treatment plants. The inoculation of
vermicompost, Azotobacter and PSB was found superior than single inoculum not only in
promoting plant growth, but also in maintaining soil fertility.
KEYWORDS: Vermicompost, PSB (Phosphate Solubilizing Bacteria), Rhizobium,
Sorghum, Azotobacter.
INTRODUCTION
Biofertilizers are the most advanced biotechnological products necessary to support
developing organic agriculture, green agriculture and sustainable agriculture. Biofertilizers
are defined as ready to use live formulates of beneficial microorganisms which on application
WORLD JOURNAL OF PHARMACY AND PHARMACEUTICAL SCIENCES
SJIF Impact Factor 6.041
Volume 5, Issue 6, 1537-1551 Research Article ISSN 2278 – 4357
*Corresponding Author
Dr. T. Vijaya
Professor, Department of
Botany, S.V. University,
Tirupati – 517502.
Article Received on
02 April 2016,
Revised on 23 April 2016,
Accepted on 13 May 2016
DOI: 10.20959/wjpps20166-6940
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Vijaya et al. World Journal of Pharmacy and Pharmaceutical Sciences
to seed, root or soil, mobilizes the availability of nutrients by their biological activity and
help to build up the soil micro flora which in turn improves the soil fertility.
Using more local organic materials from agro-industrial by-products as nutrient sources may
help. Composting is considered to be one of the most suitable ways of converting organic
wastes into products that are beneficial for plant growth.[1]
Compost inoculated with N2-
fixing bacteria, which can fix atmospheric nitrogen, solubilized phosphorous and stimulate
plant growth by biosynthesis of plant growth promoting substances (plant growth promoting
rhizobacteria, PGPR) may be particularly useful.[2]
The main sources of biofertilizers are bacteria, fungi and cyanobacteria. The most commonly
used bio-inoculants to supply the nutritional need of the plants are phosphorous soluble
microorganisms (PSM), nitrogen fixers (Azotobacter) and vermicompost. Soil
microorganisms have enormous potential in providing soil phosphates for plant growth.
Phosphorous biofertilizers (Pseudomonas sp.) can help in increasing the availability of
accumulated phosphorous for plant growth by solubilisation.[3]
Most of the soil phosphorus is
in unavailable form and hardly about 1 to 2% of it is incorporated in to the above ground
parts of the plants. Phosphorus is a major growth-limiting nutrient and unlike the case for
nitrogen, there is no large atmospheric source that can be made biologically available.[4]
Efficiency of phosphorus fertilizer throughout the world is around 10-25%[5]
and
concentration of bioavailable phosphorus in soil is very low reaching the level of 1.0mg Kg-1
soil.[6]
Soil microorganisms play a key role in soil phosphorus dynamics and subsequent
availability of phosphate to plants.[7]
Phosphate Solubilizing Bacteria (PSB) are being used as
biofertilizers since 1950s.[8]
Release of phosphorus by PSB from insoluble and
fixed/adsorbed forms is an important aspect regarding phosphorus availability in soils.
Microbial biomass assimilates soluble P and prevents it from adsorption or fixation.[9]
Phosphate solubilization is the result of combined effect of pH decrease and organic acids
production.[10]
Sorghum is one of the main staple food for the world‟s poorest and most food insecure
people. It is known to be cultivated as food grain in Africa and Asia. About 26 percent of the
Indian population is deficient in calories and 28 percent in protein (Chand et al. 2003).
Sorghum is a cheap source of energy, protein, iron and zinc next only to pearl millet among
all cereals and pulses (Rao et al. 2006). However, it is popularly grown for feed, fodder and
more recently for bio-fuel purposes in the world.[11]
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Vijaya et al. World Journal of Pharmacy and Pharmaceutical Sciences
In India, sorghum is the fourth most important cereal consumed and cultivated during both
rainy (Kharif) and post-rainy (Rabi) seasons. However, the area under sorghum in India has
declined drastically from 18.6 m ha in 1970 to 7.93 m ha in 2007-08. The total production
also declined from 9.72 m t to 7.78 m t. With emerging cash requirements, farmers
diversified from traditional mono-cropping with sorghum to commercial crops like cotton,
pulses and oilseeds. Both profit motivated and consumption driven factors led to this decline.
Also the growth in productivity varied across the important sorghum growing states. In
contrast, in the recent years, sorghum in rice-fallows in coastal Andhra Pradesh, especially in
Guntur district is gaining popularity among the farmers. It has an average sorghum
productivity of 5.7 t/ha in 2006-07, which is the highest in the country. The farmers are using
inputs especially agrochemicals indiscriminately due to lack of standardized production
technologies for this region. Although they are getting higher yields but the profit margin
could be increased by using cost-effective technologies. Farmers are also not homogenous
with respect to their behaviour in using resources optimally. Under this premises, an attempt
was made to analyze the resource-use efficiency of the sorghum growers and the
requirements in adjustments for optimum utilization of resources for sorghum cultivation in
rice-fallows.
Vermicompost, Phosphate Solubilizing Bacteria (PSB) and free living nitrogen fixing
bacteria are the most widely used biofertilizers significantly contributing N, P and K to plants
and also providing resistance to drought.[12]
However, very limited information is available
regarding the effect of the biofertilizers on the growth and yield of crop plants. In the above
contest the present study was carried out to recommend suitable combination of biofertilizers
application for cultivation of sorghum at commercial level. The present investigation was
under taken with the following objectives.
MATERIALS AND METHODS
Collection of seeds
The seeds of sorghum were obtained from Sri Venkateswara Agriculture Research Institute,
Tirupati, Andhra Pradesh. The seeds of uniform size were separated and surface sterilized
with 0.05% sodium hypo chloride after through washing with tap water before sowing.
Vermicompost
Fresh leafy vegetation was collected from different sites of Sri Venkateswara University
campus at 10 -20 % flowering stage and chopped into the small pieces (2-3 cm). Equal
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Vijaya et al. World Journal of Pharmacy and Pharmaceutical Sciences
amount of weed vegetation was used for each treatment. The material was uniformly spread
into the pits to a height of about 5 cm and sprinkled with 10 percent cow dung slurry (1 kg
dung in 10 liter water) and soil. afterwards the remaining plant material was added and
finally, the pits were sealed with dung slurry and fine clay to prevent loss of heat or exchange
of gases. After partial decomposition (15 days), first turning was given for uniform
decomposition and sufficient amount of water was sprinkled for maintaining 50 - 60 percent
moisture. Then the earthworms of the species Eiseniafoetida and Eudriluseugeniae (50 - 60
individuals per pit) were released. Identification of earthworms was done by [13]
. The
vermicomposting process was completed within 15 days and completely decomposed, fine,
dark brown coloured granular excreta was obtained for the field experiment.
Azotobacter inoculum
Culture of Azotobacter chrocooccum was obtained from Regional Biofertilizers Development
Centre, Bangalore Division, India. From this mother culture carrier based inoculum was
developed by growing it on nitrogen free nutrient broth as described by Ashby for 3 days at
250 C temperature. Then the culture was mixed with lignite powder and this carrier based
inoculum was mixed with soil at the time of planting the test plants.
Composition of medium (Ashby‟s medium) used for growing Azotobacter mother culture
(gm/lit): Mannitol - 20.0, K2HPO4 -0.1, MgSO4.7H2O-0.2, NaCl-0.2, K2SO4-0.1, CaCO3-5.0,
Distilled Water-1000ml with pH – 7.2 at 250 C.
PSB inoculum
Culture of Pseudomonas striata was obtained from Regional Biofertilizers Development
Centre, Bangalore Division, India. P. striatawas inoculated in 500 ml sterilized Pikovskya
broth and incubated at 30o
C for 3 days in a BOD chamber. After obtaining the desirable
growth (107-10
8 cells/ml), the broth was mixed with wood charcoal by maintaining moisture
content at 40 percent and pH 7.0. The slurry thus prepared was mixed with soil at the time of
planting.[14]
Composition of Pikovskaia’s medium
The following constituents were mixed to prepare Pikovskya medium in gr/lit composition.
Ca3PO4 - 5.0, (NH4)2SO4 - 0.5, Dextrose - 10.0, KCl - 0.2, MgSO4.7H2O - 0.1, KCl - 0.2,
Yeast extract - 0.5, MnSO4 – 0.0001, FeSo4 – 0.0001, Agar - 15.0, Distilled water - 1000ml
and pH - 7.0.
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Location of experimental site
The plants were maintained under glass house conditions in the botanical garden of Botany
department, Sri Venkateswara University, Tirupati, Andhra Pradesh, India. The climate was
warm and humid at the time of starting the experiment. The weekly average maximum and
minimum temperatures ranged between 27.1o C to 36.2
o C and 14.6
o C to 23.7
o C
respectively during the experimental period.
Experimental design
T1 : Control (No inoculation)
T2 : Inoculation with vermicompost
T3 : Inoculation with nitrogen fixing bacteria (A. chrocooccum)
T4 : Inoculation with phosphate solubilizing bacteria (P. striata)
T5 : Inoculation with vermicompost and A. chrocooccum
T6 : Inoculation with vermicompost and P. striata
T7 : Inoculation with vermicompost, A. chrocooccum and P. striata
Seedlings
Sorghum plants were grown in plastic pots containing a sterilized mixture of soil and sand
(1/1 w/w). Eight experimental replicates were prepared for each treatment. Seeds of sorghum
were surface sterilized with 0.005% sodium hypocholride for 45 min and rinsed twice with
sterile water and then sown into a 5 cm Depth in pots, grown in a greenhouse under natural
photoperiods (23.5/18°C day/night, 6000/4000 lux light intensity) for three months. Inoculum
of vermicompost (20gm/kg soil), 20 ml of free living N2 fixing bacteria and 20 ml of PSB
was laid around the seed.
Growth parameters
The growth parameters were measured on every 30th
, 60th
and 90th
day of the plant growth in
all the treatments.
Shoot length
The plants were uprooted carefully without damaging the root system. The shoot length of
the plants was measured from the collar region to the tip of the plant, using a standard scale
and values were recorded in centimeters.
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Vijaya et al. World Journal of Pharmacy and Pharmaceutical Sciences
Number of leaves
Number of fully opened leaves in all the treatments was counted manually.
Fresh shoot biomass
The shoot portion was separated from the root system and was blotted on the blotting paper to
absorb the moisture. The weight of the shoot was estimated using an electronic monopan
balance and the values were expressed in grams.
Fresh root biomass
The plants were carefully uprooted and roots were washed in running tap water to clear the
soil particles. The washed roots were blotted on the blotting paper and the roots were
weighed using monopan electronic balance. The values were expressed in grams.
Dry shoot biomass
After measuring the fresh shoot biomass of the plants, it was placed in a paper cover and
dried in a hot air oven at 60o C for 2 days to attain constant weight. Then dry weights of the
shoots were weighed using monopan electronic balance and recorded in grams.
Dry root biomass
To obtain the dry root biomass of the plants, the roots were placed in a paper cover and dried
in a hot air oven at constant temperature of 60o
C, for 48 hours. Then dry weights of the roots
were weighed using monopan electronic balance and recorded in grams.
PHYSIOLOGICAL PARAMETERS
Estimation of chlorophyll content
The chlorophyll content of the plants was estimated in all the treatments on 30th
, 60th
, and 90th
days according to the method of.[15]
The leaves were excised from the plants and washed with
distilled water and blotted dry. One gram of leaf sample was homogenized with 80 % acetone
in a pre-chilled mortar. A pinch of CaCO3 was added to facilitate easy grinding. The extract
was then centrifuged at 5000 rpm for 15 minutes and the supernatant was made up to 10 ml
with 80 % acetone. The supernatant was filtered through Whatmann No. 1 filter paper and
the clear supernatant was transferred to 1 cm glass cuvette. The absorbance was measured
using specific absorptions co-efficient for chlorophyll a and b at 645 nm and 663 nm using 80
% acetone as blank in Shimadzu (UV – 240) double beam spectrophotometer. The following
simultaneous equations were setup for measuring chlorophyll concentrations.
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Vijaya et al. World Journal of Pharmacy and Pharmaceutical Sciences
Chlorophyll „a‟ = (0.0127 x OD at 663 nm)-( 0.00269 x OD at 645 nm).
Chlorophyll „b‟ = (0.0229 x OD at 645 nm)-( 0.00468 x OD at 663 nm).
Estimation of carbohydrates
Carbohydrate fractions such as reducing sugars, non–reducing sugars were extracted from
shoot and root from all the treatments according to the method of[16]
and the content was
estimated on 30, 60 and 90 days of plant growth. 200 mg of oven dry powder was extracted
with 80 % boiled ethanol and was centrifuged at 2000 rpm. The supernatant was reduced to a
volume of 10 ml on boiling water bath and cooled at room temperature. About 5 ml of
saturated neutral lead acetate was added to the alcoholic extract to precipitate proteins. 10 ml
of saturated aqueous disodium phosphate was added to the contents to precipitate excess of
lead. About 300 mg of activated charcoal was added and the contents were shaken at intervals
of 30 minutes and filtered. The filtrate was diluted to 100 ml with distilled water in a
volumetric flask and was used for estimation of reducing and non-reducing sugars.
Estimation of starch
Starch was estimated from the residue left behind the alcoholic extraction of the original
material according to the method of.[17]
The residue was solubilized with 5 ml of 52%
Perchloric acid (PCA) for 30 min, filtered and was made up to 100 ml in a volumetric flask
with distilled water. About 0.2 ml of PCA extract was taken into a test tube to which 2 ml of
distilled water was added. Four ml of freshly prepared and cooled Anthrone reagent was
added to the test tube. The contents were heated for 5 min at 100o C on a water bath and later
cooled to room temperature. The colour intensity of the contents was read at 630 nm using
spectrophotometer.
RESULTS
The results of the experiments carried out on “Effect of Vermicompost, nitrogen fixing
bacteria (A. chrococcum) and Phosphate solubilizing bacteria (pseudomonas straita) on the
growth and biochemical aspects of sorghum” were presented in this chapter.
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Vijaya et al. World Journal of Pharmacy and Pharmaceutical Sciences
10.26 22.75
30.21
13.08 27.87 38.11
15.23 28.5 39.16
15.66 28.75 40.37
17.65 31.12
52.17
18.06 33.87
50.6
22.7
49.87
58.66
0
10
20
30
40
50
60
70
80
90
100
30 days 60 days 90 days
Sh
oot le
ngth
(cm
)
Number of days after treatment
T1
T2
T3
T4
T5
T6
T7
Fig: 1. Effect of vermicompost, Azotobacter and PSB on shoot length of sorghum
Table1: Effect of vermicompost, Azotobacter and PSB on fresh bio mass weight (gm) of
sorghum.
Treat-ments
Shoot fresh biomass Root fresh biomass Total fresh biomass
Days after treatment
30
days
60
days
90
days
30
days
60
days
90
days
30
days
60
days
90
days
T1 0.85 1.46 2.11 0.32 0.71 1.01 1.25 2.25 3.33
(0.03) (0.09) (0.06) (0.05) (0.03) (0.07) (0.06) (0.04) (0.29)
T2 1.73 2.73 3.27 0.65 1.38 1.51 2.39 4.11 4.81
(0.06) (0.10) (0.08) (0.04) (0.05) (0.10) (0.03) (0.24) (0.16)
T3 1.68 2.98 3.41 0.71 1.43 1.61 2.43 4.43 5.06
(0.06) (0.41) (0.19) (0.04) (0.09) (0.09) (0.04) (0.06) (0.11)
T4 1.87 2.95 3.53 0.67 1.48 1.73 2.58 4.44 5.72
(0.21) (0.21) (0.33) (0.02) (0.10) (0.06) (0.08) (0.110 (0.09)
T5 3.73 5.28 6.87 1.42 2.02 2.38 5.15 7.33 9.25
(0.19) (0.32) (0.41) (0.09) (0.08) (0.19) (0.10) (0.21) (0.23)
T6 3.82 5.77 6.91 1.35 2.08 2.68 5.23 7.86 9.59
(0.11) (0.18) (0.19) (0.05) (0.13) (0.11) (0.12) (0.15) (0.58)
T7 5.38 7.75 8.72 2.05 2.88 4.01 7.49 10.83 12.93
(0.28) (0.31) (0.25) (0.08) (0.09) (0.20) (0.15) (0.23) (0.85)
CD 0.063 0.087 0.094 0.031 0.028 0.044 0.079 0.094 0.12
SEM 0.082 0.104 0.073 0.032 0.05 0.019 0.081 0.043 0.054
Values within the brackets indicate standard deviation. Each value represents mean of eight
replications.
Table2: Effect of Vermicompost, Azotobacter and PSB on dry biomass (g) of sorghum.
Treatme-nts
Shoot dry biomass Root dry biomass Total dry biomass
Days after treatment
30
days
60
days
90
days
30
days
60
days
90
days
30
days
60
days
90
days
T1 0.29 0.47 0.71 0.11 0.26 0.44 0.40 0.73 1.19
(0.05) (0.04) (0.08) (0.02) (0.01) (0.02) (0.04) (0.03) (0.04)
T2 0.53 0.94 1.08 0.28 0.43 0.55 0.83 1.35 1.58
(0.04) (0.05) (0.11) (0.03) (0.06) (0.10) (0.03) (0.03) (0.06)
T3 0.57 0.98 1.15 0.30 0.47 0.57 0.90 1.45 2.51
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Vijaya et al. World Journal of Pharmacy and Pharmaceutical Sciences
(0.08) (0.13) (0.11) (0.04) (0.07) (0.03) (0.06) (0.04) (0.05)
T4 0.61 0.93 1.16 0.35 0.46 0.59 0.94 1.38 2.25
(0.07) (0.04) (0.12) (0.04) (0.07) (0.11) (0.05) (0.02) (0.04)
T5 1.26 1.76 1.94 0.58 0.67 0.94 1.84 2.41 2.82
(0.16) (0.18) (0.14) (0.06) (0.07) (0.13) (0.03) (0.32) (0.05)
T6 1.28 1.88 1.92 0.57 0.70 0.91 1.85 2.51 2.69
(0.12) (0.14) (0.13) (0.07) (0.05) (0.15) (0.03 (0.06) (0.03)
T7 1.77 2.58 2.89 0.83 0.98 1.05 2.56 3.25 3.33
(0.14) (0.20) (0.12) (0.10) (0.07) (0.12) (0.02 (0.24) (0.03)
CD 0.022 0.031 0.028 0.015 0.028 0.032 0.041 0.024 0.038
SEM 0.061 0.072 0.053 0.041 0.027 0.038 0.014 0.009 0.012
Values within the brackets indicate standard deviation.
Each value represents mean of eight replications.
3.78
5.75
6.12
4.75
6.87
7.12
4.83
6.75
7.25
5.12 6.22 7.12
5.75 7.07
7.25
5.37
6.89
7.12
6.12 7.27
7.87
0123456789
101112
30 days 60 days 90 days
Nu
mb
er o
f leaves
Number of days after treatment
T1
T2
T3
T4
T5
T6
T7
Fig. 2: Effect of vermicompost, Azotobacter and PSB on leaf number of sorghum.
0.43 0.62 0.78
0.48
0.7
0.89
0.5
0.73
0.99
0.51 0.71
0.95
0.66
0.88 1.09
0.6
0.86 1.05
0.73
1.11 1.32
0
0.5
1
1.5
2
30 days 60 days 90 days
Ch
loro
ph
yll
a (
mg
/g)
Number of days after treatment
T1
T2
T3
T4
T5
T6
T7
Fig 3: Effect of vermicompost, Azotobacter and PSB on chlorophyll contentof sorghum.
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Vijaya et al. World Journal of Pharmacy and Pharmaceutical Sciences
1010.56
1123.07
1402.82
1521.63
1728.12
1841.02
1413.4
1688.22
1802.39
1430.4
1712.62
1863.02
1802.23
2033.82
2233.07
1761.88
2055.21
2192.12
1855.22
2166.42
2302.28
0
500
1000
1500
2000
2500
3000
3500
30 days 60 days 90 days
Non
-red
ucin
g s
uga
rs (
µg/g
)
Number of days after treatment
T1
T2
T3
T4
T5
T6
T7
Fig 4: Effect of Vermicompost, Azotobacter and PSB on shoot non-reducing sugars
content of Sorghum.
302.12
481.41
564.93
383.66 620.73
741.09
359.82 618.11
728.46
370.23 625.86
723.34
506.36
721.63
903.14
484.23 747.29
913.44
568.11
864.32
985.23
0
200
400
600
800
1000
1200
1400
30 days 60 days 90 days
Red
ucin
g s
ug
ars (
µg
/g)
Number of days after treatment
T1
T2
T3
T4
T5
T6
T7
Fig 5: Effect of Vermicompost, Azotobacter and PSB on root reducing sugars content of
Sorghum.
10.88
12.48
18.24
14.01
19.69 27.57
15.03
18.99
26.04
13.51
18.2 23.05
20.17 30.12 38.92
22.05 31.58
37.19
25.35 34.01 41.81
0
10
20
30
40
50
60
30 days 60 days 90 days
Sta
rch
(m
g/g
)
Number of days after treatment
T1
T2
T3
T4
T5
T6
T7
Fig 6: Effect of Vermicompost, Azotobacter and PSB on shoot starch content of
Sorghum.
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Vijaya et al. World Journal of Pharmacy and Pharmaceutical Sciences
Fig 7: T1 Control, T2 vermicompost, T3 nitrogen fixing bacteria (A. chrocooccum), T4
phosphate solubilizing bacteria (P. striata), T5 vermicompost and A. chrocooccum, T6
vermicompost and P. striata, T7 vermicompost, A. chrocooccum and P. striata.
DISCUSSION
To maximize the beneficial plant growth responses, it is important to identify the efficient
strains of PGPRs for the planting situation. It was in this context that efforts were made to
study the plant growth promoting rhizomicroorganisms of sorghum plants with special
reference to vermicompost, nitrogen fixers (Azotobacter chrococumm), phosphate
solubilizers (pseudomonads putida). The results obtained pertaining to this study is discussed
hereunder. The results effect of such an enriched vermicompost and microbial inoculants on
growth, biomass and biochemical aspects of sorghum were studied in pot culture at the glass
house. Supplementing the enriched vermicompost and microbial inoculants to the red soil at
different levels was found to significantly increase the height of the plant, shoot length,
number of leaves, and fresh and dry weight of shoot and root, total fresh and dry matter of the
plant. The vermicompost and microbial inoculants with good amount of plant nutrients has
promoted plant growth.
The plant shoot length was increased significantly with the multiple inoculations compared
with single, dual, triple inoculations and control at 30th
, 60th
and 90th
days after sowing. The
maximum shoot length was recorded in the treatment T7 with22.7, 42.87 and 58.66 cm,
respectively,which received combined inoculation of vermicompost, Azotobacter chroccum,
Pseudomonas putida, which was however on par with treatment T7, which received
combined inoculation of vermicompost, Azotobacter chroccum, and Pseudomonas putida.
The combined inoculations of beneficial organisms have been reported to perform better than
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Vijaya et al. World Journal of Pharmacy and Pharmaceutical Sciences
the single inoculation treatments.[18]
The increase in plant growth in the combined inoculation
treatment of all the inoculants may be ascribed for enhanced N and P nutrient uptake.[19]
However, another mechanism with which it is possible to explain similar effects was the
synthesis and exudation of plant growth promoting substances like IAA and GA.[20]
IAA and
GA are known to enhance the shoot length root length and also the plant growth.[21]
In accordance with the root and shoot growth, the fresh and dry matter content in root and
shoot as well as total dry matter of sorghum plants were also enhanced due to the inoculation
of beneficial organisms. The maximum shoot and root dry weight was recorded in the
treatment T7. Consortia consisting of vermicompost, Azotobacter chroccum, pseudomonas
putida, inoculants increased the root with fresh and dry 5.06 g per plant and shoot fresh and
dry matter of 11.61 g per plant over uninoculated control. Combined inoculations further
enhanced the root and shoot fresh and dry biomass of 16.67 g per plant. Similar results of
increase were reported due to combined inoculation of vermicompost, Azotobacter,
phosphate solubilizers.[22]
Till now, the explanations offered to account for the beneficial action of non-symbiotic
microorganisms on plants have been two fold, first is the nitrogen fixing ability of the
microorganisms and second is the ability of microorganisms to elaborate growth promoting
substances such as vitamins, hormones and amino acids[23-24]
attributed the observed
beneficial response of crop plants to inoculation with A. chroococcum to growth substances
produced by the organisms in addition to the fixed nitrogen made available to the plants.
Chlorophyll content was maximum in the combined inoculation treatment (T7) followed by
T6, T5 at 30, 60 and 90 days after Planting significantly superior over the un inoculated
control, Similar increase in chlorophyll content in several legume crops have been reported
by[25-26]
. The increase in the chlorophyll content attributed can be ascribed to the presence of
rhizomicrobes in the rhizosphere influencing the crop roots to secrete growth promoting
substances, which in turn might have enhanced the growth of N2-fixers, P-solubilizing
organisms in situ and a synergistic effect might have achieved in the treatment, T6 and T7.
Enhancement of rhizomicrobial growth in case of treatment T7 (triple inoculation) might be
due to inoculation of vermicompost and N2-fixers, P-solubilizers (Azotobacter and PSB),
where more root hairs become susceptible for rhizomicrobial infection and also might be due
to better provision for P-availability by P-slubilizers.[27]
Moreover, N-fixers like Azotobacter
and P-solubilizers are known to enhance the plant growth.[28]
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Vijaya et al. World Journal of Pharmacy and Pharmaceutical Sciences
In the present study, vermicompost, Azotobacter and PSB treatment enhanced the plant
growth, quantity of starch and slightly reducing and non-reducing sugars. Increased carbon
fixation, activation of enzymes and increased photosynthetic rate are supposed to be the
possible reasons for increase in starch content.[29]
A similar result was observed by.[30-31]
CONCLUSION
In the present study, the effect of vermicompost, Azotobacter and PSB as single, dual or
mixed inoculum was studied on the growth and physiology of sorghum an important crop
plant. The results revealed that inoculation of vermicompost, Azotobacter and PSB enhanced
the shoot length, fresh and dry biomass of root and shoot, number of leaves compared to
control plants. The contents of chlorophyll, carbohydrates, were also found increased in
treatment plants. The inoculation of vermicompost, Azotobacter and PSB was found superior
than single inoculum not only in promoting plant growth, but also in maintaining soil fertility.
The application of vermicompost, Azotobacter and PSB as bioinoculants in agriculture,
horticulture and other land plants management systems can reduce cost and dependence on
xenobiotics chemicals enhancing our ability to exist in harmony with our living planet.
REFERENCES
1. Stantiford E.I, Deber-toldi M, M L Ferranti, P Hermite F Zucconi.. Resent developments
in composting. In Compost, Production, Quality and Use. Eds., London: Elsevier, 1987;
52–62.
2. Dobbelaere S, Vanderleyden J, Okon Y. Plant growth promoting effects of diazotrophs in
the rhizosphere. Crit. Rev. Pl. Sci., 2003; 22(2): 107-149.
3. Gyaneshwar P, Naresh Kumar G, Parekh L.J, Poole P.S. Role of soil microorganisms in
improving „P‟ nutrition of Plants. Plant Soil, 2002; 245: 83-93.
4. Ezawa T, Smith S.E, Smith F.A. P metabolism and transport in AM fungi. Plant Soil,
2002; 244: 222-230.
5. Isherword K.F, Ahmad N, Hamid (eds.) A,. Fertilizer use and environment. In: Proc.
Symp. Plant Nutrition Management for Sustainable Agricultural Growth. NFDC,
Islamabad. 1998; 57-76.
6. Goldstein A.H. Involvement of the quinoprotein glucose dehydrogenises in the
solubilization of exogenous phosphates by gram-negative bacteria. In: A. TorrianiGorini,
E. Yagil and S. Silver (eds.), Phosphate in microorganisms: Cellular and Molecular
Biology. ASM Press, Washington, DC, 1994; 197-203.
www.wjpps.com Vol 5, Issue 6, 2016.
1550
Vijaya et al. World Journal of Pharmacy and Pharmaceutical Sciences
7. Kudashev I.S. The effect of phosphobacteria on the yield and protein content in grains of
autumn wheat, maize and soya bean. DokiAkadSkhNank, 1956; 8: 20-23.
8. Krasilinikov N.A. On the role of soil micro-organism in plant nutrition. Microbiologiya.
1957; 26: 659-672.
9. Khan K.S, Joergensen R.G. Changes in microbial biomass and P Fractions in biogenic
household waste compost amended with inorganic P fertilizers. Biorecourse Technology,
2009; 100: 303-309.
10. Fanken H, Nwaga D, Denbel A, Dieng L, Merbach W, Etoa F.X. Occurance and
Functioning of P-solubilizing microorganisms from oil palm tree (Elaeisguineensis)
rhizosphere in Cameroon. African Journal of Biotechnology, 2006; 5: 2450-2460.
11. Kleih Ulrich, Bala Ravi S, Dayakar Rao B, Yoganand B. Industrial utilization of
sorghum in India. Working Paper Series No.4 ICRISAT. Patancheru 502 324, Andhra
Pradesh, India, 2000; 44.
12. Giridhar K, Sarada C, Yellamandareddy T. Efficacy of biofertilizers on the performance
of rainfed coriander (Coriandrumsativum) in vertisols. Journal of Spices and Aromatic
Crops, 2008; 17(2): 98-102.
13. Julka J.M. The Fauna of India and Adjacent Countries. Megadrile: Oligochaeta
(earthworms) Haplotaxida: Lumbricina: Megascolecoidea: Octochaetdae. Zoological
Survey of India, India, 1988; 406.
14. Gaur, A.C, Alagawadi, A.R. Inoculation of Azospirillum brasilense and phosphate -
solubilizing bacteria on yield of sorghum [Sorghum bicolor (L.) Moenc
h] in dry land. Trop. Agric, 1992; 69: 347-350.
15. Arnon D.I. Copper enzymes in isolated chloroplasts. Polyphenoloxidase in Beta vulgaris.
Plant Physiology, 1949; 24: 1-15.
16. Highkin H.R, Frankel F. Studies on growth and metabolism of barley mutant lacking
chlorophyll b. Plant. Physiol, 1962; 37: 314-320.
17. Mc Cready R.M, Guggole J, Silviera V, Owens H.S. Determination of starch and amylase
in vegetables. Application to peas. Anal. Chem, 1950; 29: 1156-1158.
18. Kamil Prajapati K.D, Yami, Singh A. Plant Growth Promotional Effect of Azotobacter
chroococcum, Piriformospora indica and Vermicompost on Rice Plant. Nepal Journal of
Science and Technology, 2008; 9: 85-90.
19. Rao P.P, Birthal P.S, Reddy B.V.S, Rai K.N, Ramesh S. Diagnostics of Sorghum and
Pearl Millet Grains-based Nutrition in India. SAT e Journal, 2006; 2(1):
[www.ejournal.icrisat.org].
www.wjpps.com Vol 5, Issue 6, 2016.
1551
Vijaya et al. World Journal of Pharmacy and Pharmaceutical Sciences
20. Tien T.M, Gaskins M.H, Hubbell D.H. Plant growth substances produced by
Azospirillum brasilense and their effect on the growth of pearl millet
(Pennisetumamericanum). Appl. Environ. Microbiol, 1979; 37: 1016-1024.
21. Brown M.E. Seed and root bacterization. Annu. Rev. Phytopathol, 1974; 12: 181-198.
22. Azcon R, Azcon-Anguilar C, Barea J.M. Effects of plant hormones present in bacterial
cultures on the formation and responses to VA mycorrhiza. New Phytologist, 1978; 80:
359-369.
23. Shende S.T, Apte R.G, Singh T. Influence of Azotobacter on germination of rice and
cotton seed. Current Science, 1977; 46: 675.
24. Mogle, Chamle D.R. Evaluation of Biofertilizers and Parthenium Vermicompost on
Tomato Crop. Journal of Ecobiotechnology, 2011; 3(2): 11-13.
25. Balamurugan. Effect of Azospirillum and nitrogen on growth and yield of bhendi cv.
PusaSawani. M. Sc. (Agri.) Thesis, Tamil Nadu Agricultural University, Madurai, 1999.
26. Poi S.C, Ghosh G, Kabi M.C, Response of chickpea (Cicer arietinum L.) to combined
inoculation with Rhizobium, phosphobacteria and mycorrhizal organisms. Zentralblatt fur
Mikrobidogie, 1989; 144: 249-253.
27. Planzinski J, Rolfe B.G, Interaction of Azospirillum and Rhizobium strains leading to
inhibition of nodulation. Appl. Env. Microbiol, 1985; 49: 990-993.
28. Krishna K.R, Bagyaraj D.J, Note on the effect of VA mycorrhizal and soluble phosphate
fertilizers on Sorghum. Indian Journal of Agricultural Sciences, 1981; 51(9): 688-690.
29. Vijayakumari B, Yadav R, Hiranmai, Raja A. Influence of Fresh, Composted and
VermicompostedPartheniumhysterphorus and Poultry Droppings on Quality Parameters
of Radish. J. Appl. Sci. Environ. Manage, 2009; 13(2): 79-82.
30. Patil N.M, Biofertilizers effect on growth, protein and carbohydrate content in Stevia
rebaudianavarbertoni. Recent Research in Science and Technology, 2008; 2(10): 42-44.