Nodulation, Growth and Yield Response of Five Cowpea (Vigna unguiculata L. Walp) Varieties to Inoculum (Mesorhizobium loti) under Different Watering Regimes

Nodulation, Growth and Yield Response of Five Cowpea (Vigna unguiculata L. Walp) Varieties to Inoculum (Mesorhizobium loti) under Different Watering Regimes
Nodulation, Growth and Yield Response of Five Cowpea (Vigna
unguiculata L. Walp) Varieties to Inoculum (Mesorhizobium
loti) under Different Watering Regimes
*1OYEWUSI, Isaac Kayode, 2AGELE, Samuel Ohikhene, 3THOMAS, Oladele Victor
1Department of Agricultural Technology, The Federal Polytechnic, PMB 5351, Ado-Ekiti, Ekiti State, Nigeria
2Department of Crop, Soil and Pest Management, Federal University of Technology, Akure, Ondo State, Nigeria
3Department of Horticultural Technology, The Federal Polytechnic, PMB 5351, Ado-Ekiti, Ekiti State, Nigeria
The experiment was carried out in the screen house of the Department of Crop, Soil & Pest
Management, Federal University of Technology, Akure, Nigeria. The experimental layout was a 5
x 3 x 2 factorial combination with 3 replications given a total of 90 treatments. Seeds of five
cowpea varieties namely: IT98K-205-8, Ife Brown, Oloyin Brown, IT98K-573-2-1 and IT96D-610
were sown in Plastic buckets of 7-liter capacity and were perforated at the bottom to allow for
drainage and filled with top soil. Watering regimes of (500ml, 700ml and 900ml) were imposed and
water was applied twice a week while cowpea plants were inoculated with 5g each of Rhizobia
strain (Mesorhizobia loti) at seedling stage. Control set was maintained without inoculation. The
effect of watering regimes on legume species was significant on nodulation, growth and yield
characters of cowpea varieties evaluated. The results revealed marked varietal differences in
plant growth, nodulation, yield and yield components. IT98K-573-2-1 and Oloyin Brown generally
expressed superior performance in most measured parameters. Mesorhizobia inoculation
significantly (p≤0.05) increased plant growth, nodulation, yield and yield components of cowpea.
The interaction effect of variety, Mesorhizobia loti and watering regimes caused significant
variations in the number of nodules, leaf area, number of seeds/pod and seed yield. The nitrogen
and crude protein content in the leaf differed among the cowpea varieties evaluated. Application
of mesorhizobium strain significantly increased seed yield of cowpea and caused substantial
increase in nodulation and this subsequently affected the Nitrogen fixation potential of cowpea
under varying soil moisture regimes.
Key words: Mesorhizobia inoculation, Watering regime, Cowpea varieties Nodulation, Seed yield
INTRODUCTION
Cowpea production like most other crop is limited by
factors such as poor yielding varieties and nutrition,
absence of the right strain of rhizobia, among other factors
of production (Chiezey et al., 1990). They complement
staple low-protein cereal crops as a source of protein and
minerals (Gharti et al., 2014). Cowpeas are also valued for
their ability to fix atmospheric nitrogen into the soil and play
an important role as a rotation crop with cereals and
vegetable crops (Jensen et al., 2012; Biswas and
Gresshoff, 2014; Stagnari et al., 2017). They also serve as
a feed crop in many farming systems and are also grown
to supplement farmers’ income (Muli and Saha, 2002;
Voisin et al., 2013). Cowpea has considerable adaptation
to high temperatures and drought compared to other crop
species, making it suitable for cultivation in semiarid areas
(Hall, 2004; Tekle, 2014). Despite its role in improving soil
fertility and serving as a food security crop, little efforts are
made to know the response of cowpea varieties to
Mesorhizobia inoculation in Nigeria. Inoculation of
legumes with rhizobia strains is a common agricultural
practice intended to promote nodule development and
*Corresponding Author: OYEWUSI, Isaac Kayode;
Department of Agricultural Technology, The Federal
Polytechnic, PMB 5351, Ado-Ekiti, Ekiti State, Nigeria.
Email: kayoyewusi@gmail.com
Co-Author 2
Email: ohiagele@yahoo.com
3
Email: owoyemioladelevictor@gmail.com
International Journal of Plant Breeding and Crop Science
Vol. 7(1), pp. 677-688, June, 2020. © www.premierpublishers.org, ISSN: 2167-0449
Research Article

Oyewusi et al. 678
encourage nitrogen fixation to increase legume yield
(Agele et al., 2017). Plant response to inoculation is
determined by a variety of factors. The presence and
quality of indigenous rhizobial populations, soil nitrogen
(N) availability, soil physicochemical constraints and
climatic conditions significantly influence the ability to
achieve increased crop yield through inoculation (George
et al., 2007). Rhizobium is a common soil bacterium, not
toxic to humans, plants or animals. It is one of the most
beneficial bacteria to agriculture Lindermann, (2015).
Rhizobia are minor components of the soil micro flora and
reach their maximum numbers in association with plant
roots (Bagayoko et al., 2000). They are stimulated by
carbon compounds in plant roots and are controlled by
microbial competition. Ditta et al., (2018). Their ability to
infect legume roots and multiply within the resulting root
nodules protected from the soil environment provides a
special advantage over their competitors (Ahmed et al.,
2008). Furthermore, Mesorhizobia inoculation of cowpea
is not a common agronomic practice among smallholder
farmers. Thus, the development of new cultural practice
which enhance yield and mineral nutrition of grain is
imperative to achieve food and nutritional security in the
country.
Water stress is one of the major causes of reduced growth,
development and yield in leguminous plants and also
reduces nitrogen fixation and its related traits Pandy et al.,
(1984. Cowpeas are very sensitive to drought which leads
to reduced yield and seed quality. Water stress is a major
factor affecting symbiosis and leads to decreased nodule
formulation, reduced nodule size and Nitrogen fixation
Graham, (2002). Leguminous plants in association with
rhizobium species have the potential to fix large amount of
atmospheric nitrogen which contributes to the soil nitrogen
pool provided that the nitrogen fixation is not restricted by
other environmental or microbial factors Kennedy &
Cockings (1997, Ullah et al., 2020). A more effective and
easy way of raising the N status of the soil is to exploit the
ability of legumes to fix appreciable quantities of
atmospheric nitrogen. (Sarfraz et al., 2019). Therefore, the
specific objectives of the study were to examine the effects
of watering regime and Mesorhizobia inoculation on the
growth, seed yield and yield components of some cowpea
varieties as well as the leaf chlorophyll concentration
among the tested cowpea varieties.
MATERIALS AND METHODS
Experimental site and ambient conditions
The experiment was conducted in the Department of Crop,
Soil and Pest Management, Federal University of
Technology Akure, located in the rain forest area of South
Western Nigeria between February and April, 2016 The
experiment was carried out to examine the interplay of soil
moisture regimes and rhizobium inoculation on nodulation,
growth and seed yield of cowpea varieties.
Planting materials
Seeds of five cowpea varieties and Rhizobia strain were
obtained from the International Institute of Tropical
Agriculture (IITA), Ibadan, Nigeria. The varieties were:
IT98K-205-8, Ife Brown, Oloyin Brown, IT98K-573-2-1 and
IT96D-610. Plastic buckets of 7 liter capacity were
perforated at the bottom and filled with top soil. Watering
regimes of (500ml, 700ml and 900ml) were imposed and
water was applied twice a week while cowpea plants were
inoculated with 5g each of Rhizobia strain (Mesorhizobia
loti) at seedling stage. The inoculant was applied close to
the crop root zone at a depth of 5 cm using the procedure
of seed and soil inoculation developed by Fatima et al.,
(2007). A Control set up was maintained without
inoculation.
Treatments and experimental design
The treatments imposed on the cowpea varieties were
rhizobial strain (Mesorhizobia loti) with or without
rhizobium inoculation. The 5 x 3 x 2 factorial combinations
(These consisted of 5 cowpea varieties, 3 watering
regimes, inoculated or not) were arranged using
Completely Randomized Design (CRD) with three
replications given a total of 90 treatments. Based on
preliminary reports on literatures, three watering regimes
were imposed namely; 900ml, 700ml and 500ml and these
were maintained throughout the experiment.
Data collection
Measurement of agronomic variables commenced three
weeks after planting and lasted for a period of two months.
Growth indices measured were vine length (cm), number of
branches, number of leaves, number of nodules, size of
nodules (g), weight of nodules (g), leaf area (cm3), days to
50% flowering, number of peduncles, number of seeds per
plant and seed yield (kg/ha). Leaf samples were taken from
the uppermost leaves of each cowpea variety during the
vegetative growth stage of cowpea from each treatment.
They were then analyzed for chlorophyll concentration,
nitrogen, and crude protein content. The concentrations of
leaf chlorophyll were determined after extraction in acetone
using spectrophotometer device. (Dey et al., 2016). Crude
protein was determined by multiplying the result of the total
Nitrogen obtained by 6.25. The number of leaves per plant:
This was estimated by counting. The plant height: This
was measured using measuring tape. The measurement
was taken from the base to the apical shoot. The number
of branches per plant: This was estimated by counting.
Number of nodules: This was done by visual counting of
nodules borne on root after terminating the experiment.
Nodule weight: The nodules of each plant were removed
and weighed using a weighing balance. Nodule diameter:
This was measured with the use of Vermeer caliper
Number of pods: This was done by visual counting of pods
borne on each plant at harvest. Number of seeds: This was
done by visual counting of seeds after removal from pod.

Int. J. Plant Breed. Crop Sci. 679
Seed weight: This was done by weighing the seeds on
weighing balance. The date to 50% flowering: This was
determined when the plants produces maximum flowers
during the growth stage. (Allito et al., 2015, Chatterjee and
Bandyopadhjay, 2017, Dew and Singh, 2014).
Determination of Selected Soil Physical and Chemical
Properties
The soil was air-dried to reduce the moisture content after
which it was taken to the laboratory where the soil textural
class was determined as sandy-loam as defined according
to FAO/USDA soil classification system. Soil pH was
determined by using 1:1 water suspension and adding 10
ml distilled water to 10 g of soil. Organic carbon was
determined by modified Walkley–Black wet oxidation
method. Soil organic matter of the soil sample was
calculated by multiplying the organic carbon by a Van
Bemmelen factor of 1.724. Potassium and sodium in the
soil extract were determined by flame photometry. Flame
photometer readings for the standard solutions were
determined and a standard curve constructed. Potassium
and sodium concentrations in the soil extract were read
from the standard curve. Available P was determined
using the Bray P1 method. The exchangeable magnesium
alone was calculated by subtracting the value obtained
from the calcium + magnesium value.
Extraction and Determination of Leaf Chlorophyll
The two uppermost leaves of cowpea varieties from each
treatment were harvested. One gram of the fresh plant
samples were cut into pieces and smashed in a mortar.
The samples were put in a test tube and its chlorophyll
content was repeatedly extracted with successive volume
of 100 ml acetone/water (80:20 v/v) until no traces of green
colour were noticed (residue became white). While adding
the solvent (acetone), the test tubes containing the
samples were kept boiling in hot water bath. The total
volume of the extract was also recorded at the end of the
extraction. Three millimeter (3 ml) of the extract was taken
and the absorbance was determined with a
spectrophotometer (Spectronic 20) at two wave lengths of
663nm and 645 nm that corresponds to maximum
absorption of chlorophyll “a” and “b” respectively. The total
chlorophyll content was calculated as follows:
Total chlorophyll content (mg/100 g tissue) = (20.2A645 +
8.02A663) (V/10 w)
Where, A645 = absorbance at 645 nm wavelength;
A663 = absorbance at 663 nm wavelength,
V = final volume (cm3) of chlorophyll extract in 80%
acetone
W = fresh weight (g) of tissue extracted (Dey et al., 2016)
Determination of crude protein
Crude protein was determined by multiplying the result of
the total Nitrogen obtained by 6.25.
Statistical analysis
Data collected on plant and soil parameters were
subjected to analysis of variance (ANOVA) and treatment
means were separated using Least Significant Difference
(LSD) at 5% level of probability and Duncan Multiple
Range Test (DMRT).
RESULTS
Pre-experiment Soil Chemical Properties
The physio-chemical characteristics of the experimental
soil in Table 1 show the soil has pH of 6.9. Organic matter,
4.01%, Nitrogen, 0.07 g/kg, Available P, 1.73 mg/kg, K,
0.02 cmol/kg, Na 0.02 cmol/kg, Ca 1.47cmol/kg and Mg,
4.20 cmol/kg.
Table 1: Pre soil chemical properties at experimental site
Chemical Properties Values
Ph (water) 6.90
Nitrogen (g/kg) 0.07
Available Phosphorus (mg/kg) 1.73
Exchangeable Na(cmol/kg) 0.02
Exchangeable K (cmol/kg) 0.02
Exchangeable Ca (cmol/kg) 1.47
Exchangeable Mg (cmol/kg) 4.20
Soil Organic matter (%) 4.01
Effects of Variety on Growth, Yield and Yield
Components of Cowpea
The result indicates that there was no significant difference
in the number of branches, number of nodules, size and
length of nodules among the tested cowpea varieties.
Shoot weight was highest for IT98K-573-2-1 (114 g). The
result also indicates that there was a significant difference
in the leaf area of the tested cowpea varieties. Leaf area
was highest for Oloyin Brown (377.8 cm3). Days to 50%
flowering were shortest for IT98K-205-8 (39 days). There
was no significant difference in the number of peduncles,
number of pods and number of seeds among the tested
varieties. Highest seed yield was recorded for Oloyin
Brown (13.5 kg/ha) while the percentage crude protein
was highest for Ife Brown (26.9%) as indicated in Table 2.
Effect of Watering Regime (WR) on Growth, Yield and
Yield Components of Cowpea Varieties
More vine length was produced under 500ml of water in
cowpea plant compared with the 700ml and 900ml. Table
3. This is attributed to the physiological stress occasioned
by the limited water supply. Plants growing under limiting
water condition tend to grow taller in an effort to scramble
for nutrients around the soil. Watering regimes under
900ml significantly increased vigor and seed yield.
Cowpea varieties under 900ml of water recorded the

Oyewusi et al. 680
highest number of leaves and branches for all tested
varieties except IT98K-205-8. Significant difference was
however observed on nodule number under 900ml of
water which had the highest value. There was no
significant difference among the parameters for number of
branches, number of nodules, length and size of nodules,
number of peduncles, 100 seed weight, harvest index and
chlorophyll concentration based on the watering regimes
imposed. Highest seed yield was recorded for Ife Brown
(9.52 kg/ha) under the 900ml of water while there was no
significant difference between the result obtained for seed
yield for Oloyin Brown and IT98K-573-2-1 under 900ml
and 700ml of water.
Effects of Rhizobial Inoculation (RI) on Growth, Yield
and Yield Components of Cowpea Varieties
Rhizobium inoculation enhanced number of leaves (Table
4). More leaves were found in inoculated plant compared
with the non-inoculated. Rhizobium inoculation of cowpea
seedlings significantly increased vigor and seed yield.
Cowpea varieties inoculated with Rhizobium recorded the
highest shoot biomass as compared with the non-
inoculated. Most of the agronomic characters of growth
and yield components were improved by rhizobium
inoculation and performed better over the non-inoculated.
The result shows that rhizobial inoculation did not
significantly improve nodule number, nodule size and
nodule length among the cowpea varieties evaluated.
Interaction Effect of Variety and Watering Regime on
Growth and Yield of Cowpea
The interaction effect shows significant difference among
all the measured parameters. There were no significant
difference in size and length of nodules, days to 50%
flowering, harvest index and chlorophyll concentration
among the tested cowpea varieties evaluated. The result
also shows that Ife Brown performed better under 900ml
of water while Oloyin Brown and IT98K-573-2-1 performed
significantly better under the 900ml and 700ml of water.
Interaction Effect of Variety and Rhizobia Inoculation
on Growth and Yield of Cowpea
Rhizobium inoculation significantly increased vigor and
seed yield of cowpea. Higher number of leaves shoot
biomass, leaf area and seed yield were obtained from
rhizobial inoculation (Table 6). The result shows that
rhizobial inoculation did not significantly improve number
of nodules, size of nodules and length of nodules among
cowpea varieties evaluated. There was no significant
difference on rhizobia inoculation for vine length on Ife
Brown, IT98K-573-2-1 and IT98K-610 while the
application of rhizobia inoculation did not have any positive
effect on size of nodules, length of nodules, days to 50%
flowering, 100 seed weight, harvex index and chlorophyll
concentration for all the tested cowpea varieties.
Conversely, the number of leaves and branches, the
number of peduncles, number of pods, seed yield and
crude protein levels were significantly affected by rhizobial
inoculation. The highest seed yield was recorded for
IT98K-573-2-1 under rhizobial inoculation (23.9 kg/ha).
Interaction Effects of Variety, Rhizobial Inoculation
and Watering Regime on Growth and Yield of Cowpea
The interaction effect shows that significant differences
were obtained for vine length, number of nodules, number
of leaves and branches, leaf area, number of pods and
peduncles, number of seed and seed yield while there
were no significant difference for size and length of
nodules, days to 50% flowering, 100 seed weight, and
chlorophyll concentration in the cowpea varieties
evaluated. The highest seed yield was recorded for Oloyin
Brown (13.5 kg/ha) Table 7.
DISCUSSION
Effects of Watering Regimes on Growth and Yield
Parameters of Cowpea
The results of this study showed that the measured growth
variables differed among cowpea varieties in response to
the watering regimes imposed. The enhancement of vines,
number of leaves, and seed yield by heavier watering (may
be attributed to higher moisture content in the crop root
zone). This observation is consistent with reports of
Henson et al., (2007), Majumder (2010) and Agele et al.,
(2012), which stated that when adequate water is
available, plant cells remain turgid and plants retain their
form, structure and function. In addition, Khalil and El-
Noemani (2012) and Bahreininejad et al., (2013) stated
that, water stress reduces plant growth through inhibition
of various physiological and biochemical processes such
as photosynthesis, respiration, translocation, ion uptake,
carbohydrates, nutrient metabolism and hormones. This is
also supported by Ullah et al., (2020) who stated that Algal
biochar had a pronounced effect on Rhizobacteria which
promoted growth and yield of maize under limiting water
conditions. The cowpea varieties that were watered
heavily with 900ml produced higher vine length, number of
leaves, shoot weights and gave higher seed yields when
compared with the 700ml and 500ml of water. This result
further confirms how essential water is to growth and
development of cowpea, a crop sensitive to water deficit
(Henson et al., 2007, Majumder, 2010, Agele et al., 2012).
Effects of rhizobial inoculation on growth characters
of cowpea
The cowpea varieties responded differently to rhizobial
inoculation. The rhizobial inoculated plants had enhanced
growth compared with the non – inoculated. These results
agree with the findings of Sakthivel and Soremi, (1987),
Ashrafuzzaman et al., (2009), and Isahak et al., (2012)
who stated that bio-fertilizers significantly improved crop
growth by increasing fixation (nitrogen) and uptake (P) of

Int. J. Plant Breed. Crop Sci. 681
soil nutrients such as nitrogen and phosphorus which
influenced plant growth and significantly enhanced plant
height and photosynthetic rate. Similarly, Chi et al., (2005)
obtained up to 23-63% increases in plant height of
inoculated rice over the non – inoculated. The authors
argued that indole acetic acid (IAA) and gibberellin
production were the key mechanisms for the observed
growth improvement. Furthermore, the results of this study
also agrees with the findings of Dar and Bali, (2007) who
stated that application of bio fertilizer improved leaf
development in crops. With respect to plant biomass,
cowpea plants inoculated exhibited significant
performance over the non- inoculated. The beneficial
effect on host plant by rhizobium inoculation may be
associated with improved plant nutrition. Furthermore,
Hussain et al., (2020) opined that maize production can be
increased by the addition of bio-activated organic fertilizer
enriched with zinc solibilizing bacteria.
Accordingly, these authors Ditta et al., (2018 & 2015), Ditta
& Khalid, (2016), who worked on rock phosphate opined
that enriched organic fertilizer with phosphate solibilizing
micro-organisms improved nodulation, growth and yield of
legume crops. Their combined work was supported by Zeb
et al., (2018) who stressed that bacteria improved yield
and Zn-fortification in flooded rice. Findings from this study
showed that rhizobia inoculation did not significantly
improve nodule length and size among cowpea varieties.
In this study, plant nodulation was positively correlated
with biomass production. Furthermore, Rapela and
Saxena, (1987) stated that, the nodules of annual plants
tend to die at flowering and seed set presumably because
at this time, flowers and developing seeds are the major
sinks of the resources thus causing nodule disintegration.
Poor inoculants viability, inadequate soil mineral nitrogen,
incompatibility of the inoculants strain with specific cowpea
variety or the presence of highly competitive native
rhizobia that restricted occupancy of the nodules by the
inoculants strains are factors which affected legume
response to rhizobium inoculation (George et al.,2007). In
his work on rhizobacteria, Sarfraz et al., (2019) opined that
growth- promoting Rhizobacteria can enhance carbon
sequestration and boost crop growth. This accounted for
the increased growth in cowpea varieties under rhizobial
inoculation.
Interaction between Variety, Watering Regime and
Rhizobium Inoculation on the Performance of Cowpea
The interaction effect in Table 5 shows that the
performance of cowpea was influenced by watering
regime and rhizobial inoculation. Seedling species that
were subjected to 900ml and 700ml of water under
rhizobium inoculation had enhanced growth. These
findings supported the observations of Read and Boyd
(1986) and Shinkafi (2000) who reported that Rhizobium
inoculation increased soil water extraction and root
development. Ali et al (2004), stressed that leaf
emergence rate is the most sensitive parameter to drought
stress. Graham (2002) stated that mild water stress and
rhizobium inoculation enhanced growth than the non-
inoculated. This was consistent with the work of Osunubi
and Mulongong, (1992) who reported that rhizobial
inoculation enhanced leaf development. Some of the
measured growth parameters of cowpea seedlings in this
study were promoted by rhizobium inoculation. The
highest number of pods/plant, number of seeds per pod
and number of nodule was obtained from inoculated
species which was significantly higher than the non-
inoculated crops. This result is in agreement with Shu-Jie
et al., (2007) and Agele et al (2017) who reported that the
number of pods per plant, number of seeds per pod, and
seed yield were significantly increased by rhizobia
inoculation .This may be attributed to the symbiotic
relationship between rhizobia and crop root zone (bacteria
and root system of legumes). The nodule contained in
roots fix atmospheric nitrogen into the roots which
improves crop yield .This is in agreement with Dashti et al.,
(1995), Ditta et al., (2018 & 2015), Ditta &Khalid, (2016)
who reported that phosphorus and rhizobium inoculation
has a pronounced effect on yield and that number of pods
per plant, number of seeds per pod and seed yield were
significantly increased by different levels of rhizobia
inoculation. In this study, there were significant (P < 0.05)
interactions of rhizobial inoculation and watering regime on
growth characteristics which includes leaf area, number of
nodules and shoot weight on yield of inoculated cowpea.
In addition, Hamidou et al., (2007) stated that water stress
reduces plant growth through inhibition of various
physiological and biochemical processes, such as
photosynthesis, respiration, translocation, ion uptake,
carbohydrates, nutrient metabolism, and hormones. This
is also supported by (Sarfraz et al., (2019). The results
further showed that watering regime significantly affected
nodule number in all tested varieties. Soil moisture deficit
stress conditions promote early flowering and maturity in
crops. The reduction in leaf area and biomass
accumulation, pod and seed yields were obtained under
500ml water applications.
The results of this study confirmed that cowpea seedlings
cannot withstand soil moisture deficit stress as was
obtained for seedlings that were watered at 500ml. (Kulac
et al., 2012). The 500 ml watering was characterized by
high intensity of soil and air moisture deficits. These
conditions have implications for survival and
establishment of seedlings. Plants exposed to soil water
deficit, exhibited a number of physiological responses in
an effort to survive stress. These include closing of
stomata and arresting cellular growth (Kulac et al., 2012).
If water stress is not alleviated, plants will close stomata
and shut down photosynthesis, carbon assimilation, and
normal metabolism (Kulac et al., 2012). These responses
means that plants growing under water stress will end up
smaller and poorer in vigor. Low soil moisture stress
reduces leaf area, number of leaves and branches in
cowpea varieties as reported by (Sarfraz et al., (2019).

Oyewusi et al. 682
Table 2: Effects of Variety on Growth, Yield and Yield Components of Cowpea
Varieties Vine
length
(cm)
(6WAP
Number
of
leaves
(6WAP)
Number
of
branches
(6WAP)
Number
of
Nodules
Size of
nodules
(g)
Length
of
nodules
(cm)
Shoot
wt
(g)
Leaf
area
(cm3)
Days
to
50%
Flo
No
of
ped
No
of
pods/
plant
No
of
seeds/
pod
100
Seed
Wt
(g)
Seed
Yield
(kg/ha)
Harvex
Index
Chlorophyll
Conc.
(Mg/100g)
Crude
protein
(%)
IT98K-
205-8
37.1d 36.1d 5.2a 6.6a 0.8a 0.6a 41.0b 293.9b 39ab 9a 7a 5a 15.3a 5.2b 0.10a 0.50a 22.9b
Ife Brown 41.4c 52.9b 5.4a 4.2a 1.1a 0.9a 14.3c 273.1b 41ab 9a 6a 6a 15.2a 7.3b 0.50a 0.40a 26.9a
Oloyin
Brown
56.5a 42.7c 6.3a 5.6a 1.0a 1.1a 49.4b 377.8a 51a 8a 9a 7a 17.4a 13.5a 0.20a 0.70a 24.5a
IT98K-
573-2-1
51.9b 53.8b 5.7a 7.7a 0.8a 0.6a 114a 293.4b 43ab 10a 8a 9a 14.6a 11.2a 0.10a 0.50a 20.8b
IT96D-
610
59.4a 67.6a 4.5a 7.4a 0.9a 0.9a 106a 344.3a 43ab 7a 6a 6a 12.4ab 4.9b 0.04a 0.60a 21.4b
Means along the column bearing same superscript are not significantly different DMRT (p<0.05)(WAP) Weeks after planting. (Days to
50% flo) - Days to 50% flowering,(No of Ped) - Number of peduncles. (Chlorophyll conc) - Chlorophyll concentration
Table 3: Effect of Watering Regime (WR) on Growth, Yield and Yield Components of Cowpea Varieties
Varieties WR Vine
Length
(6WAP)
(cm)
Number
of
leaves
(6WAP)
Number
of
branches
(6WAP)
Number
of
nodules
Size of
nodules
(g)
Length
of
nodules
(cm)
Shoot
wt
(g)
Leaf
area
(cm3)
Days
to
50%
Flo
No
of
ped
No
of
pods/
plant
No
of
seeds/
pod
100
Seed
Wt
(g)
Seed
Yield
(kg/ha)
Harvex
Index
Chlorophyll
Concen-
tration
(Mg/100g)
Crude
Protein
(%)
IT98K- 205-8 900 32.9bc 46.7b 5.5a 9.7a 1.2a 0.8a 49.8b 313.4ab 39ab 11a 9a 5a 16.2a 6.79ab 0.133a 0.977a 26.25ab
700 31.0bc 53.0ab 5.3a 7.0a 0.8a 0.6a 47.0b 346.7ab 40ab 10a 7a 7a 16.0a 7.50ab 0.177a 0.150a 22.56ab
500 47.5b 50.7ab 4.9a 3.0ab 0.4a 0.4a 26.2cd 221.8b 37ab 7a 4ab 4ab 13.8a 2.04ab 0.097a 0.383a 19.75b
Ife Brown 900 43.0b 68.0a 6.7a 6.0a 1.3a 1.2a 19.8cd 495.6a 40ab 8a 7a 8a 17.0a 9.52a 0.675a 0.810a 28.27ab
700 39.7bc 50.7ab 4.5a 4.7ab 1.1a 0.8a 11.6cd 325.7b 43ab 10a 6ab 5a 15.8a 4.49ab 0.413a 0.317a 39.99a
500 40.6b 40.0b 4.9a 2.0ab 1.0a 0.6a 11.5cd 297.9b 41ab 8a 6ab 6a 12.7a 4.13ab 0.376a 0.120a 12.54c
Oloyin Brown 900 48.5b 54.0ab 6.5a 8.7a 1.3a 1.4a 54.0b 399.9ab 55a 8a 6ab 7a 16.7a 14.2a 0.077a 0.970a 28.62ab
700 51.1ab 41.5b 6.0a 5.0a 1.0a 1.3a 50.2b 415.4a 50a 9a 9a 7a 17.7a 11.1a 0.263a 0.790a 20.49ab
500 69.8a 32.7bc 6.5a 3.0ab 0.8a 0.6a 44.0b 318.0b 48ab 7a 12a 6a 17.9a 6.98ab 0.178a 0.197a 24.45ab
IT98K- 573-2-1 900 37.8bc 61.0ab 6.0a 9.7a 1.2a 0.8a 96.3ab 382.5a 46ab 11a 7a 10a 15.8a 12.1a 0.154a 0.717a 23.78ab
700 48.7b 51.7ab 5.5a 8.7a 0.8a 0.5a 145.0a 233.4b 43ab 10a 10a 8a 14.8a 11.4a 0.043a 0.677a 19.12b
500 69.2a 48.7b 5.7a 4.7ab 0.5a 0.6a 102ab 264.3b 40ab 8a 6ab 9a 13.1a 6.84ab 0.072a 0.180a 19.37b
IT96D- 610 900 51.5ab 77.7a 5.5a 8.7a 1.2a 1.2a 96.2ab 447.6a 46ab 9a 6ab 7a 13.0a 5.48ab 0.070a 0.657a 21.83ab
700 59.8ab 68.0a 4.3a 8.7a 1.2a 0.8a 117ab 322.8ab 44ab 7a 6ab 4ab 12.1a 4.45ab 0.053a 0.767a 19.56b
500 67.0a 57.0ab 3.7b 4.7ab 0.5a 0.6a 106ab 262.5b 39ab 4ab 6ab 7a 12.1a 3.8ab 0.017a 0.277a 22.71ab
Means along the column bearing same superscript are not significantly different DMRT (p<0.05)* significant, ns not significant at (p<0.05) (WR)
-Watering regime (WAP) - Weeks after planting (No of Ped) - No of peduncles. (Days to 50% flo) - Days to 50% flowering

Int. J. Plant. Breed. Crop Sci. 683
Table 4: Effects of Rhizobial Inoculation (RI) on Growth, Yield and Yield Components of Cowpea Varieties
Variety RI Vine length
(6WAP)
(cm)
Number
of leaves
(WAP)
Number of
branches
(WAP)
Number of
nodules
Size of
nodules
(g)
Length of
nodules
(cm)
Shoot
weight
(g)
Leaf
area
(cm3)
Days
to 50%
flo
No
of
Ped
No of
pods/
plant
No of
Seeds/
Pod
100
Seed
Weight (g)
Seed
Yield
(kg/ha)
Harvex
Index
Chloro
Conc
(Mg/100g)
Crude
Protein
(%)
IT98K-205-8 + 37.8a 57.0a 5.0a 6.7a 1.5a 1.5a 30.6a 258.3b 42a 9b 10a 11a 15.8a 19.2a 0.30a 0.70a 35.9a
_ 32.9b 46.7b 5.5a 9.7a 1.2a 0.8a 49.8b 313.4a 39b 11a 9a 5b 16.2a 6.5b 0.13a 0.98a 26.3b
Ife Brown + 39.1a 86.8a 6.0a 6.0a 1.5a 1.8a 36.3a 442.0a 45a 10a 10a 9a 18.9a 17.7a 0.49a 0.94a 42.4a
_ 43.0ab 68.0b 6.7a 6.0a 1.3a 1.2a 19.8b 495.6a 40b 8a 7a 8a 17.0a 13.3b 0.68a 0.81a 28.3b
Oloyin Brown + 51.0a 78.0a 6.5a 7.7a 2.0a 2.5a 61.15a 496.6a 55a 12a 14a 10a 17.8a 10.1b 0.14a 0.66a 26.2a
_ 48.5b 54.0b 6.5a 8.7a 1.3a 1.4a 54.0b 399.9b 55a 8b 6b 7a 16.7a 14.2a 0.07a 0.97a 28.6a
IT98K-573-2-1 + 36.2a 50.7b 7.0a 10.7a 1.6a 1.4a 179.7a 222.9b 46a 13a 13a 12a 19.5a 23.9a 0.13a 0.85a 38.9a
_ 37.8a 61.0a 6.0a 9.7a 1.2a 0.8a 96.3b 382.5a 46a 11b 7b 10a 15.8a 11.8b 0.154a 0.72a 23.8b
IT96D-610 + 53.0a 80.0a 6.5a 6.7a 1.6a 1.5a 177.8a 460.5a 46a 8a 8a 8a 15.4a 9.4a 0.05a 0.65a 41.2a
_ 51.5a 77.7a 5.5a 8.7a 1.2a 1.2a 96.2b 447.6b 46a 9a 6a 7a 13.0a 6.5b 0.07a 0.66a 21.8b
Means along the column bearing same superscript are not significantly different DMRT (p<0.05) (WAP) - Weeks after planting, (RI) - Rhizobium inoculation.(Days to 50% flow) -
Days to 50% flowering. (No of ped)- No of peduncles. (Chloro Conc) - Chlorophyll concentration
Table 5: Interaction Effects of Variety and Watering Regime on Growth, Yield and Yield Components on Cowpea Performance
Varieties WR Vine Length
(cm)
(6WAP)
Number
of leaves
(6WAP)
Number of
branches
(6WAP)
Number of
nodules
Size of
nodules
(g)
Length of
nodules
(cm)
Shoot
weight
(g)
Leaf
area
(cm3)
Days to
5o% flo
No
of
ped
No of
pods/
plant
No of
Seeds/
pod
100
Seed
Weight (g)
Seed
Yield
(kg/ha
HI Chloro
Conc
(Mg/100g)
Crude
protein
(%)
IT98K-205-8 900 32.9bc 46.7b
5.5 9.7a 1.2a 0.8a 49.8b 313.4ab 39ab 11a 9a 5a 16.2a 6.79ab 0.13a 0.97a 26.2ab
700 31.0bc 53.0ab
5.3a
7.0a 0.8a 0.6a 47.0b 346.7ab 40ab 10a 7a 7a 16.0a 7.50ab 0.17a 0.15a 22.5ab
500 47.5b 50.7ab
4.9a
3.0ab 0.4a 0.4a 26.2cd 221.8b 37ab 7a 4ab 4ab 13.8a 2.04ab 0.09a 0.38a 19.7b
Ife Brown 900 43.0b 68.0a
6.7a
6.0a 1.3a 1.2a 19.8cd 495.6a 40ab 8a 7a 8a 17.0a 9.52a 0.67a 0.81a 28.2ab
700 39.7bc 50.7ab
4.5a
4.7ab 1.1a 0.8a 11.6cd 325.7b 43ab 10a 6ab 5a 15.8a 4.49ab 0.41a 0.31a 39.9a
500 40.6b 40.0b
4.9a
2.0ab 1.0a 0.6a 11.5cd 297.9b 41ab 8a 6ab 6a 12.7a 4.13ab 0.37a 0.12a 12.5c
Oloyin Brown 900 48.5b 54.0ab 6.5a 8.7a 1.3a 1.4a 54.0b 399.9ab 55a 8a 6ab 7a 16.7a 14.2a 0.07a 0.97a 28.6ab
700 51.1ab 41.5b 6.0a 5.0a 1.0a 1.3a 50.2b 415.4a 50a 9a 9a 7a 17.7a 11.1a 0.26a 0.79a 20.4ab
500 69.8a 32.7bc 6.5a 3.0ab 0.8a 0.6a 44.0b 318.0b 48ab 7a 12a 6a 17.9a 6.89ab 0.17a 0.19a 24.45ab
IT98K-573-2-1 900 37.8bc 61.0ab 6.0a 9.7a 1.2a 0.8a 96.3ab 382.5a 46ab 11a 7a 10a 15.8a 12.1a 0.15a 0.71a 23.7ab
700 48.7b 51.7ab 5.5a 8.7a 0.8a 0.5a 145a 233.4b 43ab 10a 10a 8a 14.8a 11.4a 0.04a 0.67a 19.1b
500 69.2a 48.7b 5.7a 4.7ab 0.5a 0.6a 102ab 264.3b 40ab 8a 6ab 9a 13.1a 6.84ab 0.07a 0.18a 19.3b
IT96D-610 900
700
51.5ab
59.8ab
77.7a
68.0a
5.5a
4.3a
8.7a
8.7a
1.2a
1.2a
1.2a
0.8a
96.2ab
117ab
447.6a
322.8ab
46ab
44ab
9a
7a
6ab
6ab
7a
4ab
13.0a
12.1a
5.48ab
4.45ab
0.07a
0.05a
0.65a
0.76a
21.8ab
19.5b
Variety (Var) 500 67.0a
9.30
57.0ab
11.2
3.7b
8.3
4.7ab 2.5 0.5a
0.4
0.6a
0.5
106ab
16.5
262.5b
21.4
39ab
8.5
4ab
3.0
6ab
2.2
7a
2.3
12.1a
4.5
3.8ab
0.11
0.01a
0.20
0.27a
0.30
22.7ab
3.5
W R
Var x WR
12.2
*
8.20
*
1.3
*
3.1
*
0.3
ns
0.3
ns
12.7
*
36.2
*
2.3
ns
4.1
*
3.4
*
2.1
*
3.5
ns
2.40
*
0.09
ns
0.05
Ns
8.3
*
Means along the column bearing same superscript are not significantly different DMRT (p<0.05) (WR) Watering regime. (WAP) Weeks after planting
(No of Ped) - Number of peduncles. (Days to 50% flo)- Days to50% flowering.(HI) - Harvex index. (Chloro conc) - Chlorophyll concentration (*) - significant (ns) - not
significant ns

Oyewusi et al. 684
Table 6: Interaction Effects of Variety and Rhizobial Inoculation on Growth, Yield and Yield Components on Cowpea Performance
Varieties RI Vine
length
(6WAP)
(cm)
Number
of
leaves
(6WAP)
Number
of
branches
(6WAP)
Number
of
nodules
Size of
nodules
(g)
Length
of
nodules
(cm)
Shoot
weight
(g)
Leaf
area
(cm3)
Days
to 50%
flo
No
of
ped
No of
pods/
plant
No of
Seeds/
pod
100
Seed
weight
(g)
Seed
yield
(kg/ha)
Harvest
Index
Chlro
Conc
(Mg/100g)
Crude
Protein
(%)
IT98K-205-8 + 37.8a 57.0a 5.0a 6.7a 1.5a 1.5a 30.6a 258.3b 42a 9b 10a 11a 15.8a 19.2a 0.30a 0.70a 35.9a
_ 32.9b 46.7b 5.5a 9.7a 1.2a 0.8a 49.8b 313.4a 39b 11a 9a 5b 16.2a 6.5b 0.13a 0.98a 26.3b
Ife Brown + 39.1ab 86.8a 6.0a 6.0a 1.5a 1.8a 36.3a 442.0a 45a 10a 10a 9a 18.9a 17.7a 0.49a 0.94a 42.4a
_ 43.0a 68.0b 6.7a 6.0a 1.3a 1.2a 19.8b 495.6a 40b 8a 7a 8a 17.0a 13.3b 0.68a 0.81a 28.3b
Oloyin Brown + 51.0a 78.0a 6.5a 7.7a 2.0a 2.5a 61.1a 496.6a 55a 12a 14a 10a 17.8a 10.0b 0.14a 0.66a 26.2a
_ 48.5b 54.0b 6.5a 8.7a 1.3a 1.4a 54.0b 399.9b 55a 8b 6b 7a 16.7a 14.2a 0.077a 0.97a 28.6a
IT98K-573-2-1 + 36.2a 50.7b 7.0a 10.7a 1.6a 1.4a 179.7a 222.9b 46a 13a 13a 12a 19.5a 23.9a 0.13a 0.85a 38.9a
_ 37.8a 61.0a 6.0a 9.7a 1.2a 0.8a 96.3b 382.5a 46a 11b 7b 10a 15.8a 11.8b 0.15a 0.72a 23.8b
IT96D-610 + 53.0a 80.0a 6.5a 6.7a 1.6a 1.5a 177.8a 460.5a 46a 8a 8a 8a 15.4a 9.4a 0.05a 0.65a 41.2a
_ 51.5a 77.7a 5.5a 8.7a 1.2a 1.2a 96.2b 447.6b 46a 9a 6a 7a 13.0a 6.5b 0.07a 0.66a 21.8b
Variety (Var) 9.30 11.2 8.3 2.5 0.4 0.5 16.5 21.4 8.5 3.0 2.2 2.3 4.5 0.11 0.20 0.30 3.5
RI 9.2 12.0 1.3 1.5 0.3 0.3 11.9 46.2 1.3 2.1 4.4 3.1 2.5 6.40 0.09 0.05 11.3
Var x RI Ns * Ns ns ns ns * * ns * * * ns * ns ns *
Means along the column bearing same superscript are not significantly different DMRT (p<0.05) RI) - Rhizobial inoculation (WAP) - Weeks after
planting. (Days to 50% flo) – Days to 50% flowering. (No of Ped) - Number of peduncles. (Chloro conc) - Chlorophyll concentration (*) - Significant-
(ns) - not significant at (p<0.05)

Table 7: Interaction Effects of Variety, Watering Regime and Rhizobial Inoculation on Cowpea Performance
Varieties VL
(6WAP)
(cm)
NOL
(6WAP)
NOB
(6WAP)
NON SON
(g)
LON
(g)
Shoot
weight
(g)
Leaf
area
(cm3)
Days to
50%
Flow
No of
ped
No of
pods
No of
Seeds
100
seed
weight (g)
Seed
yield
(kg/ha)
Harvex
Index
CC
(Mg/100g)
Crude
protein
(%)
IT98K-205-8
Ife Brown Oloyin
Brown IT98K-573-2-1
IT96D-610
Watering 900ml 700ml
500ml
Rhizobial Non-inocul
Variety (Var) Watering
Reg Rhizobial
37.1d
41.4c
56.5a
51.9b
59.4a
42.7a
44.3a
29.9ab
43.4a
42.7a
34.1
12.2
9.2
36.1d
52.9b
42.7c
53.8b
67.6a
61.5a
52.4ab
45.8ab
66.7a
61.3ab
61.5
8.20
12.0
5.2a
5.4a
6.3a
5.7a
4.5a
6.0a
5.1a
5.1a
6.2a
6.0a
7.2
1.3
1.3
6.6a
4.2a
5.6a
7.7a
7.4a
8.6a
6.8a
4.4ab
8.6a
7.6a
8.6
3.1
1.5
0.8a
1.1a
1.0a
a
a
1.2a
1.0a
0.6a
1.6a
1.2a
1.2
0.3
0.3
0.6a
0.9a
1.1a
0.6a
0.9a
1.2a
0.8a
0.6a
1.7a
1.1a
1.1
0.3
0.3
41.0c
14.3d
49.4b
114a
106a
63.2b
74.2ab
57.9b
97.1a
63.2b
63.2
12.7
11.9
293.9b
273.1b
377.8a
293.4b
344.3a
407.8a
328.8b
272.9c
376.9b
407.8a
407.8
36.2
46.2
39ab
41ab 51a
43ab
43ab
45a 44a
41ab
47a 45a
45
2.3
1.3
9.0a
9.0a
8.0a
10.0a
7.0a
9.4a
9.2a
6.8a
10a
9.4a
9.4
4.1
2.1
7.0a
6.0a
9.0a
8.0a
6.0a
7.0a
8.0a
7.0a
11a
7ab
7.0
3.4
4.4
5.0a
6.0a
7.0a
9.0a
6.0a
7.4a
6.2a
6.4a
10a
7.4ab
8.2
2.1
3.1
15.3a
15.2a
17.4a
14.6a
12.4a
15.7a
15.3a
13.9a
17.5a
15.7a
15.7
3.50
2.50
5.2ab
7.3ab
13.5a
11.2a
4.9ab
9.6a
7.8ab
5.7b
16.1a
10.5b
10.5
2.40
6.40
0.10a
0.50a
0.20a
0.10a
0.04a
0.22a
0.19a
0.15a
0.22a
0.22a
0.22
0.09
0.09
0.50a
0.40a
0.70a
0.50a
0.60a
0.83a
0.54a
0.23a
0.76a
0.83a
0.83
0.05
0.05
22.9ab
26.9a
24.5a
20.8ab
21.4ab
25.8a
24.3a
19.8ab
36.9a
25.8b
25.8
8.30
11.3
Var x WR Var x RHI
Var WR x RHI
* ns
*
*
*
*
* ns
*
* ns
*
ns ns
ns
ns ns
ns
*
*
*
*
*
*
ns ns ns *
*
*
*
*
*
*
*
*
ns ns ns *
*
*
ns ns
ns
ns ns ns *
*
*
Means along the column bearing same superscript are not significantly different DMRT (P0.05) (WAP) - Weeks after planting.(VL) - Vine length.
(NOB) - Number of branches. (NOL) - Number of leaves. (NON) - Number of nodules. (SON) - Size of nodules. (LON) - Length of nodules. (Days to
flow) - Days to 50% flowering, (No of Ped) - Number of peduncles. (CC) - Chlorophyll concentration. (WR) - Watering Régime. (Non-inocul) - Non-
inoculation

Oyewusi et al. 686
CONCLUSIONS
Cowpea growth and yield attributes were significantly
affected by watering regimes and rhizobial inoculation.
The results obtained in this study have shown that
mesorhizobial inoculation can improve plant growth,
nodulation and grain yield of the tested cowpea varieties
grown in the low-N soils of Akure. The higher plant growth
and increased nodulation in Rhizobium-inoculated plants
translated into increased grain yield. Based on the findings
of this study, IT98K-573-2-1 and Oloyin Brown responded
better to the application of mesorhizobial loti and could be
recommended for enhanced growth and yield
performance of cowpea. The nitrogen and crude protein
content in leaf differed among the cowpea varieties
evaluated. Application of mesorhizobium strain
significantly increased seed yield of cowpea and this
caused substantial increase in nodulation and
subsequently affected the N2 fixation potential of cowpea
under varying soil moisture regimes. Based on the
measured growth parameters in this study, rhizobium
inoculation and application of 900ml of water promoted
plant vigor and increased cowpea yield in the study area.
COMPETING INTERESTS
Authors have declared that no competing interests exist
REFERENCES
Agele, S.O, and Agbi O.M (2012): Growth and yield
responses of selected cowpea (Vigna unguiculata
L.Walp) cultivars to weather and soil factors of the
growing seasons. Trade Science Inc, Indi RRBS, 7 (7),
2013 (265-276) Vol7 Issue 7
Agele, S.O., A.P .Ajayi and F.M. Olawanle (2017): Effects
of Watering Regime and Rhizobium Inoculation on
Growth Functional and Yield Traits of Four Legume
Species. International Journal of Plant and Soil
Science. 17 (4): 1-15, 2017; Article no. IJPSS.32891
Ahmed Z.I, Ansar M, Tariq B, Anjum M.S (2008): Effect of
different Rhizobium inoculation methods on
performance of lentil in Pothowar region. International
Journal of Agriculture and Biology. 2008; 10:81-84.
Allito, B.B, Ewusi-mensah, N. and Alemneh, A.A (2015):
Rhizobia strain and host-legume interaction effects on
nitrogen fixation and yield of grain legume : A review.
Molecular Soil Biology, 6(4): 1-12. http://doi.org/10.
5376/msb.2015.06.0004.
Ashrafuzzaman, M., F.A. Hossen., M.R. Ismail, M, Hoque,
M.Z. Islam, S, M. Shahidullah and S. Meon (2009):
Efficiency of Plant Growth-Promoting Rhizobacteria
(PGPR) for the enhancement of rice growth. African
Journal of Biotechnoly. 8:1247-1252
Bagayoko M. Buerkert A. Lung G. Bationo A, Romheld V
(2000): Cereal/legume rotation effects on cereals
growth on Sudano- Sahelian West Africa: Soil mineral
nitrogen, rhizobium and nematodes. Plant and Soil.
218:103-16.
Bahreininejad, B.J. Razmjoo, and M. Mirza (2013):
Influence of water stress on mprpho-physiological and
phytochemical traits in Thymus daenensis.
International Journal of Plant Production, (2013)
7(1):151-166
Biswas B, Gresshoff PM (2014): The role of symbiotic
nitrogen fixation in sustainable production of biofuels.
International Journal of Molecular Science. 15:7380-
7397.
Chatterjee, R. Bandyopadhyoy, S (2017): Effect of Boron,
Molybdenum and Bio-Fertilizers on Growth and Yield of
Cowpea (Vigna unguiculata L.Walp) in Acid Soil of
Eastern Himalayan region. Journal Search SOC. Agric.
Sci. 16, 332-336 (Cross Ref)
Chiezey, U.F, Katung, P.D & Yayock, J.Y. (1990):
Response of cowpea (V. unguiculata (L.) Walp.), var.
Sampea-7 to nitrogen and phosphorus following a
maize crop. Samaru Journal of Agricultural Education,
4| (1): 161-168.
Chi, F.S.H., Shen, H.P. Cheng, Y.X. Jing, Y.G, Y.G.Y and
F.B. Dazzo (2005): Nitrogen Fixation in Flooded Soil
Systems. A Review. Advanced Agronomy 33:149-191
Dar, N.A & Bali A.S (2007): Defining new roles for plants
and rhizobial molecules in sole and mixed plant cultures
involving symbiotic legumes. New Physiology 158:39-
49
Dashti, N. Zhang, F. Hynes, R. and Smith, D. L. (1995):
Application of plant growth promoting Rhizobacteria to
soybean (Glycine max (L.) Merr.) Increases protein and
dry matter yield under short season conditions. Journal
of Soil Science 188, 33-41
Deo, K.gh Singh, S.B (2014): Effect of Zinc and Boron
application on Yield, Lentil and Nutrient balance in the
soil under Indo-Gangetic Plain Zones. Journal of
Agricultural Research; 206-209.
Dey, A.K, Sharma. M .Meshrem, M.R (2016): An analysis
of Leaf Chlorophyll measurement method using
Chlotrophyll meter and Image Processing Technique.
Procedia Comput. Science. 85-286-292. (Cross Ref)
Diaz, C.T.S. Krazanowski. W.J (2003): Model selection
and cross- validation in additive main effect and
multiplication interaction (AMNI) models. Crop Science,
v.43, pp 865-873
Ditta, A., M. Arshad, Z.A. Zahir and A. Jamil (2015):
Comparative efficacy of rock phosphate enriched
organic fertilizer vs. mineral phosphatic fertilizer for
nodulation, growth and yield of lentil. International
Journal of Agriculture and Biology 17: 589‒595.
Ditta, A., A. Khalid (2016): Bio-organo-phos: A sustainable
approach for managing phosphorus deficiency in
agricultural soils. In: M. Garamendi, and S. Soloneski
(Eds.). Organic Fertilizers - From Basic Concepts to
Applied Outcomes (ISBN 978-953-51-4701-5). InTech,
Croatia. pp. 109136. http://dx.doi.org/10.5772/62473
Ditta A., M. Imtiaz, S. Mehmood, M.S. Rizwan, F. Mubeen,
O. Aziz, Z. Qian R. Ijaz and S. Tu (2018): Rock

Phosphate Enriched Organic Fertilizer with Phosphate
Solubilizing Microorganisms Improves Nodulation,
Growth and Yield of Legumes. Communications in Soil
Science and Plant
George, N., Cheming’wa, J.W. Muthomi and S.W.M.
Theuri (2007): Effect of Rhizobia inoculation and
starter-N on Nodulation shoot biomass and Yield of
Grain legumes. Asian Journal of Plant Sciences 6
(7):1113-1118.Asian network for Scientific Information
Gharti D.B, Darai R, Subedi S, Sarker A, Shiv Kumar
(2014): Grain Legumes in Nepal: Present Scenario and
Future Prospects. World J. Agric. Res. 2(5):216-222.
Graham PH, Vance CP (2000): Legumes: importance and
constraints to greater use. Plant Physiology. 131:872-
8771.
Graham PH (2002): Stress tolerance in Rhizobium and
Bradyrhizobium and nodulation under adverse soil
condition. Journal of Microbiology. 135:375-485.
Hall AE (2004): Breeding for adaptation to drought and
heat in cowpea. European Journal of Agronomy.
21:447-454.
Henson, I.E. Harun, M.H. Chang, K.C. and Mohammed,
A.T (2007): Predicting soil water status,
evapotranspiration growth and yield of young oil palm
in a seasonally dry region of Malaysia. Journal of Oil
Palm Research. 19, 398-415
Hussain A., Z. A. Zahir, A. Ditta, M. U. Tahir, M. Ahmad,
M. Z. Mumtaz, and K. Hayat, S. Hussain (2020):
Production and implication of bio-activated organic
fertilizer enriched with zinc-Solubilizing bacteria to
boost up maize (Zea Mays L.) production and
biofortification under two cropping seasons. MDPI-
Agronomy 10(39) (https://doi.org/10.3390/agronomy
10010039
Isahak, A. A. Ahmad, A.B. Rosenani and H. Jamil (2012):
SRI Rice crop establishment. TRANS, Malayan Soc.
Plant Physiology. 20:20-20
Jensen E.S, Peoples M.B, Boddey R.M, Gresshoff PM,
Haggard-Nielsen H, Alves BJR, Morrison M.J (2012):
Legumes for mitigation of climate change and provision
of feedstocks for biofuels and biorefineries. Agronomy.
Sustain. Dev. 32:329-364.
Kennedy I.R, Cockings E.C. Biological Nitrogen Fixation
(1997): The global challenge and future needs.
Rockefeller foundation bellagion conference
proceedings. SUN Fix Press, University of Sydney,
Australia. 1997: 83.
Khalil, S and El-Noemani, A (2012): Interaction effect of
exogenous proline and water stress on plants.
www.researchgate.net/publication/30
Kulac, S. Nzokou, P. Guney, D. Cregg, B.M. and Turna, I
(2012): Growth and physiological response of Fraser
Fir [Abies fraseri (Pursh) Poir.] seedlings to water
stress: Seasonal and diurnal variations in
photosynthetic pigments and carbohydrate
concentration. HortScience 47(10):1512-1519.
Langyintuo AS, Lowenberg-deboer J, Faye M, Lambert D,
Ibro G, Moussa B, Kergna A, Lindermann W.C (2015):
Soil Microbiologist College of Agriculture, Consumer
and Environmental Sciences. New Mexico State
University, USA.
Majumder, A.L. (2010): Improvement of plants through
Biotechnology: An assessment of the present status.
Article. Jan, 2013. International Journal of Plant
Research
Musando, A.A O. and Ogendo J.O (2002): Effect of
Rhizobia inoculation and Fertilizer Nitrogen and
Phosphorus on the Grain Yield of Beans in Western
Kenya. In: Challenges and Imperatives for Biological
Nitrogen Fixation Research and Application in Africa for
the 21st Century, N.K. and H.P. Kalindi. (Eds). John
Philips African Limited, Nairobi.pp:86-93
Muli MB, Saha H.M (2002): Participatory evaluation of
cowpea cultivars for adaptation and yield performance
in coastal Kenya. In: Mureithi JG, Gachene GKK,
Muyekho FN, Onyango M, Mose L, Magenya O (eds.)
Participatory technology development for soil
management by small holders in Kenya. Nairobi, Kenya
pp. 267-272.
Osunubi, O. and Mulongony, K. (1992): Interaction
between drought stress and vesicular Arbuscular
mycorrhizal on growth of Faidherbia albida (Acacia
albida) and Acacia nilotica in sterile and non-sterile
soils. Biology and fertility of soils, 3:159-165.14
Pandy R.K. Herrera W.A.T, Pendleton J.W (1984):
Drought response of grain legumes under irrigation
gradient: Yield and yield components. Agronomy
Journal. 76(4):549-53.
Read, D.J. and Boyd, R.C. (1986): Water relations of
Rhizobium and their host plant in Ayres.P.C Boddy L
(Eds). Water, Bacteria and Plants. Cambridge
University press, Cambridge US.K
Sakthivel, N. and Soremi, S. S (1987): Evaluation of
Pseudomonas fluoreescens for suppression of sheath
rot disease and for enhancement of grain yield in rice
(Oryza sativa L.). Appl. Environ, Microbiol. 53:2056-
2059
Sarfraz R., A. Hussain, A. Sabir, I.B. Fekih, A. Ditta, S.
Xing (2019): Role of Biochar and plant growth-
promoting rhizobacteria to enhance soil carbon
sequestration– a review. Environmental Monitoring and
Assessment. 191: 251 https://doi.org/10.1007/s10661-
019-7400-9
Shinkafi, M.A (2000): Effects of macronutrients deficiency
and Rhizobium inoculation of Faidherbla albida (Del) A.
chev.in a semiarid environment, Ph.D. Thesis. Usmanu
Danfodiyo University Sokoto.pp. 148
Stagnari F, Maggio A, Galieni A, Pisante M (2017): Multiple
benefits of legumes for agriculture sustainability: an
overview. Chem. Biol. Technol. Agric. 4(2):1-13.
Shu-Jie, M. Yun-Fa, Q. Xiao-Zeng, H. and A, M. (2007):
Nodule formation and development in soybeans
(Glycine mux L.) in response to phosphorus supply in
solution culture. Pedosphere, 17, 36-43.
http://dx.doi.org/10.1016/S1002-0160(07)60005-8
Tekle Y (2014): Performance Evaluation of Cowpea (Vigna
unguiculata L.) Varieties under Moisture Conservation

Oyewusi et al. 688
Practices for Yield and Yield Components at Alduba,
Southern Ethiopia. J. Nat. Sci. Res. 4(7):7-11.
Ullah N., A. Ditta, A. Khalid, S. Mehmood, M.S. Rizwan, F.
Mubeen, M. Imtiaz (2020): Integrated Effect of Algal
Biochar and Plant Growth Promoting Rhizobacteria on
Physiology and Growth of Maize Under Deficit
Irrigations. Journal of Soil Science and Plant Nutrition
20: 346-356. https://doi.org/10.1007/s42729-019-
00112-0
Voisin A.S, Guéguen J, Huyghe C, Jeuffroy M.H, Magrini
MB, Meynard J.M, Mougel C, Pellerin S, Pelzer E
(2013): Legumes for feed, food, biomaterials and
bioenergy in Europe: a review. Agronomy. Sustain.
Dev. pp. 1-22.
Zeb H., A. Hussain, M. Naveed, A. Ditta, S. Ahmad, M.U.
Jamshaid, H.T. Ahmad, B. Hussain, R. Aziz, M.S.
Haider (2018): Compost enriched with Zn and Zn-
Solubilizing bacteria improves yield and Zn-fortification
in flooded rice. Italian Journal of Agronomy 13(4): 310-
316.
Accepted 30 May 2020
Citation: Oyewusi IK, Agele SO, Thomas, OV (2020).
Nodulation, Growth and Yield Response of Five Cowpea
(Vigna unguiculata L. Walp) Varieties to Inoculum
(Mesorhizobium loti) under Different Watering Regimes.
International Journal of Plant Breeding and Crop Science,
7(1): 677-688.
Copyright: © 2020: Oyewusi et al. This is an open-access
article distributed under the terms of the Creative
Commons Attribution License, which permits unrestricted
use, distribution, and reproduction in any medium,
provided the original author and source are cited.

Nodulation, Growth and Yield Response of Five Cowpea (Vigna unguiculata L. Walp) Varieties to Inoculum (Mesorhizobium loti) under Different Watering Regimes

Recommended

Recommended

More Related Content

What's hot

What's hot (20)

Similar to Nodulation, Growth and Yield Response of Five Cowpea (Vigna unguiculata L. Walp) Varieties to Inoculum (Mesorhizobium loti) under Different Watering Regimes

Similar to Nodulation, Growth and Yield Response of Five Cowpea (Vigna unguiculata L. Walp) Varieties to Inoculum (Mesorhizobium loti) under Different Watering Regimes (20)

More from Premier Publishers

More from Premier Publishers (20)

Recently uploaded

Recently uploaded (20)

Nodulation, Growth and Yield Response of Five Cowpea (Vigna unguiculata L. Walp) Varieties to Inoculum (Mesorhizobium loti) under Different Watering Regimes