Performance and Growth Analysis of Three Mungbean (Vigna Radiate (L.) Wilczek) Genotypes at Hawassa, Ethiopia
Melese Lema*, Bililign Mekonnen and Getachewu Gudero
Department of plant breeding, Southern Agricultural Research Institute, Ethiopia
Submission: June 06, 2018; Published: September 11, 2018
*Corresponding author: Melese Lema, Southern Agricultural Research Institute (SARI), Department of plant breeding. P.O Box: 06, Hawassa Ethiopia.
How to cite this article: Melese L, Bililign M, Getachewu G. Performance and Growth Analysis of Three Mungbean (Vigna Radiate (L.) Wilczek) Genotypes at Hawassa, Ethiopia. Curr Trends Biomedical Eng & Biosci. 2018; 16(3): 555940. DOI:10.19080/CTBEB.2018.16.555940.
The experiment was conducted during 2017 at the compound of Hawassa University in the College of Agriculture, Southern Ethiopia during off cropping season. To investigate the performance of different mung bean varieties on response of different growth parameters such as Specific Leaf Area, Leaf area ratio, net assimilation rate, and Relative growth and total dry Biomass. Three mung bean cultivars were grown in randomized complete block design with three replications. The objective of the study was to assess the performance of mung bean cultivars in relation to growth parameters and to estimate the analysis of growth characteristics using the primary values generated from these cultivars. Data were specific leaf area ratio, leaf area ratio, net assimilation rate, relative growth rate and above ground biomass. There is significant difference among cultivars observed for total dry biomass. The SLA and LAR of all cultivars increment from first sample to second sample as crop development progressed. The highest SLA and LAR were attributed suniana variety. Gofa local cultivar is highest total dry biomass, since in this study genetic factor and environment are a key factor for achieving optimum growth and dry matter production of mung bean cultivars.
Keywords: Leaf area ratio; Mung bean varieties; Net assimilation rate; Performance; Relative growth; Specific Leaf Area and total dry biomass
Abbreviations: LA: Leaf Area; CGR: Crop Growth Rate; NAR: Net Assimilation Rate; RGR: Relative Growth Rate; TDM: Total Dry Matter
Mungbean (Vigna radiata (L.) Wilczek) Mungbean belongs to the order Leguminosae and Papilionoideae family . It is an important short duration, self-pollinated diploid legume crop with high nutritive values and nitrogen fixing ability. Hence, it is an eco-friendly food grain leguminous crop of dry land agriculture with rich source of proteins, vitamins, and minerals . Mungbean contains 51% carbohydrate, 24–26% protein, 4% mineral, and 3% vitamins . Besides providing protein in the diet, mungbean has the remarkable quality of helping the symbiotic root rhizobia to fix atmospheric nitrogen and hence to enrich soil fertility . Smallholder farmers in drier marginal environments in Ethiopia grow mung bean. In southern Ethiopia, Farmers in some moisture stress areas (Gofa, Konso, south Omo zone and Konta) have been producing mung bean to supplement their protein needs and also effectively use scanty rainfall . However, its agricultural productivity is drastically limiting in Ethiopia due to low genetic diversity and even if there are some genotypes, they are not improved genotypes . This factor making the mung bean unknown to all farmers of the country and its production is being limiting. However, some researchers have been done they are describes morphological diversity of the crop which might not exactly isolate superior genotypes for the farmers.
Several reports have been made about the contribution of various yield components towards yield [7,8]. The yield components depend on some physiological traits. To understand the physiological basis of yield difference among the genotypes of mungbean, it is essential to quantify the components of growth, and the variation, if any, may be utilized in crop improvement. Variation in dry matter accumulation and pod production in different genotypes may be related to some factors such as leaf area (LA), crop growth rate (CGR), net assimilation rate (NAR) and relative growth rate (RGR). Mondal et al.  analyzed growth parameters of six varieties of Mungbean to study the physiological causes of yield differences and observed differences in CGR, NAR, RGR and LA among the varieties. Not only total dry matter (TDM) production, the capacity of efficient partitioning between the vegetative and reproductive parts may produce high economic yield. A better understanding of crop growth, yield parameters and the partitioning of assimilates into seed formation would help to expedite yield improvement of field crops and mungbean genotypes recent report showed in this regard [10,11] in different countries but not in Ethiopia. Hence, the present study was undertaken with the following objectives.
The experiment was conducted during 2017 cropping season
at Hawassa university college of Agriculture research field.
Hawassa is found in southern parts of Ethiopia. The area is located
6o42’ N and 38o 29’E and with an elevation of 1650masl. The soil
of experimental area was fertile and sandy loam soil with PH of
5.5. The average mean annual rain fall is 800mm with an average
annual minimum and maximum temperature of 13 and 27oC,
respectively. The research was done by supplementary irrigation
since there was shortage of rain fall during sowing time. The
lab experiment was conducted at the department of plant and
horticultural Sciences in the Physiology laboratory.
The experiment was conducted using two improved and
one local mungbean genotypes. These are Sunian, MH-97-6 and
Gofa local (local check). The experiment was conducted using
Randomized Complete Block Design (RCBD) replicated three
times. The seeds were sown in plant spacing 40x10 cm, plot
size -2m x 2m, each plot had 5 rows with total area 4m2, since
08/03/2017. Seeds were drilled and thinned after fully ground
cover. Supplementary irrigation took place immediately after
sowing and the seed was emerged or fully seen after 7 days from
sowing. Except experimental variables all other non-experimental
variables and agronomic field management practices were applied
uniformly to each plot and maximum care was taken to minimize
the possible occurrence of yield limiting factors.
Data Collected: The first and the second samples were taken
after 29 and 57 days from sowing, respectively and for both
sample, 3 plants were taken at random from the middle row for
each plot to determine the following characters (primary values):
plant height (cm), leaves area (cm2), dry weights of stems and
leaves (gm). The final sample was taken 65 days after emergence
by harvesting Two middle rows of mung bean population plants
(area 1.6m2) for each plot which was important to determine
or measure total dry matter (TDM) (g/m2). Besides, there are
other materials used to facilitate in data collection. These are
sickle for harvesting, sensitive balance for actual measuring of
the weights, portable area meter for leaf area measurement and
others, subjected to dry over an oven at 70oC for 48 hours. Then
the growth analysis like Specific leaf area (SLA), Leaf area ratio
(LAR), Relative growth rate (RCR) and net assimilation rate (NAR)
were carried out following the formula: -
Specific leaf area (SLA)
Where SLA is specific leaf area (cm2 g-1), A is leaf area (cm2 m-2)
and Wleaf is leaf dry weight (gm-2)
Leaf area ratio (LAR)
Where LAR is leaf area ratio (cm2 g-1), A is leaf area (cm2 m-2)
and W is plant dry weight (gm-2)
Relative growth rate (RGR)
Where RGR is relative growth rate (mgg-1day-1),
W1, W2 = subscripts 1 and 2 indicate the value of W (plant
dry weight) on two occasions (gm-2) T1, T2 = subscripts 1 and 2
indicate consecutive samplings at time T2 and T1.
Net assimilation rate (NAR)
Where, W1 and W2 are the DM at the time T1 and T2 respectively.
LA1 and LA2 are leaf area at the time T1 and T2, respectively.
Data Analysis: Each growth parameters were analyzed and
computed mean values ± SE (standard error) by using the above
listed formula for each treatment (genotypes). The recorded data
of the mungbean genotypes for dry weight biomass was subjected
to Analysis of Variance (ANOVA) appropriate to the experimental
design analyzed using SAS software version 9.1 and tested
significance at 5% probability level using the F test.
Specific Leaf Area: Specific leaf are is a measurement of
leaf thickness which plays an important role in leaf and plant
functioning and related to species’ strategies of resources
acquisition and use related with dry matter accumulation. Results
of this experiment indicated that there were differences between
three varieties with 108.35cm2/g, 85.62cm2/g and 103.03cm2/g
for sunian, MH-97-6 and Gofa local respectively within two
sampling times (Table 1). The numerical values told that variety
sunian had better leaf thickness which enables assimilate highly.
This show that the resources (water) contribute for good uptake
of for the formation of high dry matter and this study agree with
Ann B. The SLA of all cultivars increased as crop development
progressed. But the differences in SLA among the cultivars were relatively small. The SLA of sunian was better than MH-97-6 and
in both sampling date and better than Gofa local at second sample.
Highest specific leaf area of a crop indicates that it has larger leaf
area, and this helps the crop to have highest efficiency of light
harvesting which means higher photosynthetic rate. SLA is an
important trait characterizing plant adaptation to environmental
conditions: its plasticity is often seen as a way for plants to
increase the efficiency of light-harvesting, and/or the efficiencies
of resource-use (e.g., light, water and nitrogen-use efficiencies).
*First Sampling at 22 days after emergence and Second sampling at 50 days after emergence SE: Standard Error; SLA1: Specific Leaf Area First Sampling; SLA2: Specific Leaf Area Second Sampling; LAR1: Leaf Area Ratio First Sampling; LAR2: Leaf Area Ratio Second Sampling
Leaf Area Ratio (LAR): The ratio between leaf area and total
plant dry weight has been termed the leaf area ratio (LAR). A high
LAR has been considered a desirable characteristic because it
indicated the plant had a high photosynthetic potential in relation
to its respiratory load. The yields of bean cultivars were more
highly correlated with their LAR than with either their LAI. The
LAR of all cultivars increased as crop development progressed.
This result argued that decline. But the differences in LAR among
the cultivars were relatively high. The LAR of Sunian was better
than MH-97-6 and Gofa local with the mean values of 68.6398,
55.35 and 63.75 respectively. All cultivars showed a great
increment in LAR. Compared several dry bean cultivars and found
the yields were highly and positively correlated with the LAR. On
the other hand, a negative relationship between the grain yields of
soybean cultivars and their LAR values. The results of the present
study from the yield and biomass relationship agree with those of
Wallace and Munger (Table 2).
Net Assimilation Rate (NAR): Net assimilation rate has been
defined as the rate of increase of dry weight per unit of leaf area.
This parameter has frequently been calculated in field research
to estimate the photosynthetic efficiency of crop leaves. Donald
pointed out that the NAR value for a crop was an average value
for all leaves. From table3 result showed Sunain high NAR than
MH-97-6 and Gofa local. Several studies have found a negative
correlation between leaf area ratio and NAR the rate of decline in
LAR per unit increase in NAR has been used as a measure of the
canopy efficiency of crops. The NAR of improved cultivars showed
a slower rate of decline than the older standard ones. They
attributed this to improvements of canopy architecture. Cultivars
with a higher LAR would have a higher NAR, also; this experimental
results in line with relationship. They found that SLA had a high
heritability and suggested it would be a good characteristic for
easy, indirect selection of photosynthetic efficiency.
Relative Growth Rate (RGR): Relative growth rate is the rate
of increase in plant dry weight relatively to the total dry weight
of that plant. The relative RGR of the cultivars depended on the
stage of crop development Table 3. During the period, between
two samples date, the RGR of MH-97-6 was better than Sunian
and Gofa local numerically. The correlation between LAR, the ratio
between total leaf area and total plant weight, and RGR was very
high. This positive correlation was mainly due to the SLA, the ratio
between leaf area and leaf weight, and to a lesser extent caused by
the leaf weight ratio, the fraction of plant biomass allocated to the
leaves. Table 3 the mean separation for biomass dry weight.
The above ground total biomass showed significant
difference for Gofa local from suniana and MH-97-6 mung bean
cultivars with the mean values 767.0833, 695.5833 and 569.625,
respectively (Table 3). Leaf dry weight was the major component
of the total dry weight. Dry matter accumulation in crops has a direct relationship with leaf area ratio. The LSD shows their
significant difference between treatments that means varieties
has a positive effect on total dry matter. This implies that genetic
and environmental effect is to difference dry matter accumulation.
From Table 4 result shows that Gofa local is the highest Total dry
biomass than Suniana and MH-97-6 varieties.
The genetic and environmental factors can cause a different
level of variation of the tested characteristics of mung bean
varieties. Because yield is a complex trait resulting from the
interaction of morphological, phonological physiological and
environmental parameters on the growth of plants, Mung bean
(Vigna Radiate (L.) Wilczek). Cultivar types are important for
good agronomic performance for greater growth and total dry
biomass showed in the studied area. The SLA and LAR of all
cultivars increased and positively correlated as crop development
progressed in first and second sapling. During the period, between
samples 1 and 2, the SLA of Suniana was better than MH-97-6 and
Gofa local the same result for LAR. During the period, between
two sampling dates, the RGR of MH-97-6 was better than Sunian
and Gofa local numerically. As it is shown on the result, when
relative growth rate increase leaf area ratio and specific leaf area
also increases. So, it’s possible to conclude that both leaf area ratio
and specific leaf area affect the Mung bean growth rate. The above
ground total dry biomass showed significant difference Gofa local
from MH-97-6 and Sunaina Mung bean cultivars. Numerically
the maximum biomass 767.0833 gm/m2 from Suniana 695.5833
gm/m2 and 569.625 gm/m2 from MH-97-6. Therefore, response
of growth and growth parametrs of the performance mung bean
cultivars in the study area lead us to the conclusion different
genetic capacity for its biomass production among cultivars.
Generally, it is fair to say that these Mung bean cultivars perform
differently across their growing period.