Growth Characteristics and Some Wood Quality of Tamarix aphylla
Seedlings Irrigated with Primary Treated Wastewater under Drought Stress
Hamad A. Al-Mefarrej
Drought stress and water quality are the main causes of alteration
in plant physiological processes and reduction of plant growth. The aim of this
study is to evaluate the response of Tamarix aphylla seedlings to two
types of irrigation and three periods of water regime under greenhouse condition.
The effect of Primary Treated Wastewater (PTW) compared with Well Water (WW)
at drought stress using three intervals irrigation on growth, biomass production
and its allocation, physical properties and chemical constituents of wood is
studied. The experiment was carried out during the successive season of 2010/2011.
The results indicate that fresh weight of stem and foliage are increased without
any significant for the seedlings irrigated by PTW compared to WW. However,
fresh weight of roots and oven-dry weight of foliage are significantly increased.
No significant differences are observed for the specific gravity and fiber length
of wood produced from seedlings irrigated by either WW or PTW. The results indicated
that irrigation with PTW influenced the chemical composition of T. aphylla
wood. Under drought stress, all growth parameters and biomass production
are decreased by increasing the irrigation periods from one to five weeks. Chemically,
the contents of lignin and ash are significantly increased under drought stress;
however, the cellulose, extractive and hemicellulose contents express inverse
trends. The study conclude that the use of PTW significantly increase the produced
biomass and some of wood quality. Planting seedlings under drought stress have
significant effects on the properties of one year-old Tamarix seedling.
Received: April 10, 2013;
Accepted: September 02, 2013;
Published: September 19, 2013
Water has become an increasingly scarce resource in many arid and semi-arid
regions, thus necessitating development of water resources through untraditional
ways (Selim, 2006). Wastewater reuse in agriculture
practice has been started at the beginning of the last century in several countries
worldwide. In many developing countries, including Saudi Arabia, acute shortage
of water necessitates the development of new water sources. Land application
of wastewater is considered to be the best solution for covering this shortage
of water. The domestic wastewater generated from Riyadh City has increased from
420,000 m3 day-1 in 1993-538, 500 m3 day-1
in 2007 (Al-Othman, 2009). As well as, the treated
wastewater increased from 396,300 m3 day-1 to 536,330
m3 day-1 in the same period (GDWRR,
Saudi Arabia does not have adequate forest treasury to cover their requirements
for wood industry like fuel wood, industrial wood, sawn wood and wood-based
composition panels. The annual cost of wood and wood products import in Saudi
Arabia was estimated at 115 million dollars in 2004 and 305 million dollars
in 2007. In order to meet the increasing demand of wood products, Saudi Arabia
has planted fast growing tree species in many areas of the country (Aref
and El-Juhany, 2005). The use of treated wastewater as a new resource of
irrigation has been encouraged in Saudi Arabia during the last two decades to
increase the efficient use of water irrigation in crop production (Alderfasi
et al., 2002) and forest trees (Nasser et
Wastewater after primary treatment is safe for irrigation of tree plantations,
forestlands, green belts around the cities and non-food crops (Hassan
et al., 2006; Tabari and Salehi, 2009).
These authors reported that using the irrigating with sewage effluent improved
the soil properties because it is considered as a rich source of nutrients.
Several studies related to the influence of irrigation with sewage effluent
on some growth parameters such as wood specific gravity, fibre length and volumetric
shrinkage of forest trees as well as biomass potential and its allocations have
been investigated (Szopa et al., 1977; Guang-Cheng
et al., 2010; Ali et al., 2011).
On the other hand, a slight effect on wood specific gravity and fibre length
was detected in Melia azedarach species as a result of using sewage effluent
(Kayad et al., 2005).
Water stress is the main cause of alteration in plant physiological processes
and reduction of plant growth, which considerably affects tree seedling performance
immediately after plantation and during the whole establishment stage, causing
serious losses and affecting tree regeneration and, consequently, future stand
productivity. Severe water stress conditions significantly decreased the growth
of high plants. Therefore, several plants show some modifications of their morphological
and physiological attributes to overcome drought stress. Some of these modifications
are visible and relatively easy to measure which in turn reflect physiological
adaptation (Rao et al., 2008; Liu
et al., 2011).
Tamarix aphylla (Athel) is one of forest trees, fast growing, drought
resistant and salt-tolerant species, planted throughout the Saudi Arabia (Al-Mefarrej,
1985). Their wood characteristics are close-grained, light-coloured and
fairly hardwood with high shock strength resistance. In addition, their wood
is used for firewood and charcoal purposes (Orwa et al.,
There is a little information in the available literature about the basic effect
of wastewater irrigation and drought stress on the properties of wood (Kayad
et al., 2005; Abdel-Aal et al., 2008).
It is important to evaluate the chemical composition of wood in order to ascertain
its proper utilization. This will help to give suggestion to wood users how
the wood suitable for wood industries (such as, pulp and paper; wood composite
panels), fuel and construction purposes. Accordingly, the objective of this
study, therefore, is to determine the biomass production and allocation, growth
parameters and the main physical and chemical properties of wood of one year
old T. aphylla seedling grown in the greenhouse as affected by primary
treated wastewater irrigation and drought stresses.
MATERIALS AND METHODS
This study was carried out in the greenhouse at the nursery of the Agricultural
Experimental Station, College of Food and Agricultural Sciences, King Saud University,
Dirab, 60 km south of Riyadh. The site has the following characters: 24°6
N, latitude; 46°5 E, longitude; temperature (as an average of season)
ranged between 10°C in winter and 41°C in summer; and 50 mm rainfall
annually (Aref and El-Juhany, 2005).
Plant material: Cuttings of Tamarix aphylla were carefully selected
from healthy mother trees grown in the nursery of the Agricultural Experimental
Station. They were planted in plastic pots, 30 cm length and 25 cm in diameter,
containing 25 kg of sandy loam soil to about 2 cm from the rim. After plantation,
they were watered with well water until they attained 3-months-old. Two treatments
were applied, namely water quality (well water and primary treated wastewater)
and irrigation periods (weekly, two and five weeks intervals). Each seedling
was irrigated with about 600 mL by either Primary Treated Wastewater (PTW) or
Well Water (WW). PTW used to irrigate the plantation was derived from industrial
and municipal sources and was treated-primary before irrigation. The irrigation
was given at specific time according to treatments.
Growth parameters and biomass production: The height and diameter of
the seedlings were measured at the beginning and the end of the experiment.
Seedlings are carefully lifted from the pots. Soil particles were carefully
removed from the roots by washing first with tap water and then with distilled
water. To calculate the biomass production and their allocation, the total fresh
weight was taken and then each seedling was separated into three parts: Foliage,
stem and root. Fresh and dry weights of each part were recorded. The dry weight
was determined for all after drying at 70°C in an oven to a constant weight
and shoot/root ratio was calculated.
Foliar analysis: The stem and leaves of the seedlings were oven-dried
at 70°C to constant weight. They were separately grounded using Willey mill
into fine powder. Samples of 0.3 g of the ground material were digested using
sulfuric acid and hydrogen peroxide. The digested samples were used to measure
the nitrogen, phosphorus, potassium, sodium, cadmium, zinc, nickel and lead
content (Evenhuis and Dewaard, 1980).
Water analysis: Water samples were taken from the two types of water
used for irrigation (municipal and primary treated wastewater) and then were
transferred immediately at 4°C to the laboratory for analysis. Water analysis
was performed according to the standard methods (APHA, 1995).
Soil analysis: One sample of soil was taken before the beginning (virgin
soil) and another sample at the end of the experiment. All soil samples were
air-dried, crushed gently, sieved through 2 mm sieves and stored for analysis.
Total carbonate was determined according to Nelson (1982).
Available levels of N and P were determined. The concentrations of heavy metals
were quantified through atomic absorption spectrophotometer (Perkin Elmer model,
3080). Sodium and potassium were determined by using flame photometer (Black
et al., 1965).
Chlorophyll determination: Total chlorophyll content was determined
in fresh leaf samples using N,N-dimethyl formamide (Moran
and Porath, 1980).
Specific gravity and fiber length determination: One sample strip, 2-cm
length free from any natural defects was machine-cut from the stem bases of
each seedling used in this study. Specific Gravity (SG) of each sample was then
evaluated using the equation developed by Smith (1954).
Samples for fiber length measurements were cut from the region 10 cm above the
ground. Each sample is prepared and measured according to Franklin
Wood chemical analysis: About 2 g (40-60 mesh) of air-dried wood meal
was extracted using a Soxhlet apparatus in successively three steps with benzene-ethanol
mixture, ethanol and distilled water (ASTM, 1989). The
other main wood components of wood (cellulose, hemicellulose and lignin) were
determined using extractive-free wood meal according to the methods described
by ASTM (1989).
Experimental design and data analysis: The experimental design was a
split-plot in RCBD with three replications. Comparison among treatment means
were calculated following the Duncan Multiple Range Test at 0.05 level of probability.
RESULTS AND DISCUSSION
Table 1 is showing the physical and chemical properties of
the two types of water used for the irrigation of the experiment.
||Some physicochemical properties of the types of water used
|ND: Not detected, *PTW: Primary treated wastewater, **Limits
of wastewater for agricultural reuse FAO (1992)
It can be noted that although there are differences in their physicochemical
properties between the two types of water used, PTW has the higher values. Electrical
Conductivity (EC) of the PTW was 1.87 dS m-1 as compared to the limit
of FAO (1992) which indicating a low salinity level.
Irrigation with low salt concentration (>5 dS m-1) is often used
without considering the negative effects of poor quality water on seedlings
growth and productivity. In addition, PTW has high chloride (312.4 mg L-1)
and sodium levels (219.2 mg L-1). However, the concentrations of
the heavy metals in the two types of water are under the maximum recommended
concentrations and the pH values are within the level recommended by FAO
(1992), which falling within the 6.5-8.4 pH range appropriate for irrigation
The soil of the site was calcareous with low clay silt and its chemical properties
are shown in (Table 2). It can be noticed that under the T.
aphylla experiment, there are changes in soil properties occurred as a result
of irrigation using the two types of water quality. It is clear that the values
of soil pH were close to the virgin soil before planting. However, the EC of
the soil differ by different types of water quality, it ranged from 1.41 dS
m-1 before planting to 5.63 and 9.35 dS m-1 for WW and
PTW, respectively. The EC values in the soils after planting were higher compared
to those in virgin soil (before planting). This indicates that some salt accumulation
might occur as a result of evaporation. PTW have had high chloride (312.4 mg
L-1) and sulfate levels (369.6 mg L-1). The increase in
SO4-2 concentration with PTW irrigation may be due to
the biological oxidation of the protein sulphur in the sewage (Waly
et al., 1987). On the other hand, the contents of heavy metals increased
strongly related to the irrigation treatment.
|| Chemical characteristics of the soil used for the experiment
|*PTW: Primary treated wastewater, ND: Not detected
Generally, PTW exhibited an increase in the basic nutrients (N, P and K) contents
of the soil. This means that the PTW enriched the soil with important elements,
which are very necessary for plant growth and improve the soil chemical characteristics
under T. aphylla plantation. These results are in agreement with that
have been found by Singh and Bhati (2005) and Ali
et al. (2011).
Growth characteristics: The growth characteristics are represented by
the seedlings height, diameter and fresh and dry weights of each seedling components.
The results of the analysis of variance in Table 3 reveal
that the effect of irrigation periods and water quality on all the tested characters
is significant. However, the interaction between irrigation periods and water
quality was not significant except for fresh weight of stem and root.
Effect of water quality on growth: Table 4 showed
the effect of water quality on the growth and biomass weight of Tamarix aphylla
seedlings. It can be noted that all the growth characters were significantly
increased under irrigation with PTW compared to WW (Table 4).
There are a significant increment in stem diameter and seedling height due to
irrigation with PTW (68.92 and 61.89%, respectively) compared with WW irrigation
(20.49 and 39.44%, respectively). Irrigated seedlings with WW record the highest
values of biomass production in fresh and dry states for the three components
of the seedlings (stem, foliage and root), compared to seedlings irrigated with
PTW. These results indicate that PTW enhanced the growth and biomass production
by increasing all growth parameters. This finding is in correspondence to what
have been stated by different authors (Kayad et al.,
2005; Bedbabis et al., 2010; Ali
et al., 2011). The beneficial reuse of PTW in irrigation enriched
the soil with nutrients and organic matter which decreased soil bulk density
(Guo and Sims, 2000). On the other hand, Bhati
and Singh (2003) concluded that greater growth production may be due to
sufficient availability of water and essential elements by sewage effluent.
Effect of irrigation period on growth: It can be seen from Table
5 that all the growth parameters for the seedlings irrigated by either WW
or PTW have been decreased significantly as the irrigation period increased
from one to five weeks. The percentage increment of stem diameter and height
markedly decreased as drought stress intensified from one to five weeks (Table
5). It is obvious from this table that the seedlings which received high
level of irrigation (weekly irrigated) gave the highest significant increment
in stem diameter and height as well as fresh and dry weight of the three components
of the seedling. These results are in harmony with those obtained by Elfeel
and Al-Namo (2011) on three arid zone species. The decrease in growth parameters
with drought intensity in the current study may be due to the decline in net
photosynthesis assimilation which brought by decreased leaf water potential
(Rao et al., 2008).
|| Analysis of variance of the growth characteristics of the
T. aphylla seedlings
|*,**: Significant at 0.05 and 0.01 level of probability, respectively,
NS: Not significant
|| Effect of water quality on growth and biomass weight (g plant-1)
of Tamarix aphylla
|Each value is an average of 9 samples, WW: Well water, PTW:
Primary treated wastewater, Means with the same letters in a column are
not significantly different at 0.05 level of probability according to Duncan's
multiple range test
|| Effect of irrigation period on fresh and dry weights of the
seedlings of Tamarix aphylla
|Each value is an average of 6 samples, Means with the same
letters in a column are not significantly different at 0.05 level of probability
according to Duncan's multiple range test
|| Analysis of variance for specific gravity, fiber length and
chlorophyll of T. aphylla
|*,**: Significant at 0.05 and 0.01 level of probability, respectively;
NS: Not significant
||Effect of irrigation periods on the dry relative biomass allocation
for T. aphylla seedling
Figure 1 shows the relative distribution of the biomass components
for the individuals of Tamarix aphylla seedlings as affected by the three
water regime. It can be seen that the percentage of the dry stem has increased
as the irrigation period increased, where it was 54.49, 58.41 and 59.92% for
irrigation period 1, 2 and 5 weeks, respectively. The same trend was obtained
for the dry root, where it was 22.96, 24.74 and 26.75% for the same period,
respectively. In the current study, the root/shoot weight ratio increase from
0.298-0.365 as irrigation period increase from one to five weeks. Increasing
the percentage of the dry root biomass resulted in a higher root/shoot weight
ratio under drought (Li et al., 2009; Guang-Cheng
et al., 2010), which represents one of the most adaptive mechanisms
in plants tolerance to water stress. However, the percentage of the dry foliage
(leaf weight ratio) decreased as irrigation period increased, where it is 20.55,
16.75 and 13.32% for the same order. Reduced growth and leaf shedding as a result
of drought stress are well known phenomena (Kozlowsky and
Pallardy, 1997). These results are in agreement with those obtained by Aref
and El-Juhany (2005) and Rao et al. (2008).
This result may be attributed to the reduced development and expansion of new
leaves and/or increased leaf loss compared to seedlings under irrigated conditions
(Engelbrecht and Kursar, 2003).
Effect of irrigation periods and water quality on the specific gravity of
wood: The analysis of variance Table 6 indicates that
the effect of IP on the specific gravity of wood was significant.
||Mean values of specific gravity, fiber length and chlorophyll
content of T. aphylla
|Mean values of 6 samples except for fiber length 100 measures,
Means with the same letters in a column are not significantly different
at 0.05 level of probability according to Duncan's multiple range test
However, the effect of WQ and the interaction IP*WQ were not significant.
Table 7 shows that the mean values of the Specific Gravity
of wood (SG) were decreased as the irrigation period increased. Increasing IP
from one to two weeks significantly decreases the SG of wood from 0.659-0.619,
while increasing the IP to five weeks decreases the SG without any significant
differences between the seedlings irrigated every two and five weeks (0.619
and 0.607, respectively). It can be seen that there is a slight effect of drought
on the SG of wood, where the percentage change in the SG is about 1.94% from
one to five weeks. The basic information regarding the effect of sewage effluent
irrigation on wood properties is very limited. However, similar results on the
effect of sewage effluent irrigation had been obtained from previous studies
by Hassan (1996) who concluded that sewage water irrigation
had slight effect on specific gravity of Leucaena leucocephala seedlings
after two years of treatment and finding of Szopa et
al. (1977) when they studying white oak, Kayal (1996)
on five Egyptian tree species and Kayad et al. (2005)
Effect of irrigation period and water quality on the fiber length of T.
aphylla wood: The statistical analysis of the data in Table
6 reveals no significant effects of either irrigation periods or water quality
however, the interaction between them is significant. Table 8
shows that the fiber length for the seedlings irrigated with PTW has the lower
value (0.518 mm) compared with the value recorded by the seedlings irrigated
with WW (0.531 mm) and there is no significant difference between the two means
according to Duncan's multiple range test. This result is in agreement with
Kayad et al. (2005) on Melia azedarach but
in disagreement with Hassan (1996) who concluded chlorophyll
content was obtained with PTW irrigation for the total chlorophyll content (3.52
μmol L-1) as well as chlorophyll A (3.0 μmol L-1)
and chlorophyll B (1.54 μmol L-1). The enhancement of chlorophyll
that irrigation with high concentration of sewage water markedly decreased the
fiber length of Acacia saligna. On the other hand, no trend was obtained
for the effect of irrigation periods on the fiber length of T. aphylla and
this effect was not significant Table 8. Similar trends were
obtained for the interaction between IP and WQ but the interaction was significant
Effect of water quality on the chlorophyll content of T. aphylla leaves:
The chlorophylls are virtually essential pigments for the conversion of light
energy to stored chemical energy. The amount of solar radiation absorbed by
a leaf is a function of the photosynthetic pigment content, thus, chlorophyll
content can directly determine photosynthetic potential and primary production
(Filella et al., 1995). In addition, chlorophyll
gives an indirect estimation of the nutrient status because much of leaf nitrogen
is incorporated in chlorophyll (Moran et al., 2000).
Furthermore, leaf chlorophyll content is closely related to plant stress (Merzlyak
et al., 1999). The analysis of variance (Table 6)
showed that the effects of irrigation period and water quality on the chlorophyll
content of the seedlings of T. aphylla were highly significant. On the
other hand, the interaction WQ*IP was significant except for the chlorophyll
The analysis of variance Table 6 reveals that WQ had significant
effects on leaves chlorophyll contents. Data in Table 8 showed
that seedlings irrigated by PTW enhanced the chlorophyll content of leaves.
||Effect of water quality on specific gravity, fiber length
and chlorophyll of T. aphylla
|Mean values of 9 samples except for fiber length 150 measures,
Means with the same letters in a column are not significantly different
at 0.05 level of probability according to Duncan's multiple range test
The higher resulted from PTW irrigation may be due to the increase of nutrients
in the occupancy root zone, which have a great important role in biochemical
processes moreover Mg ion that participate in chlorophyll structure (Ali,
Regarding with the significant interaction of PI*WQ except for chlorophyll
A (Table 9), similar trend like those obtained for the effect
of irrigation periods was recorded with irrigation by either well water or PTW.
The chlorophyll contents were decreased as irrigation periods increased from
one to five weeks.
Effect of irrigation periods on the chlorophyll content of T. aphylla
leaves: Irrigation periods significantly affected the chlorophyll contents
of T. aphylla leaves (Table 6). The mean values of
chlorophyll contents as affected by irrigation period are presented in Table
7. It can be noted that the content of chlorophyll decreased with increasing
the irrigation periods from one to five weeks. The content of chlorophyll A
significantly decreased from 3.43- 2.21 μmol L-1 as irrigation
period increased from one to five weeks without any significant differences.
In the same order, the content of chlorophyll B and total chlorophyll decreased
significantly from 1.77-1.14 μmol L-1 and from 4.11-2.60 μmol
L-1, respectively. These results are in agreement with the finding
of Alvarez et al. (2009) and Liu
et al. (2011).
Effect of water quality on the chemical constituents of wood: Table
10 shows the analysis of variance for the chemical constituents of Tamarix
wood. The results indicated that the differences in the chemical composition
of wood among irrigation periods, WQ and the interaction between them were highly
significant except water quality and the interaction of the extractive content
were not significant.
||Effect the interaction between irrigation period and water
quality on T. aphylla
|Mean values of 3 samples except for fiber length is an average
of 50 measures
|| Analysis of variance of the wood chemical constituents of
|*,**Significant at 0.05 and 0.01 level of probability, respectively;
NS: Not significant
The data in Table 11 indicates that the irrigation of the
seedlings with PTW increased significantly the cellulose and ash contents of
T. aphylla wood as compared to those seedlings irrigated with WW. However,
hemicelluloses content was decreased when seedlings irrigated by PTW. On the
other hand, irrigation with PTW did not significantly affect the extractive
and lignin contents of wood. Although, the differences between the two types
of water quality used for irrigation on the chemical composition of wood were
highly significant, the percentage of change between PTW and WW as a percentage
to the later were quite low (less than <10%) and these differences could
be considered as natural and random error (Table 11). The
change percentage in the chemical composition of wood ranged from 2.27% for
hemicellulose content to 5.46% for ash content. These results are in agreement
with Abdel-Aal et al. (2008) on Casuarina
cunninghamiana. They reported that sewage irrigated trees contained significantly
higher alpha cellulose and ash contents. They attributed these results to the
increase in latewood compared to early wood or thicker fiber walls especially
in S2 layer. The decrease of hemicelluloses content and increase of cellulose
content of Tamarix aphylla wood with irrigation the seedlings by PTW
may be due to the increase of available nutrients of seedlings irrigated with
PTW which increase the photosynthesis rate and the seedling tend to create the
long polymer i.e., cellulose than the short polymer i.e., hemicelulose (Al-Mefarrej
et al., 2011).
Effect of irrigation period on the chemical constituents of wood: The
analysis of variance in Table 10 indicated that the effect
of IP on all the chemical composition of wood was highly significant.
||Effect of water quality on the chemical compositions of T.
|Means with the same letters in the column are not significantly
different at 0.05 level of probability according to Duncans multiple range
||Chemical composition of Tamarix wood as affected by
|Mean values of 6 samples, means with the same letters in the
column are not significantly different at 0.05 level of probability according
to Duncan's multiple range test
The mean values of the chemical composition of Tamarix wood as affected
by IP are presented in Table 12. In general, it can be seen
that increase the IP from one to two week did not significantly decrease the
extractive and hemicelluloses contents. However, increasing the period to five
weeks significantly decrease the three chemical components. The data in Table
12 indicated that there are two trends can be obtained. The lignin and ash
contents of wood increased with increasing the irrigation period from one to
five weeks, while the extractive, cellulose and hemicelluloses contents were
decreased. The decrease of hemicelluloses and cellulose contents of wood with
increasing the irrigation periods may be caused by the seedlings tend to synthesis
the long polymer i.e., cellulose due to the decreased the hemicellulose content,
which resulted from decreased photosynthesis. Rao et al. (2008) reported
that the rate of net photosynthetic were decreased in very high drought stress
compared to control in Albizia lebbek, Dalbergia sissoo and
Anatomically, it can be seen from Fig. 2 that drought stress
influenced the wood anatomy of T. aphylla wood by increasing the percentage
of vessels and the vessels tended to be in groups in the radial direction.
||Cross-section of T. aphylla wood as affected by irrigation
This result needs more attention in the future.
Results obtained from the current study have shown significant enhance in the
growth and biomass production of the T. aphylla seedlings under irrigation
with Primary Treated Wastewater (PTW) over six months as compared with Well
Water (WW). However, the specific gravity and fiber length as well as extractives
and lignin content of wood were not affected. Irrigation of the seedlings with
PTW significantly increased the cellulose and ash contents but decreased hemicellulose
content of T. aphylla wood as compared to those seedlings irrigated with
WW. PTW had slight effect on the properties of wood, which means that the produced
wood did not differ much than the wood irrigated with WW. Results indicated
that all the growth parameters and biomass production have decreased significantly
as the irrigation period increased from one to five weeks for the seedlings
irrigated by either WW or PTW. Chemically, the data indicated that two trends
were obtained. The lignin and ash contents of wood were increased with increasing
the irrigation period from one to five weeks, while the extractive, cellulose
and hemicelluloses contents were decreased. As mentioned above, we advice to
use primary treated wastewater in cultivating forest trees to encourage the
growth and to solve the problems of terminating excess sewage and diminishing
water supply. More studies are needed in this field for a longer experiment
to assure the effects of PTW on the wood properties especially chemical constituents
With sincere respect and gratitude, we would like to express deep thanks to
Deanship of Scientific Research (SABIC), King Saud University and Agriculture
Research Center, College of Food and Agriculture Sciences for the financial
support, sponsoring and encouragement.
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