Evaluation of Yield and Quality of Sorghum and Millet as Alternative Forage Crops to Corn under Normal and Deficit Irrigation Regimes

Abstract

Two field experiments were conducted to evaluate the possibility of increasing diversity of winter cereals- based
double cropping systems and their responses to deficit irrigation. In experiment 1, forage yield and quality of
three corn hybrids, three sorghum cultivars and three species of millet (foxtail, common and pearl millet) were
evaluated. Based on the results obtained from experiment 1, corn hybrid S.C. 704, sorghum cultivar Jumbo, and
pearl millet were selected for further investigations. In experiment 2, the effects of irrigation treatments of I100,
I75 and I50 (providing 100%, 75%, and 50% of the corn estimated water requirement, respectively) were
investigated on selected crops. Sorghum showed higher drought tolerance, but produced lower yield than pearl
millet and corn, except at I50. The highest dry forage yield in I100 was produced by corn followed by pearl millet.
A reduction of 25% in the amount of irrigation water reduced the yield of corn, sorghum and millet by 28, 13
and 24%, respectively. Corn had the highest value of digestibility and relative feed value (RFV). Deficit
irrigation led to a rise in crude protein (CP) and acid detergent fiber (ADF) content, and caused significant
reductions in digestibility and RFV values in the three crop species. Results indicated that pearl millet and
sorghum could be considered as reasonable alternatives to corn in a double cropping system under moderate and
severe deficit irrigation conditions, respectively.

Full text

Jordan Journal of Agricultural Sciences, Volume 10, No.4 2014
-699-
1 Department of Agronomy and Plants Breeding, College
of
Agriculture and Natural Resources
, University of Tehran,
Karaj, Iran.
jahansuz@ut.ac.ir
2 Department of Agronomy and Plants Breeding, College
of
Agriculture, University of Razi Kermanshah, Kermanshah,
Iran.
3
Stockbridge School of Agriculture, University of
Massachusetts Amherst, MA, USA.
Received on 20/8/2013
and Accepted for Publication on
25/11/2013.
© 2014 DAR Publishers/The University of Jordan. All Rights Reserved.
Evaluation of Yield and Quality of Sorghum and Millet as Alternative Forage
Crops to Corn under Normal and Deficit Irrigation Regimes
Mohammad Reza Jahansouz1, Reza Keshavarz Afshar1, Hassan Heidari2, Masoud Hashemi3
ABSTRACT
Two field experiments were conducted to evaluate the possibility of increasing diversity of winter cereals- based
double cropping systems and their responses to deficit irrigation. In experiment 1, forage yield and quality of
three corn hybrids, three sorghum cultivars and three species of millet (foxtail, common and pearl millet) were
evaluated. Based on the results obtained from experiment 1, corn hybrid S.C. 704, sorghum cultivar Jumbo, and
pearl millet were selected for further investigations. In experiment 2, the effects of irrigation treatments of I100,
I75 and I50 (providing 100%, 75%, and 50% of the corn estimated water requirement, respectively) were
investigated on selected crops. Sorghum showed higher drought tolerance, but produced lower yield than pearl
millet and corn, except at I50. The highest dry forage yield in I100 was produced by corn followed by pearl millet.
A reduction of 25% in the amount of irrigation water reduced the yield of corn, sorghum and millet by 28, 13
and 24%, respectively. Corn had the highest value of digestibility and relative feed value (RFV). Deficit
irrigation led to a rise in crude protein (CP) and acid detergent fiber (ADF) content, and caused significant
reductions in digestibility and RFV values in the three crop species. Results indicated that pearl millet and
sorghum could be considered as reasonable alternatives to corn in a double cropping system under moderate and
severe deficit irrigation conditions, respectively.
Keywords: Drought stress; double cropping; Forage quality; Pearl millet; Water use efficiency
INTRODUCTION
In arid and semi-arid areas of the world, water is the
principal limiting factor of agricultural production
primarily due to low and/or uneven distributions of
annual rainfall (Keshavarz Afshar et al., 2014a;
Jahanzad et al., 2011). Despite water scarcity, excessive
use of ground water is a common practice in these areas
when irrigation is employed. In recent years the rapid
expansion of irrigation has resulted in massive
exploitation of groundwater resources (Fang et al.,
2010). Deficit irrigation has been considered as a
practical method to overcome shortage of irrigation
water in these regions (Keshavarz Afshar et al., 2012).
Deficit irrigation systems are techniques to maximize
water use efficiency (WUE) and to achieve higher yields
per unit of applied irrigation water. In these methods, the
crop is exposed to a certain level of water stress, either
during a specific growth period or throughout the whole
growing season (Keshavarz Afshar et al., 2014a; Bekele
and Tilahun, 2007).

Evaluation of Yield… Mohammad Reza Jahansouz et al
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Like other types of multiple cropping, double
cropping is considered as a means for expanding the
time of land use, increasing gross profit and an
innovative approach for more efficient use of recourses.
Winter cereals – corn (Zea mays L.) double cropping
system is a common practice in many irrigated regions
(Meng et al., 2012) including Iran. Growing high quality
forage crops with greater water use efficiency in winter
cereal_based double cropping systems might be the key
for sustainable crop production in these areas. Corn is
the most common crop that is cultivated after winter
wheat (Triticum asestivum L.) or barley (Hordeum
vulgare L.) but it is considered a high water demanding
crop (Al-Kaisi and Yin, 2003). Pearl millet (Pennisetum
millaceum L.) and sorghum (Sorghum bicolor L.) are
important forages in several arid and semi-arid regions
of the world and are well adapted to environments with
limited rainfall, high temperatures and low soil fertility
(Keshavarz Afshar et al., 2014b; Amer et al., 2012). It
has been shown that sorghum and millet were more
drought resistant and have higher water-use efficiency
compared with corn and are able to produce acceptable
forage yields when exposed to drought (Jaster et al.,
1985; Singh and Singh, 1995). Therefore, they might be
a good alternative to corn in double cropping or at least
provide more options to winter cereals based-double
cropping systems in areas with limited water resources.
Therefore, two field experiments were conducted to
evaluate the possibility of increasing diversity of wheat
based-double cropping system. In experiment 1, the
primary objective was to compare the productivity of
three corn hybrids, three sorghum cultivars and three
commonly cultivated millet species; foxtail millet
(Setaria italica), common millet (Panicum miliaceum)
and pearl millet (Pennisetum americanum) cultivar
Nutrifeed to evaluate appropriate forage crop cultivars
and hybrids thus to receive further investigations of their
aptness for double cropping with winter cereals. In
experiment 2, selected cultivars and hybrids were
evaluated based on their forage yield as well as quality
under different deficit irrigation regimes.
MATERIALS AND METHODS
Site description
Field experiments were conducted at the Research
Farm of College of Agriculture and Natural Resources,
University of Tehran, Karaj, Iran (N35º56", E50º58",
altitude 1312.5 m), during 2010 and 2011. The
prevailing climate is considered as semi-arid where
average of 30-year air temperature, soil temperature,
and precipitation are 15.8°C, 14.5°C, and 262 mm,
respectively.
The region is highly prone to scanty and unevenly
distributed rainfall and hence drought is the primary
constraint to crop production. Before planting, soil
samples were taken from depths that ranged from 0 to 30
and were analyzed for various physicochemical
properties. The soil had a clay loam texture (33% sand,
36% silt and 31% clay) with no salinity and drainage
problem. The water holding capacity of the soil was 105
mm for 1200 mm soil profile. Other chemical properties
of the soil are presented in Table 1.

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Table 1. General properties of the soil of the experimental site (depth of 0–30 cm).
Year Texture EC
(dS/m)
OC
(%) pH Available P
(mg kg-1)
Available K
(mg kg-1)
N
(%)
2010 Clay loam 0.96 0.89 8.30 11 214 0.11
2011 Clay loam 1.45 0.73 8.32 10 237 0.09
Experimental layout and crop management
Experiment 1
A randomized complete block design (RCBD) with
four replicates was used to evaluate three corn hybrids
(S.C. 301, S.C. 647 and S.C. 704), three sorghum
cultivars (Speed feed, Sugar graze and Jumbo) and three
species of millet (foxtail millet, common millet and pearl
millet hybrid [cv. Nutrifeed]) which were planted as a
double crop after winter wheat was harvested. These
crops can also be classified according to their maturity
period under common planting time (i.e. mid spring).
Hybrid S.C. 301of corn, Speed feed cultivar of sorghum
and common millet are considered as early maturating
crops, whereas hybrid S.C. 647 of corn, Sugar graze
cultivar of sorghum and foxtail millet are mid-
maturating crops, and hybrid S.C. 704 of corn, Jumbo
cultivar of sorghum and pearl millet are late maturating
cultivars. Wheat was harvested on July 1st. After wheat
harvested, the experimental field was chisel plowed,
disked and all crops were planted on July 16th, imitating
the practices performed in the region. Plants were seeded
in 37.5 m2 plots (7.5 m wide and 5 m long). Further
details of cropping operations are illustrated in Table 2.
Crops received the common management practice as
performed in the region. Nitrogen and phosphorous
fertilizer were applied based on soil test and
recommendations. All plots received 250 kg ha-1 triple
superphosphate (46% P2O5) and 200 kg ha-1 granular
urea (46%N) during field preparation and prior to
planting. Other 200 kg ha-1 granular urea was applied
when crops reached 30 to 40 cm height.
Table 2. Details of agronomic practices used for cultivation of each plant
Corn Sorghum Millet
S. C. 704 S. C.
647
S. C.
301
Jumbo Speed
feed
Sugar
graze
Foxtail
millet
Common
millet
Pearl
millet
Row spacing
(cm)
75 75 75 50 50 50 50 50 50
Within a row
spacing(cm)
15 15 15 10 10 10 5 5 10
Date of planting 16 July 16 July 16 July 16 July 16 July 16 July 16 July 16 July 16 July
Date of
harvesting
23 Oct. 11 Oct. 3 Oct. 21 Oct. 5 Oct. 9 Oct. 24 Sep. 15 Sep. 23 Oct.

Evaluation of Yield… Mohammad Reza Jahansouz et al
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Experiment 2
The entries from each group in experiment 1 were
selected for the experiment 2. The experimental unit was
arranged in a factorial combination with three levels of
crop species (hybrid S.C. 704 of corn, cultivar Jumbo of
sorghum and pearl millet [cv. Nutrifeed]) and three
levels of irrigation water volume (I100, I75 and I50 by
providing 100%, 75%, and 50% of corn estimated water
requirement, respectively). Thereafter I75 and I50 are
considered as moderate and severe drought stress. A
randomized complete block design with four replicates
was employed for data analysis.
Forages were double cropped after wheat. After
harvesting the wheat in early July, the soil was plowed
and disked. Plot size, row and within row spacings,
fertilizer and weed management were similar to the
experiment 1.
In order to avoid runoff after irrigations in each plot,
both ends of rows were blocked by soil. A border of 2m
between adjacent plots in each replication and 5 m
between replicates were maintained to avoid entrance of
drainage water from other plots.
The first two irrigations in all irrigation treatments
were applied based on 100% of the corn estimated water
requirement to ensure maximum germination and
successful crop establishment. Irrigation intervals were
10-days apart as is commonly practiced in the area.
Irrigation system and estimating crop water
requirements
Irrigation was performed using polyethylene pipes
(63 mm) installed between the replications. One flow
meter (3/4 inch) was used to measure the volume of
irrigation water in each plot. Irrigation water volume
was measured using the following equation (Jury et al.,
1991):
I + P – R = ET + D + SW (Eq. 1)
Where I is the amount of irrigation water, P is
precipitation, R is surface runoff, ET is estimated
evapotranspiration, D is drainage or deep percolation and
SW is the water storage change of the soil moisture
profile. Surface runoff was negligible due to the control
of water consumption by using the earth dike. Deep
percolation or drainage did not occur, based on
controlled water use to satisfy only the depleted soil
moisture. Soil available water capacity (105 mm for
1200 mm soil profile) represented that the soil had the
capacity to hold the amount of irrigation water applied in
each irrigation interval. The amount of rainfall during
the growing season was negligible and considered non
effective due to high temperature and low relative
humidity. Evapotranspiration of corn was calculated
using equation 2.
ETC=KC (ETR) (Eq. 2
)
Where ETC is crop evapotranspiration (mm day-1),
KC is crop coefficient and ETR is the reference crop
evapotranspiration. A ten-year meteorological data,
including climatic parameters such as relative humidity
and wind speed along with the table published by F.A.O
(FAO 1998) was used for calculating the crop coefficient
(Kc).
The evapotranspiration rate of alfalfa was used as the
reference crop evapotranspiration (ETR) which was
previously calculated by Farshi et al. (1997) for the
target area. KC is the ratio of the evapotranspiration of
the crop (ETC) to a reference crop (ETR) (Piccinni et al.,
2009). Fig. 1 shows the KC variation of corn at various
growth stages. The crop coefficient for initial stage (KCi)
depends on the irrigation interval (If) and ETR . KCi was
estimated from equation 3.
Kci = 2(If)-0.49exp [(-0.01 - 0.042 LnIf) Etri] (Eq. 3
)
Where If denotes irrigation interval at the initial stage
(day), Kci denotes the crop coefficient for the initial
stage, Etri denotes average daily reference crop ET

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during the initial stage (mm day-1). KC value for stage 3
and 4 were obtained from James (1988).
Crop measurements
The edge effect was discarded, and the rest of the
plot was completely harvested and weighed. Two kg of
fresh forage from each plot was selected to determine
the moisture content and forage quality analysis. Plant
samples were dried in a forced-air oven at 70°C for 72
hours before weighing.
Irrigation water use efficiency (IWUE)
Irrigation water use efficiency (kg m-3) was
calculated as dry forage yield (kg ha-1) divided by the
volume of irrigation water (m3 ha-1).
Forage quality measurement
To determine forage quality, two kg of dried forage
from each plot was grinded and then 20 g of each sample
was used for forage quality analysis. Near Infra-Red
Spectroscopy (NIR) was used to determine various forage
quality indices, including crude protein (CP), water soluble
carbohydrate (WSC), acid detergent fiber (ADF) and
neutral detergent fiber (NDF). Crude protein yield was
calculated by multiplying forage dry yield and CP content.
Total digestible nutrients (TDN), digestible dry
matter (DDM), dry matter intake (DMI), net energy for
lactation (NEL) and relative feed value (RFV) were
estimated by following equations (Horrocks and
Vallentine, 1999):
TDN= (-1.291 × %ADF) + 101.35 (Eq. 4)
DMI= 120/%NDF dry matter basis (Eq. 5)
DDM= 88.9 – (0.779 × %ADF dry matter basis) (Eq. 6)
RFV = %DDM × %DMI × 0.775 (Eq. 7)
NEL = (1.044 – (0.0119 × %ADF)) × 2.205 (Eq. 8)
Statistical analysis
Analysis of variance (ANOVA) was performed
separately for each year. The LSD test was implemented for
the separation of the means (P ≤ 0.05). All statistics were
done using the SAS (version 9.1) statistical software.
RESULTS AND DISSCUSSION
Experiment 1
Forage Yield
Forage yield and yield components were all
significantly affected by crop species and cultivars (P ≤
0.01) (Table 3). The highest forage fresh yield was
obtained from pearl millet (61,865 kg ha-1) followed by
corn hybrid S.C. 704 (59,386 kg ha-1), while the lowest
yield was produced by common millet (16,088 kg ha-1)
and foxtail millet (18,685 kg ha1). Among the three
millet species, forage fresh yield of pearl millet was
almost four times greater than the other two millet
species. This might be due to the inherent characteristics
of pearl millet as a vigorous and more demanding crop
with at least one month longer growth period than the
other two types of millet. Among sorghum cultivars, the
lowest forage fresh yield was obtained from Speed feed
(38,111 kg ha-1), whereas Jumbo and Sugar graze
cultivars out-yielded Speed feed by 19% and 13%,
respectively. Speed feed has lower leaf to stem ratio than
the other two sorghum cultivars (Table 3), therefore; it
contains less moisture and lower fresh weight. In fact,
stem dry weight of speed feed was highest among all
forages used in this study (data not shown). Higher
forage fresh yield was obtained from later maturity corn
hybrid (S.C. 704) compared with shorter-season hybrids
(S.C. 647 and S.C. 301). Full-season hybrids have a
longer life cycle to grow and are able to produce higher
biomass than short-season plants.
Corn hybrids out-yielded sorghum cultivars and millet
species in terms of forage dry yield (Table 3). The greatest
forage dry yield was obtained from corn hybrids S.C. 704
(13,652 kg ha-1) followed by S.C. 647 (12,148 kg ha-1),
whereas foxtail and common millets were the lowest

Evaluation of Yield… Mohammad Reza Jahansouz et al
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producing forage species. Pearl millet was the only millet
species with dry yield of 12,285 kg ha-1 which was
comparable to corn and sorghum cultivars. As mentioned
earlier, foxtail and common millets were not as productive as
other forages because of their short growing duration.
Similarly, Zegada-Lizarazu and Iijima (2005) reported that
under normal irrigation, forage dry yield of pearl millet was
greater than foxtail and common millet. However, planting
foxtail and common millet might be successful in double
cropping systems in areas with shorter growing seasons
where the cold season starts earlier therefore; provides
sufficient time for the subsequent crop. Among sorghum
cultivars, Jumbo produced more dry forage than Speed feed
and Sugar graze (Table 3).
In forage crops, leaf to stem ratio is customarily
considered as an important criteria which highly affects
ration selection, forage quality and intake (Jahanzad et
al., 2013). Significant difference in leaf to stem ratio was
found among the forage species (P ≤ 0.01). The highest
leaf to stem ratio was obtained in pearl millet (1.50)
followed by Jumbo sorghum (1.25). Pearl millet seems
to consistently produce high leaf-stem ratio among
forage cereals (Rostamza et al., 2011).
Forage quality
Results showed significant differences existed among the
crop species in terms of CP content where millet species
contained the highest CP (Table 4). Among millet species,
the highest crude protein content was obtained from pearl
millet (118.5 g kg-1 dry matter) which was significantly
higher than the other two millet species. The greatest CP
content in corn group belonged to S.C. 704 (Table 4) and
among sorghum cultivars Sugar glaze had the highest CP
content (99.9 g kg-1 dry matter) followed by Jumbo (86.4 g
kg-1 dry matter). Leaves are the main contributor of protein in
forages, therefore lower leaf to stem ratio, such as in Speed
feed sorghum (Table 3), will be translated into lower CP
(Table 4). Crude protein content is often considered as one of
the major quality criteria in forages (Amer et al. 2012),
because low levels of CP in forages may reduce their buffer
capacity during ensilage for enabling fast ensilage with
minimal losses (Mirron et al., 2007).
Although CP is an important quality trait, the total
protein yield per unit area is even more important in
evaluating the superiority of forages. Protein yield
combines the total forage dry yield and forage CP
content therefore; growers are often more interested in
higher protein yield per unit area rather than specific
values of protein content and percentage (Jahanzad et al.,
2013). The highest protein yield was obtained from pearl
millet (1,456 kg ha-1) followed by corn hybrid S.C. 704
(1,249 kg ha-1). The low protein yield of foxtail and
common millet was related to their low forage dry yield
rather than CP content. Our results confirmed the earlier
reports by Ward et al. (2001) which indicated that corn
hybrid S.C. 704 and pearl millet are among forages with
highest crude protein yield.
Dry matter intake (DMI), total digestible nutrient
(TDN) and digestibility of dry matter (DDM) are also
important indices for evaluating forage quality. The
greatest value of DMI, DDM and TDN was found in
corn hybrids S.C. 704 and S.C. 647 and the lowest was
found in foxtail and common millet (Table 4). In general
the results indicated that corn S.C. 704 had the highest
and foxtail and common millet had the lowest
digestibility among the studied forages.
NDF and ADF are two other important quality
components in forages, and show opposite trends to
digestibility (Table, 4). The highest and lowest values of
NDF and ADF were found in millets and corn hybrids,
respectively. NDF and ADF content of sorghum cultivars
were within the ranges reported for corn and millet species. It
is well documented that high-quality forages have low values
of NDF and ADF, which result in higher digestibility

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(Keshavarz Afshar et al., 2012; Jensen et al., 2003).
Water soluble carbohydrates (WSC) in corn hybrids
were significantly higher than sorghum and millets (Table
4). The greatest and lowest WSC content was measured in
S.C. 640 (337.3 kg ha-1) and common millet (62.9 kg ha-1),
respectively. WSC content along with the activity of lactic
acid bacteria, determine the rate of decline in pH during the
early stages of ensiling, which is important for the
production of stable silage. It has been reported that initial
WSC contents between 60 and 80 g kg-1 DM is adequate to
produce good quality grass silages (Amer et al. 2012).
Accordingly, with the exception of common millet and
foxtail millet, all other forages in this study had adequate
WSC to produce good quality silage.
Corn cultivars S.C. 704 and S.C. 647 had the highest
NEL and RFV (Table 3), which reconfirm their high
forage quality. When RFV value is greater than 151 the
forage is considered as a prime (Horrocks & Vallentine
1999). In our study the highest value of RFV was
obtained from S.C. 704 (124.3) whereas the lowest
values were found in foxtail (63.7) and common millet
(60.1) (Table 4).
Overall, except crude protein content, corn possessed
the highest quality indices compared with sorghum
cultivars and millet species. However, in semi-arid
regions, efficient use of irrigation water plays a crucial
rule in forage production and should be considered along
with yield and quality characteristics.
Experiment 2
Experiment 2 was conducted based on the information
about forage yield and quality obtained from experiment 1.
In this experiment, corn hybrid S.C. 704, Jumbo cultivar of
sorghum and pearl millet (cv. Nutrifeed) were selected for
further investigations. In experiment 2, the effect of deficit
irrigation on yield and quality of the three superior forage
species was investigated.
Table 3. Forage fresh and dry yield and leaf to stem ratio of nine forage crops.
Leaf / stem ratio
Dry forage yield
kg ha-1
Fresh forage yield
kg ha-1
Plant species
1.50 a 12285 b 61865 a Pearl millet Millet
0.73 def 4533 f 18685 g Foxtail millet
0.60 efg 3610 g 16088 h Common millet
0.99 c 9184 e 43074 e Sugar graze Sorghum
1.25 b 10161 d 45430 d Jumbo
0.53 g 9653 de 38111 f Speed feed
0.59 fg 13652 a 59387 b S.C. 704 Corn
0.80 d 12148 b 50704 c S.C. 647
0.75 de 11333 c 46119 d S.C. 301
0.15 512 1516 LSD
Level of significance
** ** **
Within columns, means followed by different letters are significantly different at (P < 0.05)
** Significant at P ≤ 0.01

Evaluation of Yield… Mohammad Reza Jahansouz et al
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Table 4. Forage quality indices of nine forage crops.
RFV
NEL
Mcal
kg-1
WSC
g kg-1
ADF
g kg-1
NDF
g kg-1
DDM
g kg-1
TDN
g kg-1
DMI
g kg-1
Protein
yield
kg ha-1
CP
content
g kg-1
Plant species
89.1f 1.25d 97.8f 397.7b 604.7c 579.1d 500.1c 19.8e 1456.1a 118.5a Pearl millet Millet
63.7g 0.97e 74.0g 506.1a 722.7b 494.7e 360.1d 16.6f 457.5f 101.1c Foxtail
millet
60.1h 0.98e 62.9h 508.2a 763.4a 493.1e 357.4d 15.7g 395.1f 109.1b Common
millet
110.0c 1.47c 191.9e 315.2c 544.3e 643.5c 606.6b 22.1c 917.3d 99.9c Sugar griz Sorghum
104.9d 1.44c 237.9d 325.5c 563.2d 635.4c 593.2b 21.3d 877.9d 86.4de Jumbo
98.4e 1.26d 194.7e 397.1b 547.8de 597.6d 500.8c 21.9c 802.3e 83.1e Speed feed
121.7ab 1.59ab 306.7b 271.2de 518.0fg 677.8ab 663.4a 23.2ab 1249.9b 91.5d SC 704 Corn
124.3a 1.59a 337.3a 267.9e 509.2g 680.3a 667.6a 23.5a 1024.4c 84.3e SC 647
118.7b 1.56b 295.3c 281.3d 525.0f 669.9b 658.1a 22.9b 951.4cd 83.9e SC 301
3.2 0.02 10.9 11.0 15.5 8.6 15.4 0.53 75.4 5.1 LSD
Level of significance
** ** ** ** ** ** ** ** ** **
CP, crude protein; DMI, dry matter intake; TDN, total digestible nutrient; DDM, digestible dry matter; NDF, neutral
detergent fiber; ADF, acid detergent fiber; WSC, water soluble carbohydrate; NEL, net energy for lactation; RFV, relative
feed value.
Within columns, means followed by the different letters are significantly different at P ≤ 0.05
** Significant at P ≤ 0.01
Forage Yield
Fresh and dry forage yield of the three forage species
responded significantly to deficit irrigation (Table 5).
When irrigation was optimal (I100) pearl millet produced
the highest fresh weight (57,666 kg ha-1) which was 2%
and 20% higher than corn and sorghum yield,
respectively (Table 6). A reduction of 25% in irrigation
water volume (I75) resulted in considerable reduction in
yield of millet (21%), corn (17) and sorghum (14%).
Although, sorghum yield reduction in I75 was
comparably smaller than corn and millet, its overall
yield was still the lowest among the forage species.
Under severe drought stress condition (I50), the yield of
pearl millet, corn and sorghum were 41%, 47% and 28%
lower than I100, respectively. Pearl millet performed as
the champion forage crop under normal irrigation (I100),
moderate drought stress (I75) and severe drought stress
(I50) in terms of fresh forage yield.
As expected, the forage crops reached their highest
dry matter production under normal irrigation where the
highest dry forage yield obtained from corn (12,470 kg
ha-1) followed by pearl millet (11,680 kg ha-1) and
sorghum (9,682 kg ha-1) (Table 5). Deficit irrigation led
to a significant forage yield reduction in all three forage

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species. A reduction of 25% in the amount of irrigation
water reduced the yield of corn, sorghum and millet by 28,
13 and 24%, respectively. Despite of grater yield reductions
that occurred in corn and pearl millet under moderate stress,
these two species still out-yielded sorghum in terms of dry
weight (Table 6). It is assumed that when soil water content
is not enough to facilitate nutrient uptake by roots, plants face
difficulties in uptaking the essential nutrients such as nitrogen
and phosphorus which leads to yield reduction (Jahanzad et
al., 2013). Moreover, reduced transpiration due to insufficient
water in the soil can also intensify disruption of nutrient
uptake by roots and ion transportation from roots to shoots
(Jahanzad et al., 2013).
With 50% reduction in irrigation water, corn, sorghum,
and pearl millet produced 49, 28 and 44% less forage dry
yield, respectively compared with the full irrigation (Table
6). In I50 treatment, the highest dry forage yield was produced
by sorghum followed by pearl millet and corn (Table 6).
Sorghum is a drought tolerant crop which avoids dehydration
by enhanced water uptake through its dense and prolific root
system (Keshavarz Afshar et al., 2014b; Sher et al., 2013;
Singh and Singh, 1995). Also, sorghum has the ability to
maintain its stomatal opening at low levels of leaf water
potential and tolerates dehydration through osmotic
adjustment (Sher et al., 2013; Farre´ and Faci, 2006). Worth
noting that, a more drought tolerant crop is not always as
productive as sensitive crops and this fact needs to be
considered in planning crop rotation in water limited areas.
Leaf to stem ratio was significantly influenced by plant
species, irrigation treatments and their interactions (P ≤ 0.01)
(Table 5). Pearl millet and corn had the highest and lowest
leaf to stem ratio, respectively. Higher leaf to stem ratio often
results in higher forage quality since leaf contains more
valuable ingredients such as protein and considerably lower
ADF and NDF. As the water deficiency intensified, the leaf
to stem ratio of the three species decreased (Table 6). It has
been reported that one of the first impacts of drought stress
on plants is a reduction in leaf number per plant and leaf area
in order to reduce transpiration (Rostamza et al., 2011;
Carraw, 1996).
Table 5. Fresh forage yield, dry forage yield, leaf to stem ratio and Irrigation water use efficiency (IWUE) of corn,
sorghum and pearl millet as affected by irrigation treatment.
IWUE
kg m-3
Leaf / stem ratio
Forage dry yield
kg ha-1
Forage fresh yield
kg ha-1
Treatment
Plant
2.16a 0.4c 9242.1a 44131.9b Corn
2.00c 0.8b 8344.2c 39441.0c Sorghum
2.13b 1.0a 9029.0b 45687.5a pearl millet
Irrigation volume
2.18
a
1.0
a
11277.6
a
53343.8
a
I100
2.08b 0.7b 8743.9b 43718.8b I75
2.03b 0.5c 6593.6c 32197.9c I50
0.03 0.05 125.8 601.22 LSD
Level of significance
** ** ** ** Plant
** ** ** ** Irrigation

Evaluation of Yield… Mohammad Reza Jahansouz et al
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-
** ** ** ** Plant × irrigation
Irrigation treatments: I100, I75 and I50 means providing 100, 75 and 50% of the corn estimated water requirement,
respectively.
Within columns, means followed by the different letters are significantly different at P ≤ 0.05
** Significant at P ≤ 0.01
Table 6. Interaction effect of crop species and irrigation treatment on fresh forage yield, dry forage yield, leaf to
stem ratio and Irrigation water use efficiency (IWUE) of corn, sorghum and pearl millet
Plant species Irrigation
treatment
Forage fresh yield
kg ha-1
Forage dry yield
kg ha-1 Leaf / stem ratio IWUE
kg m-3
Corn I100 56375b 12470 a 0.47e 2.41a
I75 46250c 8954 d 0.35f 2.13c
I50 29770g 6301 h 0.30f 1.94e
Sorghum I100 45989c 9682 c 1.09b 1.87f
I75 39458d 8408 e 0.76d 2.00d
I50 32875f 6942 f 0.51e 2.14c
Pearl millet I100 57666a 11680 b 1.43a 2.26b
I75 45447c 8869 d 0.97c 2.11c
I50 33947e 6537 g 0.70d 2.01d
LSD 1038 317 0.10 0.08
Irrigation treatments: I100, I75 and I50 means providing 100, 75 and 50% of the corn estimated water requirement,
respectively.
Within columns, means followed by the different letters are significantly different at P ≤ 0.05
Irrigation Water Use Efficiency (IWUE)
In regions with water shortage, the relationship
between yield and the amount of irrigation water is
considerably important (Farre´ and Faci, 2009). A
significant linear relationship was found between dry
forage yield and amount of irrigation water in all forage
crops (Fig. 2). This simply emphasizes the importance of
irrigation water for optimum dry matter production in
forage species in this study. The relationship between
dry forage yield and irrigation water amount could be
affected by many factors such as climate, soil properties
and irrigation management practices. These factors
therefore should be taken into account when proposing
deficit irrigation strategies (Farre´ and Faci, 2009). The
slopes of regression lines within a normal range of
irrigated water indicate the sensitivity of the crops to
water deficit (Fig. 2). Thus, sorghum and corn were most
and least tolerant species to water deficit, respectively.
Results indicated that forage species did not respond
similarly to drought stress in terms of IWUE. As water

Jordan Journal of Agricultural Sciences, Volume 10, No.4 2014
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-
stress intensified, the IWUE of corn and pearl millet
followed a steady declining trend (Table 6), whereas an
opposite trend was observed in sorghum. In normal
irrigation (I100), the highest IWUE (2.41 kg m-3) was
calculated in corn, followed by pearl millet (2.26 kg m-3)
and the lowest IWUE belonged to sorghum (1.87 kg m-
3). Moderate and severe drought stress caused a
progressive decrease in IWUE in corn and pearl millet
while improved IWUE of sorghum.
Documented reports on IWUE response to deficit
irrigation are not consistent and in many cases are
controversial. While reduction in IWUE as a result of
deficit irrigation has been reported (Farre´ and Faci,
2009), several reports have shown an increase in WUE
in deficit irrigation (Rostamza et al., 2013; Zegada-
Lizarazu and Iijima, 2005). Apparently the effect of
water stress on IWUE depends on the severity of the
stress, plant genotype, and developmental stage when
water stress is imposed. Under the condition of this
study, sorghum responded differently to deficit irrigation
compared with corn and millet in terms of IWUE. This
may have important economic implications since it
means that under water limited conditions sorghum can
produce more yield per monetary unit spent in irrigation
water compared to corn and millet.
Fig. 1. KC Value for corn fitted to the experimental site condition.

Evaluation of Yield… Mohammad Reza Jahansouz et al
-710
-
Fig. 2: Relationship between forage dry yield of corn, sorghum, and pearl
millet with amount of irrigation water
Forage quality
Crop species and irrigation treatment had significant
influence on forage quality (Table 7). The interaction of plant
× irrigation was significant only on NDF, DMI and RFV

Jordan Journal of Agricultural Sciences, Volume 10, No.4 2014
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-
values (Table 7). Pearl millet had the highest CP content
(117. 2 g kg-1 DM) and protein yield (1,047 kg ha-1) among
the three species. Higher leaf to stem ratio in pearl millet
compared with sorghum and corn could justify the higher CP
content of millet. The results of experiment 1 and findings by
Ward et al. (2001) well support these outcomes. Deficit
irrigation led to an improvement in CP content in forage
species which is consistent with earlier reports by Jahanzad et
al. (2013) on sorghum, Rostamza et al. (2011) on pearl millet
and Crasta and Cox (1996) in corn. Increase in CP content as
a result of water stress could be explained by rising in
nitrogen concentration in plant tissues under drought stress
(Jensen et al., 2003). Despite an increase in CP content of
plants under deficit irrigation, protein yield followed an
opposite trend due to significant reduction in dry matter
production.
The highest WSC content was recorded for corn which
was considerably higher than the other two forage crops
(Table 7). WSC content did not significantly respond to
drought stress. Lower WSC results in poorer silage quality
(Ward et al., 2001); therefore, corn is a more suitable silage
crop compared with sorghum and pearl millet.
ADF and NDF were higher in pearl millet followed
by sorghum (Table 7 and 8). Other researchers also
reported higher content of fiber, especially NDF in
sorghum than corn (Marsalis et al., 2010). Deficit
irrigation increased ADF and NDF content of all three
species. Haung and Duncan (1997) reported that drought
stress may stimulate forage structural carbohydrates
content (fiber) which leads to a reduction in forage
digestibility. Increase in insoluble fibers in cell walls is
one of the physiological responses of plants towards
water stress to prevent moisture loss under water stress
conditions (Keshavarz Afshar et al., 2012).
Among the three crops, corn had the highest value of
DDM, DMI and TDN (Table 7). TDN refers to nutrients
that are available for livestock and is related to the ADF
content in forages. In parallel to ADF increase, TDN
content decreases which limits animal’s ability to utilize
the nutrients (Jahanzad et al., 2013). Deficit irrigation
imposed negative impacts on TDN, DMI and DDM.
Similarly, it has been reported that water deficiency
increased the amount of structural carbohydrates and
fibers which in turn lowered forage digestibility (Haung
and Duncan, 1997).
The highest value of NEL (1.7 Mcal kg-1) and RFV
(123.9) was found in corn which was significantly
higher than sorghum and pearl millet (Table 7). Forages
with higher RFV are more digestible and palatable.
Similarly, higher NEL and RFV for corn compared with
sorghum and millet have been reported (Marsalis et al.,
2010). Deficit irrigation caused a significant reduction in
NEL and RFV value in all three species (Table 7).
Experiment 2 reconfirmed that corn had higher forage
quality than sorghum and pearl millet, but contained
lower crude protein.
Table 7. Forage quality indices of corn, sorghum and pearl millet as affected by irrigation treatment.
RFV
NEL
Mcal
kg-1
WSC
g kg-1
DM
ADF
g kg-1
DM
NDF
g kg-1
DM
DDM
TDN
g kg-1
DM
DMI
Protein
yield
kg ha-1
CP
g kg-1
DM
Treatment
Plant species
119.5a 1.7a 356.0a 247.9c 542.6c 695.9a 693.5a 22.2a 879.4b 95.6b Corn
105.7b 1.5b 229.9b 310.7b 569.8b 646.9b 612.3b 21.1b 771.6c 92.9b Sorghum
75.6c 1.2c 118.4c 405.0a 713.6a 573.5c 490.7c 17.0c 1047.1a 117.2a Millet

Evaluation of Yield… Mohammad Reza Jahansouz et al
-712
-
Irrigation Treatment
106.9a 1.5a 225.4a 305.8b 572.1c 650.7a 618.7a 21.1a 1099.6a 97.1b I100
98.3b 1.4b 238.0a 328.2a 618.5b 633.3b 589.8b 19.8b 906.9b 103.6ab I75
95.6b 1.4b 240.9a 329.6a 635.4a 632.3b 588.0b 19.3b 691.6c 104.9a I50
4.0189 0.0504 19.848 19.214 17.821 14.967 24.805 0.5821 27.9 6.045 LSD
Level of significance
** ** ** ** ** ** ** ** ** ** Plant
** * NS * ** * * ** ** * Irrigation
** NS NS NS ** NS NS ** NS NS
Plant ×
irrigation
CP, crude protein; DMI, dry matter intake; TDN, total digestible nutrient; DDM, digestible dry matter; NDF, neutral
detergent fiber; ADF, acid detergent fiber; WSC, water soluble carbohydrate; NEL, net energy for lactation; RFV, relative
feed value.
Irrigation treatments: I100, I75 and I50 means providing 100%, 75%, and 50% of the corn estimated water requirement,
respectively.
Within columns, means followed by the different letters are significantly different at P ≤ 0.05
**, * and NS means significant at P ≤ 0.01, significant at P ≤ 0.05, and no significant, respectively.
Table 8. Interaction effect of crop species and irrigation treatment on forage quality indices of
corn, sorghum and pearl millet
RFV DMI
NDF
g kg-1 DM
Protein yield
kg ha-1
Irrigation
tretament
Plant species
123.9a 22.6a 531.0de 1153.0b I
100
Corn
116.7b 22.0ab 522.3e 878.2d I
75
118.0ab 21.9ab 549.4de 607.0g I
50
108.7c 21.6b 556.3d 856.9d I
100
Sorghum
107.1cd 21.5b 558.2d 791.7e I
75
101.3d 20.2c 594.9c 666.2f I
50
88.2e 19.1d 628.9b 1289.0a I
100
Pearl millet
71.1f 16.0e 750.1a 1050.7c I
75
67.5f 15.8e 761.9a 801.5e I
50
6.7 1.0 29.1 47.9 LSD
NDF, neutral detergent fiber; DMI, dry matter intake; RFV, relative feed value.
Within columns, means followed by the different letters are significantly different at P ≤ 0.05
Irrigation treatments: I100, I75 and I50 means providing 100%, 75%, and 50% of the corn estimated water
requirement, respectively.

Jordan Journal of Agricultural Sciences, Volume 10, No.4 2014
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CONCLUSION
Results of this study showed that corn, sorghum and
pearl millet differed in their responses to deficit
irrigation. Deficit irrigation reducedforage production
which was more profound in corn and pearl millet than
in sorghum. It was concluded that under optimum
irrigation condition corn out-yielded sorghum and pearl
millet with considerably higher forage quality. However,
under moderate water deficiency pearl millet can
substitute corn to produce high quality forage with
acceptable yield. If the scarcity of irrigation water is
more crucial, sorghum could potentially be a good
substitute for corn and pearl millet.
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ﻱﺭﻟﺍ ﻲﻤﺎﻅﻨ ﺕﺎﺠﺎﻴﺘﺤﺍ ﺕﺤﺘ ﺀﺍﺭﻔﺼﻟﺍ ﺓﺭﺫﻟﺍ ﻑﻠﻋ ﻥﻋ لﻴﺩﺒﻜ ﻥﺨﺩﻟﺍﻭ ﺀﺎﻀﻴﺒﻟﺍ ﺓﺭﺫﻟﺍ ﺔﻴﻋﻭﻨﻭ ﺔﻴﺠﺎﺘﻨﺇ ﻡﻴﻴﻘﺘ
ﺹﻗﺎﻨﺘﻤﻟﺍﻭ ﻱﺩﺎﻌﻟﺍ
ﺯﻭﺴﻨﺎﻫﺎﺸ ﺎﻅﺭ ﺩﻤﺤﻤ
1*
ﺍ ﺯﺭﺎﻓﺎﺸﻴﻜ ﺎﻅﺭ ،ﺭﺎﺸﻓ
1
ﻱﺭﺩﻴﺤ ﻥﺴﺤ ،
2
ﻲﻤﺸﺎﻫ ﺩﻭﻌﺴﻤ ،
3
ﺹـﺨﻠﻤ
ﻱﻭﺘﺸﻟﺍ ﺏﻭﺒﺤﻟﺍ ﻉﻭﻨﺘ ﺓﺩﺎﻴﺯ ﺔﻴﻨﺎﻜﻤﺍ ﻡﻴﻴﻘﺘﻟ ﻥﺎﺘﺒﺭﺠﺘ ﺕﻴﺭﺠ ﺃ ُ ﺓﺩﻤﺘﻌﻤ ﺃ ﻰﻠﻋ ﻲﻓ ﺹﻘﻨﻟﺎﺒ ﺎﻫﺭﺜﺄﺘﻭ ﺔﻠﺨﺍﺩﺘﻤﻟﺍ ﺔﻋﺍﺭﺯﻟﺍ ﺔﻤﻅﻨ ﻱﺭﻟﺍ ﻩﺎﻴﻤ . ﻰﻟﻭﻻﺍ ﺔﺒﺭﺠﺘﻟﺍ ﻲﻔﻓ)1 ( ﻥﻤ ﺔﺜﻼﺜﻭ ،ﺀﺍﺭﻔﺼﻟﺍ ﺓﺭﺫﻟﺍ ﻥﺌﺎﺠﻫ ﻥﻤ ﻉﺍﻭﻨﺃ ﺔﺜﻼﺜﻟ ﺎﻬﺘﻴﻋﻭﻨﻭ ﻑﻼﻋﻻﺍ ﺝﺎﺘﻨﺍ ﻥﺎﻜ
ﻥﺨﺩﻟﺍ ﻥﻤ ﻑﺎﻨﺼﺃ ﺔﺜﻼﺜﻭ ،ﺀﺎﻀﻴﺒﻟﺍ ﺓﺭﺫﻟﺍ)ﻱﺅﻟﺅﻠﻟﺍ ﻥﺨﺩﻟﺍﻭ ،ﻱﺩﺎﻌﻟﺍﻭ ،ﺏﻠﻌﺜﻟﺍ ﺏﻨﺫ (ﺎﻬﻤﻴﻴﻘﺘ ﻡﺘ . ﻡﺘ ،ﺞﺌﺎﺘﻨﻟﺍ ﻰﻠﻋ ﺀﺎﻨﺒﻭ  ﺱﺃ ﻥﻴﺠﻬﻟﺍ ﺀﺍﺭﻔﺼﻟﺍ ﺓﺭﺫﻟﺍ ﺭﺎﻴﺘﺨﺍ.ﻲﺴ .704 ﻕﻼﻤﻌﻟﺍ ﻑﻨﺼ ﺀﺎﻀﻴﺒﻟﺍ ﺓﺭﺫﻟﺍﻭ ،)ﻭﺒﻨﺠ ( ﻥﺨﺩﻟﺍﻭ"ﺓﺅﻟﺅﻟ " ﺕﺎﺴﺍﺭﺩﻟ ﺔﻌﺴﻭﻤ .ﺭﻟﺍ ﺕﻼﻤﺎﻌﻤ ﺭﻴﺜﺄﺘ ﻥﺈﻓ ،ﺔﻴﻨﺎﺜﻟﺍ ﺔﺒﺭﺠﺘﻟﺍ ﻲﻓﻭ ﻱI100
،I75
،I50
) ﺩﻴﻭﺯﺘ100 % ﻭ75 % ﻭ50 % ﺕﺎﺒﻠﻁﺘﻤ ﻥﻤ ﻲﻟﺍﻭﺘﻟﺍ ﻰﻠﻋ ﻩﺎﻴﻤﻟﺍ (لﻴﺼﺎﺤﻤﻟﺍ ﻙﻠﺘ ﻰﻠﻋ ﺎﻬﺘﺴﺍﺭﺩ ﻡﺘ . ﺓﺭﺫﻟﺍ ﻥﻤ ﺭﺜﻜﺃ ﻑﺎﻔﺠﻟﺍ ﺕﻠﻤﺤﺘ ﺀﺎﻀﻴﺒﻟﺍ ﺓﺭﺫﻟﺍ ﻥﺃ ﺞﺌﺎﺘﻨﻟﺍ ﺕﺭﻬﻅﺃ ﺀﺎﻨﺜﺘﺴﺎﺒ ﻥﺨﺩﻟﺍﻭ ﺀﺍﺭﻔﺼﻟﺍI50
لﻗﺍ ﺝﺎﺘﻨﺍ ﺔﻴﻤﻜ ﺕﻁﻋﺃ ﺙﻴﺤ . ﺔﻠﻤﺎﻌﻤﻠﻟ ﺝﺎﺘﻨﺍ ﻰﻠﻋﺃ ﻥﺎﻜI100
ﺭﻔﺼﻟﺍ ﺓﺭﺫﻟﺍ ﺩﻨﻋ ﻡﺜ ﺀﺍ ﻱﺅﻟﺅﻠﻟﺍ ﻥﺨﺩﻠﻟ . ﺔﺒﺴﻨﺒ ﻁﻭﺒﻬﻟﺍ ﻥﺇ25 % ﺀﺎﻀﻴﺒﻟﺍ ﺓﺭﺫﻟﺍﻭ ﺀﺍﺭﻔﺼﻟﺍ ﺓﺭﺫﻟﺍ ﺝﺎﺘﻨﺍ ﻲﻓ ﺽﺎﻔﺨﻨﺍ ﺏﺒﺴ ﻱﺭﻟﺍ ﻩﺎﻴﻤ ﺔﻴﻤﻜ ﻲﻓ ﺏﺴﻨﺒ ﻥﺨﺩﻟﺍﻭ28 ﻭ13 ﻭ24 %ﻲﻟﺍﻭﺘﻟﺍ ﻰﻠﻋ . ﻲﺒﺴﻨﻟﺍ ﻑﻠﻌﻟﺍ ﺔﻤﻴﻗﻭ ﻡﻀﻬﻟﺍ ﺔﻤﻴﻗ ﻰﻠﻋﺃ ﺀﺍﺭﻔﺼﻟﺍ ﺓﺭﺫﻟﺍ ﺕﻨﺎﻜ)RFV ( ﻡﺎﺨﻟﺍ ﻥﻴﺘﻭﺭﺒﻟﺍ ﺔﻴﻤﻜ ﻉﺎﻔﺘﺭﻻ ﻱﺭﻟﺍ ﻩﺎﻴﻤ ﺹﻘﻨ ﻯﺩﺃ)Crude Protein ( لﻴﺴﻐﻟﺍ ﺽﻤﺎﺤ ﻑﺎﻴﻟﺍﻭ)ADP ( ﻰﻟﺍ ﻯﺩﺃ ﻲﺒﺴﻨﻟﺍ ﻑﻠﻌﻟﺍ ﺔﻤﻴﻗ ﻲﻓ ﻅﻭﺤﻠﻤ ﺽﺎﻔﺨﻨﺍ)RFV (ﻡﻀﻬﻟﺍ ﺔﻤﻴﻗ ﻲﻓﻭ . ﻱﺅﻟﺅﻠﻟﺍ ﻥﺨﺩﻟﺍ ﻥﺃ ﺞﺌﺎﺘﻨﻟﺍ ﺕﻨﻴﺒ ﺙﻼﺜﻟﺍ ﺕﺎﺘﺎﺒﻨﻟﺍ ﻲﻓ
ﺽﻗﺎﻨﺘﻤﻟﺍ ﻱﺭﻟﺍ ﺔﻤﻅﻨﺃ ﺕﺤﺘ ﺔﻟﺩﺎﺒﺘﻤﻟﺍ ﺔﻋﺍﺭﺯﻟﺍ ﺔﻤﻅﻨﺍ ﻲﻓ ﺀﺍﺭﻔﺼﻟﺍ ﺓﺭﺫﻠﻟ ﺔﻟﻭﺒﻘﻤ لﺌﺍﺩﺒ ﺩ ﻤ ﺘﻌ ﺘ ﺀﺎﻀﻴﺒﻟﺍ ﺓﺭﺫﻟﺍﻭ  ﹰ ﹸ .
ﺕﺎﻤﻠﻜﻟﺍ ﺔﻟﺍﺩﻟﺍ : ﻩﺎﻴﻤﻟﺍ لﺎﻤﻌﺘﺴﺍ ﺓﺀﺎﻔﻜ ،ﻱﺅﻟﺅﻟ ﻥﺨﺩ ،ﻑﻼﻋﻻﺍ ﺓﺩﻭﺠ ،ﺔﻠﺨﺍﺩﺘﻤ ﺔﻋﺍﺭﺯ ،ﻑﺎﻔﺠﻟﺍ ﺩﺎﻬﺠﺇ .
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ﺒﻨﻟﺍ ﺔﻴﺒﺭﺘﻭ لﻴﺼﺎﺤﻤﻟﺍ ﻡﺴﻗﻥﺍﺭﻴﺇ ﺝﺍﺭﻜ ،ﻥﺍﺭﻬﻁ ﺔﻌﻤﺎﺠ ،ﺔﻴﻌﻴﺒﻁﻟﺍ ﺩﺭﺍﻭﻤﻟﺍﻭ ﺔﻋﺍﺭﺯﻟﺍ ﺔﻴﻠﻜ ،ﺕﺎﺘﺎ
jahansuz@ut.ac.ir
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ﻥﺍﺭﻴﺍ ،ﻩﺎﺸﻨﺎﻤﺭﻴﻜ ،ﻩﺎﺸﻨﺎﻤﺭﻴﻜ ﻱﺯﺍﺭ ﺔﻌﻤﺎﺠ ،ﺔﻋﺍﺭﺯﻟﺍ ﺔﻴﻠﻜ ،ﺕﺎﺘﺎﺒﻨﻟﺍ ﺔﻴﺒﺭﺘﻭ لﻴﺼﺎﺤﻤﻟﺍ ﻡﺴﻗ
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ﺓﺩﺤﺘﻤﻟﺍ ﺕﺎﻴﻻﻭﻟﺍ ،ﺕﺴﺭﻴﻫ ﻡﺍ ،ﺱﺘﻴﺴﻭﻴﺸﺎﺴﺎﻤ ﺔﻌﻤﺎﺠ ،ﺔﻴﻋﺍﺭﺯﻟﺍ ﺝﺩﻴﺭﺒﻜﻭﺘﺴ ﺔﻴﻠﻜ
ﺙﺤﺒﻟﺍ ﻡﻼﺘﺴﺍ ﺦﻴﺭﺎﺘ 20/8/2013 ﻪﻟﻭﺒﻗ ﺦﻴﺭﺎﺘﻭ5/11/2013.