沙漠研究 19-1, 153- 156 (2009 )Journal of Arid Land Studies“Desert Technology IX ”
Refereed Paper

Comparative Response of Barley Cultivars and Varieties to Deficit Irrigation
in a Mediterranean Environment
Afwa THAMEUR1, Elkadri LEFI2, Ali FERCHICHI3
Abstract: Drought is a worldwide problem, seriously constraining global crop production (Wanget al., 2003). In order to compare the response of many varieties and cultivars of barley todrought tolerance, a series of morphological parameters were investigated. A field experiment
was conducted in the south of Tunisia and barley varieties (Rihane, Roho and Manel) and cultivars(Ardhaoui and Pakistan) were grown on sandy soil. Treatments consisted of irrigated and rainfed
using meteorological data generated at the experimental site. Our results suggest that the rainfed
treatment recorded the lowest values for height. In addition, we observed a reduction in tiller
number and the number of green leaves. We noted the decrease of leaf area (LA) in allinvestigated varieties and cultivars. Analysis of variance was employed to determine levels ofsignificance. Results clearly show cv. Ardhoui tolerates more water stress when compared withthe other varieties and cultivars.
Keywords: Barley, Green leaf number, Leaf area, Plant height, Water deficit

1. Introduction
Abiotic stress conditions cause extensive losses to agricultural production worldwide and have been
subjected to intense research (Jaleel et al., 2007). Water deficit is one of the major abiotic stresses, which
adversely affects both crop growth and yield. The Mediterranean climate is characterized by cool, wetwinters and warm, dry summers. Dryland barley production under these conditions is heavily dependent onwater stored in the soil during the winter supplemented by the addition to spring rainfall (Arnon, 1972).
Coping with water deficit stress is a global issue to ensure survival of agricultural crops and sustainable foodproduction. Drought leads to water deficit in the leaf tissue, which in tern affects many physiologicalprocesses such as photosynthesis (Flexas and Medrano 2002; Morales et al., 2006). Dissimilar water
availabilities often result in significant differences in physiology, morphology, and ultimately, plant
productivity (Kramer, 1983; Lambers et al., 1998; Flexas et al., 2006). Leaf enrolment is a frequentmorphological strategy to reduce plant transpiration. Water stress reduces the leaf boundary layer andincreases evaporation, reduces the rate of leaf elongation, and plant growth by reduction of the net
assimilation rate (Lambers et al., 1998). These plants exhibit low vertical development and maintain an
optimal leaves photosynthetic area to evade high irradiance effects. In this work, we analyzed plant growthin Hordeum vulgare and its relation to rainfall during the growing season. The number of green leaves wasalso studied. The purpose of this study was to evaluate morphological strategies to reduce planttranspiration and protect leaves from excessive radiation and wind desiccation.
2. Materials and Methods
Experiment was carried out under field conditions in 2007. In this study, Ardhaoui, a local cultivar of
the south of Tunisia and a CV. ‘Pakistan’ were compared to the varieties of Rihane, Roho and Manel (northTunisian varieties. The two treatments of irrigated and rainfed using meteorological data of theexperimental site (Table 1) were applied. Leaf blade area (Houala, 1999) was then calculated as:
S= (0.7624 * L*l) + 08841
With L: the length; l: the wide; S: surface.
In addition, plant development characteristics were determined through measuring the plant height, thegreen leaf number and the tiller number. Statistical analysis was performed using analysis of variance(ANOVA) followed by Duncan’s Multiple Range Test (DMRT). The values are mean ± SD for six samples
in each group. P values < 0.05 were considered as significant.
12Laboratory of Dryland and Oasis Cropping, Institute of Arid Zone of Médenine, ElFjè 4119, Tunisia.
Faculty of sciences of Gafsa, Sidi Ahmed Zarrouk, Gafsa 2112, Tunisie.
E-mail: afwa_thameur@yahoo.fr; Fax: +21675633006; Ph: +21675633005.

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Table 1. Average temperature and monthly rainfall during the decade 1995/2005.

MonthMinimum

Temperature (°C)
Maximum
Average temperature
32,92
26,95

27,28
21,39

Rainfall (mm)Septemnber
October

21,63
15,82

13,74
34,82

November

10,20

21,65

15,92

10,78

December

7,36

18,38

12,87

14,77

January

5,42

17,52

11,47

20,95

February
March

6,13
8,99

18,4622,41

12,30
15,70

15,44
20,72

April

10,74

23,46

17,10

10,97

May

14,67

26,84

20,75

1,74

June

20,11

32,49

26,30

2,15

Table 2. Combined analysis of variance showing the mean squares of the cultivar/ variety and treatment factors
and the interaction Cultivar/Variety× Treatment for plant height, tiller number and green leaf number.

Parameter

Source of variation

Developmental stage
Heading
Maturity
487.593***180.703***1677.415***955.539***225.661**
61.197***43.541
2.116

Plant height (cm)Cultivar/Variety
Treatment
Cultivar/Variety×Treatment
ErrorTillering
197.156***590.895***
8.832
16.153

Tiller number

Cultivar/Variety
Treatment
Cultivar/Variety×Treatment
Error

0.618
7.347**
0.068
0.811

1.004
8.961
0.323**
0.862

0.860
4.909**
0.602
0.467

7.669
Cultivar/Variety
78.125**Treatment
1.421
Cultivar/Variety×Treatment
9.502
Error
*, **, *** significant at P< 0.05, 0.01, 0.001 respectively.

6.547
58.681*
0.319
11.9204.322
43.867**
0.706
4.323

Green leaf number

3. Results and Discussion
The effects of Cultivar/Variety and treatment were very highly significant (P<0.001) on plant heightin all developmental stages (Table.2).
Therefore, the effect of the treatment on tiller number was highly significant (P<0.01) at thebeginning and the end of the growth cycle. The green leaf number was influenced significantly by thetreatment. Eventually, the interaction Cultivar/Variety×Treatment was mostly observed at heading stage.
Even though a decrease of the leaf blade area under rainfed conditions was noted, the difference between
studied cultivars and varieties was not significant at 0.05 level of significance regarding significant effectof the treatment on leaf blade area at heading stage (Table 3). Besides, the comparison of means by
Duncan's test released one homogeneous group in both treatments.
Under rainfed conditions, CV. ‘Pakistan’ barley exhibited a similar behaviour as CV. ‘Ardhaoui’cultivar when considering plant height parameter at heading at maturity stages basing on Duncan's test(Table 4).
The same test did not yield significant differences between studied Cultivars/Varieties for the tiller
number and the number of green leaves (Table 4). Higher shoot extension was registered at maturity in155

Table 3. Effect of the variety on leaf blade area. Values presented are means ± SE for the set of 5 cultivars underirrigated and rainfed field conditions.

Parameter
Leaf blade area (cm2)

Cultivar/Variety
Ardhaoui
Pakistanais
RihaneRoho
ManelTreatment
Irrigated
8.02±0.60a
9.00±1.15a
8.06±0.94a
9.62±0.73a
9.23±1.04a

Rainfed7.83±0.79a
6.15±1.01a
7.40±0.98a
6.86±0.40a
7.33±0.69a

In a column, means followed by common letter (s) are not significantly different at the 5% level by Duncan's multiple
range test (DMRT).
Table 4. Effect of the variety on plant height, tiller number and green leaf number. Values presented are means ±SE for the set of 5 cultivars/varieties under irrigated and rainfed field conditions.

Parameter
Plant(cm)heightTreatment
Irrigatedconditions

Rainfedconditions

Tiller number

Irrigatedconditions

Rainfedconditions

Greennumber

leaf

Irrigatedconditions

Rainfedconditions

Cultivar/Variety
Ardhaoui
Pakistanais
RihaneRoho
Manel
Ardhaoui
Pakistanais
RihaneRoho
Manel
Ardhaoui
Pakistanais
RihaneRoho
Manel
Ardhaoui
PakistanaisRihane
Roho
Manel
Ardhaoui
Pakistanais
RihaneRoho
Manel
Ardhaoui
Pakistanais
RihaneRoho
Manel

Tillering
21.01±0.78a
20.93±0.55a
19.32±0.88b
18.16±0.94c
16.18±0.83d
15.43±0.85a
14.36±0.48b
13.6±0.36bb
12.81±0.98c
11.68±0.48c
2.23±1.04a
2±0.88a1.8±0.75a
1.73±0.80a
1.4±0.58a
1.26±0.40a
1.2±0.66a
1.16±0.57a
0.86±0.66a
0.83±0.38a
10.43±0.97a
9.2±0.72a
8.6±0.85a
8.26±0.55a
7.06±0.57a
6.8±0.38a
6.36±0.87a
6.3±0.84a
6.26±0.91a
5.33±0.94a

Developmental stage
Heading
Maturity
34.53±0.62a
47.53±0.51a
25.32±0.30b32.75±0.98b
27.85±0.51b
24.95±0.82b
41.96±0.88c
24.17±0.98b
42.08±0.74d
23.85±0.92c
35.44±0.26a
23.30±0.96a
31.02±0.91a
22.57±0.95a
22.94±0.72b
18.60±0.96b
33.33±0.40c
18.59±0.98b
35.57±0.98d
17.17±0.99b
1.86±0.33a
2.4±0.82a
1.2±0.33ab
2.36±0.97a
1.16±0.33ab
1.93±0.97a
0.93±0.33ab
1.53±0.90a
0.42±0.41a
1.3±0.67a
0.42±0.34a
1.2±0.83a
0.42±0.41a
1.13±0.71a
0.42±0.70a
1.13±0.52a
0.4±0.33a
1.03±0.80a
0.36±0.33a
0.8±0.67a
8.33±0.84a
10.43±0.99a
7.86±0.94a
10.03±0.86a
6.8±0.30a
9.3±0.88a
6.6±0.35a
8.73±0.99a
6.13±0.50a
8.2±0.35a
5.73±0.85a
8.03±0.77a
5.6±0.43a
7.5±0.86a
5.26±0.71a
7.16±0.95a
5±0.70a7.13±0.75a
4.76±0.48a
6.03±0.48a

In a column, means followed by common letter (s) are not significantly different at the 5% level by Duncan's multiple
range test (DMRT).

Ardhaoui (35.44 cm) and Pakistan cultivar (31.02 cm) that ranked in the same group. Average tiller number
in Ardhaoui was 1.26 whereas in Manel accounted for only 0.83 under rainfed conditions.
Under water deficit constraint, all varieties and cultivars exhibited continuous leaves senescence during

156

the mid and late growing season. Mean values of barley shoot length, green shoot leaves number are shownin Table 4. Modifications in aboveground structures, including tissue morphology may benefit plant–wateruse by diminishing transpirative water loss (Hinckley et al., 1978; Kramer, 1983). Modifications in leaf
area (as indicated by limited aboveground growth) in barley are characteristic of drought avoidance, and may
allow this plant to withstand and survive limited water conditions (Morgan, 1984; Jones and Corlett, 1992).
Structural avoidance of excessive irradiance can be crucial for plant survival in high-light environments(Pearcy et al., 2005). Barley morphological adaptations to water deficit appear to be an extension of shoots
only in the most favorable water availability periods and gradual leaves senescence throughout the growing
season.
4. Conclusions
Results of this investigation indicated that even if there were no significant difference between studied
varieties and cultivars at tillering stage was documented, the degree of tolerance to drought was emphasizedat maturity mainly in plant height. Morphological adaptations confer a greater degree of drought tolerance
and aid in the recovery from drought induced damage.
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