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University of Gezira
The Hydraulic Performance of Drip Irrigation System with Special
Emphasis on the Effects of Deficit Irrigation on Eggplants (Solanum
Melongena L.) Under Gezira Conditions, Sudan
Ahmed Musa Yagoub Musa
February/ 2018
The Hydraulic Performance of Drip Irrigation System with Special
Emphasis on the Effects of Deficit Irrigation on Eggplants (Solanum
Melongena L.) Under Gezira Conditions, Sudan
Ahmed Musa Yagoub Musa
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B. Sc. (Hon) in Agricultural Science (Agricultural Engineering)
Faculty of Agricultural and Natural Resources
University of Gezira (2011)
A Dissertation
Submitted to the University of Gezira in Partial Fulfillment of the
Requirements for the Award of the Degree of
Master of Science
in
Water Management
Water Management and Irrigation Institute
February/ 2018
vi
The Hydraulic Performance of Drip Irrigation System with Special
Emphasis on the Effects of Deficit Irrigation on Eggplants (Solanum
Melongena L.) Under Gezira Conditions, Sudan
Ahmed Musa Yagoub Musa
Supervision Committee:
Name Position Signature
Dr. Bashir Mohammed Ahmed Main supervisor
………………
Dr. Eltigani Elnour Bashier Co-supervisor
……………...
Date: February/2018
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The Hydraulic Performance of Drip Irrigation System with Special
Emphasis on the Effects of Deficit Irrigation on Eggplants (Solanum
Melongena L.) Under Gezira Conditions, Sudan
Ahmed Musa Yagoub Musa
viii
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Examination committee:
Name Position Signature
Dr. Bashir Mohammed Ahmed Chairperson
………………
Dr. Osman Abd Elrahaman Alfadni External Examiner
………………
Dr. Elsadig Ahmed Elfaki Internal Examiner ……
Date of Examination: 13th
/February/2018
x
This work is dedicated
To my father and mother
To my brothers and sisters
To my teachers, friends and colleagues
With my respect to all of you
For their diligence and encouragement
Through all my life
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ACKNOWLEDGEMENTS
First of all, my thanks and praise to Allah who gave me patience and ability to finish this work. I
would like to record my appreciation and thanks to my supervisor Dr. Bashir Mohammed
Ahmed for his continuous follow up, guidance, support and valuable critique. I am also grateful
to my Co-Supervisor Dr. Eltigani Elnour Bashier.
I would like to extent my heartfelt gratitude to Regional Universities Forum for Capacity
Building in Agriculture (RUFORUM) for granting the scholarship. I am sincerely grateful to Dr.
Mona Ahmed Elhaj at University of Gezira. My deeps thank goes to the staff of the Agricultural
Engineering Research and colleagues and any other persons who contributed to this work.
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Deepest appreciation and thanks to my family members for their help and encouragement during
the study period.
xiv
The Hydraulic Performance of Drip Irrigation System with Special Emphasis
on the Effects of Deficit Irrigation on Eggplants (Solanum Melongena L.)
Under Gezira Conditions, Sudan
Ahmed Musa Yagoub Musa
ABSTRACT
The increased competition for water among agricultural, industrial and domestic consumers
creates the need for continuous improvements in techniques for judicious use of water in crop
production. A field experiment was conducted at Horticultural Research Farm (HRF), Gezira
Research station (GRS), Wad Medani, Sudan, from April to September 2017. The study was
aimed to design and evaluate the hydraulic performance of drip emitters and also to investigate
the influence of full and deficit irrigation on eggplant performance and water use efficiency. A
drip irrigation system was designed and installed in an open field. The treatments were laid out
in a randomized complete block design (RCBD) with three replications. Full-irrigated treatment
(T1), deficit irrigated at vegetative stage (T2), deficit irrigated at flowering stage (T3) and deficit
irrigated at maturity stage (T4) were applied to long purple variety in Gezira clay soil. The
emitters were tested under operating pressure of 1.5 bar. The hydraulic performance results
showed that, the Distribution Uniformity (DU), Uniformity Coefficient (Cu%), Flow Variation
(Qvar), Percentage emitters clogging (Pclog%) and Coefficient of Variation (CV) were 85%,
94%, 55%, 5% and 28% respectively. Results also showed that irrigation treatments significantly
affected yield and yield components. Full-irrigated treatment (T1) and deficit irrigation treatment
(T2) showed the highest number of branches, weight of fruit and total yield. The full-irrigated
treatment had the highest total yield (30800 kg/ha), T4 scored the lowest total yield (17200
kg/ha), with percentage reduction in yield of 20, 29 and 44%, respectively compared to Full-
irrigated treatment. The average values of applied water under full-irrigated treatment were
(3750 ), while the average applied water for deficit irrigation treatments (T2, T3 and T4)
were (3187.5 ). The highest values of Irrigation Water Productivity (IWP) were obtained
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under full irrigation treatment (8.3 kg/ ), while the lowest values were recorded under the
deficit irrigation at fruit ripening stage (5.4 kg/ ). Results also indicated that exposing eggplant
to continuous water stress during maturity stage
decreased total yi
el
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كيز الخاص على آثار نقص الري علىاألداء الهيذروليكً لنظام الري بالتنقيط مع التر
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TABLES OF CONTENTS
Contents Page
Dedication iv
Acknowledgement v
Abstract English vi
Abstract Arabic vii
List of Contents viii
List of Tables xiii
List of Figures xiv
List of Appendices xv
CHAPTER ONE ............................................................................................................................1
INTRODUCTION..........................................................................................................................1
1.1 General .......................................................................................................................................1
1.2 Research Problem and Justification ...........................................................................................2
1.3 The objective..............................................................................................................................3
CHAPTER TWO ...........................................................................................................................4
LITERATURE REVIEW .............................................................................................................4
2.1 Availability of Water for Irrigation............................................................................................4
2.2 General Irrigation Definition .....................................................................................................5
2.3 Irrigation Methods......................................................................................................................5
2.3.1 Surface Irrigation System....................................................................................................... 5
2.3.1.1 Furrow Irrigation................................................................................................................. 6
2.3.1.2 Border Irrigation ................................................................................................................. 6
2.3.1.3 Basin Irrigation ................................................................................................................... 6
2.3.1.4 Sub-surface Irrigation System............................................................................................. 7
2.3.2 Sprinkler Irrigation System .................................................................................................... 7
2.3.2.1 Portable System .................................................................................................................. 7
2.3.2.2 Semi Portable System ......................................................................................................... 7
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2.3.2.3 Semi Permanent System ..................................................................................................... 7
2.3.2.4 Solid Set System ................................................................................................................. 7
2.3.2.5 Permanent System............................................................................................................... 8
2.3.2.6 Gun Type sprinkler ............................................................................................................. 8
2.3.2.7 Center-Pivot Systems .......................................................................................................... 8
2.3.2.8 Linear Move Sprinkler System ........................................................................................... 9
2.3.2.9 Advantages and Disadvantages of Sprinkler Irrigation ...................................................... 9
2.3.3 Drip Irrigation System ........................................................................................................... 9
2.3.4 History and Development of Drip Irrigation ....................................................................... 10
2.3.5 Definition of Drip Irrigation ................................................................................................ 11
2.3.6 Advantages and Disadvantages of Drip Irrigation ............................................................... 11
2.3.7 The Components of Drip Irrigation System......................................................................... 12
2.3.7.1 Pumping Station ................................................................................................................ 12
2.3.7.2 Main Line .......................................................................................................................... 12
2.3.7.3 Sub Main Line................................................................................................................... 13
2.3.7.4 Lateral Line ....................................................................................................................... 13
2.3.7.5 The Emitters ...................................................................................................................... 13
2.3.7.6 Filters ................................................................................................................................ 13
2.3.7.7 Control Valves .................................................................................................................. 14
2.3.7.8 Fittings .............................................................................................................................. 14
2.3.7.9 Fertilizers Applicators....................................................................................................... 14
2.3.7.10 Pressure Gauge................................................................................................................ 14
2.4 Criteria to Selecting the most Appropriate Irrigation System .................................................15
2.4.1 Natural Condition................................................................................................................. 15
2.4.2 Type of Crop ........................................................................................................................ 15
2.4.3 Type of Technology ............................................................................................................. 15
2.4.4 Previous Experience with Irrigation .................................................................................... 16
2.4.5 Required Labor Inputs ......................................................................................................... 16
2.4.6 Costs and Benefits................................................................................................................ 16
2.5 Crop Water Requirement (CWR) ............................................................................................16
2.5.1 Evapotranspiration (ET)....................................................................................................... 17
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2.5.2 Reference Crop Evapotranspiration (ETo) ........................................................................... 18
2.5.3 Crop Coefficient (Kc) .......................................................................................................... 18
2.5.4 Crop Growth Stages ............................................................................................................. 19
2.5.5 Water Balance ...................................................................................................................... 19
2.5.6 Soil Water Content............................................................................................................... 20
2.5.7 Soil Water Measurement...................................................................................................... 20
2.5.7.1 A Tensiometer................................................................................................................... 20
2.5.7.2 Time Domain Reflectometry (TDR)................................................................................. 21
2.5.7.3 Neutron Probe Technology ............................................................................................... 21
2.5.7.4 Micro Wave Remote Sensing ........................................................................................... 22
2.6 Water Use Efficiency (WUE) ..................................................................................................22
2.6.1 Water Productivity ............................................................................................................... 23
2.7 The Eggplant (Solanum melongena L.) ...................................................................................24
2.7.1 Origin ................................................................................................................................... 24
2.7.2 Soil ....................................................................................................................................... 24
2.7.3 Varieties ............................................................................................................................... 24
2.7.4 Eggplant in Sudan ................................................................................................................ 25
CHAPTER THREE .....................................................................................................................25
MATERIALS AND METHODS ................................................................................................25
3.1 Site Description....................................................................................................................... 26
3.2 Soil Characteristic ................................................................................................................... 26
3.3 Design and Installation of the Drip Irrigation System ............................................................ 28
3.3.1 System Calibration and Evaluation...................................................................................... 28
3.3.2 System Uniformity ............................................................................................................... 29
3.3.3 Flow Variation ..................................................................................................................... 29
3.3.4 Percentage of Completely Emitters Clogging ( %) ................................................... 30
3.4 The Experimental Design........................................................................................................ 30
3.5 Cultural Practices .................................................................................................................... 30
3.6 Data Collection ....................................................................................................................... 30
3.6.1 Days to 50% Flowering ....................................................................................................... 31
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3.6.2 Plant Height (cm) ................................................................................................................. 31
3.6.3 Number of Branches/Plant ................................................................................................... 31
3.6.4 Number of Fruits/Plant ........................................................................................................ 31
3.6.5 Total Yield (t/ha).................................................................................................................. 31
3.6.6 Water Productivity (WP) ..................................................................................................... 31
3.7 Statistical Analysis .................................................................................................................. 31
CHAPTER FOUR........................................................................................................................32
RESULTS AND DISCUSSION ..................................................................................................32
4.1 Hydraulic Performance of Drip Irrigation System.................................................................. 32
4.1.1 The Distribution Uniformity (DU %) .................................................................................. 32
4.1.2 Uniformity Coefficient (CU %) ........................................................................................... 32
4.1.3 Flow Variation (Qvar).......................................................................................................... 32
4.1.4 Percentage Emitters Clogging (Pclog) ................................................................................. 32
4.1.5 Coefficient of Variation (CV) .............................................................................................. 32
4.2 Growth Parameters.................................................................................................................. 33
4.2.1 Days to 50% Flowering ....................................................................................................... 33
4.2.2 Plant Height.......................................................................................................................... 33
4.2.3 Number of Branches/Plant ................................................................................................... 33
4.3 Yield and Yield Components .................................................................................................. 35
4.3.1 Weight of Fruit (g) ............................................................................................................... 35
4.3.2 Length of Fruit (cm) and Number of Fruit........................................................................... 35
4.3.3 Total Yield (t/ha).................................................................................................................. 35
4.4 Applied Water and Water Use Efficiency............................................................................... 36
4.4.1 Applied Irrigation Water ...................................................................................................... 36
4.4.2 Water Productivity (WP) ..................................................................................................... 36
CHAPTER FIVE .........................................................................................................................38
CONCLUSIONS AND RECOMMENDATIONS.....................................................................38
5.1 Conclusions ............................................................................................................................. 38
5.1.1 Hydraulic Performance of Drip Irrigation System............................................................... 38
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5.1.2 Evaluating Eggplant Growth and Yield under Full and Deficit Irrigation .......................... 38
5.2 Recommendations ................................................................................................................... 39
REFERENCES.............................................................................................................................40
APPENDICES ..............................................................................................................................45
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LIST OF TABLES
Table Page
(3.1) Some physical and chemical properties of the studied soils (Source: Elias, 2001) ............. 28
(4.1) Hydraulic Performance of the drip irrigation system. .......................................................... 33
(4.2) Effect of irrigation treatments on the plant height and the number of days 50%
flowering during the growing season (2017). ............................................................................... 34
(4.3) The effect of irrigation treatments on branches number and leaves number during the
growing season (2017). ................................................................................................................. 34
(4.4) The effect of irrigation treatment fruits number, length of fruit (cm), weight of fruit and
total yield t/ha of eggplant during the growing season (2017). .................................................... 36
(4.5) Mean quantity of applied water (m3/ha), total yield (t/ha) and water productivity
(kg/m3) of for irrigation treatments. .............................................................................................. 37
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LIST OF FIGURES
Figure Page
(2.1) Diagram of the LPDI System ............................................................................................... 15
(3.1) Annual average of Maximum and Minimum Temperature (°C) at Wad Medani, Sudan .... 26
(3.2) Annual average of Sunshine (%) and Relative Humidity (%) at Wad Medani, Sudan........ 27
(3.3) Annual average of Rainfall (mm) at Wad Medani, Sudan ................................................... 27
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LIST OF APPENDICES
Appendices Page
(1) Data for evaluation of hydraulic performance of drip irrigation system................................ 45
(2) Mean monthly meteorological data Rainfall, Relative humidity %, Sunshine% and
Maximum, minimum temperatures of the 2017 at Gezira research station. ................................. 46
(3) Analysis of variance for day to 50% flowering. ..................................................................... 47
(4) Analysis of variance for plant height. .................................................................................... 47
(5) Analysis of variance for number of branches per plant. ......................................................... 47
(6) Analysis of variance for number of leaves per plant. ............................................................. 48
(7) Analysis of variance for number of fruits per plant. .............................................................. 48
(8) Analysis of variance for weight of fruit. ................................................................................ 48
(9) Analysis of variance for length of fruit. ................................................................................. 48
(10) Analysis of variance for total yield. ..................................................................................... 49
(11) Analysis of variance for Water Productivity. ....................................................................... 49
1
CHAPTER ONE
INTRODUCTION
1.1 General
Agriculture accounts for about 70-80% use of available water in the world (Duhrkoop et al,
2009). Shortage of irrigation water has made it necessary to improve water usage in
Agriculture, in order to make it available to farmers throughout the season to ensure food
security (Kumasi and Asenso., 2011). Irrigation plays an important role in the Agricultural
production in Sudan. The total area irrigated by surface irrigation in the Sudan is two million
(Abdel Rhman, 1990). The performance of surface irrigation in the Sudan was not satisfactory,
due to the degradation in the canal infrastructures, which declines the total production. Drip
irrigation was introduced in Sudan more than ten years ago in small areas to solve problems
related to surface irrigation such as labor and canal maintenance and operation. On the other
hand, the initial cost for drip irrigation is higher than canal irrigation due to the high cost of
equipment and installation. However, when water is applied through surface irrigation, a
considerable amount is lost through evaporation, runoff and deep percolation making the
system less efficient. Therefor drip irrigation (trickle irrigation) is an ideal irrigation system for
increasing irrigation water use efficiency. It is also necessary to manage the scare water
resources and to maximize crop production.
The advantages of drip irrigation are that can be applied water both exactly and uniformly at a
high irrigation frequency compared with surface and sprinkler types of irrigation, moreover, it
potentially increases yield, reduces subsurface drainage, provides better salinity control and
better disease management (Mawadda, 2015). The increased competition for water among
agricultural, industrial and domestic consumers creates the need for continuous improvements
in techniques for judicious use of water in crop production. Efficient water use is becoming
increasingly important, thus an alternative methods of application such as drip and sprinkler
irrigation may contribute virtually in the efficient use of the scarce water for crop production.
Vegetables together with fruits represent very important and rich sources of essential vitamins,
minerals and dietary fiber. They also contain additional calories. Therefore, they are most
valuable and nutritious food commodities, which can substantially contribute to improve the
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social welfare and health status of the rural as well as urban populations. (Patel et al., 1998)
reported a total harvested acreage of vegetables at world level of 1,321,000 hectares, this area
represents only 0.8% of the total estimated arable land (162,684,000 ha). This demonstrates
clearly the potential for producing of more food to meet the demand of the ever-increasing
world population, which could be only achieved through irrigation system with high water use
efficiency.
Eggplant (Solanum melogena L.) is a short-lived perennial herb that belongs to the family
solanaceae. It is grown as an annual plant and is one of the most consumed fruit vegetables in
tropical Africa, probably the third after Tomato and Onion before Okra (Gruban and Denton,
2004). The fruit is rich in essential vitamins and mineral. Eggplant (Solanum melongena L.) is
important vegetable crops grown in many parts of the Sudan, locally known as ―Bedingan‖ or
―Aswad‖. It is produced mainly for local consumption with small quantities for export (Samir,
2007; Grubben, 1977). It can be cooked and eaten as vegetable, prepared in several of different
ways, and be stable in any diet (Elsidig.F and et al, 2016), also has been used in traditional
medicine for example, fruit and leaves are effective in lowering blood cholesterol. The old
introduced cultivars have almost disappeared as new improved varieties were introduced such
as, black beauty and long purple. Under Sudan condition, the best time for sowing eggplant is
the beginning of the rainy season or early in November (Mohamed et al., 1998).
1.2 Research Problem and Justification
Water is considered as scarce resource in many areas of the world, especially in arid and semi-
arid regions. Drip irrigation beside other modern irrigation systems might improve the Water
Use Efficiency (WUE). Moreover, scheduling irrigation as well as controlling irrigation
volumes, the quantity and quality of the crop could be improved under drip irrigation system.
On the other hand, the effects of deficit irrigation on growth and yield of many vegetable and
field crops are documented and reported. Reductions in eggplant fresh yield in response to
water stress are also illustrated, however, in the Sudan such information are not available yet.
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1.3 The objective
The main objective of this study was to investigate the effect of deficit irrigation on eggplant
performance under drip irrigation system, the specific objectives were:
1. To evaluate the hydraulic parameters of drip irrigation under Gezira condition.
2. To investigate the effect of four level of deficit irrigation in eggplant yield and yield
components.
3. To evaluate water use efficiency.
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CHAPTER TWO
LITERATURE REVIEW
2.1 Availability of Water for Irrigation
Sudan has subsequently fatigued their share of the Nile water agreement, consequently
through expanding in agriculture scheme, thus a new strategies concerning the irrigation
policies is required. Sudan has different water resources for irrigation. Renewable ground
water estimated within four billion cubic meters (BCM) mainly found in the Nobian sand
stone (Um Ruwaba Basin), alluvial deposits and Basement complex formations (Mukhtar,
1997). The groundwater basins of Sudan are either in a simple form or in a complex one,
according to their geological formations. Available groundwater is 900BCM, with an annual
recharge of 1,563BCM. The Nubian Sandstone Aquifer System is shared by Sudan,
Egypt and Libya. It is recharged from the Nile in Sudan, with an area of almost 29%
of Sudan; the system is the country‘s most important aquifer (Androutsos et al.,
2013). Rainfall ranges from zero in further North to about 800mm in extreme south-
west. The most abundant water resource is rainfall. Rainfall varies in amount and
frequency, with amounts generally decreasing from north to south. Sudan‘s estimated annual
rainfall since the secession of South Sudan has decreased from 1,060BCM to about
442BCM. The rainy season runs from June to September with a peak in August
(Androutsos et al., 2013). The annual rainfall in the northern Sudan varies from 200 mm
in the center of the country to 25mm northwards towards the border with Egypt. The rainy
season is limited to 2 to 3 months with the rest of the year being virtually dry (Amir, 2005).
In the areas where there is no arrival to River Nile or its tributaries, 75 % of the population
depends on groundwater and rainwater for their domestic water use (Ayoub, 1998). With the
current consumption of water in the Sudan, there are signs of a water shortage (Abdel
Rahman 1990) and (Guvele et al, 2001).
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2.2 General Irrigation Definition
Irrigation is the artificial application of water to the land to provide adequate amount for crop
production (Solomon, 1990). Phocaides (2000) also defined irrigation as the application of
water, supplementary to that supplied directly by precipitation, for the production of crops.
Irrigation water is supplied to supplement the water available from rainfall and the contribution
to moisture availability. In many areas of the world, amount and timing of rainfall are not
suitable to meet the water requirements of crops, thus irrigation is essential for crop production
to meet the needs of human for food and fibre (Michael, 1978).
2.3 Irrigation Methods
Irrigation water can be applied by four different ways:
2.3.1 Surface Irrigation System
Surface irrigation is the oldest and most common method of applying water to crops. It
involves moving water over the soil in order to wet it completely or partially. The water flows
over or ponds on the soil surface and gradually infiltrates in to the desired depth. Surface
irrigation methods are best suited to soils with low to moderate infiltration capacities and with
relatively uniform terrain with slopes less than 2-3% (Brouwer et al., 1974).
Surface irrigation consists of a broad class of irrigation methods in which water is distributed
over the soil surface by gravity flow. The irrigation water is introduced into level or graded
furrows or basins, using siphons, gated pipe, or turnout structures, and is allowed to advance
across the field. Surface irrigation is best suited to flat land slopes, and medium to fine textured
soil types which promote the lateral spread of water down the furrow row or across the basin. A
surface irrigation event is composed of four phases as illustrated graphically. When water is
applied to the field, it across as the surface until the water extends over the entire area. It may
or may not directly wet the entire surface, but all of the flow paths have been completed. Then
the irrigation water either runs off the field or begins to pond on its surface. The interval
between the end of the advance and when the inflow is cut off is called the wetting or ponding
phase. The volume of water on the surface begins to decline after the water is no longer being
6
applied. It either drains from the surface (runoff) or infiltrates into the soil. For the purposes of
describing the hydraulics of the surface flows, the drainage period is segregated into the
depletion phase (vertical recession) and the recession phase (horizontal recession). Depletion is
the interval between cut off and the appearance of the first bare soil under the water. Recession
begins at that point and continues until the surface is drained (Pereira, 1996).
Water may be distributed by any one of the following systems: furrow irrigation, border strip
and basin irrigation, (Michael, 1978).
2.3.1.1 Furrow Irrigation
Furrow irrigation avoids flooding the entire field surface by channeling the flow along the
primary direction of the field using furrows, or corrugations'. Water infiltrates through the
wetted perimeter and spreads vertically and horizontally to refill the soil reservoir. Furrows are
often employed in basins and borders to reduce the effects of topographical variation and
crusting (Michael, 1978).
2.3.1.2 Border Irrigation
The border strip width depends on the topography of the field, which determines the possible
width that can be obtained while keeping a horizontal cross-section without requiring too much
soil movement, and on the stream size. The stream size also restricts strip width, as it should be
sufficient to allow complete lateral spreading throughout the border strip width and length. The
strip width also depends on the cultivation practices, mechanized or non-mechanized for
example. Border strips should not be wider than 9 m on 1% cross-slopes (James, 1988).
2.3.1.3 Basin Irrigation
Basin irrigation is the most common form of surface irrigation, particularly in regions with
design of small fields. Basins are horizontal, flat plots of land, surrounded by small dikes or
bunds. The banks prevent the water from flowing to the surrounding fields. Basin irrigation is
commonly used for wheat production in Sudan (Shirgutre et al., 2001).
7
2.3.1.4 Sub-surface Irrigation System
Water is applied below the ground surface; it reaches the plant roots through capillary action.
Water may be introduced through open ditches or underground pipe lines (Michael, 1978).
2.3.2 Sprinkler Irrigation System
Sprinkler irrigation is a method of applying water by spray in the air. The spray of water is
developed by the flow of water under pressure through nozzles (James, 1988). A sprinkler
irrigation system generally includes sprinklers, laterals, sub mains, main pipelines, pumping
plants and boosters, operational control equipment and other accessories required for efficient
water application. The distribution of water over an area of irrigation by sprinkler systems is
primarily a function of design, operational and climatic factors. "Effects of soil characteristics
on the distribution are considered negligible" (Karmeli et al, 1978). Operating pressure and
sprinkler spacing the amount of irrigation water required to refill the crop root zone can be
applied nearly uniform at the rate to suit the infiltration rate of soil. There are many types of
sprinkler irrigation, which include:
2.3.2.1 Portable System
A portable system has portable main lines, laterals and pumping plant.
2.3.2.2 Semi Portable System
A semi portable system is similar to a portable system except that the location of water source
and pumping plant is fixed.
2.3.2.3 Semi Permanent System
A semi-permanent system has portable lateral lines, permanent main lines and sub mains and a
stationery water source and pumping plant.
2.3.2.4 Solid Set System
A solid set system has enough laterals to eliminate their movement. The laterals are positions in
the field early in the crop season and remain for the coming seasons.
8
2.3.2.5 Permanent System
A fully permanent system consists of permanently laid mains, sub mains and laterals and a
stationery water source and pumping plant.
2.3.2.6 Gun Type sprinkler
Gun type sprinklers are operated as a large single impact type sprinkler head. The sprinkler is
moved from one set to the next either by hand or small tractor depending on the size or whether
they are towable. Lateral lines are usually aluminum pipe with quick-coupled joints. Nozzle
sizes are large and can vary between ½ to 1 ¾. Operating pressures can range from 50 psi to
120psi with flow rates at 50 to 1000 gallons per minute (Chih, 1997). When irrigating, the
sprinkler is allowed to remain at one location (set) until the desired amount of water is applied.
2.3.2.7 Center-Pivot Systems
Center pivot systems consist of a single lateral supported by towers with one end anchored to a
fixed pivot structure and the other end continuously moving around the pivot point while
applying water. This system irrigates a circular field unless end guns and swing lines are cycled
on in corner areas to irrigate more of a square field. The water is supplied from the source to
the lateral through the pivot. The lateral pipe with sprinklers is supported on drive units. The
drive units are, normally powered by hydraulic water drives or electric motors. Various
operating pressures and configurations of sprinkler heads or nozzles (types and spacing) are
located along the lateral. Sprinkler heads with nozzles may be high or low pressure impact,
gear driven, or one of many low pressure spray heads. A higher discharge, part circle gun is
generally used at the extreme end (end gun), of the lateral to irrigate the outer fringe of the
lateral. Each tower which is generally mounted on rubber tires has a power device designed to
propel the system around the pivot point (O‘Shaughnessy et al., 2013) The most common
power units include electric motor, hydraulic water drive, and hydraulic oil drive. Towers are
spaced from 80 to 250 feet apart, and lateral lengths vary up to ½ mile. Long spans require a
substantial truss or cable to support the lateral pipe in place.
9
2.3.2.8 Linear Move Sprinkler System
A linear move sprinkle system is a continuous, self-moving, straight lateral that irrigates a
rectangular field. It is similar to the center pivot in that the lateral is supported by trusses,
cables, and towers mounted on wheels. Most linear move systems are driven by electric motors
located in each tower or is hydraulic driven (Sadler et al., 2005) A self-aligning system is used
to maintain near straight-line uniform travel. One tower is the master control tower for the
lateral where the speed is set, and all other towers operate in start-stop mode to maintain
alignment. A small cable mounted 12 to 18 inches above the ground surface along one edge or
the center of the field guides the master control tower across the field.
2.3.2.9 Advantages and Disadvantages of Sprinkler Irrigation
The advantages of sprinkler system are:
1. Expansive land leveling is not required.
2. Water saving irrigation intensity can be changed in accordance with the infiltration
capacity of soil.
3. High efficiency due to uniform water distribution.
4. Ease and uniform application of fertilizers and pesticides through irrigation system.
5. No special skills trained personal can operate the system reasonably well.
6. Soil moisture is maintained at optimum level by sprinkler irrigation and 20 higher yields
are obtained of crops and the quality of other crops is also good.
The disadvantages of sprinkler system are:
1. Higher initial cost.
2. High and continuous energy requirement for operation.
3. Under high wind condition and high temperature distribution and application efficiency are
poor.
4. Sprinkler irrigation is not so economical.
5. Loss of water due to evaporation from the area during irrigation (Li, 1998).
2.3.3 Drip Irrigation System
Drip irrigation is a controlled method of irrigation, consisting of tubes with emitters. It allows
increasing water use efficiencies by providing precise amounts of water directly to the root
zone of individual plants (Burt, 2004).
10
2.3.4 History and Development of Drip Irrigation
Drip irrigation is quickly becoming the standard irrigation method for many applications such
as home gardens and landscapes, greenhouses, vineyards, row crops and orchards. The
technology and materials have shown some significant changes throughout the years, but the
basic concepts have generally remained constant. One early method involved burying clay pots
filled with water within a planting area, allowing the water to gradually seep into the soil at the
plant's root zone. Modern drip irrigation began its development in Afghanistan, 1866 when
researchers Began experimenting with irrigation using clay pipes to create combination of
irrigation and drainage systems (Mawadda, 2015).
In 1913, E.B. House at Colorado state university succeeded in applying water to the root zone
of plants without raising the water table. Major improvement has been achieved by introduction
of drip irrigation through the usage of plastic pipes. This led to introduce various types of
system components began in Europe and America. The first drip type, which called (Dew
hose), was developed by Richard Chapin. In the 1920's, growers in Germany began using
perforated pipe to irrigate plants. Once plastics were developed and widely used after WWII, an
Australian inventor named Hannis Thill began to use a specific plastic pipe configuration with
long passageways to evenly distribute water to crops. In 1959, Simcha Blass and Kibbutz
Hatzerim developed and patented the first practical surface drip irrigation emitter. The emitter
concept was developed several years earlier by Simcha and his son Yeshayahu. Instead of
releasing water through tiny holes easily blocked by tiny particles, water was released through
larger and longer passageways which decreased the water velocity as it exited the piping. The
first reported work in the U.S.A. was made by house in Colorado in 1913. Subsequent to 1920;
perforated pipes were used in Germany which made this concept feasible. Since then, various
experiments have centered around the development of drip systems using perforated pipes
made of various material (Jensen, 1993).
Modern drip irrigation has arguably become the world's most valued innovation in agriculture
since the invention of the impact sprinkler in the 1930s, which offered the first practical
alternative to surface irrigation. Crops are now growing in desert climates which would not
have been feasible without drip irrigation. Water conservation efforts in some regions of the
11
world susceptible to drought have incorporated drip irrigation as the primary method of
watering crops. Crop yields in virtually all environments have significantly increased while
utilizing less water due to drip irrigation technology.
2.3.5 Definition of Drip Irrigation
Drip or Trickle irrigation is basically precise and slow application of water in the form of
discrete continuous drops, sprayed through mechanical devices (emitters) into the root zone of
the plant‖. (Singh al et., 2006) reported that by the drip system of irrigation, water reaches the
roots drop by drop and hence, it is an economic method of irrigation in all seasons. Drip
irrigation is a technique in which water flows through a filter into special drip pipes, with
emitters located at different spacing. Water is distributed through the emitters directly into the
soil near the roots through a special slow-release device. If the drip irrigation system is properly
designed, installed, and managed, drip irrigation may help achieve water conservation by
reducing evaporation and deep drainage. Compared to other types of irrigation systems such as
flood or overhead sprinklers, water can be more precisely applied to roots zone. Drip irrigation
generally achieves higher crop yield and balanced soil moisture in the active root zone with few
losses (Yildrin and Korukcu, 2000), (Fulton et al., 1991).
There are two types of drip irrigation; surface and subsurface drip irrigation. The subsurface
type uses a buried emitter, which has the potential to save irrigation water by reducing the
amount of water added to the plant (Evett et al, 1995). Both surface and subsurface drip
irrigation use the same mechanism for delivering water to each individual plant. The main
features of drip irrigation are:
1. Negligible deep percolation of water into the soil.
2. Sign of water losses due to evaporation.
3. No surface water run off (Postel et al, 2001).
2.3.6 Advantages and Disadvantages of Drip Irrigation
The advantages of drip irrigation system are:
Maximum use of available water.
No water being available to weeds.
Maximum crop yield.
12
High efficiency fertilizers, use efficiency.
Low labor and relatively low operation cost.
No soil erosion.
Improved infiltration in soil of low intake.
No runoff of fertilizers into ground water.
Less evaporation losses as compared to surface irrigation.
Decreased tillage operations.
Ready adjustment to sophisticated automatic control.
Even though the numerous advantages of drip irrigation, it has number of limitations that varies
from place to another, such as:
Expensive initial cost.
Sensitivity to clogging.
Salinity hazard.
High skill is required for design, install and operation.
2.3.7 The Components of Drip Irrigation System
The components that usually required for a drip irrigation system include the pumping station;
control head, main and sub-main lines, lateral lines, emitters, valves, fitting, Fertilizer system,
and other important appurtenances (Figure2.2) (Saaed, 2006).
2.3.7.1 Pumping Station
It consists of the power unit (internal combustion engine or electric motor) and a centrifugal
deep well, or submersible pumps.
2.3.7.2 Main Line
It is the largest diameter pipeline of the network that goes from the water source to the control
valves, which enable conveyance of the flow velocity and friction losses so as to deliver water
to the sub-main line. It is usually made of galvanized steel, copper, PVC, which is damaged by
the sun light. Therefore, the main line should be buried or protected or apply several coats of
13
paint if it is above ground. The sizes of these pipes range from 63 – 160 mm (2 – 6 inches),
which depends on the area of the farm.
2.3.7.3 Sub Main Line
It is a smaller diameter pipelines which range from 16 to 50 mm (0.5 -1.5 inches). They are
extending from the main line, to which the flow system is diverted for distribution to the
various plots (Phocaide, 2007).
2.3.7.4 Lateral Line
It delivers water to the emission devices from the sub-main or direct from main line. Its
diameter is 13, 16, or 22 mm.
2.3.7.5 The Emitters
Emitters are devices that control how fast the water drips out into the soil. Most of them are
small plastic element that either screw or snap into a drip tube or pipe. Emitters are divided by
type of flow as following:
Orifice emitter.
Vortex emitter.
Long-path emitters.
Twin-chamber tubing.
Compensating emitters.
Flushing emitters.
Micro or spaghetti tube (Ismail, 2002).
2.3.7.6 Filters
Are used to clean the suspended impurities in the irrigation water so as to prevent blockage of
holes on passage of drip nozzles is an essential part of the drip irrigation system. The filtration
of the irrigation water is essential in order to avoid blockage damage to the drip irrigation
emitter. The types of filter used depends on the kind of impurities contained in the water and
the degree of filtration required on the emitter. Their size should be the most economical with
the lowest friction losses ranging from 0.3 – 0.5 bar. The types of filters available include:
1. Screen filter.
2. Desk filters.
14
3. Media filter.
4. Gravel filter.
5. Cartridge filters.
6. Hydro cyclone (sand separator) filter (Ismail, 2002).
2.3.7.7 Control Valves
Valves are required to control water flows inside the system, and to allow flushing of irrigation
pipes (Hochmuth and Cordasco, 2000). It is made of brass, P.V.C or plastic.
2.3.7.8 Fittings
These are an array of coupling and closure devices, which are used to construct a drip system
including connectors, tees, elbows, plugs and end caps. They are of many types (Wilson and
Bauer, 1998).
2.3.7.9 Fertilizers Applicators
Fertilizers system is used to apply chemicals (fertilizers, pesticides and anti-clogging agents)
with irrigation water. This process is called (fertigation) and there are various ways of
performing fertigation.
2.3.7.10 Pressure Gauge
It is required for properly monitoring the operation of pressurized irrigation systems. It allows
quick check to ensure that the system work at the correct pressure.
15
Figure (2.1) Diagram of the LPDI System
Source: Bustan, 2008
2.4 Criteria to Selecting the most Appropriate Irrigation System
The suitability of the various irrigation methods, i.e. surface, sprinkler or drip irrigation
depends mainly on the following factors:
2.4.1 Natural Condition
The natural conditions such as soil type, slope, climate, water quality and availability play an
important role in selecting the appropriate irrigation method.
2.4.2 Type of Crop
Surface irrigation can be used for all types of crops. However, sprinkler and drip irrigation, are
mostly used for high value cash crops such as vegetables and fruit trees. They are seldom used
for the lower value staple crops. Drip irrigation is suited to irrigating individual plants or trees
or row crops such as vegetables and sugarcane. It is not suitable for close growing crops such
as rice.
2.4.3 Type of Technology
16
Energy requirements and therefore operating costs of some systems such as the big gun,
travelling gun and the high pressure travelling boom are considerably higher than for low
pressure systems such as, for e.g., drip irrigation, and should be taken into consideration with
system selection.
2.4.4 Previous Experience with Irrigation
The choice of an irrigation method also depends on the irrigation tradition within the region or
country. Introducing a previously unknown method may lead to unexpected complications. It is
not certain that the farmers will accept the new method. The servicing of the equipment may be
problematic and the costs may be high compared to the benefits.
2.4.5 Required Labor Inputs
Surface irrigation often requires a much higher labor input for construction, operation and
maintenance than sprinkler or drip irrigation. Surface irrigation requires accurate land leveling,
regular maintenance and a high level of farmers' organization to operate the system. Sprinkler
and drip irrigation require little land leveling; system operation and maintenance are less labor-
intensive.
2.4.6 Costs and Benefits
Before choosing an irrigation method, an estimate must be made of the costs and benefits of the
available options. On the cost side not only the construction and installation, but also the
operation and maintenance (per hectare) should be taken into account. These costs should then
be compared with the expected benefits (yields). It is obvious that farmers will only be
interested in implementing a certain method if they consider this economically attractive.
Cost/benefit analysis is, however, beyond the scope of this manual (Montazar and Behbahani,
2007).
2.5 Crop Water Requirement (CWR)
Crop water requirements (CWR) are defined as the water depth needed to meet the water losses
through Evapotranspiration (ETcrop). (Doorenbos and Kassam, 1979) also defined crop water
17
requirements as ‗the depth of water needed to meet the water loss through evapotranspiration of
a crop, being disease-free, growing in large fields under non-restricting soil conditions,
including soil water and fertility and achieving full production potential under the given
growing environment‘. According to (Allen et al, 1998). The amount of water required to
compensate the evapotranspiration loss from the cropped field is defined as crop water
requirement. Although the values for crop evapotranspiration and crop water requirement are
identical, crop water requirement refers to the amount of water that needs to be supplied, while
crop evapotranspiration refers to the amount of water that is lost through evapotranspiration.
Water requirement includes the losses due to evapotranspiration (ET) or consumptive use (CU)
plus the losses during the application of irrigation water (unavoidable losses) and the quantity
of water required for special operations such as land preparation, transplanting, leaching, etc.
Crop water requirement was expressed in units of water volume per unit land area (m3/ha),
depth per unit time (mm/day) according to Jensen (1993). A crop water requirement was
calculated according to Allen, (1998) using the following formula:
ETc = ETo × Kc………………………………………………………………….…. (2.1)
Where:
ETc = crop evapotranspiration [mm ],
Kc = crop coefficient [dimensionless],
ETo = reference crop evapotranspiration [mm ].
2.5.1 Evapotranspiration (ET)
Evaporation (E) and transpiration (T) are the two most important processes governing removal
of water from the land into the atmosphere. Evaporation and transpiration occur simultaneously
and there is no easy way of distinguishing between the two processes. Apart from the water
availability in the top soil, evaporation from a cropped soil is mainly determined by the fraction
of the solar radiation reaching the soil surface. This fraction decreases over the growing period
as the crop developed and the crop canopy shades more and more of the ground area. When the
crop is small, water is predominately lost by soil evaporation, but once the crop is well
developed and completely covers the soil, transpiration becomes the main process (Doorenbos
and Kassam, 1979). Evapotranspiration (ET) is the sum of the water that evaporates from the
18
soil and plant surfaces and the water that is transpired by a plant (from soil, through roots, to
leaves where it is vaporized and nearly all of it is removed through plant stomata).
2.5.2 Reference Crop Evapotranspiration (ETo)
Reference crop evapotranspiration (ETo) is defined as the rate of evapotranspiration from an
extensive surface of 8 to 15 cm tall green grass that covers the ground uniformly, is actively
growing and shades the entire ground and not short of water. The FAO Penman-Monteith
method is recommended as sole method for determining (ETo).
Penman-Monteith formula recommended by FAO 56 to estimate ETo as stated by (Allen et al,
1998).
( )
( )
( ( )
Where:
ETo =reference evapotranspiration [mm ],
Rn =net radiation at the crop surface [MJ ],
G= soil heat flux density [MJ ],
T= mean daily air temperature at 2 m height [°C],
u2= wind speed at 2 m height [m ],
es= saturation vapour pressure [kPa],
ea= actual vapour pressure [kPa],
es-ea= saturation vapour pressure deficit [kPa],
D= slope of saturation vapour pressure curve [kPa ],
γ=psychrometric constant [kPa ].
2.5.3 Crop Coefficient (Kc)
Crop coefficients (Kc) used for estimating ETc for specific crops by measuring potential or
reference (ETo) must be derived empirically for local crop based on local climatic conditions
(Doorenbos and Pruitt, 1977). Allen et al. (1998) stated that the Kc for any period of the season
can be derived by assuming that, during the initial and mid- season stage, Kc is constant and
equal to the Kc value of the growth stage under consideration. During the crop development
and late season stage, Kc varies linearly between the Kc at the end of the previous stage and the
19
Kc at the beginning of the next stage, which is Kc at the end of season in the case of the late
season stage (Allen et al., 1998). The following equation was used to compute the Kc value on
each day of the entire season:
[ ∑(
] ( ( )
Where:
i =day number within the growing season [1. length of the growing season].
Kci =crop coefficient on day I.
Lstage =length of the stage under consideration [days] and (Lprev) =sum of the lengths of all
previous stages [days].
2.5.4 Crop Growth Stages
As the crop develops, the ground cover, crop height and the leaf area change. Due to
differences in evapotranspiration during the various growth stages, the Kc for a given crop will
vary over the growing period. The growing period can be divided into four distinct growth
stages: initial, crop development, mid-season and late season (Allen et al., 1998).
2.5.5 Water Balance
A water balance can be used to measure ET by recording the mass or volume of water that
enters and leaves a system, and computing ET to satisfy the water balance equation (equation
6). The law of conservation of mass requires that all water flows across the system boundaries
sum to zero.
ET = I + P - RO - DP + CR ± ΔSF ± ΔSW ………………………………...…. (2.4)
Where:
I = irrigation,
P = precipitation,
RO = runoff,
DP = deep percolation,
CR = capillary rise,
20
SF = subsurface flow,
SW = soil water content.
2.5.6 Soil Water Content
Soil water content is expressed as the mass of water in unit mass of soil (gravimetric) or as
volume of water in unit volume of soil (volumetric) (Jalota et al., 1998). Gravimetric water
content ( ) is measured by weighing the soil when wet ( ) and again after drying at
105°C ( ).
(
) ( )
Volumetric water content ( ) is the volume of liquid water per volume of soil, and can be
calculated from using bulk density (ρ):
( )
⁄
⁄ ( )
2.5.7 Soil Water Measurement
Accurate measures of soil moisture are needed for a water balance to accurately provide a value
for ETc, change in soil moisture being one of the fluxes of a water balance. Dielectric-based
sensors have seen wide application since their development. A large disparity in dielectric
constants of soil (ε = 3-5), air (ε = 1), and water (ε = 81), provides dielectric-based soil
moisture sensors with the benefit of being somewhat insensitive to differences in soil
composition and texture (Davidson et al., 1999). Sensors of this type can be broadly divided
into those estimate the dielectric constant of a medium by measuring propagation time of an
electromagnetic pulse (time domain reflectometry) or by measuring the rate of voltage change
in response to an excitation voltage (capacitance probe).
2.5.7.1 A Tensiometer
21
A tensiometer is a measuring instrument used to determine the matric water potential
( ) (soil moisture tension) in the vadose zone. This device typically consists of
a glass or plastic tube with a porous ceramic cup, and is filled with water. The top of the tube
has either a built-in vacuum gauge or a rubber cap used with a portable puncture
tensiometer instrument, which uses a hypodermic needle to measure the pressure inside the
tensiometer. The tensiometer is buried in to the soil, and a hand pump is used to pull a partial
vacuum. As water is pulled out of the soil by plants and evaporation, the vacuum inside the
tube increases. As water is added to the soil, the vacuum inside the tube pulls moisture from the
soil and decreases. As the water in tensiometer is considered to be equilibrium with the soil
water, the gauge reading of the tensiometer represents the matric potential of the soil (Rawls et
al, 1993). Such tensiometers are used in irrigation scheduling to help farmers and other
irrigation managers to determine when to irrigate. In conjunction with a water retention curve,
tensiometers can be used to determine how much water to apply. With practice, a tensiometer
can be a useful tool for these purposes. Soil tensiometers can also be used in the scientific study
of soils and plants.
2.5.7.2 Time Domain Reflectometry (TDR)
Time Domain Reflectometry (TDR) is an effective way to indirectly and non-destructively
measure the volumetric water content of soils. TDR works by sending high frequency
electromagnetic pulses through the soil. The waves propagate down the wave guides of the
TDR probe and reflect back to the probe with a velocity that is inversely proportional the
dielectric constant of the soil-water matrix. Higher water content corresponds to lower wave
velocity and longer period. The time of this wave travel can be used to determine volumetric
water content by calibrating a probe or data logger for a soil type with known dielectric
constant and using a function that relates wave period to volumetric water content. Increasing
application of TDR can be attributed to low calibration requirements, high accuracy and
repeatability, and high spatial and temporal resolution (Rawls et al, 1993).
2.5.7.3 Neutron Probe Technology
22
In this instrument, it consists of a probe and an electron counting scalar connected by an
electronic cable. A very high energy, fast moving neutrons are ejected into the soil by a
radioactive source. The released neutrons are slowed down by the collision with the nuclei of
the hydrogen atoms present in the molecules of water in the soil (Chanasyk and Naeth, 1996).
They are accurate and irrespective of the state of the water. The output from this instrument is
directly linked to the soil moisture. The only limitation is that it is expensive equipment and
requires extensive soil specific calibrations. The depth of the resolution is inadequate, which
eventually makes soil moisture measurement a difficult task.
2.5.7.4 Micro Wave Remote Sensing
Microwave remote sensing provides a unique capability for indirect observation of soil
moisture. Remote measurements from space provide us the possibility of obtaining frequent,
global sampling of soil moisture over a large fraction of the Earth's land surface. As known,
microwave measurements have the benefit of being largely unaffected by cloud cover and
variable surface solar illumination (Das and Poul, 2015).
2.6 Water Use Efficiency (WUE)
Generally, plant growth is directly related to transpiration (T), although under field conditions
changes in soil moisture result from both T and soil evaporation (E) (Hillel, 2004). Water use
efficiency has been defined in various ways and it is important to understand the differences.
(Condon al et., 2004) defined it as the ratio of dry matter produced (Y) per unit of water
transpired by a crop (T), to expressed as kg/mm or kg/ha/mm. or as the ratio of total dry matter
per unit of ET and as the ratio of photosynthesis yield per unit of water transpired.
Consequently, care should be taken when comparing different of WUE value (Al-Jamal et al.,
2001). In the field scale as the ratio of the amount of water evapotranspired (Van et al., 2000).
With drip irrigation system, water use efficiency is maximized because there is even less
evaporation or runoff. (Raina et al, 1998) reported that water use efficiency was higher under
drip irrigation as compared with surface irrigation. Generally, E and T are commonly summed
to give evapotranspiration (ET), which can either be measured as a change in soil water or
estimated as discussed above. Both farmers and scientists are concerned with water use
23
efficiency. In irrigated crops, efficiency of water use can be affected by the method, amount,
and timing of irrigation.
2.6.1 Water Productivity
Water productivity is the ratio of the net benefits from crop, forestry, fishery, livestock and
mixed agricultural systems to the amount of water used to produce those benefits. In its
broadest sense, it reflects the objectives of producing more food, income, livelihood and
ecological benefits with less social and environmental cost per unit of water consumed.
Physical water productivity is defined as the ratio of agricultural output to the amount of water
consumed – ‗‗more crop per drop‘‘ –, and economic water productivity is defined as the value
obtained per unit of water used and this has also been used to relate water use in agriculture to
nutrition, jobs, welfare and the environment.
The denominator of the water productivity equation is expressed in terms of either water supply
or water depletion. Water is depleted when it is consumed by evapotranspiration (ET), is
incorporated into a product, flows to a location where it cannot be readily reused, or if it
becomes heavily polluted (Seckler, 1996; Molden et al., 2003). Raising water productivity is
the cornerstone of any demand management strategy. Definition of water productivity is scale
dependent. Water productivity can be analyzed at the plant level, field level, farm level, system
level and basin level. Its value would change with the changing scale of analysis (Molden et al,
2003). The classical concept of irrigation efficiency used by water engineers omitted economic
values and looked at the actual evapo-transpiration (ET) against the total water diverted for
crop production (Kijne et al, 2003).
Economic value of water in agriculture is much lower than that in other sectors (Barker et al,
2003), including manufacturing (Xie and Walther, 1993). Growing physical shortage of water
on the one hand, and scarcity of economically accessible water owing to increasing cost of
production and supply of the resource on the other, had preoccupied researchers with increasing
productivity of water use in agriculture in order to get maximum production or value from
every unit of water used (Kijne et al, 2003).
24
2.7 The Eggplant (Solanum melongena L.)
Eggplant (Solanum melongena L.) is a short-lived Perennial herb that belongs to the family
Solanaceae. It is grown as an annual plant and is one of the most consumed fruit vegetables in
tropical Africa; probably the third after tomato and onion and before okra (Grubben and
Denton, 2004). Although excessive rainfall affects both vegetative growth and flower
formation, the plant is well adapted to both wet and dry seasons of cultivation. In West Africa,
the eggfruits are eaten raw, cooked or fried with spices in stews, or dried and pound as
condiments (Fayemi, 1999).
The fruit is rich in essential vitamins and minerals. It contains 89g water, 1.4g protein, 1g fat,
8.0g carbohydrate, 1.5g celloluse, 130mg calcium, 105mg vitamin c and 1.6 mg Iron (Degri,
2014). In particular, eggplant is a good source of Calcium, Phosphorus and Iron salts for bone
and blood cell formation in the body, as well as a reasonable source of vitamin A (Carotene),
Vitamin B-complex and vitamin C, which are essential for good health (Fayemi, 1999,
Schippers, 2000). Currently, world eggplant production is 35.3 million tons from 1.9 million ha
according to the data of 2009. 93% of the eggplant production takes place in Asia, while 7% is
produced in Africa, Europe and America (Parfitt and et al., 2010).
2.7.1 Origin
The eggplants are widely distributed in the continents of Asia, Africa and South America. The
best known eggplant Solanum melongena L, also called aubergine or brinjal (Han and Lee.,
2005). Now days, this Solanaceous crop is more important in China, India, South East Asia,
Northern Africa and the Mediterranean area. Besides, it is considered one staple vegetable in
many tropical countries (Ngadi and et al., 2016).
2.7.2 Soil
Eggplants are moderately deep rooting and can be grown on a wide range of soils. To perform
better under light-textured soils such as sandy loams or alluvial soils that are deep and free
draining. A soil of pH that range between 6.0–7.0 is desirable (Lawrence, 2003).
2.7.3 Varieties
25
The plant can be a perennial but in commercial production it is treated as an annual bush. Fruit
shapes vary from the more common teardrop shape to round to slim ‗sausage‘ shape. Fruit
color is predominantly glossy dark purple to black but fruit of newer varieties are available in
light purple, crimson and cream colors (Bletsos and et al., 2003).
2.7.4 Eggplant in Sudan
The history of eggplant in the Sudan is not known but probably it came through Egypt Eggplant
is considered as an important crop especially in a complex market of vegetables production
systems, where growers may produce around eight different vegetable crops in a season. It was
grown in an area of about 3,000 ha and the total area under cultivation by this crop has
increased to reach 5000 ha in the 1998 with an average total production of 110,000 metric tons
(Patel and et al., 2014). Eggplant (Solanum melongena), some old cultivars use to be grown in
the country but they are almost replaced now by the exotic modern cultivars. Several species of
Solanum including S. incanum and S. dubium grow wild. In the Sudan the best time for planting
eggplant is the beginning of the rainy season or early in November (Anon, 1998). It is highly
productive crop grown in the Sudan all the years around by small farmers (Ummgumaa, 2009).
The current varieties grown in Sudan include, Balady, Black beauty, Wizoo and Long purple.
CHAPTER THREE
MATERIALS AND METHODS
26
3.1 Site Description
The experiment was conducted at the Horticultural Research Farm of the Agricultural Research
Corporation (ARC), Wad Medani, Sudan (latitude N, longitude E, altitude 405m
above mean Sea level). The climate of the study area is characterized by being dry and hot in
summer (Figures 3.1 – 3.3).
3.2 Soil Characteristic
The Soil of the experimental area is characterized by high clay content (above 58%), low
organic matter (0.03%), PH of 8.3, nitrogen content (0.02%) and 400-700ppm total
phosphorous.
Figure (3.1) Annual average of Maximum and Minimum Temperature (°C) at Wad
Medani, Sudan (Source: Gezira Meteorological Station, 2017).
0
5
10
15
20
25
30
35
40
45
April May June July August September October
Tem
pera
ture
(°C
)
Monthes
Max
Min
27
Figure (3.2) Annual average of Sunshine (%) and Relative Humidity (%) at Wad Medani,
Sudan (Source: Gezira Meteorological Station, 2017).
Fig
ure
(3.3
)
Ann
ual
aver
age
of
Rai
nfal
l
(mm) at Wad Medani, Sudan
(Source: Gezira Meteorological Station, 2017).
0
10
20
30
40
50
60
70
80
90
Sun s
hin
e-R
.H%
Monthes
Sun shine%
R. H %
0
50
100
150
200
250
Rain
fall
(m
m)
Monthes
Rainfall(mm)
28
Table (3.1) Some physical and chemical properties of the studied soils (Source: Elias, 2001)
Depth
(cm)
EC
(μS cm-1)
pH
Organic C
(g kg-1)
Clay
(%)
0-10 325 7.4 6.35 52
10-35 275 8.4 5.44 55
35-65 490 8.9 4.79 56
65-85 731 8.7 5.96 55
85-115 1371 8.3 6.30 58
115-150 3605 7.6 6.43 58
3.3 Design and Installation of the Drip Irrigation System
A drip irrigation system was designed and installed on an area of 4200 (0.42 ha) under field
condition. The system was supplied with water from a well in the farm which included a water
tank (30 ) rose on a platform 1.5 m above the ground surface. A submersible pump was used
to draw irrigation water from the Well to storage tank and to supply the system. The pump
discharges water through the main line (PVC) 60 m long and 76.2 mm inside diameter.
The main line was joined to a sub main line (PVC) 72 m long and 50.8 mm inside diameter.
The sub main was connected to lateral lines each 13 mm in diameter and 10m in length made of
black linear low density polyethylene (LLDPE). The spacing between lateral lines was 0.8 m
and 0.3 m between emitters. The fittings were made of polyethylene material.
3.3.1 System Calibration and Evaluation
Volumetric calibration of the emitters was done with graduated cylinders and stopwatch. This
was carried out at one operating pressures (1.5bar). The positions of checkpoints were the
average of five zones for each lateral. Each measurement was repeated three times, and then the
mean value was recorded.
29
3.3.2 System Uniformity
The mean discharge rate of the emitters was measured and recorded by the lowest one fourth
methods. The absolute deviation and the lowest one fourth (1/4) mean discharge of each
treatment was determined and recorded. The coefficient of uniformity of each treatment was
then calculated using the following Christiansen (1942) equation:
Cu = (1-ᵟ/X) × 100 ………………………………………………………….……… (3.1)
Where: -
Cu= Coefficient of uniformity (%).
ᵟ = Mean numerical deviation of the collected water depth from mean water depth (mm).
X = Mean depth of water of all catch cans (mm).
The (DU%) of each treatment was then calculated using the following equation:
D = (q25/qa) × 100………………………………………………………...………… (3.2).
Where: -
Du = Distribution (Emission) uniformity (%).
q25 = Mean of least quarter of water depths (mm).
qa = Mean depth of water of all catch cans (mm).
(CV %) between emitters was calculated using the following equation:
Cv = Sd / X.100 …………………………………………………………...……… (3.3).
Where:
Cv = Coefficient of variation.
Sd = Standard deviation of depth of water of all catch cans (mm).
X = Mean depth of water of all catch cans (mm).
3.3.3 Flow Variation
Emitter flow variation (qvar) was calculated using the following equation:
Qvar = ( )
………………………………………………………………(3.4)
Where: -
Qmax = maximum emitter flow rate.
Qmin = minimum emitter flow rate.
30
3.3.4 Percentage of Completely Emitters Clogging ( %)
The clogging percentage was determined using the following equation:
[
]………………………………...………………. (3.5)
Where:
Pclog = Percentage of clogging (%).
Nes clog = Number of clogged emitters.
Nes total = Total number of emitters.
3.4 The Experimental Design
The treatments were laid out in a randomized complete block design (RCBD) with three
replications. Four treatments were used which were:
1. Full irrigation throughout the season (T1).
2. Deficit irrigation at vegetative stage (T2).
3. Deficit irrigation at flowering stage (T3).
4. Deficit irrigation at maturity stage (T4).
3.5 Cultural Practices
Land was prepared by chiseling followed by disc harrowing, leveling and ridging to 0.8 m.
The seed were direct sown during of April 2017 in 10m rows with 0.8 m spacing between
rows and 0.6 m within row. Planting was done on ridges at a rate of five seed per hole; the
seedlings were thinned to one plant per hole after three weeks from emergence. Fertilizer was
applied as two dose of 2N (238 kg/ha). The first dose was applied 6 weeks after emergence,
while the second dose was applied 1 week after flowering. Hand weeding was carried out three
times during the season to keep the plots free of weeds. Harvesting was done after full maturity.
Harvesting was beginning in the first of August and completed in the middle October.
Irrigation water was applied every 4 to 6 days according to weather conditions.
3.6 Data Collection
The yield and yield component parameters measured include:
31
3.6.1 Days to 50% Flowering
Days from sowing to the time when 50% of plants start to flower were observed and recorded
per plot.
3.6.2 Plant Height (cm)
Five random plants per treatment were marked to measure plant height. Plant heights were
measured from the soil surface to the highest point of the plant at maturity.
3.6.3 Number of Branches/Plant
The number of branches were counted and recorded. Five plants were taken randomly in each
plot.
3.6.4 Number of Fruits/Plant
Number of fruits/plant were counted from the plant after maturity as an average of the number
of the fruits (eggplant growing season from April to October) taken from five plants that
randomly selected in each plot.
3.6.5 Total Yield (t/ha)
Yield (t/ha) was obtained from net area of 24 (6 × 4) fruits were harvested four time in each
plot to determine fruit fresh yield, fruit mean weight (g) and fruit mean length (cm).
3.6.6 Water Productivity (WP)
Irrigation water productivity was calculated using the following equation:
WP = Y/TAW ………………………………………………...…………………… (3.6)
Where: -
WP = water productivity (kg/ ).
Y = total yield (kg/ha)
TAW = total applied water ( )
3.7 Statistical Analysis
Data collected were analyzed statistically using the Gen stat analysis of variance (ANOVA).
The means were separated using Duncan Multiple Range Test at 5%level of significance.
32
CHAPTER FOUR
RESULTS AND DISCUSSION
4.1 Hydraulic Performance of Drip Irrigation System
Table (4.1) presents the results of hydraulic performance of the drip irrigation system under
operating pressure of 1.5 bars.
4.1.1 The Distribution Uniformity (DU%)
Table (4.1) shows the effect of hydraulic performance on distribution uniformity of drip
irrigation. The result was found to be 85%. This result agrees with Marriam and Keller (1978).
4.1.2 Uniformity Coefficient (CU%)
Table (4.1) shows the effect of hydraulic performance on uniformity coefficient (Cu %) of the
drip irrigation system. The result was obtained 94%. This result agrees with (Bralts et al., 1987)
and (Avars et al., 1999) i.e. is being greater than 90% Excellent.
4.1.3 Flow Variation (Qvar%)
Table (4.1) shows the effect of hydraulic performance on Flow variation (Qvar%) of drip
irrigation. Result was obtained 55%. This result does not agree with (Bralts et al., 1987). This
may be attributed to the old system and high sensitivity of these emitters to pressure.
4.1.4 Percentage Emitters Clogging (Pclog%)
Table (4.1) shows the effect of hydraulic performance on percentage of emitter clogging of drip
irrigation system. The result was presented under the same pressure (1.5bar) it was found to be
5%.
4.1.5 Coefficient of Variation (CV%)
Table (4.1) shows the effect of hydraulic performance on Coefficient Variation (CV %) of drip
irrigation system. Result was found to be 28%. This result agrees with Keller and Bliesner
(1990) is acceptable that should be between 20-30%, similar observation was reported by (Wu,
1997) who noted that a 5-10 clugging could produce CV of 23-33%.
33
Table (4.1) Hydraulic Performance of the drip irrigation system.
Coefficient
of Variation
(CV%)
Percentage
emitters
clogging
(Pclog%)
Flow
Variation
(Qvar%)
Uniformity
Coefficient
(CU%)
Distribution
Uniformity
(DU%)
28 5 55 94 85
4.2 Growth Parameters
4.2.1 Days to 50% Flowering
Table (4.2) shows the effect of deficit irrigation on day to 50% flowering. Result were found to
be the shorter period to reach 50% flowering T1 (67 days) compared to irrigation treatment T2
which required day (70 day) to complete 50% flowering. There were significant differences
(P≤ 0.05) among the different irrigation treatments. The result indicated that the vegetative
growth period increases with increases water stress. On the other hand, irrigation treatments T3
and T4 did not seem to have any significant impact on this trait.
4.2.2 Plant Height
Table (4.2) shows the effect of deficit irrigation on plant height. Result showed that no
significant difference was observed among the irrigation treatments. However, the highest plant
height was obtained with full irrigation was (60.7 cm), while the lowest plant height was
recorded by T3 (52.3 cm). This result may be attributed when eggplant is exposed to water
stress, (Sibomana et al., 2013). This result similar with (Nahar et al, 2011) observed no
difference in the height of eggplant plants subjected to different water levels. The plant height
was decreased with increasing water stress.
4.2.3 Number of Branches/Plant
Table (4.3) shows the effect of deficit irrigation treatment on number of branches/plant. The
highest number of branches was obtained by T3 (6.0), while the lowest number of branches
was achieved by T1 and T2 (5.0). Results shows there were significant difference between the
treatments.
34
Table (4.2) Effect of irrigation treatments on the plant height and the number of days
50% flowering during the growing season 2017.
T1 = control irrigated 100% of field capacity, T2 = treatment irrigated 100% of field capacity
with cut off at vegetative growth, T3 = treatment irrigated 100% of field capacity with cut off at
flowering growth, T4 = treatment irrigated 100% of field capacity with cut off at maturity
growth.
L.S = level of significant * significant at P = 0.05 level.
Table (4.3) The effect of irrigation treatments on branches number and leaves number
during the growing season 2017.
Treatments Branches Number
T1 5.0
T2 5.0
T3 6.0
T4 5.3
L.S *
SE± 0.373
C.V% 13.1
T1 = control irrigated 100% of field capacity, T2 = treatment irrigated 100% of field capacity
with cut off at vegetative growth, T3 = treatment irrigated 100% of field capacity with cut off at
flowering growth, T4 = treatment irrigated 100% of field capacity with cut off at maturity
growth.
Treatments Plant height (cm) Days to 50% flowering
T1 60.7 67
T2 56.3 70
T3 52.3 68
T4 55.3 68
L.S NS *
SE± 2.69 0.509
C.V% 8.3 1.3
35
L.S = level of significant * significant at P = 0.05 level.
4.3 Yield and Yield Components
4.3.1 Weight of Fruit (g)
Table (4.4) shows the effect of deficit irrigation on weight of fruit (g). The result showed highly
significant differences (P≤ 0.001), the highest of weight of fruit was obtained by the T1
treatment as (196 g), while the lowest of weight of fruit was achieved by the T4 treatment as
(141 g). It seems that Fruit yield was reduced by water stressed plants (T2, T3 and T4)
compared to unstressed treatment (T1). Deficit irrigation at vegetative growth (T2) induced a
reduction in average fruit weight of 15% compared to the full irrigation (196 g), while the
reductions in T3 and T4 treatments were 26 and 28%, respectively.
4.3.2 Length of Fruit (cm) and Number of Fruit
Table (4.4) shows the effect of deficit irrigation on Length of fruit and number of fruit. The
result showed that no significant differences were observed in fruit length and number of fruit
per plant of the eggplant among the irrigation treatments. These results were in line with the
findings of Sibomana et al, 2013.
4.3.3 Total Yield (t/ha)
The total yield as affected by the four irrigation treatments, are shows in table (4.4). There were
very high significant differences (P < 0.001). Treatment (T1) had the highest fresh yield (30800
kg/ha) followed by (T2) and (T3) with 24400 kg/ha and 21900 kg/ha respectively, while the
lowest fresh yield obtained by T4 (17200 kg/ha). Deficit irrigation (T2, T3 and T4) resulted
with percentage reduction in yield of 20, 29 and 44%, respectively compared to Full-irrigated
treatment T1. This is in agreement with the findings of previous studies on water stress of some
vegetables, namely bell pepper (Karam et al, 2009) and tomato (Topcu et al, 2007). A
decreased yield under water deficit or drought-stress conditions was also reported (Chaves et
al, 2003).
36
Table (4.4) The effect of irrigation treatment fruits number, length of fruit (cm), weight of
fruit and total yield t/ha of eggplant during the growing season (2017).
Treatments Number of
Fruit per plant
Length of
Fruit(cm)
Weight of fruit
(g)
Yield
(kg/ha)
T1 7 22 196 30800
T2 6 21 168 24400
T3 8 20 145 21900
T4 6 21 141 17200
L.S NS NS ** ***
SE± 0.685 0.568 8.17 1.146
C.V% 18.8 4.6 8.7 8.4
T1 = control irrigated 100% of field capacity, T2 = treatment irrigated 100% of field capacity
with cut off at vegetative growth, T3 = treatment irrigated 100% of field capacity with cut off at
flowering growth, T4 = treatment irrigated 100% of field capacity with cut off at maturity
growth.
L.S = level of significant NS = Not significant **, ***significant at P = 0.01 and 0.001 level,
respectively.
4.4 Applied Water and Water Use Efficiency
4.4.1 Applied Irrigation Water
Table (4.5) shows the water applied on full and deficit irrigation treatments. The result showed
that total applied water for full irrigation treatment (T1) along the entire season was (3750
/ha), while the deficit irrigation treatment, (T2, T3 and T4) applied of the same total amount
of water (3187.5 /ha). Table (4.5).
4.4.2 Water Productivity (WP)
The water productivity associated with the different irrigation treatment is presented in Table
(4.5). The result showed that there were very high significant differences (P < 0.001) between
the irrigation treatments. The highest of WP value was observed by full irrigation treatment T1
(8.3kg/ ), while the lowest of WP was achieved by T4 (5.4kg/ ), T1 much higher was
37
achieved compared with (T4) which were similar to the result from (Kirnak et al, 2002), and
bell pepper (Karam et al, 2009). Deficit irrigation (T2, T3 and T4) resulted with percentage
reduction in WP of 8, 20 and 36%, respectively compared to Full-irrigated treatment T1.
Table (4.5) Mean quantity of applied water (m3/ha), total yield (t/ha) and water
productivity (kg/m3) of for irrigation treatments.
Treatments Applied water
( /ha)
Total Yield
(kg/ha)
Water Productivity
(kg/ )
T1 3750 30800 8.3
T2 3187.5 24400 7.6
T3 3187.5 2190 6.7
T4 3187.5 17200 5.4
L.S - *** ***
SE± - 1.146 0.134
C.V - 8.4 3.3
T1 = control irrigated 100% of field capacity, T2 = treatment irrigated 100% of field capacity
with cut off at vegetative growth, T3 = treatment irrigated 100% of field capacity with cut off at
flowering growth, T4 = treatment irrigated 100% of field capacity with cut off at maturity
growth.
L.S = level of significant *** significant at P = 0.001 level.
38
CHAPTER FIVE
CONCLUSIONS AND RECOMMENDATIONS
5.1 Conclusions
5.1.1 Hydraulic Performance of Drip Irrigation System
Based on the results achieved the following points of conclusion could be drawn:
Emitter's hydraulic performance was affected by the operating pressure which was 1.5 bars
used in this study.
The hydraulic design and component selection of the affordable continuous-flow drip
system offer satisfactory hydraulic performance.
Adoption of the med-emitter in particular, contributes significantly to the achievement of
high spatial uniformity. Otherwise, the precise slope of the earth becomes crucial to
achieving water distribution.
5.1.2 Evaluating Eggplant Growth and Yield under Full and Deficit Irrigation
From the results of this research work the following conclusions could be drawn:
Eggplant growth under full irrigation treatment (T1) gave better results in terms of growth
parameters as compared to deficit irrigation treatments (T2, T3 and T4). In general, plant
height, number of leaves, number of fruits, and length of fruit under irrigation treatments
was statistically similar (no significant difference).
Day to 50% flowering and number of branches gave significant difference
Total yield and weight of fruit gave highly significant difference. full irrigation (T1) gave
better results compared with (T2, T3 and T4), this result indicated that eggplant was high
sensitive to water deficiency during flowering and maturity stages, but low sensitive at
vegetative stage and was more adapted to the irrigation program where the water deficit
was applied.
The full irrigation (T1) gave the highest efficiency of water productivity.
39
5.2 Recommendations
1. The optimum operating pressure should be selected in order to insure water distribution
(1.5bar).
2. Eggplant should be fully irrigated or adequate water should be added during maturity
development otherwise, under limited irrigation water, stopping of irrigation during
vegetative stage.
3. It is still necessary to have more studies for better understanding of eggplant reaction to
drought stress.
40
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APPENDICES
Appendix (1) Data for evaluation of hydraulic performance of drip irrigation system
160 167 165 157 165
164 126 161 169 163
171 170 150 0 150
0 165 156 161 148
156 174 158.6 161 165
160 161 165 165 115
165 164 159 165 104
155 161 142 150 170
160 171 170 107 117
172 155 173 95 172
160 115 170 162 164
167 166 0 0 162
152 151 161 159 150
0 115 0 162 160
169 0 159 154 158
0 160 156 155 178
158 155 113 116 149
104 0 155 154 151
143 160 160 140 157
160 150 157 161 151
130 0 152 138 134
146 142 148 138 149
146 142 90 138 120
144 120 158 138 170
146 140 152 134 114
140 134 136 126 118
134 136 124 122 136
138 154 88 136 140
102 138 138 138 140
134 154 0 132 130
124 134 138 136 156
46
172 138 138 136 132
0 152 136 136 134
130 136 138 118 182
158 130 134 138 134
95 110 140 142 0
130 130 140 138 158
138 110 132 128 130
140 144 132 144 128
130 138 132 140 138
182 178 170 196 140
140 184 188 188 198
186 186 150 118 196
159 188 182 182 184
180 184 180 180 182
180 189 188 189 130
188 182 180 190 170
182 189 157 180 190
128 181 158 180 130
103 160 182 178 139
85 192 182 100 105
174 182 180 0 188
190 172 0 188 158
182 118 172 188 178
139 188 184 0 182
192 130 182 190 170
189 189 122 190 172
192 188 185 188 193
190 178 182 188 182
188 180 100 144 115
8602 8906 8600.6 8546 8994
Appendix (2) Mean monthly meteorological data Rainfall, Relative humidity%,
Sunshine%, Maximum and minimum temperatures during 2017 at Gezira research
station.
Month Rainfall (mm) Relative
humidity
(%)
Sun
shine(%)
Temperature (°C)
Max Min
April 0 20 63 42.2 23
May 37.7 44 72 41 25
47
June 25.5 51 68 40.8 26.4
July 101.5 66 60 38 24
August 215.4 78 48 34.4 23
September 32.4 48 42 35.1 22
October 9.4 54 83 37.1 21.3
Mean 60.3 51 62 38.3 23.5
Appendix (3) Analysis of variance for day to 50% flowering.
Source of variation D.F S.S. M.S. V.R. F
PR.
Rep stratum 2 6.0000 3.0000 3.86
Rep.*Unit* stratum Trt 3 7.3333 2.4444 3.14 0.108
Residual 6 4.6667 0.7778
Total 11 18.0000
Appendix (4) Analysis of variance for plant height.
Source of variation D.F S.S. M.S. V.R. F
PR.
Rep stratum 2 50.17 25.08 1.15
Rep.*Unit* stratum Trt 3 107.00 35.67 1.64 0.277
Residual 6 130.50 21.75
Total 11 287.67
Appendix (5) Analysis of variance for number of branches per plant.
Source of variation D.F S.S. M.S. V.R. F PR.
Rep stratum 2 0.1667 0.0833 0.20
Rep.*Unit* stratum Trt 3 4.2500 1.4167 3.40 0.094
Residual 6 2.5000 0.4167
Total 11 6.9167
48
Appendix (6) Analysis of variance for number of leaves per plant.
Source of variation D.F S.S. M.S. V.R. F PR.
Rep stratum 2 715 358 0.19
Rep.*Unit* stratum Trt 3 4603 1534 0.82 0.527
Residual 6 11169 1861
Total 11 16487
Appendix (7) Analysis of variance for number of fruits per plant.
Source of variation D.F S.S. M.S. V.R. F PR.
Rep stratum 2 9.415 4.707 3.34 0.106
Rep.*Unit* stratum Trt 3 9.147 3.049 2.17 0.193
Residual 6 8.444 1.407
Total 11 27.006
Appendix (8) Analysis of variance for weight of fruit.
Source of variation D.F S.S. M.S. V.R. F PR.
Rep stratum 2 101.1 50.5 0.25
Rep.*Unit* stratum Trt 3 5764.7 1921.6 9.59 0.010
Residual 6 1202.0 200.3
Total 11 7067.8
Appendix (9) Analysis of variance for length of fruit.
Source of variation D.F S.S. M.S. V.R. F PR.
Rep stratum 2 1.7150 0.8575 0.89
Rep.*Unit* stratum Trt 3 5.4133 1.8044 1.86 0.237
Residual 6 5.8117 0.9686
Total 11 12.9400
49
Appendix (10) Analysis of variance for total yield.
Source of variation D.F S.S. M.S. V.R. F PR.
Rep stratum 2 17.007 8.503 2.16
Rep.*Unit* stratum Trt 3 289.282 96.427 24.49 <001
Residual 6 23.620 3.937
Total 11 329.909
Appendix (11) Analysis of variance for Water Productivity.
Source of variation D.F S.S. M.S. V.R. F PR.
Rep stratum 2 0.09682 0.04841 0.09
Rep.*Unit* stratum Trt 3 14.22329 4.74110 88.02 <.001
Residual 6 0.32318 0.05386
Total 11 14.64329