11-AGR1939-02 - جامعة الملك...

Use of saline water for tomato production in hydroponic greenhouse 11-AGR1939-02

Use of saline water for tomato production in hydroponic greenhouse

NSTIP Project under Advanced and Strategic Technologies

Sub-Program / Technology AreaAgricultural TechnologyTrackHydroponic TechniquesSub-TrackWater RelationsProject Duration Nov 2015 – Nov 2017Proposed Budget 1,868,975 Saudi Riyal

February, 2015

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Precision Agriculture Research Chair (PARC).

College of Food & Agriculture Sciences,King Saud University,Riyadh, Saudi Arabia

http://c.ksu.edu.sa/parc

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Project TeamPrincipal Investigator:Dr. Ranga Swamy Madugundu

Co-Investigator(s):Prof. Dr. Khalid A Al-GaadiProf. Dr. Abdulaziz R. Al-HarbiDr. Mahmoud A.E. Wahb-Allah

Research Associate(s):Dr. ElKamil Tola

Masters Student(s):Eng. Ahmad Mahmoud Hassan ZeyadaEng. Ahmed Galal Ahmed Abd Elall Kaiad

External Consultant(s):Prof. Nick Sigrimis (Agricultural University of Athens, Greece)Prof. V. C. Patil (Former Chair Professor, PARC, KSU, Riyadh)

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Overview

Hydroponic production technologies in greenhouses ensure increased food production, improve quality, conserve resources, and protect the environment. Hydroponic production systems can yield 10-20 times conventional farming systems, while using only 20% of the water. Tomato is one of the most important vegetable crops grown in Saudi Arabia. However, Saudi Arabia imported 190,000 metric tonnes of tomatoes worth US $ 62 million in 2009. In the Netherlands, tomato yields of up to 100 kg m-2 per year under hydroponics have been reported. The water use efficiency has been observed to be 60-70 kg of tomato per cubic meter of water as compared to 12-15 kg of tomato per cubic meter of water observed in traditional agricultural practices. Hydroponics is an extremely efficient, environmentally friendly agricultural production system that is ideally suited to widespread adoption in Saudi Arabia, where water is becoming increasingly scarce. Saline water can be used for growing salt tolerant or moderately salt tolerant crops such as tomatoes in hydroponic greenhouses. However, investigations on the use of saline water without adverse effects on productivity and quality of crops are necessary. The proposed project envisages use of saline water in hydroponic tomato production. The main objectives of the project are 1. To study the effects of saline water on the yield and quality of tomatoes in hydroponic greenhouses. 2. To determine the effects and Best Management Practice of conjunctive use of saline and non-saline water on the productivity of tomatoes in hydroponic green houses.3.To assess the impact of grafting on salt tolerant root stock, improved plant nutrition (elevated levels of P, K, Ca, Fe and Si) and mist cooling on salt tolerance in hydroponic tomatoes. 4. To provide training on hydroponic greenhouse technology to students and the farming community. Controlled polyethylene/glass green houses with Open and Closed hydroponic systems will be used in the study. One greenhouse will be earmarked for the Open system and the other one for the Closed system. Coco coir will be used as the growing medium. The experiments in both the Open and Closed system greenhouses will be laid out in split- split plot design with four replications. There will be two strips (main treatments): one for tomato seedlings and the other for grafted tomato plants. In these two strips, the following two sub-treatments will be allocated. 1. Nutrient solutions at different crop growth stages as recommended by Hochmuth and Hochmuth (2008). 2. Modified nutrient solutions at different crop growth stages with elevated levels of P, K, Ca, Fe (40% higher than in treatment 1) and Si@ 2.25 mg L1, coupled with mist cooling. In these strips, ten saline water irrigation treatments with constant EC levels of 2.5, 5.0, 7.5, 10.0, 12.5, 15.0, and differential EC levels with mid-day reductions in EC to 2.5 dsm-1 (2.5/7.5, 2.5/10.0, 2.5/12.5 and 2.5/15.0 dsm -1 ) will be superimposed as sub-sub treatments. The nutrient solutions will be supplied through drip-irrigation system. The drip fertigation system will be designed to deliver 100 mL of nutrient solution per plant using drippers/capillary tubes. One dripper/capillary tube will be provided to each plant. The irrigation frequency will be based on the crop growth stage, plant transpiration demands and solar radiation. Drainage will be through a gutter system placed along each row. The minimum percent drainage of EC nutrient solution of 10-15 %, will be adopted

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and it will be adjusted by manipulating irrigation frequency through the automatic irrigation scheduler. A programmable irrigation timing controller will be used to schedule and control the fertigation cycles and the midday reduction of EC. However, same amounts of water will be delivered in both the Open and Closed systems. This fertigation system will also have the capacity to operate automatically to adjust the irrigation frequency when we plan future experiments to target a specific “drain EC & pH”. Drainage water will be recycled to increase water and nutrient-use efficiency in hydroponic greenhouses and reduce the environmental impact of the drainage water discharge. The pH, and EC of the influx and efflux of nutrient solutions will be monitored constantly. Environmental data inside both the greenhouses will be collected using sensors and climate control systems. Periodic data on crop growth and yield parameters will be recorded in all the treatments. Fruit trusses will be harvested weekly based on colour of fruits. A truss in which at least 80% of the fruits attain red ripeness stage will be harvested. Harvested fruits will be graded, weighed and properly stored for fruit quality assessment. Fruit quality parameters such as lycopene, chlorophyll and total soluble solid (TSS) concentrations of fruits will be measured every week for all harvested tomatoes. Data collected in the experiment will be analyzed using SAS software. Significance among individual treatments will be analyzed by analysis of variance (ANOVA) and least significant difference (LSD) test. The salient findings of the project will be documented in the form of bulletins, booklets and folders. The relevant photographs, graphs, tables will be included in these extension education materials. The findings will also be documented in multi-media format which will all be utilized for periodic on-site training of farmers and students.

�ة��بيوت المحمي��اطم في ال� استخدام المياه المالحة إلنتاج الطمالمائية

ملخص تقنيات االنتاج في البيوت المحمية المائية ضمان لزيادة اإلنتSاج الغSذائي، وتحسSين الجSودة، والحفSاظ

مSSرة20-10على الموارد وحماية البيئة. يمكن لنظم الزراعة المتحكم بها بيئيSSا ان تزيSSد من العائSSد ٪ فقSSط من الميSSاه. يعتSSبر الطمSSاطم احSSد أهم20من النظم الزراعية التقليديSSة، في حين تسSSتخدم

محاصSSيل الخضSSروات الSSتي تSSزرع في المملكSSة العربيSSة السSSعودية. ومSSع ذلSSك اسSSتوردت السSSعودية . في هولنSSدا، انتاجيSSة2009 مليSSون دوالر في عSSام 62طن منه‘ اي ما يمثSSل مSSا قيمتSSه 190000

في السSSنة باسSSتخدام الزراعSSة المائيSSة. وقSSد لوحSSظ أن كفSSاءة2كجم /م100الطمSSاطم تتجSSاوز-12 كجم من الطماطم لكSل مSSتر مكعب من الميSSاه بالمقارنSSة مSSع 70-60استخدام المياه تكون

كجم من الطماطم لكل متر مكعب من المياه باستخدام الطريقSSة التقليديSSة بالزراعSSة المفتوحSSة15 بالحقل. الزراعة المائية هي فعالة للغاية ونظام انتاج زراعي صديق للبيئة والذي يعتبر مثاليا العتماده

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على نطاق واسع في المملكة العربية السعودية، حيث أن المياه أصبحت نSSادرة بشSSكل متزايSSد. يمكن استخدام المياه المالحة لزراعSة نباتSات تتحمSSل بشSSكل عSالي او معتSSدل مثSSل الطمSSاطم في الSبيوت المحمية المائية. ومع ذلSSك، فاالبحSSاب المتعلقSSة باسSSتخدام الميSSاه المالحSSة من دون آثSSار سSSلبية على إالنتاجية وجودة المحاصيل ضSSرورية. يتSSوخى المشSSروع المقSSترح اسSSتخدام الميSSاه المالحSSة في إنتSSاج

. لدراسSة اآلثSار الناجمSة عن اسSتخدام1الطمSاطم دون تربSة. األهSداف الرئيسSية للمشSروع هي : . لتحديSSد2الميSSاه المالحSSة على انتاجيSSة وجSSودة محصSSول الطمSSاطم في الSSبيوت المحميSSة المائيSSة.

الجدول الزمني األمثل إلدارة االستخدام المشترك للمياه المالحة وغير المالحSSة في الSSبيوت المحميSSة . لتقييم التاثير المحسSSن للتغذيSSة النباتيSSة الجيSSدة (مسSSتويات مرتفعSSة من3المائية إلنتاج الطماطم.

الفوسفور والبوتاسيوم و الكالسيوم والحديد والسيلكيا) إلى جانب نظام التبريد الضبابي على تأثيرات . لتوفير التSSدريب على تقنيSSة الزراعSSة المحميSSة المائيSSة المسSSببة4كفاءة استخدام المياه المالحة و

للطالب والمجتمع الذي يعمل بالزراعة. سيتم استخدام البيوت البالستيكية البولي ايSSثيلين مSSع أنظمSSة التحكم المائية المفتوحSة وشSبه المفتوحSة في الدراسSة. كمSا سSيتم تخصSيص أحSد الSبيوت المحميSة للنظام المفتوح واآلخر للنظام شبه المفتوح. سيتم استخدام بقايا الكوكSSا باعتبSSاره بيئSSة جبSSدة للنمSSو. تصميم التجارب بتصميم وحدات منفصلة شريطية مSSع أربعSSة مكSSررات. وسSSيتم تخصSSيص المعSSاملتين الرئيسيتن احدها للشتالت واالخSSرى للنتSSات المطعمSSة. وتحت كSSل معاملSSة رئيسSSية سSSتقام معSSاملتين

Hochmuth. استخدام محلول مغذي 1فرعيتين هما and Hochmuth بطSSول موسSSم(2008) وP ، K ،Ca، Fe 40%. محلول غذائي معدل مع رفع مستويات عناصر 2النمو في البيت المحمي

Si اه2,25الىSSامالت من ميSSرة معSSرائط، عشSSذه الشSSبابي. في هSSملجم/لتر، إلى جانب التبريد الض ECw2,5 ، 5,0 ، 7,5 ، 10,0 ، 12,5الري المالحة مع مستويات ثابتة من االتوصيل الكهربي للماء

، ديسSSمنس/م2,5 مSSع منتصSSف النهSSار مخفضSSة إلى قيمةECديسمنس/م، ومستويات من 15,0 ،SS 2,5/7,5بالنسSSب التاليSSة ( 2,5 SS/10,0منس/م) وهي قيم2,5/15,0 2,5/12,5 ، وSSديس

مليلSSتر من100للمعاملSSة الفرعيSSة بالتصSSميم. سSSيتم تصSSميم نظSSام الرسSSمدة بالتنقيSSط العطSSاء مم من الداخل)، بواقع منقط لكSSل3 باستخدام الضغط واألنابيب الشعرية (المحلول المغذي للنبات

والظSSروف المناخيSSةنبSSات. تكSSرار الSSري اعتمSSادا على االحتيSSا جSSات المائيSSة للنبSSات ومراحSSل النمSSو الخارجية. سيتم التخلص من الصرف منها بشكل سليم من خالل إنشاء نظام صرف يوضع على طول

،15-10كل صف ومن ثم إلى المجSSاري الصSSحية. الحSSد أالدنى من الصSSرف للمحلSSول المغSSذي S٪ وهي نسبة تمارس على نطاق واسع في إنتاج الطماطم المائيSSة وسSSيتم تعديلSSه من خالل التحكم في تكرار الري من خالل جدولSSة الSSري اآللي. سSSيتم برمجSSة الSSري اليSSاُ باسSSتخدام وحSSدة التحكم لجدولSSة دورات الرسمدة وانخفاض قيم التوصيل الكهربي في منتصف النهار، مع الحرص على ان تصل نفس كميات المياه إلى النظم المفتوحة وشبه المفتوحة. نظام الرسمدة هذا له القدرة على العمSSل تلقائيSSا

".pH و ECفي ضبط تكSرار الSري عنSدما نخطSط في المسSتقبل لتجSارب محSددة الهSدف "لقيم

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سيتم اعادة استخدام مياه الصSرف لزيSادة كفSاءة اسSتخدام الميSSاه والمغSذيات في الSبيوت المحميSSة المائية والحد من التأثير البيئي لتصريف مياه الصرف. سSSيتم رصSSد الSSرقم الهيSSدروجيني ، و التوصSSيل الكهربي من تدفق المواد الغذائية إلى النباتات او الصرف من وسط بيئة النمSSو باسSSتمرار باسSSتخدام عدادات الرسمدة. سيتم جمع البيانات البيئية داخل البيتين المحميين على حد سواء باستخدام أجهSSزة

االستشعار واجهزة قياس المناخ. سيتم تسجيل البيانات الدوريSSة على نمSSو المحاصSSيل وعناصSSر االنتSSاج في جميع المعامالت. سوف تحصد الثمار بناء على لون الفاكهة عموما مرة واحSSدة كSSل أسSSبوع. سSSيتم

تSوزن الفواكSSه وتSدرج على الفSSور٪ من ثمار مرحلة النضج الحمSراء. سSSوف 80حصادها عندما تصل سSSاعة. وسSSوف يقSSاس24في غضSSونبعد الحصاد وتخزينها تحت التبريد لتقييم معايير الجودة الحقSSا

) من الفواكه كل أسSSبوع لجميSSعTSSتركيزات كل من الليكوبين، الكلوروفيل، والمواد الكلية الذائبة(طمSSاطم المعSSامالت. وسSSيتم تحليSSل البيانSSات الSSتي تم جمعهSSا في التجربSSة باسSSتخدام البرمجيSSات (

SAS) اينSSل التبSSق تحليSSة عن طريSSامالت الفرديSSة بين المعSSة المعاملSSل دالالت وأهميSSوسيتم تحلي ، (ANOVA) واختبار الفرق األقل معنوية ، (LSDارزةSSائج البSSذه النتSق هSيتم توثيSSوالي. وسSSعلى الت ،(

للمشروع في شكل كتيبات ونشرات وابحاث منشورة. الصور ذات الصلة، والرسوم البيانية والجداول سوف تدرج في هذه المواد المنشورة. كما يتم توثيق النتائج في شكل وسائط متعددة والSتي سSSوف

يتم استخدامها كافة لتدريب المزارعين والطالب.

1. IntroductionThe Kingdom of Saudi Arabia lies in the tropical and sub-tropical desert region of the Middle East. The oil resources of the Kingdom have enabled it to be one among the highest per capita GDP nations in the world. Agriculture is an important sector in the economy of the Kingdom. It assumes strategic significance not only in attaining food security but also in generating gainful employment to the rural people. The agriculture sector witnessed an impressive annual growth rate of 10.9 per cent as compared to GDP growth of 11.6 per cent between 1969 and 2004. This was possible due to private sector investment in agriculture, adoption of modern technologies and substantial financial support by the Government. As a result, the country not only achieved self-sufficiency in wheat, milk, and vegetables, etc., but also exported wheat for some time. The rapid progress witnessed in agriculture sector was at the cost of the fast dwindling non – renewable underground water resources. Thus, the country is now faced with a formidable challenge of adopting a sustainable agricultural policy to meet food requirements of a population of 27 million people, growing at the rate of 2.9 per cent annually. This challenge necessitates striking a delicate balance between Food Security and Water Security. Soil and water resources coupled with use of fertilizers determine the production potential of agricultural ecosystems. Increased crop yields are associated with increased water and fertilizer use and modern research is focused on maximizing the Water and Fertilizer Use Efficiency (WFUE). The fast dwindling global fresh water and renewable water resources coupled with increased demands for water from agricultural sector are threatening the food and water security of nations around the world. As a result, approaches to water resources management are also

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changing dramatically. This “Changing Water Paradigm” has many components: a shift away from reliance on finding new sources of supply, a growing emphasis on ecological values, a re-emphasis on meeting human water needs and a conscious breaking of the ties between economic growth and water use (Gleick, 2000).Agricultural situation in Saudi Arabia: The nation’s cultivated area in 2007 was 1.074 million hectares (m. ha) with a production of 2.967 million tons (m.t.) of grains, 2.6 m.t. of vegetables and 1.581 m.t. of fruits including 982,000 tons of dates. Saudi Arabia imported 190,000 metric tonnes of tomatoes worth US $ 62 million in 2009.The soils in Saudi Arabia are sandy in nature, with low organic matter content and poor water and nutrient holding capacities. The long term annual precipitation of the country has been estimated at 114 mm per year. The annual water demand has been steadily increasing due to comprehensive development in all sectors coupled with high growth rates in population and living standards. Agricultural sector utilizes around 80 per cent of the total quantity of water used in the Kingdom (Abderrahman 2001). The available surface and ground water resources are limited, precipitation rates are low and evaporation is high. Such eco-physical conditions pose significant challenges to agricultural activities. The sustainability of agro-ecosystems of Saudi Arabia depends heavily on conservation of natural resources such as soil and water. However, steady decline in finite water resources and continued degradation of soil resources make the task much more challenging. Besides, the external inputs required for agricultural production are becoming scarcer and costlier. Thus there is an urgent need to conserve the natural resources and to increase the input use efficiencies to achieve sustainability of agriculture in the kingdom. Greenhouse construction and protected cultivations alter microclimate conditions to favour plants’ productivity but they also predominantly reduce transpiration and increase water productivity (litres of water per Kg of production) by a factor of 3-5.Hydroponics: Increasing demand for food and rising food prices have created a dire need for adoption of sustainable food production strategies. In recent times, skyrocketing of food prices have led to social unrest in many parts of the world. Production of crops in hydroponic greenhouses results in increased food production, improved quality, conservation of resources, and protection of the environment. Hydroponics means cultivation of plants without soil. It is also referred to as nutrient-solution culture, soilless culture, water culture, gravel culture and nutriculture (Marr, 1994). Soil is medium of plant growth that offers mechanical support to the plant, stores water and provides plants with the required nutrients. However, continuous and intensive use of soil in greenhouses has led to infestation by plant pathogens and deficiency of essential nutrients. This has resulted in the use of soil disinfections leading to pollution of the environment and damage to fertigation systems. Hydroponics is a viable system that overcomes these problems. Growing of plants in nutrient solutions (water and fertilizers) with or without the use of rooting medium (e.g., rock wool, perlite, peat, vermiculite, gravel, coir, sand, gravel, and sawdust) is known as hydroponics. There are two types of hydroponic systems:1. Open System, where in, nutrient solution that is fed to plants is drained out and not reused 2.Closed System where in the excess nutrient solution is reused. In hydroponics, either organic substrates or inert substrates are used as media or there could be total absence of substrate. In the latter, there will be a thin water film which is known

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as Nutrient Film Technique (NFT). The substrates used in hydroponics, act as anchorage to plants and have a very low cost of replacement; and there will be no need for costly disinfections. Extensive research on plant nutrition in hydroponic systems has been carried out. Hydroponic systems that are automated use considerably less water and yield much higher than the conventional agricultural systems. The ecological footprint is improved and this leads to “zero emissions” greenhouse or the “green” greenhouse. Saline water can be used for growing salt tolerant or moderately salt tolerant crops such as tomatoes in hydroponic greenhouses. In Saudi Arabia, water is not only scarce but also precious. In such a situation, studies on the use of saline water without sacrificing on yield and quality of crops are very much necessary to determine appropriate water management practices. The various options that facilitate for the use of saline water are: conjunctive use of saline water with non-saline water, improved plant nutrition, mist cooling and elevated levels of CO2. However, in Closed systems the salinity build up that occurs due to recirculation of excess nutrient solution can be dealt with by practicing a ‘run-to-waste’ system. Hydroponic production of vegetable crops is possible throughout the year without any problems of soil salinity, adversaries of climate, infestation by weeds, pests and diseases. Since hydroponic production is possible throughout the year and the quality of the produce is also better, premium rates can be obtained for the produce obtained during off-season. Tomato yields of 100 kg m -2

per year under hydroponics have been reported from The Netherlands. The water use efficiency of 60-70 kg of tomato per cubic meter of water in hydroponics has been reported as compared to 12-15 kg of tomato per cubic meter of water obtained through traditional agricultural practices. Hydroponics is an extremely efficient, environmentally friendly agricultural production system and ideally suited to widespread adoption in Saudi Arabia, where water is becoming increasingly scarce. The country is faced with a difficult situation of meeting the food needs of a growing population by reducing the dependence on imported fresh food produce. At the same time, increasing productivity per drop of water even under extremely high temperature conditions is really a challenge. Therefore farmers are looking for sustainable agricultural technologies that also result in conservation of resources. Hydroponic production technology meets most of these specific requirements.

2. Project Objectives:1. To study the effects of saline water on the yield and quality of

tomatoes in hydroponic green houses.2. To determine the effects and Best Management Practice of conjunctive

use of saline and non-saline water on the productivity of tomatoes in hydroponic green houses.

3. To assess the impact of grafting on salt tolerant root stock, improved plant nutrition (elevated levels of P, K, Ca, Fe and Si) and mist cooling on salt tolerance in hydroponic tomatoes.

4. To provide training on hydroponic greenhouse technology to students and the farming community.

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3. Review of Literature

Types of Hydroponic System: Two types of hydroponic system are exists namely i) Closed and open/semi open systemsClosed System: The nutrient solution is recirculated in closed systems (Donnan, 1994a). There are two types of closed systems: Nutrient film Technique (NFT) with continuous recirculation and, flood and drain system with intermittent recirculation. In NFT, there will be reduced consumption of water and fertilizers and the environmental pollution that is generally associated with over irrigation of soil- or soilless-grown greenhouse crops. Closed systems are compulsory in the Netherlands. The systems are leached at a threshold level of 8 mol m -3 Na+ in tomato (Baas and Berg, 1999). In closed systems, water and nutrient efficiencies are improved but the EC of nutrient solution increases (Conversa et al, 2003). Lopez et al (2003) reported negative effect of recirculation of the nutrient solution on the fruit yield and quality of greenhouse grown tomato. Donnan (1994b) while comparing open and closed systems, reported that irrigation water and EC management are usually easier in recirculating systems while nutrient management is difficult; hence, currently no more than 10% of the world’s commercial hydroponic crop production uses these systems. According to the conclusions of a simulation study carried out by Stanghellini et al. (2005), closed systems are not financially viable. Anastasiou et al (2009) has concluded that in closed systems the critical process is the balancing of nutrient solution whereas in open systems irrigation scheduling is more critical to save water and fertilizers.Open and Semi Open Systems: In open systems the nutrient solution is not recirculated (Donnan, 1994a). Also known as run to waste systems, they use dripper irrigation of soilless media in containers. In open hydroponic systems, since solution is not recovered and recycled, the quality of the irrigation water is less critical. In Semi open systems, solution is recirculated and drained occasionally. A content of up to 500 ppm of extraneous salts is easily tolerated, and for tomatoes even higher salinities are permissible. The drainage should be collected and tested periodically for total dissolved salts and if salinity of the drainage reaches 3,000 ppm or above, the bags must be leached free using plain water in the irrigating system. Given the fact that hydroponic systems allow for drainage sampling and on-line measuring of pH and EC, Sigrimis et al (2001) achieved control of watering at high precision of drainage percentage and fertilizer injection at target EC of drainage solution, irrespective of changes in transpiration conditions.Media and irrigation scheduling in hydroponics: Root anchorage and plant support must be supplied in solution hydroponics systems. Media such as sand, peat gravel, scoria, and mixtures of vermiculite, bark, sawdust, peat, and perlite, have been used successfully (Cotter and Corgan 1974; Johnson 1985) to support the plants in a manner similar to that of soil. A complete plant nutrient solution is regularly added to these media. Medium solution retention may be limited (particularly with the coarse aggregate materials), and this requires frequent rewetting throughout the day. Conventional greenhouse and nursery systems usually deliver nutrient solutions in appropriate quantities and times so that the medium is fully wetted and a small amount leaches away (about 10-30 percent).

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In hydroponic culture the nutrient solution can be recycled or used only once. Frequently one-time use of a solution is convenient. Even more recently, techniques that deliver complete nutrient solutions to the roots in a continuous nutrient film (Cooper 1979, 1985; Edwards 1985) have been described and used successfully. Regardless of the system, the availability of adequate oxygen (O2) in a root zone is essential. The nutrient film technique (NFT) innovation reported by Cooper (1985) includes the use of a split root technique that alternately provides dissolved nutrients to one half of the root system at a time. In the other half, root O2 exchange is enhanced. Donnan (1992) recommended recirculating NFT or flood and drain gravel channels for short term crops such as lettuce, and non-recirculating, media-based systems for longer term crops or those very vulnerable to root disease. He further observed that recirculating systems aren’t suitable for water with high dissolved salts. The level of salts which can be tolerated in the water depends on their composition and the type of crop is to be grown. Even 50 ppm of sodium can be toxic to plants such as lettuce, straw berry and rose. In contrast tomato could cope with over 200 ppm (Donnan, 1994a).The optimum supply of water and nutrients is crucial in hydroponic growing systems in order to use water efficiently, avoid stress situations and improve production. Adaptive and learning techniques, based on Solar Radiation (Sigrimis et al 2001) for prediction of system response have attained a drain regulation accuracy of better than 3%. Lizarraga et al (2003) evaluated two irrigation scheduling techniques for hydroponic tomato production in Navarra, northern Spain. The results showed that irrigation scheduling by time clock was not flexible enough to satisfy the varying crop water requirements through the day and during the season. With constant irrigation intervals and volumes, water and fertilisers were wasted during the morning (excessive irrigation) whereas during the afternoon, the plants suffered water stress. Their recommendation of scheduling of irrigation at a radiation level of 0.81 MJ m−2, with some supplementary time clock irrigation applications during the hours of darkness (in order to keep the growing medium wet) has come in to practice. Hochmuth and Hochmuth (2008) reviewed the nutrient solution formulations designed by them in 1990, for hydroponic tomato production systems. They reported that the media (perlite, rock wool or NFT) required frequent irrigations during the day, ranging from 10 to 20 cycles per day, depending on the weather and greenhouse environment, in order to maintain about 20% solution leach. Effects of saline water on yield of hydroponic tomato fruitsTomato has been reported to be a moderately salt-tolerant crop (Maas, 1986) with differences among the cultivars (Dasgan et al., 2002). Salt stress was found to result in reduced growth and yield (Yurtseven et al., 2005). However, salt stress produced fruits of better quality which fetched higher market price (Zushi and Matsuzoe, 2009). The crops that can be grown with saline water in hydroponics are limited to salt tolerant and moderately salt tolerant species such as tomato, asparagus, cucumber, rose and carnation. Even among salt tolerant species, varietal differences may exist. Varietal trials need to be conducted to determine the most tolerant varieties. Salt tolerance of varieties, stage of development, frequency of irrigation and addition of deficit nutrients are some factors to be considered in using saline water. Tomato has been reported to be salt sensitive during early development (Kütük et al. 2004). Olympios et al. (2003) reported that tomato is more susceptible to high salinity (8.7 dSm -1) at an early stage of development than in the later growing stages.

http://www.sciencedirect.com/science/article/pii/S0304423810004437#bib0200





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However,Stanghellini et al. (2002) observed that the effects of salinity on tomato were reversible and the leaching of the salts from the root environment resulted in full recovery of growth in the plant parts that had not reached the rapid growth phase at salinity of EC 9 dS m−1. The optimum EC range for tomato is 2 to 3.5 ds m-1. The concentration expressed by 0.4 atm osmotic pressure was recommended as best for good development of tomato plants in tropical areas (Steines, 1968). Schwarz (1968) reported yield reductions of 10-15 per cent in tomatoes grown with water containing 3000 ppm of salts. He found that extremely high osmotic pressures (over 10 atm) for short periods are less damaging than long periods of moderately high pressures (4-5 atm). Increasing the EC to greater than 2.3 dSm-1 has shown to increase TSS yet decrease tomato yield (Adams and Ho, 1989). The reduction in yield of tomatoes under high EC was attributed to smaller fruit weight and fewer fruits harvested (Adams, 1991; Adams and Holder, 1992). Another problem often observed in tomato grown under high EC is the increased incidence of blossom end rot (BER) caused by a reduction of calcium (Ca2+) uptake by roots and increased resistance to xylem transport inside the fruit (Ho and Adams, 1989). However, increasing levels of only Ca2+ to the nutrient solution reduced the incidence of BER (Adams and Holder, 1992). Dorais et al. (2001) reported that tomato yields at 4.6, 8.0, and 12.0 dSm-1 were lower compared with 2.3 dS m-1. Yield at 4.6 and 8.0 dS m-1 was reduced because of fruit weight, whereas at 12.0 dSm-1, fruit number and weight were reduced. Another study reported yield reduction when EC was increased from 2.3 to 5.1 dSm-1, whereas fruit quality was improved when EC was increased from 3.5 to 9.0 dSm-1 (Dorais et al., 2001). Yield and fruit weight of cultivars with smaller fruit size, such as cherry tomato, are less affected by higher EC than cultivars with larger fruit size (Cuartero and Ferna´ndez-Munoz,1999). Therefore, growing cultivars with smaller fruit size may be advantageous where water salinity is moderate or high. However, Alarcon et al. (1994) showed that cherry tomato yield was lower due to reduced number of fruits that were smaller in size at EC of 14 dS m -1, whereas fruit quality was increased with the high EC. Adams (1991) grew tomato plants in rockwool and compared a salinity of 3000 µmhos/cm with those at 8000 and 12000 µmhos/cm and reported that the highest yields were obtained at 3000 µmhos/cm and the lowest at12000 µmhos/cm. CropKing, Inc. (1993) recommended the following EC ranges of a feeding solution at each of the following growth stages of tomato: for germination and the early growth stage: EC between 1800 and 2000 µmhos/cm; for the seedling stage: EC between 2300 and 2500 µmhos/cm; for vegetative, early fruiting, and mature fruiting stages, EC between 2300 and 2500 µmhos/cm on sunny days, and between 3500 and 4000 µmhos/cm in the dark winter conditions. Tomato fruit yield decreases by 5.1 % per dSm-1 above 2 dSm-1 (Ling Li et al., 2001). Mpelasoka and Nichols (2003) conducted two experiments in a greenhouse, one in the winter and the other in the summer using the Nutrient Film Technique (NFT) at four EClevels: 2.0, 4.0, 6.0, 8.0 mScm -1. They observed reduction in yield with increasing EC for the summer crop, but no reduction in yield was found with increasing conductivity for the winter crop. Magán et al (2003) studied the effects of five salinity levels (2.5, 3, 4, 6 and 8 dSm -1) on greenhouse tomatoes grown in perlite containers with re-circulation. They observed smaller fruits with lower fresh and dry weights with increasing salinity. The percentage of dry matter in fruit increased linearly with salinity. Agong et al., (2003) evaluated the performance of thirteen tomato genotypes under hydroponics at salt applications ranging from 0 to 2% NaCl, with the resultant EC

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values of 1.4 to 37 dSm-1. Among them two tomato genotypes ('Siozawa' and 'Gambaru Ne-3') displayed superior performance. Chadirin et al (2007) evaluated the application of Deep Sea Water (DSW) as a nutrient supplement for tomato cultivation. They observed highest tomato fruit yield in nutrient film technique (NFT) system circulated with nutrient solution of 10 dSm-1 EC as compared to 1.5 dS m-1(control), 15 dSm-1 and 20 dSm-1 EC levels. Effects of saline water on the quality of hydroponic tomato fruits: Saline water has been used on field-grown tomato crops to improve fruit quality and is a well-proven technique. Moderate brackish water is particularly recommended for production of high quality tomatoes. However, the improvement gained in the quality of tomato fruits by water deficit or saline water irrigation are usually accompanied by reduced yields. Schwarz (1968) reported that saline waters have some favourable effects on tomatoes in giving them a sweeter taste than those grown with fresh water. Increasing the salinity from 3000 to 8000 µmhos/cm improved both the quality and composition of tomato fruits (Adams, 1991). The plants supplied with nutrient solution of higher EC level produced fruits of smaller size (Eltez et al., 2002; Okano et al., 2002). Tomato fruit quality was found to improve with increased conductivity from 2 to 8 dsm -1 (Mpelasoka and Nichols, 2003). The production and quality of tomato (cv. Naomi) grown in NFT (Nutrient Film Technique, with discontinuous cycle) at two levels of nutrient solution EC (2-5 and 4-10 dS m-1) was studied by Conversa et al, (2003). They observed higher production from low EC plants than the high EC plants (2.9 vs. 2.2 kg/plant) due to higher weight and size of fruits. However, the high EC treatment increased fruit dry matter content (9.0 vs. 7.8%), total soluble solids (7.4 vs. 6.7 °Brix), titratable acidity (0.70 vs. 0.64 g/100 ml of juice of citric acid), Na+, K+, and Cl- contents. The low EC plants consumed more water than high EC plants (100 vs. 87 L), but they had the same water use efficiency. The lycopene (the red pigment and a strong antioxidant) concentration in tomato fruit was enhanced when plants were grown hydroponically using a nutrient solution with a high electrical conductivity (EC) of 4.8 dS m-1 compared to those grown under the standard low EC of 2.4 dSm-1 (Wu et al., 2004). Lycopene concentration in tomato fruit was reportedly increased by manipulating level of salinity in the nutrient solution (De Pascale et al., 2001; Krauss et al., 2006). Fanasca et al. (2007) observed an increase in lycopene concentration on both fresh weight and dry weight basis by raising the EC from 2.5 to 8 dS m -1. Lycopene content in tomato fruit was enhanced under high EC (Wu and Kubota, 2008). Kubota (2009) observed significantly higher Brix, lycopene concentration (20% higher) with some seasonal changes (higher lycopene in summer and lower lycopene in winter), β-carotene, phenolics, and ascorbic acid of tomato under high EC levels. Suhardiyanto (2009) determined the optimal EC values of nutrient solution for tomato fruit quality in hydroponic system by using Artificial Neural Network and Genetic algorithms. They reported the optimal EC values of 1.4, 10.2 and 9.7 mS/cm, in the flowering, the fruiting and the harvesting stage, respectively. In other experiments, Varlagas et al (2010) have determined how salinity builds up of different initial salt concentrations as well as the uptake rate of salt ions, which determine the appearance of salt effects.Amelioration of the adverse effects of saline water: High salt contents and sulfate concentrations affect calcium uptake leading to "blossom end rot" symptoms in tomato. Saline conditions reduce the availability of iron. In addition to chloride and sodium, boron toxicity is also common with saline water. Yield

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loss resulting from use of saline water can be minimized by strengthening the root system and reducing plant stress. High rates of oxygenation in the root zone have recently proved to be highly beneficial under increased EC treatments in tomatoes. Adding mineral pyrophyllitic clay suspension to the nutrient solution has also been shown to assist plant growth, yield and fruit composition under conditions of plant stress (raised salinity levels) in hydroponically-grown tomato crops (Lennard and Morgan, 2004). Silicon was implicated to ameliorate the adverse effects of salinity (Bradbury and Ahmad, 1990; Liang et al., 1996; Stamatakis et al.2003). The plants benefit from supplemental soluble silicon. The benefits include greater tolerance to cold, heat, drought, salinity, mineral toxicity or deficiency, improved growth rates and resistance to insects and fungi. Silicon gets deposited in epidermal cell walls resulting in increased mechanical strength. It also enhances metabolic functions and improves pollen fertility, flower and fruit count. The effects of silicon added to the nutrient solution either at a standard electrical conductivity (EC) of 2.2 dS m-1 or at an increased EC of 4.8 dS m-1 on yield, nutritional status and fruit quality were investigated in a tomato crop grown in a closed hydroponic system (Stamatakis et el 2003).The increase of the EC up to 4.8 dS m-1 by adding NaCl had no significant influence on the fruit yield of tomato, when Si was added to the saline nutrient solution. In contrast, the fruit yield per plant was significantly restricted at this level of salinity, when no Si was added to the NaCl-enriched nutrient solution. In a study on the effects of diurnal fluctuation in nutrient EC, it was found that a 2 dSm –1 daytime EC combined with 6 dSm–1 nighttime EC level did not affect total yield, fruit number, fruit weight, or plant water consumption (Santamaria et al. 2004). Buck et al (2008) studied the effect of three EC levels on cherry tomatoes and found that mid-day reduction of high EC level as a potential alternative to a more commonly practiced continuously high EC treatment in semiarid greenhouses. Inoculation with Arbuscular Mycorrhizal Fungi (AMF) has been found to enhance plant growth and uptake of nutrients, decrease yield losses of tomato under saline conditions and improved salt tolerance of tomato (Li et al., 1991 a, b; Ruiz-Lozano, et al., 1996; Al-Karaki, 2000; Al-Karaki et al., 2001; Huang et al., 2010; Abdel Latef and Chaoxing, 2011; Basak et al., 2011). The deleterious effects of salinity on tomato biomass production can be ameliorated by an enhanced supply of calcium (Grattan and Grieve 1999). According to Flores et al. (2001) and Ben-Oliel et al. (2004), the supply of part of the nitrogen in the form of NH4-N in salt-stressed tomato seems to increase the rate of N assimilation, as well as the levels of Fe and chlorophyll in the plant tissues, thereby mitigating salt injury. Furthermore, better root aeration, which enhances the oxygen supply to the root cells, may considerably enhance the salinity tolerance of tomato (Bhattarai et al. 2006). Grafting tomatoes on salt tolerant root stock to overcome salinity stress: Grafting is an integrative reciprocal process and, therefore, both scion and rootstock influence salt tolerance of grafted plants (Etehadnia et al., 2008). The possible reasons for grafting-induced salt tolerance are: higher accumulation of proline and sugar in the leaves (Ruiz et al.,2005); higher antioxidant capacity in the leaves (López-Gómez et al., 2007); and lower accumulation of Na+ and/or Cl− in the leaves (Fernández-García et al., 2004; Esta˜n et al., 2005; Goreta et al., 2008; Zhu et al., 2008a,b). Grafting tomato with tolerant rootstock has been highly effective at producing a saline-tolerant plant and research indicates that several rootstocks prevented the translocation of sodium and chloride into the shoot. Scion genotypes play an important role in the growth of grafted tomato

http://en.wikipedia.org/wiki/Chloride

http://en.wikipedia.org/wiki/Sodium

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plants, regardless of the salinity in the growing media, whereas rootstock has little influence (Chen et al. 2003). In tomatoes, characteristics of the rootstock conferring salt tolerance depend also on the salt tolerance of the shoot genotype (Santa-Cruz et al., 2002). Colla et.al. (2010) while presenting an overview of the recent literature on the salinity response and the mechanisms of salt tolerance of grafted plants, observed that grafting tomato plants for increased salinity tolerance is a promising practice. Improved growth and higher fruit yield was obtained at higher salinity (50 nM NaCl) by grafting a salt sensitive tomato variety (Moneymaker) on to a salt tolerant rootstock Pera than self-grafted plants (Santa-Cruz et al. 2001). Estan et al. (2005) reported improved salt tolerance and fruit yield in a tomato hybrid (Jaguar) grafted on to different rootstocks (Radja, Volgogradskij, Pera, and Volgogradskij×Pera) and inferred that the tolerance induced by the rootstock in the shoot was related to ionic rather than osmotic stress caused by salinity. Grafting Moneymaker a scion with an ‘excluder’ character on to rootstocks Radja and Pera resulted in higher tomato fruit yield when grown at 50 mM NaCl (Martinez-Rodriguez et al. 2008). Mohammed et.al.(2009) grafted tomato cultivar Cecilia F1on to three rootstocks: Beaufort, He- Man and Syrian local, using tube grafting technique. These grafted plants were grown in glass house in Astra Farms, Tabuk, north-west of Saudi Arabia. The productivity of grafted tomato on He-Man rootstock increased by 21 % as compared to control plants. Colla et.al. (2010) inferred that salt tolerance of the shoot depends on the root system, independently of the genotype used as a scion, although the positive effect of rootstock may show to a different degree depending on the higher or lower exclusion ability of the shoot genotype.There are no reports of research on hydroponics from the Kingdom. This proposal would address the most important and relevant researchable issues such as water management that would greatly help in overcoming the major constraints in crop production. The major research gap identified for the project is lack of research on using saline water in hydroponic production of vegetable crops. The research team consisting of PI, the team of Co-Investigators and Consultants have rich experience in various facets of hydroponics. The team is truly interdisciplinary, and is capable of implementing the project for the benefit of farming community of this country.

Research Approach

Objectives Approaches for achieving the objectives

1. To study the effects of saline water on the yield and quality of tomatoes in hydroponic green houses.

A. Assessing the effects of saline water on tomatoes under both Open and Closed hydroponic systems.B. Assessing the performance of tomatoes under varying levels of salinity in hydroponic green houses. C. Assessing the effects of water of different salinity levels on the quality of tomato fruits grown in hydroponic greenhouses under both open and Semi open systems.

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2. To determine the effects of conjunctive use of saline and non-saline water on the productivity of tomatoes in hydroponic green houses.

A. Studying the effect of conjunctive use of saline water and non-saline water on tomato yield.B. Studying the effect of conjunctive use of saline water and good quality water on the quality of tomato fruits.

3. To assess the impact of grafting on salt tolerant root stock, improved plant nutrition (elevated levels of P, K, Ca, Fe and Si) and mist cooling on salt tolerance in hydroponic tomatoes.

A. Using tomato grafts for salt tolerance. B. Improving plant nutrition and mist cooling for inducing salt tolerance.

4. To provide training on hydroponic greenhouse technology to students and the farming community.

A. Prepare relevant training material to train students and farmers.B. Arrange training programmes at regular intervals.

Research MethodologyThe major objectives of the project are to determine the effects of saline water on the productivity and quality of tomatoes grown in hydroponic green houses. The brief details of the methodology that will be adopted to achieve the objectives of the project are presented here. The investigations on the effects of saline water on tomatoes will be carried out in 10 m x 30 m north - south oriented controlled polyethylene/glass hydroponic greenhouses. The greenhouses will be equipped with fan-and pad evaporative cooling systems.Hydroponic Systems and the growing medium: Open and Closed hydroponic systems will be used in the study. One greenhouse will be earmarked for the Open system and the other one for the Closed system. Coco coir / Perlite will be used as the growing medium in these greenhouses. Tomato seedlings and grafts will be transplanted into Coco Coir / Perlite soaked with nutrient solution. The tomato seedlings and grafts will be placed inside hydroponic plastic channels which lie on the greenhouse floor covered with white polyethylene film and will be soaked with nutrient solution before transplanting. MACQU SCADA systems will be used for the research.MACQU SCADA systems for greenhouse climate control and hydroponics (www.geomations.com) (www.aua.gr/ns/hortimed/): MACQU SCADA systems were developed under the support of E.U. and incorporated the latest technological advancements. With a new sponsorship of E.U., research program HORTIMED extends MACQU capabilities in the area of maximum water saving and maximum possible usage of saline water for crop production in the Mediterranean. Hortimed has extended MACQU with a hydroponics simulator good for examining scenarios for decision making or for education in water scarce regions (students working in hydroponics, workshops

http://www.aua.gr/ns/hortimed/

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etc).The basic characteristic of MACQU technology is based on an open system architecture at all levels, from the visual presentation on the PC to the level of control (virtual variables). Using virtual variables, the user can develop models based on which the climate and hydroponics control becomes self-adaptive. This technology allows the direct coordination between climate and hydroponics and provides the means to the development of an integrated way of production. MACQU systems can adapt to the size of the greenhouse facility to offer to the producer: maximum water saving (decrease of water usage up to 40%), energy saving (up to 30% in cold places), fertilizers saving (proportional to the water saving), increase in production (up to 100%) and quality and reduction of production cost (mainly because of the production increase). The MACQU-C system cooperates with the hydroponics device MACQU-H for integrated management. The system comprises ready to use control programs that incorporate the latest scientific progress in greenhouse control. The software involves: Temperature control, Control of up to 4 window sets, Humidity control, Shading screen, Thermal screen, Light and black out screen, CO2 control, Fog systems, Cooling panel, Dynamic air ventilation and Irrigation control.Grafting on salt tolerant root stock: The most common commercial technique for grafting tomato is Tube grafting or Japanese Top-Grafting. Tube grafting has been adopted as the primary method for vegetable grafting as it can be easily carried out with small healing chambers with typical success rates ranging from 85 to 90 percent. This technique has been highly effective as it can be carried out when plants are very small, thereby eliminating the need for large healing chambers while increasing the output. Both grafted tomato plants and seedlings will be used in this study. Tomato grafts will be obtained by adopting tube grafting method. In tube grafting, severed seedlings of both the scion and salt tolerant rootstock will be reattached with a small (1.5-2 mm) silicone tube or clip. Tube grafting will be carried out when the plants are very small.Experimental Details: The experiments in both the Open and Closed system greenhouses will be laid out in split- split plot design with four replications. There will be two strips (main treatments): one for tomato seedlings and the other for grafted tomato plants. In these two strips, the following two sub-treatments will be allocated. 1. Nutrient solutions will be supplied at different crop growth stages as recommended by Hochmuth and Hochmuth (2008) (Table 1). 2. Modified nutrient solutions with elevated levels of P, K, Ca, Fe (40 % higher than in sub-treatment1) and Si @ 2.25 mg L1, coupled with mist cooling. In these two sub-treatment strips, ten saline water irrigation treatments with constant EC levels of 2.5, 5.0, 7.5, 10.0, 12.5, 15.0, and differential EC levels with mid-day reductions in EC to 2.5 dsm-1 (2.5/7.5, 2.5/10.0, 2.5/12.5 and 2.5/15.0 dsm -1 ) will be superimposed as sub-sub treatments. The higher EC solutions will be obtained by adding NaCl and CaCl2. During the first 2 weeks in the green houses, plants will be grown under EC of 2.5 dSm-1 nutrient solution.

Table 1. Fertilizer recommendations for hydroponic tomatoes (Hochmuth and Hochmth, 2008)

Stage of growth1 2 3 4 5

Nutrien Transplant to 1st cluster 2nd cluster 3rd cluster 5th cluster to

http://en.wikipedia.org/wiki/Silicone

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t 1st cluster to 2nd cluster

to 3rd cluster

to5th cluster termination

--------------- Final delivered nutrient solution concentration (ppm) --------------

N 70 80 100 120 150P 50 50 50 50 50K 120 120 150 150 200

Ca 150 150 150 150 150Mg 40 40 40 50 50S 50 50 50 60 60Fe 2.8 2.8 2.8 2.8 2.8Cu 0.2 0.2 0.2 0.2 0.2Mn 0.8 0.8 0.8 0.8 0.8Zn 0.3 0.3 0.3 0.3 0.3B 0.7 0.7 0.7 0.7 0.7

Mo 0.05 0.05 0.05 0.05 0.05NOTE: Ca, Mg, and S concentrations will be varied depending on Ca and Mg

concentration in water and amount of sulfuric acid used for acidification (1ppm = 1mg/liter)

After 2 weeks, plants will be subjected to the different EC treatments. The plant density of 3.0 plants per m2 will be adopted. The mid day EC reduction treatments will be achieved by supplying higher EC nutrient solutions to the plants as per the treatments in the morning until 10 am, and then replacing it with the low EC (2.5 dSm-1 ) nutrient solution until 4 pm. Thereafter, the plants will be provided with higher EC nutrient solutions as per the treatments until 6 pm in winter and 8 pm in summer months depending on the ending of feeding cycle. At least one night cycle will be practiced during summer period.Nutrient and Water Management: The nutrient solutions will be supplied through drip-irrigation system. The drip fertigation system will be designed to deliver 100 mL of nutrient solution per plant using drippers/capillary tubes. One dripper/capillary tube will be provided to each plant. Automatic Irrigation scheduler based on the measured incoming radiation integral will be used. The "irrigation start" will be set with a certain threshold on accumulated radiation and the "irrigation stop" will be set based on the dose selected. The irrigation frequency will be based on the crop growth stage, plant transpiration demands and solar radiation. Drainage will be properly disposed of by creating a gutter system placed along each row. The minimum percent drainage of EC nutrient solution of 10-15 %, will be adopted and it will be adjusted by manipulating irrigation frequency through the automatic irrigation scheduler. A programmable irrigation timing controller will be used to schedule and control the fertigation cycles and the midday reduction of EC. The irrigation rates will be scheduled based on stage of the plant and environmental conditions. Threshold day and night air temperature of 240 and 180 C, respectively will be set to activate temperature control system. Common greenhouse plant maintenance, including weekly leaf pruning and removing side shoots will be carried out.

Data collectionCrop environmental parameters: The pH, EC, No3, K, Ca and Na of the influx and efflux nutrient solutions to plants and drained from the growing medium will be monitored frequently, using hand-held EC and pH meters (HI 98312 and HI

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98127, Hanna Instruments, Inc., Woonsocket, RI, USA) and nutrient meters, which will be calibrated weekly. Environmental data inside the greenhouse on photosynthetic photon flux (PPF), air temperature, relative humidity (RH), and atmospheric VPD will be collected using sensors which will be connected to a data logger (CR-1000; Campbell Scientific, Logan, UT, USA). The PPF will be measured using a LI- 190SA Quantum Sensor (LI-COR, Lincoln, NE) placed over the plant canopy. RH and VPD will be computed by measuring wet and dry bulb temperatures using Type-T thermocouples placed inside the greenhouse. Solar radiation outside the greenhouse will be obtained from Weather Station located nearby. Alternatively all above sensors will be connected to a powerful fertigator which will be able to store data in PC data base as well as use the data for controlling the greenhouse and the experiments.Crop growth and yield parameters: Periodic data on crop growth and yield parameters will be recorded in all the treatments. Periodic canopy chlorophyll measurements will be made using handheld NDVI meter (Spectrum Technologies, USA). NO3, K and Ca levels in leaf petioles and fruits will be determined/recorded periodically. Fruit trusses will be harvested based on overall fruit color once every week. A truss in which at least 80% of the fruits attain red ripeness stage will be harvested. Fruits will be weighed and graded immediately after the harvest and stored under refrigeration for assessing quality parameters. Fruit quality measurements: Fruit quality measurements will be made within 24 h. Lycopene, chlorophyll and total soluble solid (TSS) concentrations of fruits will be measured every week for all harvested tomatoes. The lycopene content of tomato fruits will be extracted and determined as per the method described by Fish et al. (2002). TSS will be determined by a hand refractometer and the measured values will be corrected to a standard temperature condition of 200C. Chlorophyll of tomato fruit puree will be extracted and measured using a modified method of Moran (1982). Lycopene and chlorophyll concentrations will be converted to a dry weight basis using fruit dry/fresh weight ratio obtained each week. Statistical analysis of the data: Data collected in the experiment will be analyzed using SAS software. Significance among individual treatments will be analyzed by analysis of variance (ANOVA) and least significant difference (LSD) test. Such analysis and subsequent interpretation and inferences will lead to scientific publications.Training of students and farmers: The salient findings of the project will be documented in the form of bulletins, booklets and folders. The relevant photographs, graphs, tables will be included in these extension education materials. The findings will also be documented in multi-media format which will all be utilized for training purpose. During the second year Open days for farmers will be organised to enhance farmers’ and consumers’ awareness about the advantages of the hydroponic systems in both the quality for the consumer and the greenness of the greenhouse (carbon footprint).Contingency Plan

1. The system will have capability for manual operation for limited time, until a technician can deliver "first aid".

2. Internet connectivity will zoom into the possible problem.

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3. The User training and the Internet mediated assistance usually takes care of 95% of events.

4. Installation will include local technicians or University technicians so we can deliver "first aid" with local people within the day. This takes care of another 4% of problems (fixing pressure lines, sticky valves, wiring problems)

5. Malfunctioning parts (1% of cases) can be identified through Internet within the hour and sent by courier for next day delivery and replacement by skilled technician. Meanwhile manual operation will sustain experiments.

6. It is understood that Electricity supply must be backed up by University Infrastructure and the power of the Unit (the main pump) will have a backup unit within this normal quotation. Other mechanical units may have local replacement possible and will be identified at project installation.

Value to the Kingdom:Technologies developed for use of saline water for tomato production in hydroponic green houses would result in considerable savings in fresh water resources. The results would facilitate for use of diluted sea water depending on the EC tolerance level of tomato, which is considered as a moderately salt tolerant crop. The present proposal would determine the threshold EC tolerance level and salinity amelioration measures for successful tomato production in hydroponic greenhouses using diluted sea water. The results would thus have tremendous impact on water security of the country. Further, the results would help in reduced dependence on import of fresh vegetables and increased economic benefits in addition to associated environmental benefits. The benefits derived from the outcome of the project would result in sustainability of agriculture in Saudi Arabia. The target end users of the outcome of the project would be farmers. The technology developed in the project will be transferred to the stake holders through field days and mass media. The crucial savings made in fresh water resources in agricultural sector can be diverted to civic use and industrial sectors.

11-AGR1939-02 - جامعة الملك...

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Transcript of 11-AGR1939-02 - جامعة الملك...