الفهرس 
LITERATURE REVIEWOnly 14 pages are availabe for public view
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Abstract
The maintenance is considered one of the main axes of drip irrigation system management. Therefore this study was conducted to select the most suitable maintenance program for improving drip irrigation systems and laterals performance.
For such purpose, three field trials were conducted at central greenhouses of the Ministry of Agric. at Dokki, Fac. of Agric. Exp. Sta. greenhouses, Cairo university, and Agric. Engineering Dept. irrigation unit, Cairo University, at Giza, during the period from 2006 to 2008 seasons.
The experiments carried out to study the effect of maintenance programs were divided into two main flushing procedures (MP1: Flushing with fresh water), including three sub main programs (MS1P1, MS2P1, MS3P1), each of them was studied in four interval time, ”weekly, bi-weekly, monthly, and at the end of the season. The second one (MP2: flushing with acids) included two sub main programs (MS1P2, MS2P2), using sulfuric acid ”H2sO4”, and Phosphoric acid ”H2PO4 ” at recommended PH=4.5 (Capra and Scicolone, 2005).
All programs include maintenance of control unit, and any damaged or broken parts in the network.
The results showed that Bi-weekly application of continuous flushing for 5 minutes program (MS1P12) proved to be the best maintenance program for flushing with fresh water, it decreased clogged emitters percentage 44.21 % to be closer to the standard with 4.85 %. Also partially clogged emitters percentage decreased by 46.76 %, while emission uniformity (EU%) and distribution uniformity (DU %) increased by 19.44 %, and 13.91 % more than the control treatment respectively. (MS1P12) was followed by the weekly application of third maintenance subprogram ,flushing continuously for ten minutes program (MS3P11) as it raised DU with 12.34% and gave the highest value of pressure uniformity (UP%) that reached 93.14%.
On the other hand for flushing with acids, the best program was the weekly application of sulfuric acid sub- program (MS1P21), as it gave DU % of 91.96% which was the closest value to the standard new network.
• The monthly and season end sub-programs were preferred by farmers for less labor.hr requirement and water consumption, but these sub-programs were neglected according to scientific evaluation parameters in this study.
Keywords: drip irrigation, performance, maintenance, flushing, distribution uniformity, clogging ratio