الفهرس 
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Abstract
V-SUMMARY AND CONCLUSION : The limited water resources and the remarkable increment in population in Egypt force the research workers to find various ways of saving water without a critical reduction in rice yield. So, this study was conducted to assess the response of rice plants to different irrigation intervals, different types of irrigation water and foliar applications of some antitranspirants. For this purpose, three irrigation intervals were applied throughout the period of plant life until crop harvest (starting after first irrigation) as follows; I1 : irrigation every 4 days, I2 : irrigation every 8 days and I3 : irrigation every 12 days. Three types of irrigation water treatments were used as follows; W1: normal irrigation water (100% canal water), W2 : agricultural drainage water and W3 : alternate irrigation with canal water and agricultural drainage water. Three antitranspirants treatments were sprayed as follows; A1 : Control (without any applications), A2 : KCl at a rate of 7% and A3: MgCO3 at a rate of 7%. The results obtained could be summarized as follows: 1- Vegetative growth parameters. The interaction effect among irrigation intervals, irrigation water types and foliar spraying applications was significant. The highest values of plant height (cm) and panicle length (cm) of rice plant were recorded when rice plants irrigated every 4 days (I1) by normal irrigation water (100% canal water) (W1) and foliar application of MgCO3 at 7 % (A3), while the lowest values were recorded when rice plants irrigated every 12 days (I3) by agricultural drainage water (W2) without any antitranspirants applications (A1). This trend was found for the two studied seasons. In this connect; spraying rice plants with MgCO3 or KClunder irrigation with normal water (100% canal water) (W1) every 8 days (I2) or 12 days (I3) gave better results than untreated plants (A1)under irrigation with normal water (100% canal water) (W1) every 4 days (I1) and this may due to that antitranspirants, in general, reduce the transpiration loss of water occurring mainly through closing stomatal pores present on the leaf surface. Also ; spraying rice plants with antitranspirants (A2 and A3) under irrigation with low-quality water (W2 and W3) every 8 days (I2) or 12 days (I3) gave better results than untreated plants (A1) under irrigation with normal water (100% canal water) (W1) every 4 days (I1).This trend was found under both studied seasons. 2- Yield and its components parameters. The values of 1000 grains weight (g), grain yield (kg fed-1), straw yield (kg fed-1), No. of filled and unfilled grains/spike of rice plant were significantly affected due to the addition of all investigated treatments. For all above mentioned parameters except No. of unfilled grains/spike,the highest values were at [I1( irrigation every 4 days)×W1 (normal water)×A3 (foliar application of MgCO37 %)] treatment, while the lowest values were at [I3( irrigation every 12 days)×W2 (agricultural drainage water)×A1 (without any antitranspirants applications)] treatment . 3- Quality parameters. The interaction effect between irrigation intervals, irrigation water types and foliar spraying applications was significant. For the N, P and K (%) in rice grains, the highest values were recorded when rice plants irrigated every 4 days (I1) by normal irrigation water (100% canal water) (W1) and foliar application of MgCO37 % (A3), while the lowest values of N, P and K (%) in rice grains were recorded when rice plants irrigated every 12 days (I3) byagricultural drainage water (W2) without any antitranspirants applications (A1). This trend was found for the two studied seasons. For the protein % of rice grain, the highest values were recorded when rice plants were irrigated every 4 days (I1) by normal irrigation water (100% canal water) (W1) and foliar application of MgCO37 % (A3), while the lowest values were recorded when rice plants were irrigated every 12 days (I3) byagricultural drainage water (W2) without any antitranspirants applications (A1).On the contrary, the lowest value of SOD (Unit.g-1 F.W) was noticed at [I1(irrigation every 4 days) × W1 (normal water) ×A3 (foliar application of MgCO37 %)] treatment, while the highest value was found at [I3(irrigation every 12 days) × W2 (agricultural drainage water) ×A1 (without any antitranspirants applications)] treatment. This trend was realized for the two studied seasons. As we mentioned before, antitranspirants reduced the transpiration loss of water occurring mainly through closing stomatal pores present on the leaf surface as well as it increases plant resistance to environmental stress and therefore raising the protein % in rice grain with reducing rice plant production from antioxidative enzymes. 4- Water relations parameters. It can be observed that rice plants irrigated with normal irrigation water (100% canal water) (W1) every 12 days (I3) under foliar application of KCl 7% (A3) used less amount of irrigation water, while rice plants irrigated with normal irrigation water (100% canal water) (W1) every 4 days (I1) without foliar application of (A1) used the highest amount of total water as compared with the other treatments. Spraying rice plants with antitranspirants improved the water use efficiency (WUE) as compared with rice plants without antitranspirants under different deficit irrigation levels with different irrigation water types. The irrigation regimes pronouncedly affected the water use efficiency (WUE) in both growing seasons. The obtained results (as average of the two studied seasons) indicate that the WUE was higher under I3then I2 and lately I1. 5- Soil properties. t can be said that using alternate irrigation regime (W3) consider less severityon salinity soil properties than irrigation by agricultural drainage water (W2). CONCLUSION :- In our opinion, according to the obtained results in this investigation it can conclude that rice plants could be treated with antitranspirants to save water, where the growth and yield of rice plant under water-stress condition were positively influenced by the application of antitranspirants. Also, alternate irrigation with canal water and agricultural drainage water may be acceptable to save the water and also minimize the hazard effects on soil properties and environment.