Two field experiments were conducted at Rice Research and Training Center ( RRTC ) Farm, Kafr-El-Sheikh Governorate, Egypt, during two successive seasons of 2009 and 2010. The main objectives of this study are; identifying both the optimum seeding rates and hill spacing to increase the yield of hybrid rice seed for the hybrid IR69625A/Giza181R (2046H), this study included, three seeding rates for cytoplasmic male sterile line (6kg/fed, 8kg/fed and 10kg/fed) and three hill spacing ( 15×10, 15×15 and 15× 20cm).The treatments were arranged in split plot design with three replications, where seeding rates distributed as main plots while hill spacing were allocated in the sub plots. Data were recorded on different traits relating to yield and its components .The results showed that, the seed rates had highest significant on plant height , panicle weight, panicle length, panicle exsertion, no. of spikelets/ panicle seed set, 1000 grain weight and grain yield . The optimum treatment to produce high quantity of hybrid rice seed from the hybrid combination of IR69625A/Giza181R (SK.2046H) was 8kg seeds/fed, for the seeding rate.Moreover, hill spacing treatments had highest significant on all studied characters,except no. of panicles/m 2 character. The best hill spacing for cytoplamic male sterile was 15 x 15cm.The interaction between seed rates and hill spacing was significant for all studied characters.It could be concluded that the optimum treatments to produce high quantity of hybrid seed from the hybrid combination IR69625A/Giza 181R (SK.2046H) was 8kg seeds/fed for the seeding rate and (15×15cm) for hill spacing, because this treatment was recorded the highest values of panicle exsertion (81.61%),seed set (46.06%) and grain yield (1.32 t/fed).

Integrating rice crop management involving using salt tolerant variety and proper cultivation is the main strategy to increase rice production under saline soils. Two field Experiments were conducted during 2006 and 2007 Rice growing seasons at the research farm of El-Sirw Agricultural Research Station Damietta Governorate, Egypt. The experiments were conducted to study the effect of three nitrogen levels o, 35 and70 kg N/fed and three potassium levels o, 24, 48.kgK2O/fed and their interaction on growth yield and its components of some rice genotypes (SK2046H or EHR1) (SK2034H or EHR2) i.e. hybrid ones and Giza 178 i.e. inbred one under saline soil conditions. Splitsplit plot design with four replications was used in the experiments , the varieties were distributed in the main plots the sub-plots were allocated to three nitrogen rates the sub plot were devoted to three potassium rates. The main obtained results could be summarized. The nitrogen levels had positive and significant effects on plant height, tiller number, panicle length, panicle number, filled grain / panicle, panicle weight, 1000grain weight, grain yield and straw yield. All rice cultivar significantly responded to nitrogen fertilizer up to 70 kg N/fed. Potassium fertilizer significantly increased rice growth, yield components and rice grain yield in both seasons. Rice response to potassium fertilizer was significantly up to higher potassium level of 48 kg K2O/fed. Egyptian hybrid one EHR1 (SK2034H) with 70kgN/fed and 48kgK2O/fed gave the highest values of estimated growth parameters, yield components and grain yield under current study. Rice genotypes significantly varied in their growth traits, yield component and grain yield as well as harvest index. (SK2034H) hybrid rice variety significantly surpassed other two tested genotypes followed by Giza 178 rice variety. (SK2046H) occupied the last rank. It could be concluded that EHR1 had to be fertilized by70 kg N/fed and 48 kg k2o /fed under current saline conditions for producing considerable grain yield.