Two filed experiments were conducted during 2015 and 2016 seasons at the Research Farm of El-Sirw Agricultural Research Station, Damietta Governorate, Egypt. The experiments were performed to study the response of Giza179 rice cultivar to eight nitrogen sources Viz; ammonium sulfate (AS), ammonium nitrate (AN), urea (U), Di-ammonium phosphate (DAP), mono ammonium phosphate(MAP), calcium ammonium nitrate (CAN), and calcium nitrate (CN) and potassium nitrate (KN) under saline sodic soil conditions. The experimental soil was clay with salinity level 7.5 and 7.3 dSm-1 and sodicity (ESP) level 41and 40% dSm-1 in 2015 and 2016 seasons, respectively. The experiment was performed in randomized complete block design and repeated four times. The main obtained results could be summarized as follows; The nitrogen source had significant differences on nutrients leaf contents (NPK), rice growth (leaf area index, dry mater production and chlorophyll content), yield attributes and grain yield in both seasons. Ammonium sulphate showed good and better regarding nitrogen leaf content, while, CAN and KN recorded the highest values of K leaf content. However, DAP and MAP recorded the highest values of P leaf content in both seasons. Ammonium sulphate recorded the highest values of studied growth traits while, the sources contain nitrate (AN, CAN, CN and KN) had the lowest values. The DAP and MAP were comparable regarding their favorable effect on rice growth occupying the second position after ammonium sulphate. The ammonium sulphate had high yield component giving high grain yield followed by DAP and then MAP. Generally, urea or ammonium nitrate as well as any sources contains nitrate is not efficient to apply it for rice under the same saline sodic soil conditions.

Studies were carried in the two seasons of 2017 and 2018 at the Experimental Farm of El-Sirw Agriculture Research Station, Damietta Governorate, Egypt. The main objective of study was to determine the effect of foliar spraying with some chemical substances during panicle initiation+ mid booting stages on rice growth, yield, yield attributes and grains quality characteristics of rice cv. Giza179. The experimental design was performed in randomized complete block design with four replications. Foliar application treatments were 1-Control (non-treated treatment), 2-Di ammonium phosphate spray (DAP 1.5%) 3-Potassium (K 2 O 1.5%) 4-N+K + mixture (1.5% for each) 5-Gibbrilic acid (GA 3 10ppm)+K + (1.5%) 6-Salicylic acid (SA 500ppm)+K(1.5%) 7-Humic acid (HA)+1.5%K). Salinity levels of experimental were 8.4 and 8.5 dSm-1 in both seasons, respectively. The plant growth, yield, yield components parameters, and grains quality characteristics were collected. The tested chemical substance significantly improved the studied characteristics rice grain quality, yields and yield contributes compared with the control treatment. Foliar spray with mixture of humic acid +K + at panicle initiation + mid booting stages was significantly the most efficient treatment in improving rice grain quality, growth and yields without significant difference with the mixture of N+K treatment regarding rice grain quality improvement. The mixture of humic+ K + could be recommended for improving rice quality and productivity of Giza 179 under salt stress.

The study was carried out in of 2015 and 2016 seasons at the Experimental Farm of El-Sirw Agriculture Research Station, Damietta Governorate, and Egypt. The main objective of an attempt was to determine the effect of short, medium and prolong irrigation intervals (irrigation every three, six and nine days) and gypsum rates (0, 0.5,1.0 and 1.5 t ha -1 CaSO 4 ) on some soil prosperities, some plant elements, plant growth and grain yield of Sakha 104 rice cultivar, under saline soil conditions. A strip plot design, with four replicates, was used. The horizontal plots were devoted to irrigation intervals, however, the gypsum rates were allocated in the vertical plots. The soil of the experimental site was clayey and salinity levels were 7.5 and 7.3 dSm -1 in 2015 and 2016 seasons, respectively. The results obtained could be summarized as follows: Irrigation every three days increased chlorophyll content, LAI, plant height, number of tillers, panicle length, number of panicles, filled grains/panicle, panicle weight, 1000-grain weight, grain and straw yields as a compared with irrigation every nine days, which recorded the highest values of unfilled grains. Irrigation every three days significantly increased soil bulk density as well as Ca ++ and K + (in the soil and plant). However, it decreased the soil EC, Na + (in the soil and plant) and Na/K ratio in the plant. Irrigation every three days consumed the highest amount of irrigation water, while prolonged irrigation intervals up to six and nine days tended to decrease the amount of water used. Furthermore, nine days treatment recorded the highest water use efficiency. Gypsum (as a soil amendment) rated 1.5 t 1 CaSo4 hasignificantly raised all studied growth parameter (except plant height), grain yield and its components without any significant differences with 1.0 t ha -1 CaSo 4 in some traits in both seasons. Gypsum at the rate of 1.5 t ha -1 CaSo 4 mitigate the hazardous effect of salinity by decrease soil EC, Na + (in the soil and plant) and Na/K ratio in the plant. Generally, under the same condition, irrigation every three days and gypsum at the rate of 1.5 t ha -1 CaSo 4 are favorable for improve soil properties and enhance rice productivity under saline soil conditions.

Tow field experiments were conducted at El-Sirw Agricultural Research Station, Damietta Governorate, Egypt during 2015 and 2016 seasons. The main objectives of this study is to estimate the physiological and biochemical performance of some rice varieties under various salinity levels. The experiments were performed in randomized complete block design with four replicationsfor each salinity level apart and the results were statistically analyzed as split plot design after homogeneity test as combined. Soil survey of the experimental farm was annually done to find the following used salinity levels viz; 2, 6 and 10dSm -1 .Giza177, Giza178, Giza179 and Egyptian hybrid one (EHR1) ricevarieties were used. Anti -oxidants, physio-morphological and growth parameters were measured at heading stage as well as grain yield and yield attributing characteristics were measured at harvest. The obtained results indicated that: increasing salinity levels led up to decreased potassium percentage (K %), increased sodium percentage (Na %) and Na + /K + ratio in rice plant. Furthermore, increment of salinity levels reduced dry matter accumulation (g),relative water content RWC(%), chlorophyll a,b and total chlorophyll (µg ml -1 ) and, increased a/b ratio and antioxidant system peroxidase (POD)(µmol min -1 g -1 protein) Catalase (CAT)(µmol min -1 g-1 protein),proline (mg g -1 FW).Increasing salinity levels decreased the studied growth characteristics; flag leaf area, chlorophyll content (SPAD value), plant height, panicle weight, panicle length, number of filled grains, 1000-grain weight and grain yield/ha -1 but increased unfilled grains per panicle. EHR1gave the highest values of most studied characters followed by Giza179 while, Giza178 came in the third order. Giza177 gave the lowest values of the most studied traits. Egyptian hybrid one under the three salinity levels was distinction compared with other rice varieties in both seasons. Based on current biochemical and physiological traits and yield under different salinity levels, the tested rice varieties could be ranked as follows; EHR1>Giza179>Giza178 regarding their salinity tolerance. Giza 177 was found to be more salt sensitive variety.

Acetone (5% v/v) inhibited growth of four isolates of Rhizoctonia solani which differ in their pathogenicity on squash seedlings. Acetone (5% v/v) showed best inhibition on the most aggressive isolate 4 followed by the less aggressive ones (1, 2 and 3, respectively); IAA had no effect on the growth of all R. solani isolates compared to the controls.