Abiotic stresses represent a major impediment to crop productivity, especially in arid regions. Thus, over two years of 2014 and 2015, a field experiment was undertaken at El Nubaria region, Egypt to assess the productivity and water use efficiency (WUE) of sunflower as affected by planting dates (April 21, May 21, and June 21) and  irrigation levels (ET100%, ET85% and ET70%,). Results clarified that leaf chlorophyll a content was higher by sowing in May than in either April or June sowings, while leaf carotenoides of plant sown in May or June surpassed those sown in April. The minimal value of proline was obtained with sowing in May. Sowing in May increased plant height by 52.2 and 22.3 as well as LAI by 19.3 and 73.1% than sowing in April and June, respectively. The reductions in seed yield, oil yield and WUE amounted to 10.5 and 12.8, 13.7 and 18.3 as well as 11.8 and 9.8 % with April and June sowings, respectively, compared to May sowing. ET100% showed superiority over than ET85% and ET70% in improving sunflower yields and its attributes, but WUE did not affect. Sunflower sown in May and irrigated with ET100% gave the maximum values of seed yield and its attributes and WUE surpassing other interaction treatments. In June, WUE value increased under severe water deficit i.e. ET70% comparing to moderately water–stressed (ET85%) or well–watered conditions (ET100%).

A greenhouse pot experiment was carried out to investigate the effect of salinity and potassium at different levels alone or in various combinations on growth, mineral and proline content in leaves of plantlets of Phoenix dactylifera L. cv. Bartomouda (in vitro production, two years old from acclima tized them). The following treatments were applied: three levels of salinity Na Cl + Ca C12 w.w 2:1 (14000, 16000 and 18000 ppm.) and two levels of potassium (2000 and 3000 ppm) in addition to control (no salts or potassium used), salts and potas sium were added in the irrigation water. In general, all levels of salinity significantly decreased various growth parameters such as plant height, number of leaves and roots, root length, fresh and dry weights of leaves than that of the control. These parameters were decreased with increasing salinity levels, whereas it, significantly increased Na, Ca and K contents in leaves with high content of proline. The treatment 18000 ppm salts gave the highest significant reduction of the growth parameters, while caused an increase in proline Na, Ca, and K contents compared to control treatment (no salts) . This was true in both seasons. The applications of potassium significantly increased the previous growth parameters as compared with the control treatment (without salts and potassium) the treatment 3000 ppm had the highest results. Moreover the applications of potassium gave high alleviated the negative effects of salt stress, the treatment 3000 ppm gave the best results on the growth parameters of date palm plantlets grown under salinity condition . Regarding the interaction the obtained data revealed that the interaction between treatment 3000 ppm potassium and 14000 salts produced the highest significant results. Gen erally, from the obtained results it can conclude that the plantlets of date palm produced by tissue culture can be tolerated salt stress by addition of potassium which can significantly ameliorate the harmful effects of salts, positive effects on the growth parameters of the plantlets was showed by potassium applications.

This investigation was conducted at Hada Elsham Experimental Research Station, King AbdulAziz University during 2007/2008 and 2008/2009 seasons, to study the effects of two irrigation water salinity levels (1200 mg/L and 10000 mg/L), three irrigation water intervals (3, 6 and 9 days) and three sulphur fertilizer rates (0.0, 4.0 and 6.0 t/ha) on seed yield; yield components and seed quality of canola, Pactole cv. The obtained results showed that seed yield kg/ha was significantly increased (Received June 1, 2009) (Accepted June 27, 2009) under the 1200mg/L irrigation water and 6t/ha of sulphur more than the seed yield/ha under the effect of 1200 mg/L irrigation water with 4 t/ha sulphur or 10,000 mg/L irrigation water with 6t/ha sulphur with no significant differences between the two later treatments. Irrigation every 3 days significantly dominated over the irrigation every 6 or 9 days on seed yield and yield components. Irrigation with 10.000 mg/L salinity water significantly decreased No. of branches /plant, No. of fruit/plant and seed weight/ plant. Besides, Protein content of the seed as well as oil content increased as water salinity increased in both seasons. As sulphur fertilizer rate increased seed yield, yield components protein and oil contents of seed significantly increased, in the two studied seasons.

Field experiment was carried out on one of the turf (lawn) , category  (Passpalm 10) to study the effect of irrigation systems on soil moisture distribution in the root zone. Experimental plot area was (4.5*4.5  ), soil media used was sandy soil and three treatments (spray, sub surface drib irrigation (SDI) , hydrogel) irrigation and every treatment replicated three times . Results of this research could be summarized as follows:  Annual water consumption was less by 77.3%, 71.3% when using hydrogel material, compared with other irrigation systems (spray, and SDI) resp. , this is due to the quantity of loss water from evaporation in spray irrigation treatment , where evaporation parameters are more effective than the others (SDI, hydrogel) irrigation treatments.   The hydrogel treatment has highest water saving by 170% ,300% compared with (SDI and spray) irrigation treatments , because the hydrogel's ability to hold water and has a large period between irrigation when using hydrogel in the soil .   The SDI treatment has highest electrical saving by 520% ,55% compared with (spray and hydrogel ) irrigation treatments resp.   The turf quality index (color, density, ground cover ) give high degree at hydrogel treatment compared with others, this is due to the hydrogel has many materials , both nat urally occurring and synthetic and ability of water saving around root zone of turf .  The average of soil moisture contents at (10cm and 15cm) depth of soil under hydrogel treatment was highest compared with (Spray and SDI) irrigation systems  resp.