Water scarcity is a major environmental stress that adversatively impacts wheat growth, production, and quality. Furthermore, drought is predicted to be more frequent and severe as a result of climate change, particularly in arid regions. Hence, breeding for drought-tolerant and high-yielding wheat genotypes has become more decisive to sustain its production and ensure global food security with continuing population growth. The present study aimed at evaluating different parental bread wheat genotypes (exotic and local) and their hybrids under normal and drought stress conditions. Gene action controlling physiological, agronomic, and quality traits through half-diallel analysis was applied. The results showed that water-deficit stress substantially decreased chlorophyll content, photosynthetic efficiency (FV/Fm), relative water content, grain yield, and yield attributes. On the other hand, proline content, antioxidant enzyme activities (CAT, POD, and SOD), grain protein content, wet gluten content, and dry gluten content were significantly increased compared to well-watered conditions. The 36 evaluated genotypes were classified based on drought tolerance indices into 5 groups varying from highly drought-tolerant (group A) to highly drought-sensitive genotypes (group E). The parental genotypes P3 and P8 were identified as good combiners to increase chlorophyll b, total chlorophyll content, relative water content, grain yield, and yield components under water deficit conditions. Additionally, the cross combinations P2 × P4, P3 × P5, P3 × P8, and P6 × P7 were the most promising combinations to increase yield traits and multiple physiological parameters under water deficit conditions. Furthermore, P1, P2, and P5 were recognized as promising parents to improve grain protein content and wet and dry gluten contents under drought stress. In addition, the crosses P1 × P4, P2 × P3, P2 × P5, P2 × P6, P4 × P7, P5 × P7, P5 × P8, P6 × P8, and P7 × P8 were the best combinations to improve grain protein content under water-stressed and non-stressed conditions. Certain physiological traits displayed highly positive associations with grain yield and its contributing traits under drought stress such as chlorophyll a, chlorophyll b, total chlorophyll content, photosynthetic efficiency (Fv/Fm), proline content, and relative water content, which suggest their importance for indirect selection under water deficit conditions. Otherwise, grain protein content was negatively correlated with grain yield, indicating that selection for higher grain yield could reduce grain protein content under drought stress conditions.

The present study was carried out at the experimental farm of Tag El-Ezz Agricultural Research Station (30 o 59 \ N latitude, 31 o 58 \ E longitude´), Agricultural Research Center, Dakahlia Governorate, Egypt, to study the effect of foliar spraying of arginine on four soybean cultivars under salinity stress. This experiment was laid out in a split plot design with three replicates during the two successive summer seasons of 2020 and 2021. The main plots were occupied by four soybean cultivars (Giza 111, Giza 21, Giza 35 and Crawford), while subplots contained arginine treatments i.e. without spray (control), spray with arginine at 200 and 300 mg l -1 . The obtained results showed that, cultivars showed a wide range of variation in their salinity sensitivity where, Giza 111 gave the highest values of the most vegetative growth parameters i.e., chlorophyll content, relative water content (RWC%), nutrients content in leaves, proline content as well as catalase and peroxidase enzymes activities, thus increased seed yield, seed nutrients, protein, carbohydrates and oil %. Concerning, foliar spraying of arginine ameliorate inhibitory effect of salinity on soybean cultivars in comparison to the control. The highest values of most studied vegetative growth parameters, yield and yield components were achieved by foliar spray of arginine at 300 mg l -1. The interaction between soybean cultivars and foliar spraying of arginine revealed that, Giza 111 treated with arginine at 300 mg l -1 gave the highest values of growth, yield and yield components.

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A field experiment was carried out at the Experimental Farm of Sakha Agricultural Research Station during the winter season of 2014/2015 and 2015/2016 to study the impact of foliar application with potassium on growth, yield, its components and the economic yield as well as on irrigation water productivity of barley Giza 126 cultivar under water deficit conditions. The experiment was laid out in spilt plot design with four replications. The main plots were designated to irrigation treatments i.e. I 0 = full irrigation (control), I 1 = two irrigations at 35 and 70 days after sowing (DAS), and I 2 = one irrigation at 35 days after sowing (DAS), while the sub plots were devoted to four treatments of foliar application with potassium (K 0 = without spray, K 1 = 1% K 2 O, K 2 = 2 % K 2 O and K 3 = 3% K 2 O) in the form of potassium sulfate (48%). Results showed that, increasing water stress significantly retard photosynthetic pigments, flag leaf area, relative water content (RWC %), yield and its components and carbohydrate content. On the other hand, plants under water stress showed marked increase in grain protein content. Foliar spraying with potassium markedly increased most growth and yield parameters and quality of barley grains. The results showed that high irrigation water productivity (IWP) is attainable without significant yield penalty (utilizing a two irrigations at 35 and 70 days after sowing (DAS), or one irrigation after 35 DAS and foliar spraying with potassium (1% K 2 O, or 2 % K 2 O, or 3 % K 2 O) offering chance for improving land level water use and enhancing the crop economic return.

A field experiment was conducted at El-bostan Farm, Faculty of Agriculture, Damanhur University in the two successive summer seasons of 2018 and 2019. The aim of this study was to investigate the effect of humic acid application on sunflower (Helianthus annuus L.) growth, yield & its components and some chemical constituents grown under saline soil conditions. The experiment was laid out in a split plot design in four replicates. The main plots were occupied by three sunflower genotypes Sakha 53, Giza 102 and Line 120. While subplots contained four treatments of humic acid (HA) i.e.; without HA (control), HA soil application, foliar HA spray and a combination of both foliar spray and soil addition of HA. The results showed that, different genotypes did not perform similarly under salinity stress conditions. Line 120 had the highest leaf area/plant, head diameter, seed yield/ plant and seed yield/ha. With regard to humic acid application, it caused improvement for most growth, physiological parameters, yield and its components compared to control. Obtained results also, showed that humic acid application as both soil and foliar spray on Line 120 and Sakha 53 led to obtain the highest values of most studied parameters in the two growing seasons. Finally, it could be concluded that humic acid application can ameliorate negative effects of salinity on sunflower.