Application of nitrogen (N) fertilizer is one of the most important actions that increases grain yield and improves grain quality in winter wheat (Triticum aestivum L.) production. Presently, there are a large number of investigations in the field on different nitrogen fertilizer application regimes. However, there is little information available about the optimum level of N for drip irrigated wheat. Filed experiments in Randomized Complete Block Design (RCBD) conducted to study the response of drip irrigated wheat to three levels of N (120, 180, and 240 kg N ha−1). The field experiments were carried out at the Agricultural Experimental Station farm of the Faculty of Agriculture, Assiut University, Egypt during the two successive growth seasons of 2013/14 and 2014/2015. The application of N significantly (P0.05) enhanced the growth of drip irrigated wheat. The highest rate of nitrogen increased the uptake of N, P, and K by 61, 75, and 57% compared to the lowest treatment. Increasing rate of nitrogen to 240 kg N per hectare increased the Water Use Efficiency (WUE) by 34 and 22% in the first and second season, respectively, compared to N120 treatment. The number of spike per m2, number of grains per spike, and grain weight per spike of wheat were affected significantly (P0.05) by N treatments. The application of N240 increased the wheat grain yield by 34 and 22% in the first and second season, respectively, compared to N120. Based on the obtained results, it is recommended to fertilize drip irrigated wheat by 240 kg N per hectare.

Optimal use of nutrients based on soil analysis can improve crop productivity and minimize environmental pollution. Therefore this study aimed to assess forms of both potassium and phosphorus in soils of Assiut and the relationship between both elements and some soil properties. The study area was divided into 10 transects and 54 soil profiles were selected. Soil samples from two depths (0- 30 and 30- 60 cm) at each location were collected then they were analyzed by standard methods. Available and total content of both phosphorus and potassium were measured. The correlation matrix of soil properties shows that several physical and chemical variables were correlated with each other especially, CaCO3, OM, pH, EC and CEC. Soil salinity (EC) of 90% of soil samples were less than 2 dS/m. Soil reaction (pH) of Assiut Governorate ranged from 7.22 to 8.92 with average value of 7.98. The soil organic matter (SOM) content of Assiut governorate ranged from 0.33 to 4.09% with average value of 1.51 %. Available phosphorus was low in 63.9%, medium in 21.3% and high in 14.8% of the soil samples. Available phosphorus was low in 63.9%, medium in 21.3% and high in 14.8% of the soil samples. Available potassium was low in 16.7% soil samples and 60.2% of soil samples were medium. The remaining 23.2% of soil samples were high. Soil Nutrient Index of the study area was found in category of low phosphorus, medium potassium and high OMC.

Optimal use of nutrients based on soil analysis can improve crop productivity and minimize environmental pollution. Therefore this study aimed to assess forms of both potassium and phosphorus in soils of Assiut and the relationship between both elements and some soil properties. The study area was divided into 10 transects and 54 soil profiles were selected. Soil samples from two depths (0- 30 and 30- 60 cm) at each location were collected then they were analyzed by standard methods. Available and total content of both phosphorus and potassium were measured. The correlation matrix of soil properties shows that several physical and chemical variables were correlated with each other especially, CaCO3, OM, pH, EC and CEC. Soil salinity (EC) of 90% of soil samples were less than 2 dS/m. Soil reaction (pH) of Assiut Governorate ranged from 7.22 to 8.92 with average value of 7.98. The soil organic matter (SOM) content of Assiut governorate ranged from 0.33 to 4.09% with average value of 1.51 %. Available phosphorus was low in 63.9%, medium in 21.3% and high in 14.8% of the soil samples. Available phosphorus was low in 63.9%, medium in 21.3% and high in 14.8% of the soil samples. Available potassium was low in 16.7% soil samples and 60.2% of soil samples were medium. The remaining 23.2% of soil samples were high. Soil Nutrient Index of the study area was found in category of low phosphorus, medium potassium and high OMC.

Two field experiments were carried out at the Research and Production Station, National Research Centre, Al - Nubaria district, El-Behaira Governorate, Egypt, during the two successive winter seasons 2013/2014 and 2014/2015.The aim of this study was to investigate the effect of humic acid (two levels (control and 20 mg/L)) and zinc foliar application (four levels of chelated zinc (0, 1.5, 3 and 4.5 g/L)) on yield, yield components and quality traits of two wheat cultivars (Seds-1 and Seds-13). The obtained results indicated that Seds-13 cultivar significantly surpassed Seds-1 in spikelet number per spike, grain yield/ spike, grain yield in kg/feddan (fed. = 4200 m2), harvest index, protein % and protein yield (kg/fed.). Humic acid foliar spray significantly surpassed without spray (control) in all studied characters except harvest index. Foliar application of 4.5 g/L zinc gave the best results for all studied characters. Cultivar Seds-13 sprayed by humic acid gave the highest values of grain, straw, biological and protein yields/fed. Meanwhile, Seds-13 under4.5 g/L zinc application gave the best values of grain yield/ spike and biological, straw and grain yields/fed. the interaction between humic acid (20 mg/L) and 4.5 g/L zinc recorded the highest values in most of studied characters. Seds-13 x humic acid (20 mg/L) x 4.5 g/L zinc gave the highest values of grain yield/ spike and biological, straw and grain yields/fed. protein % and protein yield/fed. while, Seds-1 x humic acid (20 mg/L) x 4.5 g/L zinc gave the highest values of plant height, straw yield/ teller and grain index.

This study was carried out in the two growing seasons of 2008 and 2009. Five experiments were conducted in each season in the Experimental Agricultural Farm, Faculty of Agriculture, Assiut University. Each experiment represented one planting date. Through each experiment two variables were designed in split-plot design in which time of thinning was allotted in the main plots, whereas splitting NPK was in the sub-plots. The obtained results could be summarized as follows: 1-Total soluble carbohydrates, number of open bolls per plant, weight of seed cotton per boll in gram and Seed cotton yield of Kentar/fed were decreased significantly as planting date was delayed, On the contrary node number of the first sympodium was lowered. 2-The data revealed that thinning before the second irrigation favoured Plant height, total soluble carbohydrates, number of open bolls per plant, weight of seed cotton per boll and Seed cotton yield of March plantings, whereas the reverse was true with regard to the late plantings, i.e., thinning before first irrigation., On the contrary of that node number of the first sympodium was lowered in march plantings. 3-The data revealed that splitting fertilization increased significantly total soluble carbohydrates, number of open bolls per plant, weight of seed cotton per boll and Seed cotton yield. On the contrary of that node number of the first sympodium was lowered.

This study was carried out in the two growing seasons of 2008 and 2009. Five experiments were conducted in each season in the Experimental Agricultural Farm, Faculty of Agriculture, Assiut University. Each experiment represented one planting date. Through each experiment two variables were designed in split-plot design in which time of thinning was allotted in the main plots, whereas splitting NPK was in the sub-plots. The obtained results could be summarized as follows: 1-Total soluble carbohydrates, number of open bolls per plant, weight of seed cotton per boll in gram and Seed cotton yield of Kentar/fed were decreased significantly as planting date was delayed, On the contrary node number of the first sympodium was lowered. 2-The data revealed that thinning before the second irrigation favoured Plant height, total soluble carbohydrates, number of open bolls per plant, weight of seed cotton per boll and Seed cotton yield of March plantings, whereas the reverse was true with regard to the late plantings, i.e., thinning before first irrigation., On the contrary of that node number of the first sympodium was lowered in march plantings. 3-The data revealed that splitting fertilization increased significantly total soluble carbohydrates, number of open bolls per plant, weight of seed cotton per boll and Seed cotton yield. On the contrary of that node number of the first sympodium was lowered.

This study was carried out in the two growing seasons of 2008 and 2009. Five experiments were conducted in each season in the Experimental Agricultural Farm, Faculty of Agriculture, Assiut University. Each experiment represented one planting date. Through each experiment two variables were designed in split-plot design in which time of thinning was allotted in the main plots, whereas splitting NPK was in the sub-plots. The obtained results could be summarized as follows: 1-Total soluble carbohydrates, number of open bolls per plant, weight of seed cotton per boll in gram and Seed cotton yield of Kentar/fed were decreased significantly as planting date was delayed, On the contrary node number of the first sympodium was lowered. 2-The data revealed that thinning before the second irrigation favoured Plant height, total soluble carbohydrates, number of open bolls per plant, weight of seed cotton per boll and Seed cotton yield of March plantings, whereas the reverse was true with regard to the late plantings, i.e., thinning before first irrigation., On the contrary of that node number of the first sympodium was lowered in march plantings. 3-The data revealed that splitting fertilization increased significantly total soluble carbohydrates, number of open bolls per plant, weight of seed cotton per boll and Seed cotton yield. On the contrary of that node number of the first sympodium was lowered.

This study was carried out in the two growing seasons of 2008 and 2009. Five experiments were conducted in each season in the Experimental Agricultural Farm, Faculty of Agriculture, Assiut University. Each experiment represented one planting date. Through each experiment two variables were designed in split-plot design in which time of thinning was allotted in the main plots, whereas splitting NPK was in the sub-plots. The obtained results could be summarized as follows: 1-Total soluble carbohydrates, number of open bolls per plant, weight of seed cotton per boll in gram and Seed cotton yield of Kentar/fed were decreased significantly as planting date was delayed, On the contrary node number of the first sympodium was lowered. 2-The data revealed that thinning before the second irrigation favoured Plant height, total soluble carbohydrates, number of open bolls per plant, weight of seed cotton per boll and Seed cotton yield of March plantings, whereas the reverse was true with regard to the late plantings, i.e., thinning before first irrigation., On the contrary of that node number of the first sympodium was lowered in march plantings. 3-The data revealed that splitting fertilization increased significantly total soluble carbohydrates, number of open bolls per plant, weight of seed cotton per boll and Seed cotton yield. On the contrary of that node number of the first sympodium was lowered.

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Drought is an important abiotic stress causing the major crop losses worldwide. Identification of genomic regions associated with drought-related traits is essential for improving drought tolerance in barley. Association mapping was implemented to investigate the associations between 76 SSR markers and six drought-related traits on a set of 107 barley accessions evaluated under well-watered and drought-stressed conditions. Highly significant differences between well-watered and drought-stressed conditions were observed in all measured traits. A high level of polymorphism with SSR markers was observed. A total of 36 significant marker–trait associations for drought-related traits were detected. A high extent of significant LD (> 61%) was observed between markers on different chromosomes, suggesting epistatic interaction. Several molecular markers are significantly associated with more than one phenotypic trait, suggesting the possible presence of pleiotropic or indirect effects. The phenotypic variation, explained by individual marker–trait associations, ranged from 6.33% to 35.78%.