The objective of this study was to identify tolerant and susceptible genotypes of bread wheat under different irrigation treatments and determine the type of gene action and some genetic parameters in three bread wheat crosses; (Line 1 × Line 2), (Line1 × Giza 171) and (Misr 2 × Line 3) under normal irrigation and water stress treatments. Genetic materials included six populations (P1, P2, F1, F2, BC1 and BC2) for each cross. Positive and high significant values for heterotic effects relative to the mid-parent of grain yield were found for the second (Line1 × Giza 171) and third cross (Misr 2 × Line 3) under both irrigation treatments, while positive values heterosis for better parent detected for the third cross under both irrigation treatments. Non-allelic interaction was found for all studied characters in all the crosses under both irrigation treatments. Dominance effects were greater than the additive gene effect. Dominance × dominance gene interaction was higher in magnitude than additive × additive and additive × dominance for most characters under both irrigation treatments, indicating that these characters greatly affected by dominance and non-allelic interactions. Heritability in the broad sense was high for all the studied characters in three crosses under both irrigation treatments, while narrow sense heritability estimates were moderate to high for all the studied characters under both irrigation treatments. In general, the highest values of grain yield/plant were in the third cross (Misr2 × Line 3) under both irrigation treatments, based on tolerance index (Line 1) and (Line 2) are the most tolerant for water stress and the first cross (Line1 × Line2) was the most one for water stress tolerant, so this cross is recommended under water stress conditions.

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In 2015/2016 and 2017/2018 Two experiments were carried out at Sakha Agricultural Research Station, to investigate the response of wheat crop to nitrogen fertilization levels(0, 25, 50 and 75 kg N/fed)on growth, chemical composition and productivity of six wheat genotypes(Misr 1, Sakha 95, Giza 171, Shandaweel 1, Misr 2 and promising line developed from Sakha breeding program(SPL2015).This research conducted using the split-plot design with four replications. In which, the main-plots and sub-plots assigned to levels of nitrogen fertilization and wheat genotypes, respectively. Results showed that high levels of nitrogen levels(75 kg N/fed)gave the highest values of crop growth rate, flag leaf area, photosynthetic pigments and Nitrogen percentage in grains. Moreover, increasing nitrogen fertilizer increased yield and its components significantly. Sakha 95 cultivar produced the highest values of all studied characteristics in both growing seasons. Meanwhile, the cultivar Misr 2 showed the highest number of spikelets/spike, additionally recorded the second best results after Sakha 95.On the other hand, Shandaweel 1 cultivar gave the longest spikes; Giza 171 cultivar recorded the highest values of 1000-grain weight,Misr1 gave the highest N% content for the grain. However, Sakha 95 under 50 kg N/fed ranked secondly in most treatments without significant differences between Sakha 95 under 75 kg N level /fed for both seasons. It can be concluded that Sakha 95 had the highest nitrogen use efficiency and this reflecting in reduction of production costs and environmental pollution by saving 25 kg N/fed under such environmental conditions of Sakha district,

Two factorial field experiments on wheat (Var. Msr 2) have been carried out during two successive seasons of (2015 / 2016 and 2016/2017), at Sakha Agric. Res. Station. The factors comprised organic fertilizer rates (0, 10 and 20 m 3 fed-1) and phosphorus fertilizer rates (0, 30 and 45 kg P 2 O 5 fed-1) in four replicates. The soils of the experimental locations is a clay loam in texture and have mean values of EC e = 6.1dS.m-1 , ESP = 8.4 % and pH = 8.15; which indicated moderate effects with salinity and sodicity.The important results could be summarized as follows:(1) organic manuring (as compost) with rates of 10(OM 10) or 20(OM 20) m 3 fed-1 led to higher values of wheat grain and straw yields ,as well as grains-protein content relative to the nonemanured treatment.(2) Phosphorusfertilizationwithrates of 30 and / or 45 kg P 2 O 5 fed-1 have been resulted in better grain and straw yields beside higher values of wheat grains-protein content as compared to the controltreatment (P 0).(3) The interaction treatment of (20 m 3 compost x 45 kg P 2 O 5 fed-1) was the best onewhich recorded the maximum values for the previous studied parameterswith increments of[(79.8 %) S1 , (78.6 %) S2 ] N ; [(69.2 %) S1 ,(100 %) S2 ] P and [(79.9 %) S1 , (78.6 %) S2 ] prot over control treatments (OM 0.0 × P 0.0) and for the two seasons, respectively.(4) The co-fertilization of organic manure along with Pfertilization enhanced many biochemical reactions which have beenincreased the availability of phosphate ions and subsequent increment in P-relative efficiencies of P-fertilizer, which have been led to higher wheat yields.

A field experiment was conducted during two winter seasons 2018/2019 and 2019/2020 at Sakha Agricultural Research Station, Kafr El-Sheikh Governorate, Egypt to study the effect of deficit irrigation and weed control treatments on grain yield and water productivity of three bread wheat genotypes. The experimental design was stripe split-plot, with three replicates. Irrigation treatments were in the vertical plots which include I1 irrigation at all stages (full irrigation), while I2, I3 and I4 were deficit irrigation through withholding one irrigation at elongation, booting, and anthesis stages, respectively. Four weed control treatments were allocated in horizontal plots that include, W1 (Gerostar + Action), W2 (Atlants), W3 (hand weeding twice), and W4 control (untreated), Sub-Subplots were three wheat genotypes G1 (Giza 171), G2 (Sakha 95) and G3 (promising Line). The results revealed that the highest values of plant height, number of spikes m -2 , number of kernels spikes -1 , 1000-kernel weight, biological yield, grain yield and straw yield were recorded under I1 compared to all the studied irrigation treatments, as well as under W1 compared to other weed control treatments and G2 compared to others genotypes in the two seasons. The highest values of water consumptive use (CU), and applied water (AW) were recorded under I1 to be 37.67, and 48.26 cm respectively, the values of AW under I2, I3 and I4 were reduced by 18.5%, 17.6%, and 22.3% respectively compared to I1 as mean of the two seasons. The values of productivity of irrigation water (PIW), and water productivity (WP) were taken the descending order W1> W2 > W3 > W4 and G2 > G1 > G3 for weed, and genotypes respectively. It could be recommended the I2 × W1 × G2 interaction which recorded the highest grain yield, PIW and WP, moreover saved a reasonable amount of irrigation water.