The agricultural sector is the main pillar of the Egyptian economic structure, as it represents main source of food and clothing. In addition, it contributes to of the national income and Egypt faces a deficit in agricultural production, on the other hand consumption exceeds local production, and food is considered a vital necessity for people that cannot be dispensed. This research includes the statistical assessment of the macroeconomic econometric model of the variables of demand and supply of maize during the period (2005-2019), and the problem has become one of the most important problems threatening development in Egypt It has dangerous dimensions for the agricultural sector in particular and for the Egyptian economy in general, and that Egypt is still suffering from a food gap in most food commodities in a way that threatens Egyptian food security, as the equation of imports of corn shows that the volume of imports decreases by about 0.31%, 0.70% each An increase in the import price in dollars per ton, the average per capita production of the current year by 1%, meaning that the most influential variable in the volume of imports of corn in a particular year was the import price in dollars per ton, the average per capita production. It was also found that about 65% of the changes in imports of corn are due to the change in the independent variables under study, and that the average imports, production, and consumption of maize during the same period is 10.39, 6.67, 17.60 million tons, respectively, 15 % increase in the import price causes decreased in the quantity imported by 0.31%, The average of imports, production, and consumption of maize during the same period was 10.66, 7.70 and 17.80 million tons, respectively.

Several field trials and laboratory studies were conducted to evaluate the impact of the implementation of the activities and processes of the development of the field irrigation systems at ElMahmoudia area, El-Beheira Governorate, Egypt, during the successful growing seasons winter 2016/17 and summer 2017 to investigate the effect of irrigation systems improvement projects on water productivity. The measurements were conducted in a tertiary canal (Mesqa) at the head of Nekla canal (Arafa Mousa Mesqa). Water consumption values for different crops were calcaulated, and water application was calculated through calibrating the capacities of the pumps and recording the operation hours. The most important results were as follows: Applied irrigation water decreased after irrigation improvement. Applied irrigation water for wheat, rice, maize, sweet potatoes and watermelon before irrigation improvement were higher than the corresponding values after irrigation improvement by 9.0%, 15%, 11%, 15% and 10% respectively. The productivity of wheat, rice, maize, sweet potatoes and watermelon increased after irrigation improvement by 7.0%, 4.0%, 3.0%, 8.0% and 9.0% respectively. Water productivity increased after irrigation improvement, and the increase ratios for wheat, rice, maize, sweet potatoes were 14.0%, 16.0%, 13.0%, 20.0%, and 18.0% respectively.

This work aimed to study the effect of FYM rates (0, 10 & 20 m3 fed-1) and application in time of N fertilizer on maize grain yield and its attributes using single cross hybrid 130 at two field experiments. The technique of treatment - trait (TT) biplot graph was used to study the interrelationships among maize traits. The Results showed that application of 10 or 20 m3 FYM and adding the recommended N fertilizer on these doses with first, second or third irrigations gave highest values for the grain yield and most agronomic traits. It is obvious that the highest correlation coefficients were obtained between grain yield and each of number of ears plot-1 (NE),ear length (EL), ear diameter (ED) and 100 kernel weight (KW),under Gemmeiza location, while the traits of days to 50%tassiling and silking, plant height (PH), ear height (EH),   number of ears plot-1 (NE) and 100 kernel weight (KW) were the most associated traits with grain yield under Sids location. Using the TT biplot graph, results revealed that the best performance treatments for most studied across the two locations were the application (T11) before as well as application (T10). The results showed that TT biplot graph was an effective statistical tool to study the effects of treatments on yield and its attributes and also to discover the interrelationships among these traits. Accordingly, the maize breeder should give interest in the interrelationships among grain yield and its attributes when planning the breeding program.

The heat shock protein (HSP) family is one of the proteins universally accumulated under heat stress condition. Four Egyptian maize inbred lines (Zea mays L.) were studied to identify heat shock proteins under heat stress at 45°C as protein markers for detecting the thermo-tolerance inbreds. The protein fingerprints of four inbred lines were performed by grain total-soluble protein electcophoretic analysis. The protein electrophoretic analysis showed 18 bands in a distinct pattern of K1 and K7 inbred lines, while 17 bands were present in G342 and Rg59 inbred lines as another distinct pattern indicating different genotypes. The high temperature effect on four maize inbred lines exposed to 45°C for 2 and 4 hours at 14-days old seedlings besides control (25°C) was studied. Several protein bands varied between low and intermediate molecular weights were induced after exposing to heat stress at 45°C. Four bands of heat shock proteins with molecular weights of 82, 22, 17 and 10 kDa appeared in the inbred line K1 after exposing to 45°C for 2 and 4 hours which may be indication of thermo-tolerance. Four and seven bands were enhanced after exposing to high temperature for 4 hours at 45°C which appeared more concentrated in the patterns of K7 and G342 inbred lines, respectively.

Two field experiments were carried out at a private farm (newly reclaimed soil) at Somusta city, Bani-Suif governorate, Egypt, during 2014 and 2015 growing seasons. These experiments aimed to evaluate the application of different nitrogen sources and their combinations for increasing the productivity and quality of yellow maize (zea mays). Results showed that:                 Maize plants fertilized with120 kg MN/fad. recorded the greatest leaves number/plant (12.67) and number of green leaves /plant (12.67) after 45 days from sowing, however, the applied application of 60 kg MN/fad + 60 kg ONP /fad gave the maximum number of leaves /plant (15.17 and 17.83) and number of green leaves /plant (15.17 and 16.33) at stages of vegetative growth after 60 and 75 days from sowing, respectively. application of 60 kg MN/fad + 60 kg ONP /fad gave the highest values of leaf area index (LAI) at all stages of vegetative growth 3.16, 3.98 and 6.39 from 45, 60 and 75 days from sowing, respectively.                 At harvest maize plants fertilized with 60 kg MN/ fad + 60 kg ONP /fad recorded the highest value of grains number/row (32.83) followed by 60 kg MN/fad + 60 kg ONC/fad. the highest values of ears number/plant were recorded with the treatments 60 kg MN/ fad + 60 kg ONC /fad, 60 kg MN/fad + 60 kg ONP/fad and 60 kg MN/fad + 60 kg ONF/ fad with the same value (2.00). Data also revealed that the highest value of grain weight/plant (274.49) was recorded at 60 kg MN/fad + 60 kg ONP/fad treatment.                 Application of 60 kg MN/fad + 60 kg ONP/fad produced significant maximum grain yield (3.05 ton/fad.), biological yield (6.37 ton/fad) and grain crude protein yield (296.83 kg/fad).                 Maize plants treated with 60 kg MN/fad + 60 kg ONP/fad gave the highest values of grain and straw nitrogen percentage by 1.17 and 0.42% respectively. In addition the highest values of grain and straw phosphor percentage (0.49 and 0.20 %) and potassium percentage (4.30 and 1.90%) respectively were recorded with 120 kg ONP/fad.

Two field experiments were performed at Sids Agriculture Farm Research Station, Bani Swif Governorate during 2003 and 2004 seasons, to study the suitability of different tillage treatments, i.e. chisel plough two and three passes at 10, 15 and 20cm depths and intercropping patterns of maize and soybean i.e. two ridges of maize : two ridges of soybean (2:2) and two ridges of maize : four ridges of soybean (2:4) on water consumption, growth characters, yield and quality of maize (cv. T.W.C. 310) intercropped with soybean (cv. Clark). The results indicated that using chisel plough 3 passes decreased the value of mean weight diameter (M.W.D) by 33.00%, 27.92% and 31.87% as compared when using chisel plough 2 passes for 10, 15 and 20cm depths respectively. On other hand, yield and quality of maize, as well as, yield and quality of soybean were significantly increased by using tillage with chisel plough 3 passes. Both yield of maize and soybean per feddan. in pure stand were always higher than those within any intercrop combination, these results were true in both seasons. The data also revealed that maize yield in (2:2) pattern and using chisel plough 3 passes at 15cm depth gave the highest yield whereas, the highest yield of soybean per feddan was obtained when soybean plants grown in (2:4) pattern with 3 passes of chisel plough at15cm depth. On other hand the highest values of water use efficiency (W.U.E) in the two seasons were recorded when (2:4) pattern was applied and using chisel plough 3 passes at15cm depth The highest values of land equivalent ratio (LER) in the two seasons were 1.54 and 1.53 respectively   when (2:4 ) pattern was applied.

Identification of specific physiological differences among maize genotypes (six inbred lines, four single crosses and four three-way crosses) to drought would be useful to plant breeders for improving selection criteria. Two field experiments were conducted in optimum and stress moisture conditions at Gemmeiza Agricultural Re-search Station in 2001 and 2003 growing seasons. The treatments were 14 geno-types, (six inbreds and eight hybrids), which were separately established under three irrigation treatments in split plot design with four replications. The genotypes were compared under water-deficit conditions on the basis of certain rapid techniques to determine leaf area index (LAI), photosynthetic efficiency (photo), canopy tempera-ture depression (CTD), stomatal conductance (SC) and chlorophyll (CHL) content which were deleteriously affected by water stress in the sensitive genotypes. Results revealed that values of LAI, photosynthetic efficiency, canopy temperature depres-sion, stomatal conductance and chlorophyll content of maize hybrids surpassed those of inbred lines. This was true at 30, 45 and 60 days after planting (DAP). Dif-ferences among maize hybrids and among inbred lines were significant at different growth stages for the same studied traits, except of the LAI for the inbreds, at 30 DAP and CTD for the hybrids at 30 as well as 60 DAP. Detecting certain physio-logical criteria, i.e. LAI, photosynthetic efficiency (photo), canopy temperature de-pression (CTD), stomatal conductance (SC) and chlorophyll content (Chl) could be used as reliable techniques to explore the physiological activity of maize genotypes at early stages of growth and may be recommended in screening different genotypes in maize breeding programs.

Six population’s seeds of four yellow maize crosses were formed during 2001 and 2002 growing seasons. Their plants were evaluated during 2003 growing season under two planting dates (14th May and 29th June) for six agronomic traits at the Agric. Res. Stat. of Fac. of Agric., Ain Shams Univ., Shalakan, Kalubia Gover-norate, Egypt. The present work aimed to determine the genetic parameters and their interactions with planting dates for grain yield per plant, 100-kernel weight, number of kernels per row, ear length, ear diameter, and days to silking in the six popula-tions (P1, P2, F1, F2, BC1 and BC2). Mean values of the six populations for all studied traits in all crosses were higher under normal planting date than those under late one. Therefore, normal planting date seemed to be non-stress environment. The potence ratio for all traits in the four crosses exceeded (+1) except days to silking where it was less (-1). The highest heterosis percentage relative to mid and better parent reached 192.06% and 152.01% in cross 1 for grain yield per plant under late plant-ing date. Inbreeding depression values were not-significant in all studied traits ex-cept ear diameter and 100-kernel weight in crosses 1 and 3 as well as grain yield per plant in all crosses also, it was positive for most studied characters in the four cross-es except days to silking trait. Dominance occupied the first rank, additive or domi-nance type of epistasis occupied the second or the third contributor to the genetic ef-fects in order of importance according to cross with exception of days to silking, where additive and additive occupied the first and the second ranks. Narrow sense heritability was relatively high for yield attributes whereas it was low for grain yield per plant. Meantime, expected genetic advance was relatively moderate or low for all traits. Therefore, it could be suggested that selection for most studied traits in the subsequent generations will be relatively more effective than in the early genera-tions.

F1 and F2 seeds of four crosses were formed during 2001 and 2002 growing sea-sons. The F2 population’s plants were evaluated during 2003 growing season under the two planting dates (14th May and 29th June) to estimate the phenotypic correla-tion coefficients among eight plants characters and their contributions in the varia-tion of grain yield/ plant at the Agric. Res. Stat. of Fac. of Agric., Ain Shams Univ., Shalakan, Kalubia Governorate, Egypt. Results showed that grain yield/ plant under normal planting date correlated positively and significantly - in most cases - with each of ear diameter, ear length, number of kernels/ row, 100-kernel weight, number of rows/ ear, ear height, plant height and days to silking, while under late planting date, it correlated with each of number of kernels/ row, ear diameter, 100-kernel weight, ear length, number of rows/ ear, ear height and days to silking. Path coeffi-cient analysis estimates indicated that ear diameter; ear length and number of ker-nels/ row can be considered as the most important sources of plant grain yield varia-tion under normal planting date while, under late planting date they were number of kernels/ row, ear diameter, 100-kernel weight and ear length. It was concluded that each of ear diameter, ear length and ear length through its indirect effects via ear di-ameter are considered as the most important sources of plant grain yield variation.

Two trials were carried out at the Experimental Station farm of Desert Research Center, Teggzerty from Siwa Oasis, Matroh Governorate during the two summer seasons, 2015 and 2016. Trials were performed to study response of two maize hybrids.(Single hybrid 131 and Triple hybrid 329) to organic manure (OM) levels (15 and 30 m3/fed.) and five combinations between mineral and nano nitrogen (N) fertilizers: 1)100% mineral N from the recommended dose (120 kg N/fed.), 2)75% mineral + 25% nano N fertilizers, 3)50% mineral + 50% nano N fertilizers, 4)25% mineral + 75% nano N fertilizers, 5)100% nano N as the recommended rate (500 ppm as foliar application). Mineral N rates were added in three equal doses, with foliar application by nano N rates, after 30, 45 and 60 days from sowing. Treatments, included twenty treatments, was laid out in a splilt-split plot design, with three replicates, OM levels were arranged in the main plots, maize cvs. were allocated in the sub plots, and mineral nano N fertilizer treatments were assigned in the sub-sub plots. At harvest the following characters were recorded, plant height (cm), number of rows/ear, ear length (cm), ear diameter (cm), number of grains/row, 100-grain weight (g), ear weight (ton/fed), grain, straw and biological yields (ton/ fed), shelling (%) and harvest index(%). Results indicated that increasing OM levels significantly increased ear length harvest index and protein content (%), in the 2nd season only, triple hybrid gave the maximum values of all pa rameters, except no. of rows/ear and harvest index, in the 1st season, and 100-grain weight and carbohydrate (%), in both seasons, which had no significant difference with single hybrid in the most cases. Concerning with the effect of mineral and nano N, all parameters, except carbohydrate (%), were increased with increasing mineral N (%) and/or with decreasing nano N (%). Fertilized maize crop by mineral N at 100% or 75% plus 25% nano N fertilizer gave the maximum values of plant ht., no. of rows/ear, ear length and diameter, no. of grains/row, 100-grain wt.,ear weight, grain, straw and biological yields, shelling (%), protein (%), protein yield and harvest index in both seasons. However, fertilized maize crop by nano N at 100% produced the highest value of carbohydrate content (%) in two seasons. Results suggested that selected triple maize hybrid cv. (329), at 30 m3 OM, with 100% mineral N (120 kg N/fed.) or with 75% mineral N (90 kg N/fed.) plus 25% nano N (125 ppm as foliar application) fertilizers could be utilized for attaining the maximal improvement in farmer income by increasing the maize yield under saline conditions at Siwa Oasis, Egypt.