In order to study the effect of heterosis and nature of genetic on plant height and yield traits were studied in a 7x7 diallel cross without reciprocals and their F 2 generation in wheat to define and select an efficient and prospective material for immediate use in hybridization programs to improve grain yield of wheat in Egypt. Parents, F 1 and F 2 were evaluated for quantitative traits in 2016/2017 season. Significant genotype mean squares and its components (parents and crosses) were obtained for all traits in both generations. Significant heterosis in F 1 generation was obtained for all studied traits. Heterosis of grain yield/plant relative to mid parent varied from 4.64 to 75.50% in F 1 crosses. The P2xP3, P1xP4 and P2xP5 were the best crosses for grain yield heterosis. General (GCA) and specific (SCA) combining ability mean squares were significant for all traits. MS (GCA)/ MS (SCA) ratios indicated the relative importance of additive and non-additive gene action in their inheritance for all the traits. The nine crosses i.e. P1xP2,

Significant differences were detected among the studied sowing dates, where; the first sowing date gave the heaviest shoot dry weight and the highest leaf area index at 50, 65 and 80 days in the two studied seasons. The highest value of CGR at 50-65 days at the first sowing date in the first season, also CGR and NAR achieved the highest values at 65-80 days from sowing at 30 November in the second season and at 15 December in the first season. Number of days taken to emergence, tillering and jointing were gradually reduced with wheat planting from 15 December to 1 November, however, number of days to maturity was gradually increased. Moreover life cycle of wheat gradually decreased with delayed planting. Sowing date at 1 st of November achieved the highest values of GDD in tillering, jointing, booting, heading and maturity, while sowing date at 15 th December achieved lowest values of GDD in both studied seasons. The highest chlorophyll content, heat use efficiency, harvest index and heaviest biological and grain yield/ fed were obtained at sowing date 30 November in the two studied seasons. Tested wheat genotypes significantly difference, where Gemmieza 11 cultivar and Line 4 had the heaviest shoot dry weight and highest leaf area index at 50, 65 and 90 days in both seasons. Moreover, at 80-95 days Giza 171 gave the superiority for net assimilation rate in both seasons and for crop growth rate in the second season only, also at 50-65 days Line 3 and 65-80 days Line 4 gave the highest value of CGR in the first season. Moreover, maximum days and accumulated GDD detected for Giza 171 at jointing stage and Line 4 at maturity in the two seasons. Giza 171 gave the highest value for chlorophyll content and 1000-kernel weight in both seasons and HUE, plant height and harvest index in the first season, while biological yield in the second season. The highest number of tillers/m 2 was recorded in Sids 13 cultivar and spike length for Gemmieza 11 in both studied seasons. Also, Line 3 had the highest biological yield in the first season and Line 4 for HI in the second season. The interaction between sowing dates and genotypes had significant, where; in most cases, delayed sowing (15 December) had adverse effects on shoot dry weight, leaf area index, crop growth rate, net assimilation rate, phenological stages and growing degree days but the intensity varied among wheat genotypes. Sustaining the growth in late sown conditions of Shandaweel 1, Giza 171, Line 3 and Line 4 was clear indication of its adaptability measures to terminal heat stress. Planting of Giza 171, Gemmieza 11 and Line 4 on 15 or 30 November seemed the most productive combination. The finding of this investigation may help both physiologists and breeders in determining the sowing dates and genotypes could be selected for good growth and high yield.

A half diallel cross between eight common bread wheat varieties and/or lines (Triticum aestivum vulgare L.) was evaluated under three different nitrogen rates for six quantitative characters in RCBD with three replications. Nitrogen rates, genotypes, parents, hybrids, genotypes x nitrogen rates interaction and hybrids x nitrogen rates mean squares were significant for all traits under study. General and specific combing ability mean squares were found to be significant for all traits. High ratios which largely exceeded the unity were obtained for all studied traits except grain yield/plant in low and normal nitrogen fertilization rates indicating that large part of the total genetic variability associated with these traits was additive and additive by additive gene action. For the exceptional case GCA/SCA ratios was less than unity, therefore, it could be concluded that the large portion of the total genetic variability associated with this case is due to non-additive gene action. The largest heterotic magnitude express by the previous traits. May strength ened the conclusion about the 9 importance of non-additive gene effects in their inheritance. For grain yield/plant; eight, ten, eight and sit crosses expressed significant and positive (ij

Two field experiments were conducted at Etay El-Baroud Experiment station of El-Behira Governorate, Egypt during 2017/2018 and 2018/2019 seasons to examine three planting methods of intercropping green and full mature onion with wheat i.e. 1-planting in flat soil (without ridges), wheat was planted in rows 20cm apart and onion was transplanted among the rows of wheat, 2-growing wheat on ridges (60cm apart) in 2 rows on top and northern side of the ridge and onion was transplanted on southern side of the same ridge and 3-growing wheat on the wide ridges (120cm apart) in 4rows and onion was transplanted on both sides of the same ridge and two intercropping systems (100% wheat + 50% green onion and 100% wheat +50% full mature onion as well as sole wheat, sole green and full mature onion. Results show that, planting methods had no significant effect on yield and its components of wheat, except spike length and number of spikes/m 2 were significantly affected by planting methods in the two growing seasons while, 1000 grain weight was significantly affected by planting methods in 2018/2019 season only. The tallest spikes length were recorded under planting method {120cm (M 3 )} while, the highest number of spikes/m 2 and 1000 grain weight were recorded under planting method {without ridges (M 1 )}.On the other hand, green and full mature onion per feddan were significantly affected by planting methods, the highest main values were recorded by growing onion on the two sides of ridges {120cm apart (M3)}. Intercropping green and full mature onion had no significant effect on yield of wheat, while the sole onion achieved the highest yield/fed compared to intercropping systems. Generally, growing green onion on the two sides of wide ridges {120cm apart (M3)} with wheat recorded the highest Land Equivalent Ratio (LER), Relative Crowding Coefficient (K) and net returns compared to sole wheat. In all intercropping treatments, wheat was the dominant whereas, onion was the dominated.