Field experiment was carried out during the spring and fall seasons of 2019 at the Abu Ghraib Research Station of the Agricultural Research Office/ Ministry of Agriculture, was aimed to investigate the effect of plant growth inhibitors on growth and yield of several sorghum varieties .Randomized Complete Block Design within split plot arrangement with three replications was used. The main plot consists of three growth inhibitors (Cycocel, Ethiphon, and Mebiquat), which were added at stages six and eight leaf stage, in addition to the control treatment (distilled water only), the sub plot was included three cultivars (Mabrouk, Buhooth 70 and Giza 113). The results showed in both seasons significant interaction between cultivars and growth inhibitors in most of the studied traits. The plants of the variety Giza 113 sprayed with Ethiphon recorded the lowest period of reaching physiological maturity, the highest average dry matter yield, and the highest weight of 1000 grains (89.00 days, 17.32 ton ha-1, and 39.33 gm) respectively. The same variety recorded the highest content of chlorophyll in the leaves and the highest grain yield due to the effect of Mebiquat (49.50 spad, 3.93 ton ha-1. The cultivar Buhooth 70 with the effect of Cycocel achieved the highest average of dry matter yield of 33.27 ton ha-1.

The experiment was carried out according to the randomized complete block design (R.C.B.D) and the arrangement of split-split plot with three replications, at the Field Crops Research Station of the Agricultural Research Department - Abu Ghraib during the spring season for the years 2019 and 2020. With the aim of studying the effect of amino acids, planting dates and their effect on some of the yield characteristics and its components for three varieties of maize in the spring season. Planting dates (March 15, March 25 and April 5) occupied the main plots, while amino acids and the control treatment (proline, arginine, and distilled water) occupied the sub-plot, whereas the varieties (Rabi, Baghdad 3 and Fajr 1) occupied the sub-sub-plot, and the most important results were summarized as follows:The two cultivars, Rabi and Fajr-1, achieved a significant increase in most of the yield characteristics and its components for the seasons. The addition of the amino acid proline also led to a significant increase in most of the studied traits (the number of grains in ear, weight of 500 grains, total grain and biological yield, and harvest index), planting dates also have a significant effect on most of the studied traits. The first date (15/3) recorded increase in the number of grains per ear, the weight of 500 grams, and the grain and biological yield. The plants of the Rabi variety when cultivated on March 15 th and sprayed with the amino acid proline achieved the highest average for the grain yield, which reached 7.48 ton. ha-1 for spring 2019.

A field experiment was carried out at the Field Crops Research Station of the Agricultural Research Department - Abu Ghraib during the spring season for the years 2019 and 2020. With the aim of studying the effect of amino acids and planting dates on some growth characteristics, for three varieties of maize. A split-split plot was used according to a randomized complete block design (R.C.B.D) with three replications. The experiment included three planting dates (March 15, March 25 and April 5) that represented the main plot, while amino acids (proline and arginine) and the control treatment (distilled water) occupied the subplot. Whereas, the three varieties (Rabi’, Baghdad 3, and Fajr 1) allocated to the sub-sub plot. The Rabi cultivar gave the fewest days to reach 75% male and female flowering (70.33 and 72.78 days) respectively. The Fajr 1 variety scored the highest average percentage of proline and arginine in leaves for the first season. Plants sprayed with proline at a concentration of 200 mg achieved the highest mean number of leaves, leaf area, chlorophyll content in leaves, and proline concentration in leaves for both seasons. When spraying arginine, its percentage increased in leaves. Planting dates affected most of the studied traits, planting plants on March 15 achieved a significant increase in all growth traits. The two and three way interactions had a significant effect on most growth traits, and the best interaction was for the Rabi variety when planted on March 15 th and sprayed with proline.

Field experiment carried out in the seasons 2011/2012 and 2012/2013 in Abu Ghraib Research Station/ Agricultural Research Office. Experiment included 16 genetic entrance from ICARDA in addition to the local variety (D7) for comparison. Treatments were distributed in (RCBD) design with three replications. Significant differences were observed among all genotypes and studied traits. ICARDA-14 and local variety, gave higher values (84 and 85.11 cm) for plant height, local variety and ICARDA -16 (9.5 and 8.940 cm) for spike length, ICARDA-8 and 12 (20.57 and 20.5) for spikelet number/spike, ICARDA-9 and 16, (70.2 and 66.32) for grain number/sike, ICARDA -6 and 2 gave highest weight of 1000 seed, (41.18 and 38.76 g), while ICARDA -12 and 3 were superior in spikes number/m 2 (527.5 and 490.2), grain greater for ICARDA -12 and 3 (5.187 and 4.787 t / h). The highest biological yield was for each ICARDA-1 and the local variety, which were superior in dry weight also (19.95 and 17.61 t / ha) but the highest harvesting index was for ) in both seasons, respectively.