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.