Foliar application of Potassium to Enhance Growth and Yield of Bread Wheat Cultivars Under Rainfed and supplemental Irrigation

A field study was conducted during the winter season of 2023-2024 in Mosul City, Nineveh Governorate, northern Iraq, to evaluate the impact of potassium fertilizer application on the growth and productivity of wheat grown under varying irrigation conditions. The experiment was designed with a randomized complete block design (RCBD) in a split-split-plot arrangement with three replications. The main plots owned two irrigation conditions (rainfed and supplemental irrigation), the sub-plots contained three potassium fertilizer levels (0, 1.5, and 3.0 L/ha), and the sub-sub-plots involved six bread wheat cultivars (Tamoz 2, Wafia, Jihan 99, Adna 99, Aliz 66, and Aras). The findings revealed that Wafia cultivar exhibited the highest values of Number of days to flowering (126.97 day), Spikes number (326.2 spike/m2), Grains number (51.73 grain/spike), Biological yield (8165 kg/ha), Grain yield (2946 kg/ha). Additionally, the application of potassium at 3 L/ha significantly improved various growth traits. Furthermore, supplemental irrigation enhanced all observed traits. In summary, increased potassium application boosted plant drought resistance and improved growth and yield traits.