The effect of potassium fertilizer and planting dates on the growth and production of maize (Zea mays L.)

An agricultural field study was conducted in Ramadi City, located in the Western region of Iraq, during the fall season of 2023, with the objective of examining the effect of three planting dates. viz 25 March, 5 and 15 April, and three levels of potassium fertilizer, including 100, 150 and 200 kg K2O per hectare, on maize, variety Buhuth 106. Variations in planting dates exerted a notable impact on traits, including plant height, leaf area, ear length, number of ears per plant, weight of 300 grain total grain yield. The planting date of 25 March gave the highest rate of the studied traits, reaching 202.00 cm, 3990 cm2, 15.138 cm, 1.824, 73.82 g and 4.372 tons. ha-1 respectively. Significant differences were observed between the levels of potassium fertilizer for the same traits above. the potassium fertilizer level of 100 kg K₂O. ha-1 was associated with the highest average values observed across all of the measured traits, which amounted to 187.156 cm, 3490 cm-2, 13.413 cm, 1.752 cm, 71.15 g and 3.301 tons. ha-1 respectively. The combined effect of the experimental variables also demonstrated a clear influence on grain yield, as planting on 25 March combined with the application of 100 kg K₂O per hectare resulted in the highest recorded grain yield of 5.210 tons.