Optimum Nitrogen Fertilizer Dosage for Composite and Hybrid Varieties of Maize
Maize productivity in Indonesia needs to be increased, including using superior varieties and proper fertilization. The study aimed to determine the optimum nitrogen fertilizer dose for the growth and yield of composite and hybrid maize. The experiment used a split-plot design with varieties as the main plot and the dose of nitrogen fertilizer as the sub-plots. Two maize varieties of Bisma (composite) and Pioneer 27 (hybrid) were grown and fertilized with nitrogen at 0, 67.5, 135, 202.5, and 270 kg ha-1. The increasing nitrogen dose up to 270 kg ha-1 linearly significantly increased total biomass, ear weight with husk, ear weight without husk, ear diameter, seed weight per ear, and weight of seed per plot. Plant height, number of leaves, and ear length showed a quadratic response to the dose of nitrogen with an optimum of 167.7, 174.0, and 221.6 kg ha-1, respectively. The nitrogen dose of 221.6 kg ha-1 is optimum to achieve high productivity for both varieties.
Keywords: biomass weight, ear weight, ear diameter, optimum dose, productivity