Optimizing nutrient management for flowering induction in maize inbred lines

Abstract

Fertilizer management and synchronization of flowering for inbred lines play a vital role in commercial maize hybrid seed production. The objective of this study was to optimize nutrient management for flowering induction by evaluating the combined application of chemical fertilizers and specific plant growth regulators (Auxin, Gibberellic Acid, and 2,4-D) in the inbred lines, viz. RML-86, RML-96, and RML-95. The research was conducted in the research field of the National Maize Research Program, Rampur, Chitwan, Nepal, over two consecutive spring seasons, 2020 and 2021. The experiment was laid out in a Randomized Complete Block Design with three replications and nine treatment combinations. The research results revealed that flowering induction in response to the fertilizer and growth regulator applications was highly dependent on the specific maize inbred lines. Throughout the two seasons, grain yield varied among maize inbred lines in response to NPK and plant growth regulator management. Based on the pooled data across the nine treatments, grain yield differed considerably among the three maize inbred lines. RML 96 recorded the highest mean grain yield (3374 kg ha⁻¹), followed by RML 95 (3161 kg ha⁻¹), while RML 86 had the lowest mean grain yield (1666 kg ha⁻¹). Across the two years, the maximum yield was 3846 kg ha⁻¹ in RML 95 under 120:60:40 kg NPK ha⁻¹ + recommended micronutrients, followed by 3719 kg ha⁻¹ in RML 96 under 150:60:40 kg NPK ha⁻¹. The minimum yield was 909 kg ha⁻¹ in RML 86 under 120:60:40 kg NPK ha⁻¹ + 2,4-D. Overall, RML 96 and RML 95 showed greater yield potential and better response to optimized nutrient and hormone management for further evaluation under similar agro-ecological conditions. Maximizing yield and synchronizing flowering in commercial maize hybrid seed production requires a genotype-specific approach, as different inbred lines require distinct levels of fertilization and hormones to reach their full potential. Ultimately, combining customized nutrition with beneficial growth regulators like auxin and gibberellic acid, while avoiding suppressive treatments such as 2,4-D, is the most effective strategy for optimizing floral induction and achieving high yields.