INTEGRATED APPLICATION OF BIO-STIMULANTS AND PHOSPHORUS ENHANCES PHENOLOGY, GROWTH, AND YIELD OF MAIZE

Abstract

Maize productivity is often constrained by suboptimal nutrient availability and poor early crop establishment, which can limit growth, reproductive development, and yield. This study investigated the effects of varying levels of bio-stimulants (0, 8, 10, and 12 L ha⁻¹) and phosphorus (0, 60, 90, and 120 kg ha⁻¹) on maize phenology, growth, and yield attributes at Charbagh Nursery Farm, Swabi, during Kharif 2024 using a randomized complete block (RCB) design with four replications. The results showed that both factors significantly influenced maize development, with notable interactions for several traits. Bio-stimulant application accelerated seed emergence, increased single leaf area, and enhanced plant height, while higher phosphorus levels improved leaf area and growth vigor. Tasseling and silking were delayed by bio-stimulants, allowing prolonged vegetative growth, with the combined application of 12 L ha⁻¹ bio-stimulant and 120 kg ha⁻¹ phosphorus producing the greatest delay. Grain yield components, including grains per ear and thousand-grain weight, as well as biological and grain yields, were significantly enhanced under higher levels of both factors, with the highest values recorded under combined application (408 grains ear⁻¹, 252.7 g thousand-grain weight, 12,958 kg ha⁻¹ biological yield, and 4,326 kg ha⁻¹ grain yield). Harvest index was also improved, reaching 41.6% under 10 L ha⁻¹ bio-stimulant × 90 kg ha⁻¹ phosphorus. In conclusion, integrating bio-stimulants with phosphorus at optimal levels enhances early crop establishment, promotes reproductive development, and maximizes maize yield, offering a practical strategy for sustainable intensification of maize production.