Integrated Application of Bio-stimulants and Inorganic Fertilizers on Growth and Productivity of Ragi (Eleusine coracana)

Finger millet (Eleusine coracana) cultivated under semi-arid conditions often experiences significant yield gaps due to imbalanced nutrient management. Integrated nutrient approaches combining inorganic fertilizers with bio-stimulants may enhance nutrient use efficiency and crop productivity in such environments.

A two-year field experiment was conducted during Rabi 2024-25 and 2025-26 at Hyderabad, India, to evaluate the integrated use of bio-stimulants with inorganic fertilizers on growth, yield and nutrient uptake of finger millet. The experiment was laid out in a randomized block design with eight treatments and three replications. The treatments included control (T¹), 100% recommended dose of fertilizers (RDF; T₂) and 100% RDF combined with seaweed extract (2 and 4 mL L^-1; T₃-T₄), humic acid (2 and 4 mL L^-1; T₅-T₆) and chitosan (2 and 4 mL L^-1; T₇-T₈) were applied at tillering and pre flowering stage as foliar spray using knap sack sprayer. Pooled data of two years were subjected to statistical analysis, including correlation and regression studies.

Pooled analysis revealed that 100% RDF+humic acid @ 4 mL L^-1 (T₆) significantly outperformed all other treatments. It recorded the highest plant height (76.2 cm), tillers hill^-1 (9.95), leaf area index (4.18) and dry matter production (5527 kg ha^-1). The same treatment also achieved superior yield attributes, including productive tillers m^-2 (128) and grains ear head^-1 (515), resulting in the highest grain yield (2140 kg ha^-1) and straw yield (3638 kg ha^-1). Nutrient uptake was also maximum under T₆ (N = 78.0, P = 13.1, K = 54.2 kg ha^-1). Grain yield increased by approximately 27% over RDF alone and 106% over the control. Correlation and regression analyses indicated strong positive relationships between nutrient uptake and grain yield (R²>0.9). The results demonstrate that integrating humic acid (4 mL L^-1) with RDF enhances growth, nutrient use efficiency and productivity of finger millet under semi-arid conditions.