Vol. 9, Issue 5, Part E (2025)

Onion is also known as Allium cepa L., is a bulbous biennial herb from the Alliaceae family. Inoculation with Azotobacter increases sporulation and mycorrhizal infection in onions due to growth-promoting substances produced by the bacteria, leading to enhanced plant growth, nitrogen and phosphorus uptake, ultimately improving crop productivity. Similarly, Azospirillum bacteria, through symbiosis with onion roots, fix atmospheric nitrogen, increasing nitrogen availability in the soil. Gibberellic acid (GA₃) is a plant growth regulator that influences onion growth by promoting stem elongation, increased internode length and cell division in leaves, stems, and bulbs. Result of this study, it can be deduced that the optimal approach to achieving a favorable crop growth, yield parameters, coupled with an impressive highest yield (248.69 q/ha) involves the application treatments. Specifically, the combined utilization of Azotobacter (5 kg), Azospirillum (5 kg), GA₃ (100 ppm) and humic acid (2 kg) has proven to be highly effective.