Journal of Biology and Nature

A field experiment was conducted during the Rabi season of 2024 at the Research Farm, Department of Agriculture (Horticulture), Mewar University, Gangrar, Chittorgarh (Rajasthan) to evaluate the effects of bio-enzyme and humic acid on growth and yield attributes of onion (Allium cepa L.), variety ‘Nasik Red’. The experiment was laid out in a factorial randomized block design comprising two factors: four levels of bio-enzyme (control, salicylic acid @ 100 ppm, citrus peel-based bio-enzyme @ 60 ppm, and a combination of both), and four levels of humic acid (control, 1, 2, and 3 kg/ha), making a total of 16 treatment combinations with three replications. The results revealed that the combined application of salicylic acid @ 100 ppm and citrus peel-based bio-enzyme @ 60 ppm along with humic acid @ 3 kg/ha (treatment B4H4) significantly improved various growth parameters such as plant height (48.23 cm), number of leaves per plant (7.15), and leaf length (44.13 cm). Likewise, yield attributes including polar diameter (5.87 cm), equatorial diameter (6.64 cm), neck thickness (1.13 cm), average bulb weight (64.15 g), and total yield (27.15 t/ha) were also highest under the B4H4 treatment. These results suggest that salicylic acid and citrus-based bio-enzymes enhance physiological processes, while humic acid improves soil fertility, thereby synergistically promoting onion growth and productivity. In conclusion, the combination of salicylic acid and citrus peel-based bio-enzyme with humic acid at 3 kg/ha proved to be the most effective for optimizing the growth and yield of onion. This integrated approach can be recommended for sustainable and efficient onion cultivation under similar agro-climatic conditions.