Effect of Bio Stimulants and Farm Yard Manure on Growth and Yield of Potato (Solanum tuberosum L.) at Thulasen, Achham

Potato (Solanum tuberosum L.), a member of the Solanaceae family, is considered the world's leading non-cereal crop, providing daily nourishment to over a billion people. A common misconception among farmers is the belief that only synthetic fertilizers can enhance yields, while locally prepared biostimulants are ineffective. This misconception is one of the key factors contributing to the low productivity of potatoes in Nepal. A field experiment was carried out at Thulasen- 6, Achham, in 2024 to study the effect of bio-enhancers and farm yard manure on the growth and yield of potato. The experiment was laid out in a Randomized Complete Block Design with six treatments and four replications. The ‘Khumal Rato’ variety was used for planting. The six treatments used in the research field were T1 (control), T2 (application of Farm Yard Manure @30 t/ha), T3 (seed treatment with Azotobacter @10 ml/kg seed tuber), T4 (seed treatment with Bijamrit @200ml/kg seed tuber), T5 (seed treatment with PSB @10 ml/kg seed tuber) and T6 (seed treatment with Jibamrit @200 ml/kg seed tuber).  The results indicated that T5 and T3 performed best initially in plant height and number of leaves, respectively, followed by T4 and T6 at later stage of plant growth. There was no significant difference among treatments in the number of stems per hill throughout the entire growth period of the crop. The maximum number of branches per plant was recorded in T3, along with a maximum number of unmarketable tubers. T5 showed best result in weight and number of marketable tubers per plot along with the maximum yield of 25.39 t/ha among all treatments, whereas T1 had the highest weight of unmarketable tubers. In terms of growth and yield performance, biofertilizers i.e., Phosphorus Solubilizing Bacteria (PSB) and Azotobacter gave the best results, followed by bio-enhancers i.e., Bijamrit and Jibamrit on different parameters. Also, in terms of economic feasibility, soil health, and sustainable production, T3 and T5 can be recommended.