Vol. 9, Special Issue 9, Part T (2025)

The study was conducted to characterize Azotobacter and PSB and assess the impact of bio-inoculants on the rhizosphere microbial and enzymatic status of chillies. The experiment was conducted with seven treatment and four replications. Azotobacter isolates (Azoto-122, Azoto-146 and Azoto-137) in Jensen’s medium produced circular, gummy, convex, with entire margin, whitish in colour while PSB (PSB-126) isolated in Pikovskaya’s agar media produced creamy to yellowish round with entire margin and, showing moderate clear zone surrounding the colony growth. Azoto-137 isolate showed positive reaction for starch hydrolysis, while positive reaction for catalase test, urease test, and oxidase test was observed for all isolates. Glucose fermentation and Gas evolution occurred with PSB isolate and in Azotobacter strain (Azoto-137). Analysis of rhizosphere soil of pot grown chilli crops, showed significant increase in the Azotobacter population from (8.64 log₁₀ cfu g^-1 soil) to (8.79 log₁₀ cfu g^-1 soil), PSB population from (6.09 log₁₀ cfu g^-1 soil) to (7.54 log₁₀ cfu g^-1 soil) also improved dehydrogenase activity from (2.86 μg TPF g^-1 soil h^-1) to (12.49 μg TPF g^-1 soil h^-1), phosphatase activity from (2.23 μg PNP g^-1 soil hr^-1) to (15.11 μg PNP g^-1 soil hr^-1), and basal soil respiration rate from (0.55 mg CO2 h^-1 100g^-1) to (1.07 mg CO2 h^-1 100g^-1) were recorded under the treatment T₇ (Azoto-137+PSB-126) as compare to control. Thus, the dual application of bio-inoculants Azotobacter and PSB showed significant best result and in the treatment T₇ (Azoto-137+PSB-126) recorded significant highest plant growth and rhizosphere soil analysis of chilli.