The experiment was conducted to study the effect of 4 organophosphate (OP) chlorpyrifos, malathion, phorate, dimethoate and 4 bio-pesticides (BP) bio-sanjeevani, biosoft, neemta, karanj extract on growth response of non targeted beneficial soil bacterium. Three strains of bacteria (Sphingomonas sp. SZL-1, Pseudomonas mendocina sp. PC19, Brevundimonas sp. XJ-412) were isolated from ICAR Research Complex for Eastern Region, Plandu, Ranchi by 16S rDNA gene sequence analysis. In spectrophotometer analysis organophosphate (Conc.1000µl) treated bacteria resulted in the declination of optical density (OD) while biopesticides (Conc.1000µl) treated bacteria showed optimal response as compared to control (0 to 40 hours time interval). Statistical analysis was carried out using Levene’s test of homogeneity for analysis of variance and Dunnett’s test for comparative mean estimation of better option among organophosphates and bio-pesticides for soil bacteria which play essential role in sustainable soil fertility. Levene’s test of homogeneity justified for growth of pseudomonas (F = 10.14), sphingomonas (F = 8.57), brevundimonas (F = 11.96) on treatment with OP and BP. Dunnett’s test estimated that, bio-sanjeevani has maximum growth response (0.64 ± 0.4) and critical difference (+0.41), while malathion has minimum growth response (0.26 ± 0.18) and critical difference (-0.04) with respect to control (0.73±0.48) for pseudomonas.
