In vitro evaluation of five different neem based bio-pesticides viz., neem oil, neem leaf difusate, replin, nimakil and nimboli for their efficacy against mycelial growth of Rhizoctonia solani AG 3 isolate SL-41 was assessed at 0.5, 1, 1.5 and 2% concentrations of the potato dextrose agar medium. Antifungal activity of bio-pesticides in inhibiting mycelial growth of the fungus differed and depended on bio-pesticides and their concentrations. Replin was found to be the most effective as it caused complete (100%) inhibition in mycelial growth of the fungus at 2% concentration followed by nimboli and nimakil. Neem leaf diffusate was least effective in reducing the mycelial growth of the fungus. Neem oil at 2% concentration was as effective as Nimakil at 1.5% concentration. All the tested bio-pesticides completely inhibited the induction of stem girdling and stem canker symptoms of the disease. Black scurf management by potato tuber treatment with three bio-pesticides, selected on the basis of their antifungal activity against mycelial growth of the isolate SL-41, differed in terms of number of eyes germinated, sprout killed and black scurf incidence & severity. Maximum eye germination was achieved through the application of Replin. Nimakil was the most effective in decreasing black scurf incidence and severity over non-treated inoculated control while nimboli resulted in the least number of sprouts killed but overall manifested the least effectiveness.