Production of low cost Bacillus thuringiensis based-biopesticide for management of chickpea pod-borer Helicoverpa armigera (Huebn) in Pakistan

Abstract

The biopesticide was prepared from locally available low cost ingredients: dried beef blood, molasses and mineral salts (ZnCl2, MgCl2, MnCl2, CaCl2CaCl2, and FeCl3) which were used as medium for the laboratory scale production of Bacillus thuringiensis (B.t.) bio-pesticide by shake flask technique. Indigenous B.t. isolate PA-Sb-46.3 which produced two crystals—bi-pyramidal and cuboidal was found 73.6 times toxic against H. armigera than reference strain Bacillus thuringiensis var. kurstaki (HD-I-S-1980) used. Medium was fermented for 72 hours at 30˚C ± 2˚C and 160 rpm. 72 h fermented medium showed 95% - 99% sprulation, with spore yield of 3.97 × 109 spores/ml, and LC50 value to 1st instar larvae of H. armigera was 0.53 μg/ml diet. Preservatives and diluents used in the biopesticide were found to be effective to store at room temperature over a period of 30 months. These observations suggested that the biopesticide produced was effective and highly economical for the industrial scale production to manage H. armigera in Pakistan.