Improving the Efficacy of Biopesticides Based on BT

Three features of biopesticides that differentiate them from synthetic pesticides and make them attractive to producers are the following:- (i) biopesticides can be used for resistance management, especially since many have multiple modes of action which would reduce the chance of resistance occurring in a particular crop pest; (ii) many biopesticides have no or low restricted entry intervals, meaning that post-application, restricted entry into fields is very low (0-4 h) and there are often no limitations prior to harvest; and (iii) there are generally exemptions for biopesticides from maximum residue limits because they are considered acceptable and relatively safe. Even though insecticidal formulations based on Bt toxins have been used for many years, it was the development and commercialization of insect-resistant transgenic Bt crops expressing Cry toxins that revolutionized the history of agriculture. Benefits of this technology include high specificity and potency, reduction in chemical pesticide applications, increased crop yield and has the potential to be recommended for pest management in organic farming.