Abstract

An outcry is exhibited against the use of pesticides due to their hazardous effects on human as well as the environment. There is a great concern regarding the nano materials, which have the potential to exert hazardous effects on humans and the environment, and when we have a nano-pesticide, it becomes a double-edged weapon. In the present study, nanohexaconazole was synthesized by nano-encapsulation of hexaconazole with polyethylene glycol (PEG), and the resultant nano-dispersion has shown excellent efficacy against a number of important fungi like Rhizoctonia solani. Nanohexaconazole was characterized by SEM, TEM, and FT-IR etc., and it was found to be less than 100 nm in size. Appropriate formulations have been developed for future field level use under proper regulatory measures. Patent application on nanohexaconazole has been filed. The present study also evaluated the effect of nanohexaconazole on the total microbial count, soil enzymes and seed germination. Comparing the results of various enzyme activities, like soil dehydrogenase (DHA), fluorescein diacetate (FDA), alkaline phosphatase (Alk P), acidic phosphatase (Acid P) and microbial count after application of a nanomaterial was taken as a criterion for testing, whether such materials are causing an adverse effect of soil health or not. Contrary to the expectation, the enzymatic activities were found significantly higher than untreated control as well as in samples treated with commercial hexaconazole. The dehydrogenase activity of nano hexaconazole treated soil increased to 309.59 µg TPF g–¹ 24 hrs–¹ in comparison to untreated control 178.4 µg TPF g–¹ 24 hrs–¹ on 30th day. Statistical analysis proved that the soil health was not adversely affected by application of the nanopesticide. Nanopesticides developed by us are better than conventional and are required in a lesser dose, resulting in less pollution of the environment for sustainable agriculture. We have to ensure the materials we introduce in environment are evaluated before launching. The process of Registration of pesticides will need to be modified and also a protocol for handling them has to be developed specially for nanomaterials. Newer technologies can therefore be adapted with surveillance and social control for sustainable agriculture.