Imidazole based nanofungicides: antifungal efficacy against Rhizoctonia solani and biosafety assessment

Various nanotechnology advancements are used to protect crops and the safety concerns of nanopesticides for soil quality need to be addressed. Soil enzymes and certain beneficial bacteria play a vital role in preserving soil health by carrying out required biochemical reactions. In the present study, clotrimazole, econazole nitrate, and miconazole nitrate based nano-fungicides were investigated for their antifungal efficacy followed by their biosafety assessment. Antifungal studies of all the test nano-fungicides demonstrated their effectiveness against Rhizoctonia solani. The relative lesion heights were 29-38% under field conditions and they ranged from 17% to 33% in pot experiments. Impact of these nano-fungicides on urease activity in soil was comparable with the conventional fungicide hexaconazole, as evident from the presence of 0.5-2.7 mg/kg urea-nitrogen after 24 h of 200 mg/kg urea-nitrogen application. In all the treatments, the activity of soil nitrifiers was not adversely affected after application of these nano-fungicides. After 21 days of incubation, the nitrate-N contents were in the range of 150-180 mg/kg in nano-fungicide treated soils as compared to 180 mg/kg of nitrate-N in urea control. Virtual risk assessment using docking of these imidazole derivatives on soil enzymes revealed their behavior similar to that of hexaconazole.