New nano-fungicides for the management of sheath blight disease (Rhizoctonia solani) in rice

Abstract

Rice sheath blight, caused by Rhizoctonia solani, is one of the increasing concerns in rice causing severe economic losses worldwide. Chemical control measures are already in practice for the management of this disease but approach for discovery of new chemicals with improved disease control potential is essential. The present investigation involves the development of nanoformulations of halogen substituted azomethines as new potent fungicide for the management of sheath blight disease in rice. The halogen substituted azomethines were synthesized and screened for in-vitro bioefficacy. Then the azomethines were nanoformulated for their in-vivo pot culture evaluation against Rhizoctonia solani. Transmission electron microscopy confirmed the particle size of the developed nanoformulations in the range of 1–100 nm. In-vitro inhibition results of test compounds revealed their ED50 values in the range of 11.9 to 22.4 μg/ml with best performer 2,4,5-trichloro-N-(2,4-dichlorobenzylidene)aniline. 3-Chloro-N-(2,6-dichlorobenzylidene)-4-fluoroaniline displayed maximum in-vivo efficacy against R. Solani which was comparable with that of hexaconazole, a standard recommended fungicide.