Efficacy of nanocompounds against Pyricularia oryzae causing rice blast disease under in vitro conditions

Abstract

The study was conducted to assess the ability of nano-formulated compounds to directly inhibit mycelial

growth and conidial formation of Pyricularia oryzae, the causal agent of rice blast disease. The findings indicated

that zinc-based nanocomposites combined with aqueous extracts of Annona glabra (0.024%), of Impatiens

balsamina (0.024%), and of Catharanthus roseus (0.024%), as well as nano chitosan–SA formulations at

concentrations of 0.006%, 0.013%, and 0.027% incorporated into PDA medium, all exhibited direct inhibitory

effects on the pathogen growth under in vitro conditions. Among the treatments, nano chitosan–SA at 0.027%

demonstrated the highest suppression of colony development, reaching 17.58% at 12 days after putting fungal

slices. This formulation also strongly inhibited conidial formation, achieving 62.60% suppression at 22 days after

fungal slices, highlighting its potential for application in rice blast management.