Comparison of the efficacy of Rhizome extracts of some family Zingiberaceae plants for antifungal Rhizoctonia solani Kuhn

Abstract

This research aims to compare the effectiveness of extracts from dried rhizomes of three Zingiberaceae species: ginger (Zingiber officinale Roscoe), galangal (Alpinia galanga (L.) Willd.), and fingerroot (Boesenbergia rotunda (L.) Mansf.). Extracts were obtained using Dichloromethane (CH₂Cl₂) and Methanol (CH₃OH) as solvents and tested for their ability to inhibit the growth of Rhizoctonia solani Kuhn., a pathogenic fungus causing sheath blight in rice. Laboratory experiments utilized the poisoned food method and followed a Completely Randomized Design (CRD). Mean values were compared using Duncan’s Multiple Range Tests (DMRT) with three replications at a concentration of 1,000 mg/L. Results showed that the Dichloromethane extract from galangal exhibited the highest inhibition (86.30%), with statistical significance (p≤0.05). Further analysis at concentrations of 200, 400, 600, 800, 1,000, and 1,200 ppm revealed an IC₅₀ of 583.02 ppm and 100% inhibition at 1,176 ppm. This study suggests that the Dichloromethane extract from galangal is a promising antifungal agent against R. solani, with potential applications in developing treatments for sheath blight in rice.