Effect of plant extracts against sheath blight of rice caused by Rhizoctonia Solani

Abstract

A total of 11 plant (parts of plants) were extracted with three different solvents (hexane, chloroform and methanol) sequentially and tested against Colletotrichum musae (anthracnose of banana) and Rhizoctonia solani J.G.Kuhn (sheath blight of rice) @ 0.2% concentrations of 20EC formulation. Among the different plant extracts leaves of clerodendrum (Clerodendrum infortunatum L.), polyalthia (Polyalthia longifolia Sonn.) and rhizomes of ginger (Zingiber officinale Roscoe) were found most active against the pathogens. These active plant extracs were tested further in pot culture and field experiment on rice plant against Rhgizoctonia solani. In general the Plant extracts showed significant inhibition of radial growth of all the test pathogen but the most effective plant extracts was clerodendrum extract, found to be most effective against rice sheath blight pathogen both in pot culture and field experiment. Carbendazim 50WP (1g/lt) was used as standard fungicides for comparison. Test fungicides at applied concentration also expectedly inhibited the fungal growth and lesion length in pot cultured plants and disease severity under field condition.