Journal of Environmental Biology

Survey and occurrence of Rhizoctonia solani (Kuhn) causing sheath blight of rice and in vitro efficacy of bacterial antagonists against Rhizoctonia solani (Kuhn)

K.V. Neha, P. Balabaskar and R. Naveenkumar

 Department of Plant Pathology, Faculty of Agriculture, Annamalai University, Annamalainagar, Chidambaram-608 002, India

*Corresponding Author E-mail: chuidruv91@gmail.com

 Publication Data

Paper received:

13 October 2015

Revised received:

16 May 2016

Accepted:

20 August 2016

Abstract

Sheath blight of rice caused by a soil-borne fungal pathogen, Rhizoctonia solani Kuhn is a destructive disease in all crop-growing areas of the world. A survey carried out to assess the occurrence of sheath blight disease incidence in major paddy growing areas of Cuddalore district of TamilNadu, India revealed the endemic nature of disease. Maximum PDI was recorded in Naduthittu (36.5%) followed by Vadakkumangudi (32.4%), Vallampadugai (26.5%), Muttlur (21.4%) villages and moderate incidence was noticed in Shivapuri, Periyakannadi, Vandurayanpattu, Keerapalayam, Vadalore, Kanthakumaran, Orathur, Permapattu, Thiththampalayam, Bhuvanagiri villages and least incidence was noticed in Ramapuram (10.5%) location. Generally, the crops grown in clay soil and at panicle initiation stage of the crop recorded fairly higher disease incidence. Among the antagonists tested under in vitro conditions, P. fluorescens was found to be more antagonistic than R. solani. Under pot culture conditions, the combined application of P. fluorescens as ST @ 10 ml kg^-1 of seeds + seedling root dip @ 3.0 l ha^-1significantly reduced the incidence of sheath blight in rice to minimum, and increased the plant growth and yield of rice to maximum.   

 Key words

Antifungal activity, Rhizoctonia solani, Pathogenicity, Bacterial antagonists, Rice

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