Abstract

Rice sheath blight is one of the prominent diseases caused by Rhizoctonia solani causes significant losses in rice growing regions of Tamil Nadu. The present study was undertaken with an objective to assess the prevalence and incidence of rice sheath blight in different regions of Tamil Nadu, India during 2018–2019 and assess the cultural, morphological characters and pathogenic variability among ten numbers of isolates of R. solani. The survey in different regions of Tamil Nadu revealed the endemic nature of the sheath blight disease with the maximum disease incidence (19.97%) recorded in Chitrakudi of Thanjavur region (RS5). Also, the isolates of R. solani exhibited cultural, morphological and pathogenic variability among them the isolate RS5 was exhibit faster mycelial growth, maximum sclerotial production and sclerotial size and recorded the maximum incidence of root rot disease under pot culture conditions. Also, in this study potato dextrose agar medium was found to be as best medium for supporting the mycelial growth and sclerotial production of isolate RS5. Hence, RS5 was found to be most virulent isolate and may be taken up for further studies.