MALIKIREDDY SWATHI*, M.K. JYOSTHNA, R. SARADA JAYALAKSHMI DEVI, L. PRASANTHI AND S. GOPALAKRISHNAN

Department of Plant Pathology, S.V. Agricultural College, ANGRAU, Tirupati-517502.

ABSTRACT  

Diseased samples of sheath blight was collected from the fields of RARS, Nandyal and isolation of pathogen was done by following different methods. Evaluation of different methods of artificial inoculation of R. solani was carried out. The efficiency of R. solani infection was tested on susceptible cultivar, NLR-34449 using four different methods (agar block, liquid cultured mycelia ball, mycelia suspension and typha bit method). Observations were taken 10 days after inoculation by measuring the relative lesion height (RLH), where RLH in each tiller was calculated. Typha bit inoculation method of R. solani longer lesions than other methods, liquid cultured mycelia balls, including agar block and mycelia suspension. Inoculation by Typha bit method was found to be more efficient for artificial inoculation of R. solani. The pathogen was re-isolated and maintained in PDA slants for further studies.

KEYWORDS: Isolation, Inoculation, Pathogenicity, Koch postulates.