Vol. 12, Issue 8 (2023)

Root rot of fenugreek (Trigonella foenum-graecum L.) caused by Rhizoctonia solani has become an important constraint to the growers of fenugreek in Rajasthan. Root rot affected plants of fenugreek were collected from surveyed areas of Rajasthan viz., Jaipur, Ajmer, Jhunjhunu, Bikaner and Nagaur districts. Isolation was done from the diseased roots of fenugreek samples, collected during survey from the fields showing higher per cent of disease incidence. Purified cultures of twelve samples were provisionally identified as Rhizoctonia solani based on morphological and colony characters. Thus, twelve isolates were established from each district and decoded as JPR Rs-1, JPR Rs-2, BKN Rs-3, BKN Rs-4, AJM Rs-5, AJM Rs-6, JJN Rs-7, JJN Rs-8, NAG Rs-9, NAG Rs-10, LCL Rs-11 and LCL Rs-12. Among twelve isolates, JPR Rs-1 (23.85 mm day^-1) indicated slow growing nature and does not covered whole petri plate within 96 h followed by LCL Rs-12 (25.28 mm day^-1) and fastest growth rate observed in JJN Rs-7 (39.12 mm day^-1). The isolate JPR Rs-1 showed texture as smooth and raised at periphery, isolate LCL Rs-12 i.e., rough and raised colony and showed dull white, JPR Rs-2 i.e., smooth colony and looked hyaline white in colour whereas, JJN Rs-7 i.e., wrinkled colony appear off white colour. JPR Rs-1 caused maximum disease incidence (57.36%) which was significantly higher over other isolates, followed by LCL Rs-12 (53.44%) and JPR Rs-2 (52.99%). Lowest disease incidence (35.61%) was observed with NAG Rs-10 isolate. Among these twelve isolates, highly pathogenic was JPR Rs-1 isolate while NAG Rs-10 isolate was weak pathogenic.