Studies on Growth Phase and Characteristics of Rhizoctonia solaniCaused Root Rot in French Bean on Different Solid and Liquid Media

The experiment were conducted on growth and development of sclerotial production of Rhizoctonia solani on different solid media and also studied the growth phase of R.solani on potato dextrose broth medium. The various solid media viz., Potato dextrose agar, Malt Extract Agar, Oat Meal Agar, Czapeck's, Sabouraud's Agar and Host extract Agar mediumwere used to knowthe nature of the fungal growth. Among the six solid media, PDA (89.66 mm) and MEA (89.43 mm) medium showed better growth of the fungus followed by Oat meal agar (88.06 mm). The sclerotial production of Rhizoctonia solani varied in different solid media tested. Highest number of sclerotia per microscopic field was recorded on PDA (74.68) followed by MEA (73.03) and least production were in CA (70.83). Observations on colony colour, type of margin, topography and number of sclerotia production of Rhizoctonia solani at the end of seventh day of incubation are recorded. With reference to colony colour and sclerotia productions of Rhizoctonia solani showed blackish brown colour with flat growth on all the media tested except the colony colour which was dark brown in host extract agar and white in case of Czapeck's Agar. The dry mycelial weight of Rhizoctonia solani was highest on 12^th and 14^th day of incubation period and the dry mycelial weight was 194.21 and 198.00 mg respectively.