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Soybean (Glycine max (L.) Merrill) is affected by many soil borne diseases. Of these, collar rot caused by Sclerotium rolfsii Sacc. is gaining a serious status. In Karnataka, it is prevalent in soybean growing areas under rainfed ecosystem. Management of soil borne diseases incited by species of Sclerotium, Rhizoctonia and Fusarium through one approach is quite difficult (Anahosur, 2001). Hence various seed dressing fungicides and bio-agents were evaluated in vitro and further the effective ones in vivo singly and in combinations against this disease. Sixtyfour soybean genotypes were also evaluated for resistance against S. rolfsii. Seven systemic fungicides (Table 1) were evaluated under in vitro condition against S. rolfsii following poisoned food technique (Zentmeyer, 1955). Radial growth was measured when the growth in control plates reached 90 mm diameter and percent inhibition of mycelial growth over control was calculated using the formula of Vincent (1927).

Sterilized soil: sand: FYM (1: 1: 0.5) was uniformly mixed with four percent S. rolfsii inoculum multiplied on sand-corn meal medium and filled in 40cm x 30 cm sized pot. Seeds treated with fungicides, bio-agents and their combinations were sown in eight pots@ 10 seeds per pot. Pots were regularly watered and observations were recorded on 7th and 20th day after sowing for pre-and post-emergence seedling mortality and was converted as per cent seedling mortality. Sixty-four genotypes were screened under glass house in pot culture (Agrawal and Kotasthane, 1971) as also described earlier. Surface sterilized seeds were sown@ 10 seeds per pot separately. The pots devoid of …