Chandra, SatishTabyo, Tilling2023-02-172023-02-172010https://krishikosh.egranth.ac.in/handle/1/5810193984The disease is commonly referred to as pod blight complex by many researchers as more than one fungus have been reported from a number of soybean producing countries. The present investigation was focused on etiology, yield loss, resistance and management of disease by integrating botanicals, bioagents and fungicides in vitro as well as in vivo. Microscopic examination revealed the association of Colletotrichum truncatum with pod blight complex. Conidia (13.5-24.3 X 2.7-4.5 flm) were single celled, falcate and hyaline. Dual culture test revealed that the Trichoderma viride was more effective in reducing the radial growth than Trichothecium roseum. The slide test (agar block) for presence or absence of hyperparasitism and colonization potential of bioagents also confirmed the efficacy of T. viride in vitro. Two botanicals viz., Cymbopogon sp. and Neemazol (Azadirachta indica) were tested against C. truncatum by poisoned food technique. Cymbopogon sp. was found to be more effective as compared to Neemazol in reducing the radial growth of test pathogen. Simultaneously, four fungicides viz., propiconazole, tricyclazole, mancozeb and copper oxychloride were also evaluated. Results revealed that propiconazole was highly effective in reducing the growth followed by tricyclazole, mancozeb and copper oxychloride. Efficacy of botanicals and fungicides was evaluated for inhibition of conidial germination. Both were effective in inhibiting the conidial germination of C. truncatum but chemical fungicides were superior to botanicals. The highest inhibition percent was observed in case of propiconazole followed by tricyclazole, mancozeb, copper oxychloride, Neemazol and Cymbopogon sp. Neemazol was effective in inhibiting the conidial germination compared to Cymbopogon sp. Thirteen genotypes of soybean were screened under field conditions. Genotypes DSB 12, DS 2614, MACS 1188, MAUS 417 and MACS 1184 were moderately resistant while TS 2, MACS 1039, DS 2613, AMS I, RKS 52, NRC 80, MACS 1140and JS 335 were susceptible. Out of these, seven genotypes were selected for estimation of yield losses under protected and unprotected conditions. Out of seven genotypes MACS 1188, TS 2, AMS 1 and JS 335 were found to be tolerant against C. truncatum. This was calculated using maximin-minimax method. Management trial using different treatments revealed that propiconazole was best (PDT 2.33) with yield of 1396 kg/ha, followed by tricyclazolse, mancozeb, Neemazol and T.viride.EnglishThesis