Seedling diseases and collar rot/stem rot caused by Sclerotium rolfsii are the major constrains of soybean production in Bangladesh. A series of experiments were conducted to control seedling mortality and stem rot of soybean caused by S. rolfsii through Trichoderma fortified compost at BSMRAU research field. Pathogenicity test confirmed that S. rolfsii (isolate SR4) was causing 95% seedling mortality therefore, considered as the most aggressive isolate. Trichoderma harzianum (Isolate-Chan 6) was used for inocula preparation with different composting substrates like cow dung, saw dust, rice straw, water hyacinth and poultry manure to prepare Trichoderma fortified composts. Among the composts, Trichoderma fortified poultry manure was found as the best treatment in reducing 75.45% pre-and post-emergence seedling mortality and diseases severity (84.53% reduction) as well as increased yield (80.91% increase) and yield attributing characters such as 55% increase of plant height and 27% increase of 1000 grain weight compared to control. However, other composts also showed good response in reducing seedling mortality and growth promotion though they were not similar in performance with Trichoderma fortified poultry manure. Therefore, Trichoderma fortified composts have the immense potentiality to suppress diseases and improve yield of soybean. These studies should be conducted at the farmers field before validating the substrates as Trichoderma fortified composts.
Key words: Trichoderma, compost, growth promotion, pathogenicity test.
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