Antagonistic Effect of Trichoderma Isolates against the Fusarium Wilt of Bael under Soil Condition

The investigation entitled “Biological Management of Nursery Diseases (Root rot and wilt) of Bael (Aegle marmelos Correa)” was conducted in the Narendra University of Agriculture and Technology, Kumarganj, Faizabad during 2012-2013. At nursery stage about 35-40% seedlings of Bael (Aegle marmelos Correa) were died due to root rot and wilt. The disease is highly prevalent during rainy season under warm and high humidity as well as low sunshine hours (4-6 hrs/day) that further aggravated the situation. The affected seedlings may come out on soil surface but failed to grew further. The root rot affected seedlings remained alive for sometimes but under highly disease conducive condition none of the seedlings survived beyond one month. They either toppled over or become necrotic black and finally died. The population of F. solani infested soil could be minimized by treating the soil with T. harzianum, T. virens and T. viride. Trichodema harzianum and T. virens grew very fast. Beside T. harzianum parasitized over F. solani, resulted into lyses of its hyphae. The antagonistic activity of T. viride happened due to its yellow pigments secreted in the rhizosphere. The yellow coloured metabolite was toxic and killed the hyphae of F. solani. Thereafter, T. viride grew over the space cleared by its metabolite on the basis of the results of the present experiment. Application of T. viride and T. virens as preventive measures and that of T. harzianum as curative one may be suggested.