Biological control of Fusarium solani sp. dalbergiae, the wilt pathogen of Dalbergia sissoo, by Trichoderma viride and T. harzianum.

The fungus Fusarium solani sp. dalbergiae was isolated from infected trees of Dalbergia sissoo. Several efforts of controlling the disease including biological means, both in vitro and in vivo, were tried. It was concluded that the fungus had been successfully destroyed by the two antagonists, Trichoderma viride and T. harzianum. Microscopic studies demonstrated mycoparasitism at different stages of hyphal interaction between the antagonists and the tested fungus. A distinct line of demarcation was produced between them in Petri dishes. In the in vivo tests, seven-month-old seedlings were placed in plastic pots containing soils inoculated with the pathogenic culture. Positive results were obtained in healing the seedlings in the fields. The efficacy of T. viride was superior to T. harzianum