Effect of fungal and bacterial biological agents on seedling damping-off of fungus disease

The current study been conducted to achieveto effective antagonists for diseases control of seedling damping-off greenhouse pepper, casead by Rhizoctonia solani. Experiments has conducted based on completely randomized design in the faculty of agriculture and natural resources of Lorestan University in 2016-17. First, the fungi and biological agents were isolated and identified of the rhizosphere of Solanaceae plants. The antagonistic ability of fungal and bacterial isolates, such as Trichoderma harzianum and Trichoderma virens fungi and Bacillus subtilis bacteria, against R. solani was studied by using dual culture method. As well as antagonistic ability of fungal and bacterial agents and Trichomix HV biological fungicide were study in a greenhouse condition. The results showed that both species of T. harzianum and T. virens the prevented growth of fungi 9.45 and 15.59 percent respectively by colonization and sporulation in PDA. Antagonistic bacterial also caused effects such as outpour of the contents of hyphae, color change at the tip of hyphae, thinning and reduction of mycelium up to 8.47 percent. Also, results in greenhouse condition showed that B. subtilis and T. harzianum treatments have the most positive effects on growth traits such as height and weight (wet and dry) of the root and stem and reduced the severity of the disease up to 60.33 and 70.33 respectively; therefore they are the best antagonistic agents to control R. solani on pepper.