Abstract:
Big onion ( Allium cepa L.) is an important condiment crop grown in Sri Lanka and is an essential part in the daily diet. Fungal pathogens cause damage to onion crops at all stages of growth and damping off disease at the nursery stage is a major constraint on onion production. Chemicals are used for the control of this disease at present. However, as the use of chemicals has many deleterious effects, biological control of plant diseases using antagonistic microorganisms is a promising strategy in sustainable agriculture. Some members of the genus Trichoderma are used widely as biological control agents of plant diseases, the present study was carried out to assess the ability of selected Trichoderma sp. isolated from local onion fields in suppressing the damping off pathogen Fusarium sp. in A. cepa L. under in vitro and green house conditions.