S14 - Session P1- Antagonistic activity of extremophilic fungal and bacterial strains against soil borne diseases of vegetable crops

Authors: Abdullah Al-Sadi *, Rethinasamy Velazhahan

The production of vegetable crops has increased dramatically in Oman over the last years (i.e. tomato production increased by 1500% over 40 years), making them an important source of income to growers in the country. Despite the importance of vegetable crops in the economy of growers in Oman, soilborne diseases have been a major challenge to their production, resulting in losses that were reported to reach 100%. These diseases are caused by different fungal and oomycete species, including Pythium, Fusarium, Rhizoctonia and Monosporascus . Management of soilborne diseases has relied mainly on the use of fungicides. However, the frequent application of fungicides has brought with it concerns from environmental and health hazards. In addition, it has resulted in the development of fungicide resistance among populations of fungal and oomycete pathogens. Such challenges to the use of fungicides necessitate the development of efficient ways for the management of soilborne plant diseases under arid conditions. Work in our laboratory over the last four years has resulted in screening more than 500 microorganisms (fungi and bacteria). Among them, several agents proved to have high efficacy in suppressing soilborne plants diseases, mainly damping-off and wilt. Findings on the most efficacious strains, their mechanisms of actions, and their growth promoting features will be presented, with a special focus on the extremophilic strains.