The potential of thyme essential oil in controlling gray mold and Fusarium wilt and inducing systemic
acquired resistance in tomato seedlings and tomato grown in hydroponic system was evaluated. Thyme
oil highly reduced 64% of Botrytis cinerea colonization on pretreated detached leaves compared to untreated
control. Also, it played a significant decrease in Fusarium wilt severity especially at7 days post
treatment when it was reduced to 30.76%. To explore the plant pathways triggered in response to thyme
oil, phenolic compounds accumulation and peroxidase activity was investigated. Plant response was
observed either after foliar spray or root feeding in hydroponics which was mostly attributed to peroxidases
accumulation rather than phenolic compounds accumulation, and thyme oil seems to be more
effective when applied to the roots.