Indian clove essential oil in the control of tomato bacterial spot

Abstract

The goals of this work were to assess the potential of Indian clove essential oil in the reduction of tomato bacterial spot, and the activation of some plants biochemical defense responses. Tomato plants of cv. Santa Cruz Kada were sprayed with Indian clove essential oil (0.2 mg ml-1) and inoculated with Xanthomonas vesicatoria seven days later. Acibenzolar S-methyl (0.2 mg ml-1) was used as control. Indian clove essential oil and acibenzolar-S-methyl gave a control of 53.0% and 89.0%, respectively. The expression of resistance induced by Indian clove essential oil was made evident by an increase in β-1,3-glucanase, chitinase and peroxidase activity, which was also observed in plants sprayed with acibenzolar-S-methyl. This increase started in the first hours after spraying and continued for up to 12 days, while the lignin content increase was observed 12 days after spraying. Indian clove essential oil is a potential resistance inducer of tomato bacterial spot.