Chemical composition and anti-Xanthomonas citri activities of essential oils from Schinus molle L. fresh and dry leaves and of its major constituent spathulenol

Citrus canker, which is caused by Xanthomonas citri, is a severe disease that affects citrus plants worldwide. This paper aimed to compare, for the first time, the chemical composition and anti-Xanthomonas citri activities of essential oils from Schinus molle fresh and dry leaves (EO-FL and EO-DL, respectively). Anti-X. citri activity of spathulenol, the major constituent of oils, was also evaluated. Activities were screened by the broth microdilution method on 96‐well culture plates. Three major constituents were identified in EO-FL and EO-DL by GC-MS and GC-FID: spathulenol, β-caryophyllene and caryophyllene oxide. EO-DL (MIC = 31.25 µg/mL), EO-FL (MIC = 62.5 µg/mL) and spathulenol (MIC = 100 µg/mL) were active against X. citri strains (resistant, tolerant and sensitive to copper). Even though results showed that in vitro potential of EO-FL, EO-DL and spathulenol against X. citri, further in vivo studies are needed to prove their applicability to the biocontrol of citrus canker.