BACTERIOSTATIC AND BACTERICIDAL ACTIVITY IN VITRO OF DIFFERENT ESSENTIAL OILS AS ALTERNATIVE TREATMENTS TO CONTROL XANTHOMONAS CITRI SUBSP. CITRI

Xanthomonas citri subsp. citri, the causal agent of citrus canker, is a pathogen difficult to control. Excessive use of pesticides has caused environmental contamination and has resulted in the selection of resistant strains of many pathogens, so the search for alternative control methods is of great importance. Several essential oils have shown bactericidal activity. The objective of this research was to evaluate the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of essential oils from Citrus aurantium (sour orange), Cymbopogon winterianus (lemongrass), Foeniculum vulgare (fennel), Pinus elliottii (pine) and Ocimum gratissimum (basil) against X. citri. To assess MICs, an ELISA plate micro-dilution method was used, and to assess MBCs, a 5-μl aliquot from the sample used for MIC determination was spread on Nutrient Agar (NA) plates. The essential oils from C. winterianus and C. aurantium were the most efficient against X. citri, with MIC and MBC values ≥0.487 µl/ml and ≥0.47 µl/ml, respectively. Further in vitro and in vivo research is needed to establish whether these essential oils are potentially useful for the integrated management of citrus canker.