Essential oil of Lippia origanoides possible product biorrational in the potato crop (Solanum tuberosum)

Abstract

Background: Lippia origanoides H.B.K. (Verbenaceae) is a wild bush with high essential oil (A.E.) contents, this fraction reports different biological properties including biocidal effect on microorganisms. Because essential oils can be integrated into the concept of biorational products, this research was proposed as an alternative to pesticide reduction in potato cultivation. Objectives: Evaluate the biocidal activity of the L. origanoides essential oil against potato pathogens: Phytophthora infestans and Alternaria solani at in vitro level. Methods: Essential oil was obtained from L. origanoides leaves by steam distillation, the volatile chemical composition was determined by gas chromatography-mass spectrometry (GC/MS). The biocidal activity of essential oil was assessed by culture medium dilution technique calculating the percent inhibition. Finally, the sensitivity of plant pathogens versus the essential oil was determined by changes in reproductive structures by morphometric analysis. Results: The major component of essential oil was thymol 60,7%. Phytopathogenic P. infestans and A. solani showed high sensitivity to the extract, which was established the relationship 300μl.ml-1 cause’s inhibition in mycelial growth of pathogens. The morphometric analysis showed differences in reproductive structures that underwent to essential oil, presenting a smaller size compared to the control. Conclusions: There is a high potential for the use of L. origanoides essential oil as a biorational product against phytopathogenic P. infestans and A. Sonali in potato crops. © 2016, Universidad de Antioquia. All rights reserved.