Khalil I. Al-Mughrabi1, Warren K. Coleman2, Appanna Vikram1 and René Poirier1
Partner: Potato Research Centre, Agriculture and Agri-Food Canada
Abstract: The effectiveness of plant essential oils or their individual components (S-carvone, peppermint oil, L-menthone, and spearmint oil) was tested in vitro against the potato pathogens Fusarium coeruleum, F. sambucinum, F. avenaceum, F. oxysporum, Alternaria solani, Rhizoctonia solani, Helminthosporium solani, Phytophthora infestans (A1), P. infestans (A2), Phytophthora erythroseptica, Phoma exigua and Pythium ultimum. All pathogens tested were found to be susceptible to S-carvone, peppermint, L-menthone and spearmint but their degree of susceptibility varied. Among all pathogens tested, R. solani, H. solani, P. erythroseptica, and P. infestans (A1 and A2 strains) were completely inhibited for periods ranging from 1-18 weeks by single continuous treatments of S-carvone, peppermint, spearmint and L-menthone. The effectiveness of mixtures of L-menthol or peppermint oil and aluminum starch octenylsuccinate (ASOS; Dry-Flo® Pure) on suppressing the growth of F. sambucinum and R. solani was tested in vitro. The percent inhibition of F. sambucinum by the combination of ASOS + L-menthol and ASOS + peppermint oil decreased over time while the same combinations were able to consistently inhibit the growth of R. solani over time. The antifungal activities of essential oils and their component against all tested pathogens suggest their potential as alternative tools for control of storage potato pathogens.
1Potato Development Centre, New Brunswick Department of Agriculture and Aquaculture, 39 Barker Lane, Wicklow, New Brunswick, Canada E7L 3S4; and
2Potato Research Centre, Agriculture and Agri-Food Canada, 850 Lincoln Road, P.O. Box 20280, Fredericton, New Brunswick, Canada E3B 4Z7