Abstract
The objectives of this work were to assess the in vitro effect of essential oils extracted from cinnamon, citronella, lemon grass, India clove, tea tree, thyme, neem and eucalyptus on the conidia germination and on mycelial growth of Cercospora coffeicola, and their efficacy to control the brown eye spot in coffee seedlings (cultivars Catucaí 2SL, Catuaí IAC 62 and Mundo Novo 379/19) in a greenhouse, as well as their effects on the initial germination and infection events by scanning electron microscopy. All essential oils promoted the inhibition of conidia germination with increasing concentrations. India clove, cinnamon, neem, thyme and lemon grass oils inhibited the mycelial growth of C. coffeicola. The cinnamon and citronella oils were the most promising for brown eye spot control in all cultivars. In scanning electron microscopy, the cinnamon and citronella oils reduced germination and mycelial development of C. coffeicola in vivo, eight and 16 hours after inoculation, promoting, in some cases, the leakage of the cellular content. Essential oils of cinnamon and citronella reduced the incidence and severity of brown eye spot, in addition to presenting direct toxicity to the pathogen.
Highlights
The brown eye spot, caused by Cercospora coffeicola Berk & Cooke, is one of the most important disease of the coffee plant (Coffea arabica L.), causing yield losses of up to 30%
The use of essential oils extracted from medicinal plants makes up a promising strategy, since, besides presenting antimicrobial properties (Schwan-Estrada & Stangarlin, 2003) and they were found to be promising for the alternative control of some plant diseases (Guiraldo et al, 2004)
The cinnamon, citronella, lemongrass and thyme oils totally inhibited the germination of the conidia starting from 1000 μL L-1, while India clove and tea tree oils totally inhibited the conidia germination starting from 1500 and 2000 μL L-1, respectively
Summary
The brown eye spot, caused by Cercospora coffeicola Berk & Cooke, is one of the most important disease of the coffee plant (Coffea arabica L.), causing yield losses of up to 30%. The disease usually causes intense plant defoliation, predisposing the fruits to infection by others pathogens. Affected fruits have their maturation process accelerated, which provokes their fall before the harvest and, depreciation of the drink quality (Pozza, 2008). The brown eye spot is conventionally controlled using protective and systemic fungicides (Zambolim et al, 2005; Abrahão et al, 2009). The use of essential oils extracted from medicinal plants makes up a promising strategy, since, besides presenting antimicrobial properties (Schwan-Estrada & Stangarlin, 2003) and they were found to be promising for the alternative control of some plant diseases (Guiraldo et al, 2004). The use of essential oils extracted from medicinal plants makes up a promising strategy, since, besides presenting antimicrobial properties (Schwan-Estrada & Stangarlin, 2003) and they were found to be promising for the alternative control of some plant diseases (Guiraldo et al, 2004). Fiori et al (2000) reported the fungitoxic activity of essential oils extracted from lemongrass (Cymbopogon citratus (A.D.) Stapf and eucalyptus
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
