Control of Rhizopus stolonifer in strawberries by the combination of essential oil with carboxymethylcellulose

Strawberry has a limiting postharvest shelf life, especially because of soft rot. The antifungal activity of the essential oils (EOs) of Eucalyptus staigeriana, Lippia si doi des and Pimenta pseudocaryophyllus was tested in vitro against plant pathogen Rhizopus stolonifer. The chemical composition of the EO with the highest activity and its effects on pathogen morphology were verified. The in vivo antifungal activity of this EO associated with carboxymethylcellulose (CMC) coating, in preventive and curative applications, was also evaluated. L. sidoides EO presented the highest in vitro antifungal activity. The analysis of the chemical composition of this EO showed a prevalence of the compound thymol and the scanning and transmission electron microscopy showed that L. sidoides EO was able to cause damage to the cell wall and the intracellular components of the pathogen. Strawberries treated with L. sidoides EO associated with CMC presented a reduction in disease severity, especially when treated in a curative way.