Abstract The objective of this work was to associate the use of biofilms to Lippia sidoides (Lippia) and Morinda citrifolia (Noni) essential oils and their respective major constituents in post-harvest quality components. The evaluations in this study were chromatographic analysis the essential oils, fruit mass reduction effect, total soluble solids, peel color and fruit firmness. Regarding the adjustment and viability of the essential oil concentrations to be used in the treatments, a phytotoxicity test was performed. The main constituent found in Noni essential oil was octanoic acid, while for Lippia essential oil was thymol. The concentration of 3% of Noni and Lippia essential oils was the maximum to reach an acceptable level of phytotoxicity on papaya fruit peel. The paraffin + L. sidoides and paraffin + M. citrifolia treatments achieved the lowest reduction in pulp mass. In relation to total soluble solids, treatments did not show a significant difference. The best result for firmness was found in sunflower oil + noni coating. Sunflower oil + noni and sunflower oil + octanoic acid were the treatments that maintained normal yellow color in fruits for longer time.

RESUMO: A ferrugem, causada pelo fungo biotrófico Olivea neotectonae, destaca-se como uma doença importante nas plantações de teca no Brasil. Considerando a importância atual dessa ferrugem e a necessidade de obter informações básicas adicionais sobre seu agente causal para melhor manejo da doença, o presente estudo teve como objetivo analisar a morfologia da O. neotectonae utilizando microscopia de luz e demonstrar o processo de infecção em folhas de teca por meio de técnicas de microscopia eletrônica de varredura (MEV). As características morfológicas observadas em microscopia de luz foram semelhantes às descritas na literatura para essa espécie. A MEV revelou que as estruturas de infecção do patógeno penetraram na folha de teca através do complexo estomático. Este estudo fornece a primeira evidência microscópica do processo de infecção de Olivea neotectonae em folhas de plantas de teca.

ABSTRACT: Rust, caused by the biotrophic fungus Olivea neotectonae, stands out as an important disease in teak plantations in Brazil. Considering the current importance of this rust and the need to obtain additional basic information about its causal agent to better disease management, the present study aimed to analyze the morphology of O. neotectonae using light microscopy and demonstrate the infection process in teak leaves using scanning electron microscopy techniques (SEM). The morphological characteristics observed using light microscopy were similar to those described in the literature for this species. SEM revealed that the infection structures of the pathogen penetrated the teak leaf through the stomata complex. This study provides the first microscopic evidence of the infection process of Olivea neotectonae in leaves of teak plants.

ABSTRACT The objectives of this study were to evaluate the effect of lemon grass, citronella grass, Mexican-tea and noni essential oils on urediniospore germination of Olivea neotectonae , the agent responsible for rust in Teak (Tectona grandis L.f.); to evaluate the phytotoxic effect of these essential oils on teak seedlings; and to evaluate the use of essential oils to control rust in teak plants when preventively and curatively applied. We found that the noni and lemon grass essential oils inhibited 100% of urediniospore germination. On the other hand, the essential oils from noni and lemon grass caused phytotoxicity when applied to seedlings at concentrations of 2000 and 1500 μL L-1, respectively. The major constituents found in lemon grass essential oil were Geranial and Neral, while Octanoic Acid was found in noni oil. Lower values in the area below the rust progress curve were observed with the preventive application of lemon grass and noni essential oils.