Chemical composition of the essential oil of Psidium guajava leaves and its toxicity against Sclerotinia sclerotiorum

• Published in: Semina. Ciências agrárias : revista cultural e científica da Universidade Estadual de Londrina Vol. 39; no. 2; pp. 865 - 874
• Main Authors: Silva, Elizabeth Aparecida Josefi, Silva, Vanessa Paula da, Alves, Cassia Cristina Fernandes, Alves, José Milton, Souchie, Edson Luiz, Barbosa, Luiz Cláudio Almeida
• Format: Journal Article
• Language: English
• Published: Universidade Estadual de Londrina 01.03.2018
• Subjects: Atividade antifúngica; Fungos fitopatogênicos; Metabólitos secundários; Psidium guajava; Sesquiterpenos
• ISSN: 1676-546X; 1679-0359
• DOI: 10.5433/1679-0359.2018v39n2p865

Globally, the fungus Sclerotinia sclerotiorum is considered as one of the most important phytopathogens, since it affects the production of several economically important crops. Further, it is difficult to control, thus increasing the use of pesticides. Therefore, the search for new substances, especially those extracted from plants, has received special attention to control this plant pathogen. The objective of the present study was to evaluate the yield and chemical composition of the essential oil extracted from the fresh leaves of guava collected during the rainy and dry seasons, and also to evaluate its toxicity against S. sclerotiorum. The experiment was a completely randomized design with five treatments and six replicates. The essential oil was extracted by hydrodistillation of the leaves and analyzed by gas chromatography-flame ionization detector and gas chromatography-mass spectrometry. The main compounds identified in the essential oil were trans-caryophyllene and ?-humulene. The essential oil at a concentration of 300 ?L exhibited 90% inhibition of the mycelial growth of S. sclerotiorum. This confirmed the antifungal potential of the essential oil of the guava leaves during both the sampling seasons.