Investigation of Pesticidal Activities of Essential Oil of Eucalyptus camaldulensis Dehnh

Abstract

In this study, chemical compositions of the volatile oil extracted from Eucalyptus camaldulensis Dehnh. were analyzed by using GC and GC-MS. The oxygenated sesquiterpenes, monoterpene hydrocarbons, sesquiterpene hydrocarbons and oxygenated monoterpenes compositions were detected in the sample studied. Pesticidal effects of this oil were investigated on storage insect pests like Rhizopertha dominica F. (Col.: Bostrychidae), Sitophilus granarius L. (Col.: Curculionidae), Tribolium confusum Duv. (Col.: Tenebrionidae), Callosobruchus maculatus F. and Acanthoscelides obtectus Say. (Col.: Bruchidae). The essential oil was tested on some fungal pathogens and weeds. As fungal pathogens, Verticillium dahliae Kleb, Fusarium oxyporum Schl., Phytium debaryanum Auct. non R. Hesse, Sclerotinia sclerotiorum (Lib.) de Barry and Rhizoctania solani KUlm. were used while tests on the weeds were performed on Convolvulus arvensis L., Melilotus officinalis L. and Amaranthus retroflexus L. in invitro conditions. E. camaldulensis essential oil was found to be effective at 10 and 20 mu L against all the tested insect pests. Our results also showed that growth of fungal mycelial as well as weed stems and roots were significantly affected by essential oil. In 10 and 20 mu L, V dahliae, P. debaryanum, F. oxyporum and S. sclerotiorum mycelial growth were inhibited in 7 days, while no effect was observed on R. solani mycelial growth in this duration. On the other hand, the applications of the oil to the weeds showed different results for each species examined. Although at 5, 10 and 20 mu L concentrations of E. camaldulensis essential oil did not affect the root and stem growth of C. arvensis, the stem and root growth of M. officinalis and A. retroflexus were reduced by the tested essential oil at the same concentration and time. The research results suggest that E. camaldulensis essential oil might have potential to be used as a natural pesticide as well as fungicide.