Chemical composition, physico-chemical properties, antifungal and herbicidal activities of Pinus halepensis Miller essential oils

The chemical composition, physico-chemical properties, and antifungal and herbicidal activities of essential oils obtained by hydrodistillation from needles, stems and cones of Pinus halepensis Miller were investigated. The chemical composition analysed by GC and GC/MS varied significantly among organs. Among the 67 identified components, -pinene (63% and 51.7%, respectively, in stems and cones) and (Z)-caryophyllene (33.9% in needles) were found to be the major ones. Moreover, it was found that chemical composition of essential oils extracted from different organs of P. halepensis Miller growing in Tunisia showed noteworthy differences with the same species cultivated in Algeria, Morocco, Greece and Italy based on a comparison with published results. In addition, the physico-chemical properties of essential oils from different organs of P. halepensis were analysed. The analysis of the refraction index, density and acid index of different oil samples showed a weak variability among organs. The in vitro antifungal activity of the essential oil samples evaluated against 10 cultivated crop fungi was found to be low, probably due to the low level of oxygenated compounds in P. halepensis oils. In contrast, the herbicidal activity investigated towards three common weeds in Tunisian cereal crops was very strong and seed germination was inhibited at 2lml(1). Thus, P. halepensis essential oil appears to have more value as a bioherbicide than as a biofungicide.