Abstract
The chemical composition of essential oils isolated by hydrodistillation from the needles of Tunisian Pinus nigra L. subsp. laricio was analyzed by GC and GC/MS. 27 compounds were identified, representing 97.9% of total oil, which was found to be rich in oxygenated diterpenes (38.5%) particularly manool oxide (38%) and sesquiterpene hydrocarbons (41.4%) that included germacrene D (16.7%), delta-cadinene (9%) and (E)-caryophyllene (8.9%). Results of the herbicidal effects of the oil when tested on Phalaris canariensis L., Trifolium campestre Schreb. and Sinapis arvensis L., indicated that the oil completely inhibited germination and seedling growth at a high concentration (5 mu L/mL(-1)), while at low doses the oil acted by decreasing germination and partially inhibiting seedling growth of all tested weeds. (C) 2014 Production and hosting by Elsevier B.V. on behalf of King Saud University.