Composition and yield of commercial essential oils from parsley. 1: Herb oil and crop development

Essential oils were extracted from aerial parts of plain and curled leaf parsley cultivars in commercial crops, from spring in the crops' second year until full seed ripeness. Continual and extensive changes in fresh weight, oil content, yield and composition in whole plants were associated with plant development stages during the growing season, and within different parts of dissected crop plants. Contribution ratios (% oil yield/% fresh weight) were calculated to identify the plant parts which accumulated oil most efficiently. Stem and leaf tissues were less efficient than umbels and more costly to extract. The aromatic characters of the oils from the different parts were determined by the balance of two groups of compounds. The typical parsley leaf character was associated most closely with p-mentha-l,3,8-triene and the stronger seed character with myristicin and apiole. Single sampling of oils is inadequate for comparisons between cultivars or for effective management of commercial crops. The commercial significance of the results is discussed.