Influence of Co-distillation with Weed Biomass on Yield and Chemical Composition of Rose-Scented Geranium (PelargoniumSpecies) Oil

A laboratory experiment was performed to study the influence of distilling rose-scented geranium (Pelargonium species) biomass together with different proportions (0, 5, 10, 15 and 30% by weight of rose-scented geranium biomass) of biomass of weed species growing in rose-scented geranium fields, on the yields % and compositions of oils of cultivars Algerian, Bourbon and Kelkar. Crop:weed mixtures reduced oil yields of all the three cultivars in comparison to control (pure crop biomass). Combined distillation of biomass of cv. Algerian with weed biomass decreased the concentrations of linalool, geraniol, geranyl formate, 10-epi-γeudesmol and increased the contents of isomenthone, citronellol and citronellyl formate in its oil. This distillation method resulted in enhancements in isomenthone, citronellol and reductions in geraniol and geranyl formate in the oil of cv. Bourbon. In cv. Kelkar, the percentages of linalool and isomenthone increased, but that of citronellol and geraniol decreased in crop:weed mixed distillations.