Variation in the chemical composition and yield of essential oil of rose-scented geranium (Pelargonium sp.) by the foliar application of metallic salts

摘要

The effects of foliar application of metallic salts (0.5% aqueous solution of sodium chloride, calcium chloride, iron sulphate, zinc sulphate, copper sulphate and nickel sulphate) on the chemical composition and yield of essential oil of rose-scented geranium (Pelargonium sp.) was studied in a pot experiment. The content of linalool, geraniol and 10-epi-γ-eudesmol in the geranium oil significantly increased and that of geranial and β-bourbonene decreased by the foliar application of metallic salts as compared to control plants. The increase in the content was 53.3%, 15.8%, 6.6%, 109.2%, 13.3% and 54.2% in linalool and 17.8%, 26.8%, 39.1%, 36.6%, 24.8% and 38.8% in geraniol over the control by the application of sodium chloride, calcium chloride, iron sulphate, zinc sulphate, copper sulphate and nickel sulphate, respectively. The content of 10-epi-γ-eudesmol was increased by 24.2%, 16.3%, 36.9%, 24.2%, 17.1% and 23.7% over the control by the application of sodium chloride, calcium chloride, iron sulphate, zinc sulphate, copper sulphate and nickel sulphate, respectively. The level of cis- and trans-rose oxide in geranium oil significantly increased and that of neral decreased by the application of sodium chlorides, zinc sulphate and nickel sulphate as compared to control. cis-3-Hexenol, isomenthone, neo-isomenthol, citronellol and citronellyl formate 2-phenylethyl tiglate and geranyl tiglate content in geranium oil was not significantly affected by the foliar application of metallic salts. The herbage and oil yield of geranium significantly increased by the foliar application of metallic salts as compared with control plants. The increase in yield was 9.9%, 9.4%, 30.6%, 29.7%, 28.6% and 21.6% in herbage and 41.9%, 23.4%, 29.6%, 29.6%, 41.9% and 41.9% in oil yield over control by the application of sodium chloride, calcium chloride, iron sulphate, zinc sulphate, copper sulphate and nickel sulphate, respectively. The oil content in the geranium was enhanced by the application of sodium chloride, calcium chloride, copper sulphate and nickel sulphate, whereas application of iron sulphate and zinc sulphate had no significant effect on the oil content.