|ZHELJAZKOV, VALTCHO - Mississippi State Extension Service|
|ASTATKIE, TESS - Nova Scotia Agricultural College|
Submitted to: Agronomy Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/1/2011
Publication Date: 3/20/2011
Citation: Zheljazkov, V.D., Cantrell, C.L., Astatkie, T., Cannon, J.B. 2011. Lemongrass productivity oil content and composition as a function of nitrogen sulfur and harvest time. Agronomy Journal. 103(3):805-812.
Interpretive Summary: Lemongrass (Cymbopogon flexuosus) is one of the most widely grown essential oil plants in the tropics and subtropics of India, Indonesia, Madagascar, and countries in Africa and South America. Lemongrass is grown as a perennial crop under either irrigated or non-irrigated conditions, but a large area is harvested from wild natural habitats such as in mixed forests or along banks of canals and rivers. Lemongrass biomass is steam distilled for the extraction of essential oil, a natural product with wide application in the food and pharmaceutical industries, perfumery and cosmetics, and eco-friendly pesticides. Field experiments were conducted at Verona and Poplarville, Mississippi, to evaluate the effects of nitrogen (N) and sulfur (S) on lemongrass biomass productivity, essential oil content, yield, and oil composition. Overall, the essential oil content varied little. Overall, dry weight yields increased with the application of 80 kg N/ha relative to the 0 kg N/ha and with 160 kg of N/ha relative to the 0 and 40 kg N/ha treatments. The development of lemongrass as an essential oil and biofuel crop in the southeastern United States would provide a new cash crop for growers. Lemongrass oil production may also encourage local value-added processing of the essential oil, a spin-off effect that may improve the economic sustainability of the region.
Technical Abstract: Lemongrass [Cymbopogon flexuosus (Steud.) Wats, (syn. Andropogon nardus var. flexuosus Hack; A. flexuosus Nees)] is one of the most widely grown essential oil plants in the world. Field experiments were conducted at Verona and Poplarville, Mississippi, to evaluate the effects of N (0, 40, 80, and 160 kg N/ha) and S (0, 30, 60, and 90 kg S/ha) on lemongrass biomass productivity, essential oil content, yield, and oil composition. Overall, the essential oil content varied within 0.35%–0.6% of the dried biomass. The major constituents were geranial (25%–53%), neral (20%–45%), caryophyllene oxide (1.3%–7.2%), and t-caryophyllene (0.3%–2.2%). Biomass yields at Verona ranged from 9,486 to 19,375 kg/ha, while oil yields ranged from 30 to 139 kg/ha. Overall, dry weight yields increased with the application of 80 kg N/ha relative to the 0 kg N/ha and with 160 kg of N/ha relative to the 0 and 40 kg N/ha treatments. At Poplarville, biomass yields varied from 8,036 to 12,593 kg/ha, while oil yields ranged from 23.5 to 89.5 kg/ha. The application of N at 160 kg/ha at Poplarville increased dry weight yields relative to the N at 0 or 40 kg/ha rates, irrespective of the rate used for S. At Verona, within each S application rate, biomass yields were highest in harvest 2, lower in harvest 1, and the lowest in harvest 3 (regrowth). The combined biomass yields of harvest 1 and harvest 3 would be lower, but oil yields would be higher compared to harvest 2 (single-harvest system). Lemongrass can be grown as an annual essential oil crop in the southeastern United States, with a potential for dual utilization: essential oil and lignocellulosic material for ethanol production.