|Chrysopogon zizanioides |
Chrysopogon zizanioides, commonly known as vetiver (from Tamil வெட்டிவேர்), is a perennial grass of the Poaceae family, native to India. In western and northern India, it is popularly known as khus. Vetiver can grow up to 1.5 metres high and form clumps as wide. The stems are tall and the leaves are long, thin, and rather rigid; the flowers are brownish purple. Unlike most grasses, which form horizontally spreading mat-like root systems, vetiver's roots grow downward, 2–4 metres in depth. Vetiver is most closely related to Sorghum but shares many morphological characteristics with other fragrant grasses such as lemongrass (Cymbopogon citratus), citronella (Cymbopogon nardus, C. winterianus), and Palmarosa (Cymbopogon martinii). Though it originates in India, vetiver is widely cultivated in the tropical regions of the world. The world's major producers include Haiti, India, Java, and Réunion. Because vetiver propagates itself by small offsets instead of underground stolons, it is noninvasive and can easily be controlled by cultivation of the soil at the boundary of the hedge. Vegetatively propagated, almost all vetiver grown worldwide for perfumery, agriculture, and bioengineering has been shown by DNA fingerprinting to be essentially the same nonfertile cultigen (called "Sunshine" in the United States, after the town of Sunshine, Louisiana).
The Vetiver System, a technology of soil conservation and water quality management, is based on the use of the vetiver plant.
The vetiver grass has a gregarious habit and lives in bunches. Shoots growing from the underground crown make the plant frost and fire resistant and allow it to survive heavy grazing pressure. The leaves can become up to 120-150 centimeters long and 0.8 centimeters wide. The panicles are 15-30 centimeters long and have whorled, 2.5-5.0 centimeters long branches. The spikelets are in pairs, and there are three stamens.
The plant stems are erect and stiff. They can persist deep water flow. Under clear water, the plant can survive up to 2 months.
The root system of vetiver is finely structured and very strong. It can grow 3–4 meters deep within the first year. Vetiver has no stolons nor rhizomes. Because of all these characteristics, the vetiver plant is highly drought tolerant and can help to protect soil against sheet erosion. In case of sediment deposition, new roots can grow out of buried nodes.
Vetiver grass is grown for many different purposes. The plant helps to stabilise soil and protects it against erosion, but it can also protect fields against pests and weeds. Vetiver has favourable qualities for animal feed. From the roots, oil is extracted and used for cosmetics and aromatherapy. Due to its fibrous properties, the plant can also be used for handicraft, ropes and else.
Soil and water conservation
The close-growing culms also help to block the runoff of surface water. It slows water's flow velocity and thus increases the amount absorbed by the soil (infiltration). It can withstand a flow velocity up to 5 metres per second (16 ft/s).
Vetiver can be used for crop protection. It attracts pests such as the stem borer (Chilo partellus), which lay their eggs preferably on vetiver. Due to the hairy architecture of vetiver, the larvae can not move on the leaves, fall to the ground and die.
As a mulch, vetiver is used for weed control in coffee, cocoa and tea plantations. It builds a barrier in form of a thick mat. When the mulch breaks down, soil organic matter is built up and additional nutrients for crops become available.
The leaves of vetiver are a useful byproduct to feed cattle, goats, sheeps and horses. The nutritional content depends on season, growth stage and soil fertility. Under most climates, nutritional values and yields are best if vetiver is cut every 1-3 months.
Perfumery and aromatherapy
Vetiver is mainly cultivated for the fragrant essential oil distilled from its roots. Worldwide production is estimated at about 250 tons per annum (Lavania). Due to its excellent fixative properties, vetiver is used widely in perfumes. It is contained in 90% of all western perfumes (Lavania).
Haiti is one of the leading producers of vetiver in the world. Vetiver processing was introduced to Haiti in the 1940s by Frenchman Lucien Ganot. In 1958, Franck Léger established a plant on the grounds of his father Demetrius Léger's alcohol distillery. The plant was taken over in 1984 by Franck's son, Pierre Léger who expanded the size of the plant to 44 atmospheric stills each built to handle one metric ton of vetiver roots. Total production increased in ten years from 20 to 60 tonnes annually, making it the largest producer in the world. The plant extracts vetiver oil by steam distillation. Another major operation in the field is the one owned by the Boucard family.
Réunion is considered to produce the highest quality vetiver oil called "bourbon vetiver" with the next favorable being Haiti and then Java.
In perfumery, the older French spelling, vetyver, is often used.
Vetiver oil or khus oil is a complex oil containing over 100 identified components, typically:
The oil is amber brown and rather thick. The odor of vetiver oil is described as deep, sweet, woody, smoky, earthy, amber, balsam. The best quality oil is obtained from roots that are 18 to 24 months old. The roots are dug up and cleaned then dried. Before the distillation, the roots are chopped and soaked in water. The distillation process can take up to 18 to 24 hours. After the distillate separates into the essential oil and hydrosol, the oil is skimmed off and allowed to age for a few months to allow some undesirable notes which form during the distillation to dissipate. Like patchouli and sandalwood essential oils, the odor of vetiver develops and improves with aging. The characteristics of the oil can vary significantly depending on where the grass is grown and the climate and soil conditions. The oil distilled in Haiti and Réunion has a more floral quality and is considered of higher quality than the oil from Java which has a smokier scent. In the north of India, oil is distilled from wild-growing vetiver. This oil is known as Khus or Khas and is considered superior to the oil obtained from the cultivated variety. It is rarely found outside of India as most of it is consumed within the country.
Vetiver has been used in traditional medicine in South Asia, Southeast Asia, and West Africa.
Old Tamil literature mentions the use of vetiver for medical purposes.
In the Indian Subcontinent, khus (vetiver roots) is often used to replace the straw or wood shaving pads in evaporative coolers. When cool water runs for months over wood shavings in evaporative cooler padding, they tend to accumulate algae, bacteria and other microorganisms. This causes the cooler to emit a fishy or seaweed smell into the house. Vetiver root padding counteracts this smell. A cheaper alternative is to add vetiver cooler perfume or even pure khus attar to the tank. Another advantage is that they do not catch fire as easily, while (dry) wood shavings catch fire easily.
Mats made by weaving vetiver roots and binding them with ropes/cords are used in India to cool rooms in a house during summer. The mats are typically hung in a doorway and kept moist by spraying with water periodically and cool the passing air as well as emitting a cool and refreshing aroma.
In the hot summer months in India, sometimes a muslin sachet of vetiver roots is tossed into the earthen pot that keeps a household's drinking water cool. Like a bouquet garni, the bundle lends distinctive flavor and aroma to the water. Khus scented syrups are also sold.
A recent study, made in the volcanic institute in Israel, by Dr. Nativ Dudai found out that the plant is capable of growing in a fuel-contaminated ground. In addition to that, the study discovered that the plant is also able to clean the ground, so in the end, the soil is almost fuel-free.
Vetiver grass is used as roof thatch (it lasts longer than other materials), mud brick making for housing construction (such bricks have lower thermal conductivity), strings and ropes and ornamentals (the light purple flowers).
Vetiver is planted in long, neat rows across the slope for easy mechanical harvesting. The soil should be wet. Trenches are 15-20 centimeters deep. A modified seedling planter or mechanical transplanter can plant large numbers of vetiver slips in the nursery. Flowering and non-flowering varieties are used for cultivation. Sandy loam nursery beds ensure easy harvest and minimal damage to plant crowns and roots. Open space is recommended, because shading affects vetiver growth.
Overhead irrigation is recommended for the first few months after planting. More mature plants prefer flood irrigation. Weed control may be needed during establishment phase, by using 3 liter atrazine per hectare 3 days after planting.
To control termites which attack dead material, 1 kilogram of benzene hexachloride (BCH) can be applied for every 150 meter of the vetiver hedge. Brown spot seems to have no effect on vetiver growth. Black rust in India is vetiver-specific and does not cross-infect other plants. In China, stemborers (Chilo spp) have been recognised, but they seem to die once they get into the stems. Further, vetiver is affected by Didymella andropogonis on leaves, Didymosphaeria andropogonis on dead culms, Lulworthia medusa on culms and Ophiosphaerella herpotricha. Only in Malaysia white flies seem to be a problem. Pest management is done not only by using insecticides but also by appropriate cultural management: hedges are cut to 3 centimeters above ground in the end of the growing season. In general, vetiver is highly tolerant to herbicides and pesticides.
Harvest of mature plants is performed mechanically or manually. A machine uproots the mature stock 20-25 centimeters below ground. To avoid damaging the plant crown, a single blade bouldboard plough or a disc plough with special adjustment should be used.
- Molecular Ecology 7:813-818
- ^ P. Tuong, T. Tan Van, E. Pinners (2008). Vetiver Systems Application, Technical Reference Manual. The Vetiver Network International. pp. 89. https://docs.google.com/fileview?id=0B93pPxeKEsjRMjE0ZjBiZDctNjY0NS00YWMxLTlhMTctZDYwOTU5ZTE4OTg4&hl=en.
- ^ James A. Duke, Judith L duCellier. CRC Handbook of alternative cash crops.
- The Fragrance Industry- Profiles c. 2007 by Glen O. Brechbill
- © International Trade Centre, International Trade Forum - Issue 3/2001
- Narong Chomchalow, "The Utilization of Vetiver as Medicinal and Aromatic Plants with Special Reference to Thailand", Office of the Royal Development Projects Board, Bangkok, Thailand September 2001, Pacific Rim Vetiver Network Technical Bulletin No. 2001/1.
- ynet.co.il The plant that cleans the ground (in Hebrew).
- Greenfield, John C. (2008). The Vetiver System for Soil and Water Conservation. ISBN 1438203225.
- Germplasm Resources Information Network: Chrysopogon zizanioides
- Veldkamp, J. F. (1999). A revision of Chrysopogon Trin., including Vetiveria Bory (Poaceae) in Thailand and Malesia with notes on some other species from Africa and Australia. Austrobaileya 5: 522–523.
- Other Uses and Utilization of Vetiver: Vetiver Oil - U.C. Lavania - Central Institute of Medicinal and Aromatic Plants, Lucknow-336 015, India
- E. Guenther, The Essential Oils Vol. 4 (New York: Van Nostrand Company INC, 1990), 178-181, cited in Salvatore Battaglia, The Complete Guide to Aromatherapy (Australia: The Perfect Potion, 1997), 205.]
- Ruh Khus (Wild Vetiver Oil)/Oil of Tranquility - Christopher McMahon
- The Vetiver Network International
- Caldecott, Todd (2006). Ayurveda: The Divine Science of Life. Elsevier/Mosby. ISBN 0723434107. Contains a detailed monograph on Chrysopogon zizanioides (Ushira), as well as a discussion of health benefits and usage in clinical practice. Available online at http://www.toddcaldecott.com/index.php/herbs/learning-herbs/338-ushira
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