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Description

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Origin

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  • here I will integrate the already existing stuff (Name, Systematics, Origin...)

Morphology[1]

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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 [2]. The panicles are 15-30 centimeters long and have whorled, 2.5-5.0 centimeters long branches[2]. 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 burried nodes.

Usage

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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

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Erosion Control

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Original entry is good, but some sentences can be added...

Water disaster mitigation

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Original entry is good, but some sentences can be added...

  • The close-growing culms also help to block the runoff of surface water. It slows down flow velocity of water and thus increases the infiltration. It can withstand a flow velocity up to 5 meters per second[1].

Water conservation

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Vetiver mulch increases water infiltration and reduces evaporation, thus protects soil moisture under hot and dry conditions. The mulch also protects against splash erosion[1] .

Crop protection

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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.

Animal feed

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The leaves of vetiver are a useful byproduct to feed cattle, goats, sheeps and horse. The nutritional content depends on season, growth stage and soil fertility[1]. Under most climatic, nutritional values and yields are best if vetiver is cut every 1-3 months.

Young Vetiver Mature Vetiver Old Vetiver
Energy [kcal/kg] 522 706 969
Digestibility [%] 51 50 -
Protein [%] 13.1 7.93 6.66
Fat [%] 3.05 1.30 1.40

In-house use

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Fuel cleaning

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Oil (here I will integrate the already existing stuff about oil)

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Other uses[1]

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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).

Agricultural Aspects

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Environmental requirements[1]

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Factor Requirements
Soil type Sandy loam is prefered. Clay loam is acceptable, but clay not.
Topography Slightly sloping land avoids water-logging in case of over watering. Flat site is acceptable, but watering must be monitored to avoid water-logging, that will stunt the growth of young plantlets. Mature vetiver, however, thrives under waterlogged conditions.
Nutrition Absorbs dissolved nutrients like N and P. Is tolerant to sodicity, magnesium, Al and Mn
pH Accepts soil pH from 3.3 to 12.5 (in another publication it's 4.3-8.0 [2])
soil conditions tolerant to salinity
Heavy metals Absorbs dissolved heavy metals from polluted water. Is tolerant to As, Cd, Cr, Ni, Pb, Hq, Se and Zn.
Light Shading affects vetiver growth (C4 plant), but partly shading is acceptable.
Temperature tolerant to temperatures from -15°C to +55°C, depending on growing region. 25°C is the optimal soil temperature for root growth. Root dormancy occurs under a temperature of 5°C. Shoot growth is affected earlier, at 13°C is only very little shoot growth, but root growth is continued at a rate of 12.6 cm/day. Under frosty conditions, shoots become dormant and purple, or even die, but the underground growing points survive and can re-grow quickly if the conditions become better.
Water tolerant to drought (because of it's deep roots), flood, submergence; annual precipitation of 6.4 - 41.0 dm is tolerated, but it has to be at least 225 mm [2].

Crop Management[1]

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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[3]. 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[2].

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[1]. 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[2] . 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.

Literature

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mostly The Vetiver Network International

  1. ^ a b c d e f g h i j P. Tuong, T. Tan Van, E. Pinners (2008). Vetiver Systems Application, Technical Reference Manual. The Vetiver Network International. p. 89.{{cite book}}: CS1 maint: multiple names: authors list (link)
  2. ^ a b c d e f James A. Duke, Judith L duCellier. CRC Handbook of alternative cash crops.
  3. ^ Greenfield, John C. (2008). The Vetiver System for Soil and Water Conservation. ISBN 1438203225.