Article Index
LEMONGRASS
1. Medicinal Properties & Use
2. Botany & Varieties
3. Chemical Constituents
4. Types
5. Improved Varieties
6. Soil & Climate
7. Propagation
8. Planting & Aftercare
9. Pest & Diseases
10. Harvest & Processing
11. Distillation
12. Purification & Storage
13. Seed Harvest
All Pages

LEMONGRASS

 

East Indian LEMONGRASS / Cochin grass / Malabar grass

Lemongrass is a tropical perennial plant which yields aromatic oil on steam distillation of the herbage.
The oil has a typical lemon-like odour.
The crop is suitable for marginal and waste lands and also along the bunds as live mulch.

India contributes to about 85% of total world production.

LEMON GRASS

Scientific name: Cymbopogon flexuosus (Nees ex Steud ) Wats.

Family            :  Gramineae (Poaceae)
English           : East Indian Lemongrass
Malayalam      : Inchippullu, Theruvappullu, Malabar grass
Sanskrit         : Karpoorathrina, Sugandhathrina, Bhustarah
Tamil             : Vaasanappullu, Karpoorappullu
Telugu           : Vaasanagaddi, Chippagaddi, Nimmagaddi
Hindi              : Gandhatran
Bengali           : Gandhabena
Gujarathi        : Lilacha
Punjabi          : Khavi
Kannada        : Majjigehallu                             

East Indian lemongrass oil is known as Cochin oil in the world trade and it accepted as the finest oil.
The crop is grown in Kerala, Assam, Maharashtra and Uttar Pradesh  and also in countries like Guatemala and China.
In Kerala, it is grown mainly in Marayoor and Peermede regions in Idukki district.


MEDICINAL PROPERTIES & uSE

Parts used: Oil, oleoresin, leaf, spent grass

Perfumery and cosmetic uses
Oil is used   in making of citrusy soaps and perfumes. 
Oil is used in floor cleaning lotions and personal care products, like deodorant.
Taking bath in water with a few drops of  oil in it, gets rid of body odour.

Medicinal uses
Lemongrass oil helps relieve pain in muscles, joints, toothache and headache etc. resulting from viral infections like cough and cold, influenza, fever, pox etc.

Oil also helps cure body pain resulting from sudden exercises, sports etc.

The oil is diluted with coconut oil five times and massaged for rheumatic pains.
Steam Inhalation with boiled leaves is a cure for cold and influenza.
Taking in of two to three drops of oil mixed with powdered sugar candy (kalkandam), dried ginger and pepper will get rid of fever and cough.
The oil when given with tea can bring down fever.
Oil is used on various types of skin infections, usually as a wash or compress and is especially effective on ringworm and infected sores. Application of a  paste of the leaves of lemon grass made in butter milk  is useful in treating ringworm.

It is good for curing external and internal wounds and hence an ingredient of the anti septic lotions and creams.

It strengthens stomach, stimulates appetite, promotes digestion, and regulates nervous system and vascular expansion.

Lemongrass oil can relieve gas trouble.

Lemon grass oil prevents formation of pimples and acne and acts as a muscle and tissue toner. It reduces the puffiness in skin and is a good hair tonic.

Lemongrass also finds use in aromatherapy. Fresh herb or oil of lemongrass is used for foot bath. The patient additionally benefits by inhaling the scent.  It also treats pain arising from rheumatism and nerve conditions. This refreshing fragrance reduces headache and prevent drowsiness and rejuvenates mind and soul. It is also used to make aroma therapy candles.

The oil should be mixed with a carrier oil before application on the body. Its use may be avoided during pregnancy.  

Insect repellant
Lemongrass is quite popular as an insect repellent. It is widely used in mosquito repelling formulations.
It helps to keep pets clean of fleas, ticks and lice. It is used in pet shampoos as a bug repellant.

Culinary Flavouring
Leaves
Lemongrass flavour  has an edge over the Lemon flavor since this oil is not acidic in nature.

Dried lemongrass leaves are widely used as a lemon flavour ingredient in herbal teas, prepared either by decoction or infusion of 2-3 leaves in 250 or 500 ml of water  and other formulations.

Lemongrass tea is a diuretic and imparts no biochemical changes to the body in comparison with the ordinary tea.
Lemongrass iced tea is prepared by steeping several stalks in a few quarts of boiling water. This can also be combined with green or black teas.
It is also used in instant beverages. It not only adds lemon flavor but also provide vitamin A and promotes digestion of fat.

Lemongrass is commonly used in Asian cooking. It is used extensively in Thai cuisine in the form of fresh grass or dried and ground grass. The dishes include soup, grilled chicken and curries. It adds a lemon taste to the food.

Essential oil
Lemongrass oil is used in culinary flavouring. It is used in most of the major categories of food including alcoholic and non alcoholic beverages, frozen dairy desserts, candy baked foods, gelatins and puddings, meat and meat products and fat and oils.
It is used to improve the flavour of some fish and can be used to flavour wines, sauces etc.

Oleoresin
Oleoresin, comprising of the volatile and non-volatile components responsible for the characteristic flavour and aroma, can be separated by subjecting the herb to extraction with a suitable solvent or a mixture of solvents. The solvent residue in the product should be   minimal; typically less than 25-30 ppm. The oleoresin is a concentrated wholesome product with better storage characteristics.
Oleoresin is mainly used in flavouring foods, drinks and bakery preparations. It is very good for flavouring tea.


Spent grass (Plant residue after extraction of oil)
It can be used as cattle feed fresh or after ensilaging.
It can be used for mulching or manuring crops as such or after composting.
Dried spent grass can be used as a fuel for distillation. 
It is also a cheap packing material.
Leaves of lemongrass can be used as a source of cellulose in manufacture of paper and cardboard
It can be made use of in mushroom production.


Production of aromatic constituents
Pure citral is isolated from lemongrass oil and it is used as a precursor in the synthesis of Vitamin A and other industrially important products.
 
Citral is also used in the production of soft drinks, beverages, desserts, confectioneries, bakery items, chewing gums etc.


Botany & Varieties

It has a tufted appearance. C. flexuosus is a tufted robust perennial grass of about 2 m height. Leaves are linear and lanceolate. Leaves are aromatic and have 1-2 cm width and 75 cm length. The surface of the leaves are rough. It flowers freely.

The plant flowers in October –November. Inflorescence is very large and a highly branched terminal drooping panicle bearing paired spikes on tertiary branches.
Spikes bear spikelets in pairs of which one is sessile and other pedicellate. The sessile spikelet is an awned bisexual floret where as the pedicellate is an awnless staminate floret. 
Inflorescence is greenish when tender and becomes pinkish on maturity.
The seeds are very light and are covered with husk. One gram of the seed material, named as ‘fluff’,  contains about 1700 seeds.


Chemical constituent

Essential oil
OIL      CONTENT : 0.2 – 0.4
Main constituent : Citral  
Analysis of  Typical  East Indian Lemongrass Oil
Citral
: 70%
Linalool
: 1.34%
Geraniol
: 5.00%
Citronellol, nerol
: 2.20%
Citronellal
: 0.37%
Linalyl acetate, geranyl acetate : 1.95%
α-Pinene : 0.24%
Limonene
: 2.42%
Caryophyllene, β-pinene, β-thujene, myrcene : 0.46%
β-Ocimene : 0.06%
Terpenolene
: 0.05%
Methyl heptanone : 1.50%
α-terpineol
: 0.24%
Oleoresin
East Indian lemongrass contains 17.3% oleoresin in leaf and 15.6% in inflorescence  on methanol extraction.
Oleoresin Oil


Types of East Indian Lemongrass (C. flexuosus)

Two types are identified in this species based on colour of stem.
a. C. flexuosus var. flexuosus.
Stem and leaf sheath are reddish or purple.
Oil content : 0.3 to 0.5%.
Citral: 80-86%
Oil has good solubility in alcohol and hence is superior in quality.
It is recognized as true lemongrass and is commercially cultivated.

b. C. flexuosus var. albescens is the white grass
Stem and leaf sheath are white in colour
Oil content : 0.4 to 0.7%.
Citral: 55-70%
Oil has poor solubility in alcohol and hence is inferior in quality.
It is normally seen wild.

Red stemmed variety White stemmed variety


Improved Varieties of East Indian Lemongrass

1. OD- 19 (Sugandhi)

Release centre: AMPRS , Odakkali, KAU, Kerala

Characters : A red stemmed variety with plant height 1 to 1.75 m and profuse tillering.  

Oil content: 0.3 – 0.4%
Oil  yield  :  40 -50 kg/acre  

Citral  :  84 – 86 %

Adaptability : Adapted to a wide range of soil and climatic condition. much suited for rainfed cultivation

2.  Pragathi

Release centre: CIMAP, Lucknow, U.P.

Characters:  Dwarf , broad , erect  and dark green leaves,  high oil &  Citral content
Average Oil  yield : 0.63 %  Citral  :  85-90 %

Adapatability: High  fertile / Irrigated soils;  suitable for north Indian Plains & tarai beltof subtropical and tropical climate

3.  Nima

Release centre: CIMAP, Lucknow, U.P.

Characters:   High yield of bio mass (25-28 Mt/ha) with high oilyield (230-250 kg/ha.) Tall , Citral  type 
Adapatability:  Indian plains

4.  Cauvery

Release centre: CIMAP, Lucknow, U.P.

Characters:   White stemmed selection from OD-19  with an improvement in yield in terms of oil and citral content. Tall, Citral  type   Adapatability:  Requires high soil moisture and is evolved for river valley tracts of  Indian  Plains

5.  Krishna

Release centre: CIMAP sub centre, Bangalore.

Characters:   Medium  tall , high  tiller  and  herb  with  high  oi  yielding Citral type High yield of bio mass (25-28 Mt/ha) with high oil yield (230-250 kg/ha) 

Adapatability:  Indian  Plains

6.   NLG 84

Release centre:  . AINRP  on  M & AP , NDUAT,  Faizabad , Uttar Pradesh. Released  in  1994
Characters:    High  herbage  yield , 100 -110cm  tall , broad  leaves with dark  purple  sheath. It  is a  selection   from  germplasm.   Oil  content    -  0.4  % , Citral  content  -  84  % 
Adapatability:   Uttar Pradesh

Source: NMPB (National Medicinal Plants Board) (2009),  High – Yielding Varieties of some medicinal  and aromatic plants with general guidelines for seed production and certification.  Published  by Alakananda Advertising Pvt. Ltd., New Delhi. p. 19-21

Improved accession for high oleoresin yield

OD 410
Name of  centre: AMPRS , Odakkali, KAU, Kerala
Oleoresin content of leaf: 18.6%
Oleoresin yield      : 1050 kg /acre /year
Ideal solvent for extraction: Methanol


SOILCLIMATE

Lemongrass grows well between 900 and 1250 m from mean sea level. Requires  a warm humid climate  with  plenty  of sunshine  and  rainfall  ranging from  2500-3000 mm


Day temperature of 25-30°C is optimum for maximum oil production
Rainfed areas with annual precipitation of more than 500mm and with limited availability of irrigation water; salt affected areas and plantations having about 30% shade etc can be utilized for lemongrass cultivation.
The species can be grown on a range of soils with good drainage and pH range 5.5 to 7.5.

Plants growing in sandy soils have higher leaf oil yield and citral content.

                                          



  Propagation

Lemongrass is generally propagated through seeds.
Seed germination is very poor in fresh seeds due to dormancy; it can be sown after two months of storage. 
The seeds collected during the months of January-February are usually sown in the nursery during April-May. Seeds lose viability beyond six months of storage.

Seedlings can be raised in a nursery in one-tenth of the area of the main field. This method which requires 1-1.5  kg seeds/acre  is ideal for uniform stand and better growth of the plants.
Seed is mixed with dry river sand in the ratio of 1:3, uniformly broadcasted on the beds and covered with a thin layer of soil. The seed bed is irrigated daily. Seeds germinate in 5-7 days.
45-50 days old seedlings are planted during the monsoon season.


Planting  &  aftercare

Planting is done with the onset of monsoon.
Land is prepared by 2-3 deep ploughings and  spent lemongrass compost at 4 t/ acre and wood ash at 1 t/acre, byproducts of grass distillation are applied at the time of bed formation. In slopes, beds are formed along the contours.
Application of 20 kg urea, 50 kg Rajphos and 15 kg Potash at the time of planting promotes early establishment and growth.
The uprooted seedlings are bundled, top portion cut and transported to the main field for planting.
A spacing of 30 cm x 30 cm with a plant density of 40000/acre is recommended. 

Small plantations of lemongrass can be established by planting of slips from existing healthy clumps. Clumps are uprooted, roots pruned and top portion cut at a height of 20-25 cm before separation of slips.
Seedling crop is superior since higher yield of good quality oil is obtained from this crop; longevity of the plants also is higher.
Field should be kept weed free for initial period of 3-4 months after planting. 
The crop may be topdressed with 80 kg urea /acre/year in 3 4 splits after every harvest.
Excess fertilizer application is undesirable as it promotes more vegetative growth and produce oil with less citral content.

Setting of fire
Under rainfed conditions, the field gives a dried appearance during December–May. The dry grass and stubbles of crop is set on fire in May, prior to onset of monsoon. This practice kills termites attacking crop stubbles,  ward off pests, diseases and weeds and also helps to rejuvenate old clumps.
 With the receipt of summer showers, new vigorous shoots develop. Weeding, manuring and earthing up is carried out during May – June.                                 

Cultivation using seedlings

Cultivation using slips
Setting up fire in Lemongrass field


Pest & Diseases

Pest Stage of pest/symptom of damage Management measures
Termites Drying of clumps Localised drenching of chlorpyriphos 2-3 ml /L

Mealy bug

Dysmicoccus brevipes / Pseudococcus bromeliae

Adults and nymphs seen colonizing near base of the clumps esp. during dry months,

sucking of juice cause drying of clumps

Sanitary measures are to be adopted. The plot should be kept weed free.

Remove and destroy all dried up clumps.

Localised application of neemoil garlic emulsion (2%) in affected areas

Stem borer

Chilotrea sp. (Lepidoptera: Pyralidae)

Caterpillar – death of tillers Spray mercaptothion 50EC @0.2%

Spittle bug

Clovia bipunctata Walk. (Hemiptera: Cercopidae)

Adults and nymphs – stunted growth Not a serious pest

Nematodes:

Tylenchorhynchus vulgaris

Rotylenchus reniformis

Helicotylenchus spp.

Pratylenchus spp.

Adults and nymphs – root damage causing stunted growth Not serious

Disease Causal organism Management measures

Little leaf

Leaves become smaller in size and flowers in inflorescence get converted to very small leaves

Virus

Destruction of affected plants to reduce spread of disease

Avoid collecting seeds from such plants.

Control of vectors

Leaf rust

Elongated, stripe like, dark brown lesions develop on both sides of leaf surfaces

Puccinia nakanishikii Spray any contact fungicide such as Mancozeb 0.3% or Zineb 0.3%
Leaf spot (eye spot)

Helminthosporium

cymbopogi

Spray BM 1% or COC 0.2% or zineb 0.3% thrice at 15 days interval
Blights
Curvularia Leaf Blight (CLB) Curvularia andropogonia Spray Bordeaux mixture (BM) 1% or Zineb 0.3% or Mancozeb 0.2-0.3% thrice at 15 days interval
Leaf blight Rhizoctonia solani
Grey blight Pestalotiopsis magniferae
Collar rot Spray BM 1% or COC 0.2% or Zineb 0.3% thrice at 15 day interval


Harvest & processing

Grass is harvested when individual tiller has 4-5 fully opened leaves. The plants are cut about 10-20 cm above the ground level with sickles. First harvest is obtained after 4-5 months of transplanting.
Crop should not be allowed to produce inflorescence as it adversely affects growth and development of plants on subsequent harvests.

The harvesting season begins in May and continues till the end of January. Sunny days are preferable, since cloudy and misty conditions tend to depress leaf oil content.
Grass harvested at an interval of 60-90 days. If harvesting interval is below 60 days, oil quality will be poor. Under normal conditions, 2-3 harvests are possible during the first year of planting and 3-4 in subsequent years.

Herbage yield : 3-4 tonnes/acre per harvest.

Average oil yield is 50-70 kg/acre/year. In second and subsequent years, 80-100 kg oil/acre  may be produced with good management and use of recommended variety.

In general, the recovery of oil is lower in rainy seasons (June - August) than in summer.


  Distillation


Lemongrass oil is collected by distillation of the herbage for 1.5 to 2 hrs.  The distillate on cooling separates out into a layer of oil, floating over bulk of water which is collected by decantation.

The grass is distilled either fresh or after wilting.

There are  two types of distillation

i.    Hydro-distillation: In this method, the herb is packed in a vessel and partly filled with water. The vessel is heated by direct fire without an external boiler. This country method of distillation is less efficient, but the unit is simple and cheaper.


ii.    Steam distillation:  In this method, steam generated in an external boiler is introduced into the chamber. This method, though involves higher initial cost, is more efficient and the quality of oil obtained is superior.

For effective running of 500 l capacity stem distillation unit, herbage from 20 acre area is required.


Purification and storage


Freshly distilled oil may contain some impurities and moisture. For removing moisture in the oil,  anhydrous sodium sulphate at the rate of 2 g/kg oil is added and kept overnight. The oil then can be filtered through filter paper or muslin cloth.

Oil of lemongrass is caustic in nature and volatile under ambient temperatures. It a viscous liquid, yellow to dark yellow or dark amber in colour turning red on prolonged storage due to chemical changes when exposed to air and sunlight.

During storage, oil should be filled up to the brim and containers should be kept in shaded or cool area away from direct heat and sunlight.
If the oil quantity is less, it can be easily stored in glass b
ottles.
For large quantities, stainless steel or aluminium containers are preferred.


Seed harvest


Lemongrass crop kept for seed purpose is not cut as yield of seeds from plants subjected to regular harvest is very low.

Lemongrass is cross pollinated. Hence to maintain genetic purity, isolation distance of 300-400 m should be given between two varieties.
Generally, plant flowers during October –November  and mature seeds are collected during January-February.

The whole inflorescence is cut and dried in sun and seeds are collected by thrashing against floor or beating with sticks.
Seed mass which is commonly known as ‘fluff’ is dried and stored in gunny bags lined with polythene.

Seed yield is about 25 kg /acre.