Profile on Lemongrass Plant

 

Background information

1.1 Rationale of the study

Lemongrass is a perennial plant that is universally accepted as oil-bearing grass. The name of the lemongrass is derived from the typical lemon-like odor of its essential oil extracted from the shoot.  The herb originated in Asia and Australia. Lemongrass belongs to the family Poaceae (Graminae) and the genus Cymbopogon. Generally, three species are identified as Cymbopogon flexuosus, Cymbopogon citratus and Cymbopogon pendulus.  It is very much valuable for both Industrial and Medicinal use because of its main components like Geraniol, Citral, Limonene, Myrcene, Neral, Nerol, Citronellol, etc., . Lemongrass is widely cultivated and commercialized all around the world.  In India, the state of Kerela had a monopoly in the production and export of lemongrass oil. The annual world production of lemongrass oil is around 1000 tons from an area of 16000 ha. In India, it is cultivated in an area of 4000 ha with an annual production of around 250 tons which are extensively cultivated in the poor, marginal, and wastelands (Dutta et al., 2016). Although it's large industrial and medicinal uses as well as suitable climatic and soil condition, it is very underrated in Nepal due to lack of its information about cultivation and market value. The cultivation and commercialization of lemongrass have great scope to improve the livelihood of rural society. Therefore, this paper attempt to survey the literature on this important grass to finds its medicinal and industrial values and motivates people for its cultivation.  

1.2 Objective

Plants are utilized as therapeutic agents in both organized (Ayurveda, Unani) and unorganized (folk, tribal, native) since time immemorial. Lemongrass has been identified as an important medicinal plant, due to the presence of nutritional (vitamins and minerals) and non-nutritional (fibers, lignans, carotenoids, saponins, sulfides, polyphenolics, plant sterols, etc.) component. The present paper highlights the uses of lemongrass in different fields such as medicinal and non-medicinal. This paper explains the suitable climatic and soil condition to grow lemongrass plants and how they can be cultivated and commercially use to support society economically. Several papers were studied to find out the industrial values including medicinal and non-medicinal uses of this plant as medicines, cosmetics, food ingredients, tea, and essential oil, etc. The main objective of this paper is to find out;

 (1) The agro-climatic requirements to grow this plant and cultivation,

 (2) The medicinal uses of this plant and

 (3) The non-medicinal uses of this plant.

1.3 Limitation of the study

The crop grows well in both tropical and subtropical climates at an elevation up to 900 m. Although having the suitable climatic and geographical condition of Nepal, it was very hard to found this plant in the local level to study its morphology and physiology. Therefore, the whole paper is based on secondary data from various journals. During the collection of data, there are so many research papers and articles related to lemongrass are found but there is very little research that has been done in Nepal. All the materials that have been collected through the secondary method of data collection were done outside Nepal. There is so much similarity between India and Nepal in the context of climate, soil, temperature, geography, ethnicity, and culture so most of the Indian research paper has been studied for this paper.    

METHODOLOGY

This study is completely based on the desk review of the published and unpublished kinds of literature from digital resources such as Google Scholar, Academia, PubMed, and Research gate, etc. Through Medicinal and Aromatic Plant Abstract (MAPA), different journals, books we could obtain reliable information to continue this work. From these resources, we have reviewed the various works related to the agro climate requirements of lemongrass, medicinal uses, industrialization, etc.

 

Findings (Description of lemongrass)

Lemongrass is an aromatic perennial tall grass with rhizomes and dense fibrous roots. It has short underground stems with ringed segments, coarse, green slightly leathery leaves in dense clusters (Carlini et al., 1986).  The plant is a native herb from India and is cultivated in other tropical and subtropical countries (Figueirinha et al., 2008). The Botanical classification of lemongrass is presented below;

 

Table No. 1 The Botanical classification of lemongrass

Kingdom	Plantae
Clade	Tracheophytes
Clade	Angiosperms
Clade	Monocots
Clade	Commelinids
Order	Poales
Family	Poaceae
Sub-family	Panicoideae
Super tribe	Andropogonodae
Tribe	Andropogoneae
Sub tribe	Andropogoninae
Genus	Cymbopogon
Species	flexuosus
Species	citratus
Species	pendulus

3.1 Agro-climatic Requirements and cultivation:

3.1.1 Climate

A warm and humid climate with sufficient sunshine and 2500-3300 mm rainfall per annum, evenly distributed over most parts of the year are considered to be the ideal conditions for growing lemongrass. A temperature ranging from 20-30°C with good sunshine throughout the year is very conducive to high crop yield. Day temperature of 25-30°C is considered optimum for maximum oil production, with no extremely low night temperature. Short periods above 30°C have a little general effect on plants, but severely reduce oil content (Singh, 1999). Lemongrass can also be grown in the area receiving low to moderate rainfall in semi-arid regions.

3.1.2 Soil

Lemongrass can grow well over medium fertile soils and moderate irrigation. Well-drained soil is considered the most suitable soil for the growth of the plant. It can be grown on soils ranging from rich loam to poor laterite. In sandy loam and red soils, it requires good manuring. Plants growing in sandy soils have higher leaf oil yield and citral content. Waterlogged soils should not be used as they are unsuitable for cultivation.

3.1.3 Propagation

Lemongrass is generally propagated through seeds. Dry river sand is mixed with seed in the ratio of 3:1 and sown in the field at the rate of 20 to 25 kg/ha. Seedlings can be raised in a nursery in 1/10th of the cultivation area and transplanted after 45 days. This method which requires 3-4 kg seeds/ha is ideal for uniform stand and better growth of the plants. A small plantation of lemongrass can be established by the planting of slips (Joy, 2016).

3.1.4 Nursery raising

For one hectare of land, a 1000 m2 nursery has to be raised. Beds of 1 to1.5 m width and convenient length are prepared. The recommended seed rate is 3-4 kg/ha. The seeds are uniformly broadcasted on the beds and irrigated frequently. It has a dormancy of a few weeks and they lose viability in a few months. The seeds are collected during January-February and usually sown in the nursery during April-May (Joy, 2016).

3.1.5 Transplanting

The seedlings raised in the nursery are transplanted in the plantation site at the 6-7 leaf stage. During the monsoon season, 50-70 days old seedlings are planted with a spacing of 30 cm x 30 cm (Joy, 2016). The oil quantity depends upon its cultivation.

3.1.6 Manuring

Soluble nitrogen fraction and total carbohydrate content increased essential oil content. Manure is added according to the need of the soil. Lemongrass requires 275 kg N, 50 kg P2O5 and 175 kg K2O/ha/annum.

3.1.7 Irrigation

In case of drought, the crop should be irrigated every alternate day for about a month after planting. It is recommended that 4 to 6 irrigations are given during the period from the month of  February to June. The quality of the essential oil is not affected by soil moisture regimes (Singh, 1999).

3.1.8 Weed control

Generally, 2-3 weeding are necessary in a year. The first month after planting is considered as the crop weed competition period. Weeding should be done in the initial period of 3 to 4 months for a good establishment of the plant.

Some herbicides for weed control are diuron, oxyfluorfen,  f 2-4- D (sodium salt)

3.1.9 Plant protection

The plant should be protected from two main problems that is pests and diseases.

Pests

Few pests like spindle bug, stem boring caterpillar of Chilotrea sp, and some nematodes like Tylenchorhynchus Vulgaris, Rotylenchulus reniformis, etc. damage lemongrass which can be controlled by Spraying malathion (0.2%)(Joy, 2016).

Diseases

The common diseases are little leaf, leaf spot, leaf blight, smut, etc. which can be managed by prophylactic sprays of dithane Z-78 @ 3g/l thrice, at intervals of 15 days (Joy, 2016).

 

3.1.10 Harvesting of the herb

Harvesting is done by cutting the grass 10 cm above the ground level, with the help of sickles. The number of harvests in a year depends on climatological factors such as rainfall, temperature and humidity, and level of soil fertility. Generally, the crop thrives best in humid conditions. The first harvesting can be done at 90 days after planting and subsequent harvesting at 50-55 days intervals up to 5-6 years from the same crop.

3.2 Medicinal Uses

Though there are little scientific data on the medical claims of lemongrass, it has been traditionally used as medicine for the treatment of several ailments. It is used in different parts of the world in the treatment of digestive disorders, fevers, menstrual disorders, rheumatism, and other joint pains. The infusion or decoction of aerial parts of Lemon Grass has widely used in folk medicine. This plant is also recommended to treat inflammation, nervous disorder, and other health problem (Carlini et al., 1986).

 

Lemongrass contains some major components that may be cancer chemopreventive. In fact, the extract has been shown to inhibit rat colon carcinogenesis in animals (Puatanachokchai et al., 2002). Extracts of both the leaves and stalks of lemongrass are used as herbal medicine to treat nervous conditions and inflammation. Lemongrass is also popular for tea which has diuretic properties and can help in urinating difficulties and water retention.

 Lemon Grass has been recommended for stomachaches, diarrhea, gas, bowel spasms, vomiting, fever, the flu, and headaches, and other types of pain. The essential oil of lemongrass can be applied externally to help treat acne, lower back pain, sciatica, sprains, neuralgia, and rheumatism. Some authorities recommend rubbing a few drops of Lemongrass oil on the skin of affected areas to treat circulatory disorders by improving the blood flow. Like many other essential oils, Lemon Grass is also used in aromatherapy.

It is consumed as a refreshing tonic. Two-three drops of oil in hot water are administered orally for gastric troubles and with lemon juice for cholera (Ravinder, Kuman Pawan et al., 2010). Its oil is a mosquito repellent and is employed as a household fumigant Lemongrass is an emetic, diuretic, sedative, antispasmodic, anti-inflammatory, carminative, and insect repellent.

 

3.3 Non-medicinal uses

3.3.1 As a Food ingredient

Lemongrass is commonly used in Asian cooking. In Thailand, lemongrass is used in Thai cuisines also known as “Takrai”. It is used in many popular drinks in many countries. Lemongrass flavors meat, chicken, and seafood dishes of South Asia and Southeast Asia. It used for the preparation of soft drinks and as an aromatic, pleasant-tasting herbal tea. In the western part of the world, it is used in curries and seafood soups. It is also used as salads in Vietnam and they smoke meats with chopped lemongrass. In Java, it is often used in the preparation of highly spied “sherbet”. Lemongrass, along with black pepper, is also a remedy for menstrual disorders. The herb decoction is tonic and digestive. Some cuisines made with lemongrass are listed below; Spiced carrot soup with ginger and lemongrass

·         Lemongrass coconut rice

·         Vegetarian Pad Thai

·         Tom Ka Kai

·         Yum

·         Yum seafood

3.3.2 In Cosmetics

Lemongrass is used as a flavoring ingredient in several beauty products. It is widely used in the field of cosmetics like soap, face wash, perfume, because of its several benefits to the skin such as reduces oiliness, acne-fighting qualities, detoxifies the skin, and antioxidant property which helps to neutralize damaging free radicals in the skin. As the herb is packed with vitamins A and C, it keeps your skin and hair glossy.

3.3.3 Insect repellent, candle

Lemongrass oil (Cymbopogon citratus) is an effective repellent against mosquitoes (Diptera: Culicidae) and house flies (Diptera: Muscidae)(Baldacchino et al., 2013). It is used in the form of bottle spray, body lotion, liquid hand soap, lemongrass candles, etc.

Conclusion

 Lemongrass is an oil-bearing plant that has multiple uses. It is popular for essential oil extracted from its shoot which contains Geraniol, Citral, Limonene, Myrcene, Neral, Nerol, Citronellol, etc. It can be cultivated in an area having sufficient sunshine with 2500-3300 mm rainfall per annum and soil having good drainage. Lemongrass is a good therapeutic agent which can be used to treat various ailments like digestive disorders, fevers, menstrual disorder, rheumatism, gastritis, etc., and can also be used in the skin to remove facial oils and pimples. Lemongrass is widely used in several beauty products and also used as an insect repellent. Due to its flavoring property, it is used in the field of cooking all over the world especially in Thai cuisines and as herbal tea. Therefore, lemongrass can be commercially cultivated in Nepal and has a great market value (domestic as well as international) as well as the potential to uplift society economically.        

References

Baldacchino, F., Tramut, C., Salem, A., Liénard, E., Delétré, E., Franc, M., Martin, T., Duvallet, G., & Jay-Robert, P. (2013). The repellency of lemongrass oil against stable flies, tested using video tracking. Parasite, 20(1). https://doi.org/10.1051/parasite/2013021

Carlini, E. A., De D.P. Contar, J., Silva-Filho, A. R., Da Silveira-Filho, N. G., Frochtengarten, M. L., & Bueno, O. F. A. (1986). Pharmacology of lemongrass (Cymbopogon citratus Stapf). I. Effects of teas prepared from the leaves on laboratory animals. Journal of Ethnopharmacology, 17(1), 37–64. https://doi.org/10.1016/0378-8741(86)90072-3

Figueirinha, A., Paranhos, A., Pérez-Alonso, J. J., Santos-Buelga, C., & Batista, M. T. (2008). Cymbopogon citratus leaves: Characterization of flavonoids by HPLC-PDA-ESI/MS/MS and an approach to their potential as a source of bioactive polyphenols. Food Chemistry, 110(3), 718–728. https://doi.org/10.1016/j.foodchem.2008.02.045

Joy, P. P. (2016). 43,930 (Issue July).

Puatanachokchai, R., Kishida, H., Denda, A., Murata, N., Konishi, Y., Vinitketkumnuen, U., & Nakae, D. (2002). Inhibitory effects of lemon grass (Cymbopogon citratus, Stapf) extract on the early phase of hepatocarcinogenesis after initiation with diethylnitrosamine in male Fischer 344 rats. Cancer Letters, 183(1), 9–15. https://doi.org/10.1016/S0304-3835(02)00111-8

Ravinder, Kuman Pawan, K., Gaurav, S., Paramjot, K., & Gagan, Shah Appramdeep, K. (2010). Pharmacognostical Investigation of Cymbopogon citratus (DC) Stapf. Pharmacia, 2(2), 208–220. http://scholarsresearchlibrary.com/ABR-vol1-iss2/ABR-2010-1-2-87-90.pdf

Singh, M. (1999). Effect of irrigation and nitrogen on herbage, oil yield and water use of lemongrass (Cymbopogon flexuosus) on alfisols. Journal of Agricultural Science, 132(2), 201–206. https://doi.org/10.1017/S0021859698006236