Package of Practices for Cultivation of Lemon Grass
Three types of lemon grasses viz. East Indian lemongrass (C flexuosus), West Indian lemon grass (C. citrates), and Jammu lemongrass (C. pendulus) are in cultivation in our country as the important sources of citrates.
C. flexuosus grown commercially in Kerala and nearby adjacent state, its oil is popularly known as "Cochin oil" as it is shipped mainly through Cochin port. India is annually producing nearly 1000 MT per year while the world demand is much more. Annually, we are exporting lemon grass oil in a tube of about Rs. 5 crores. Our country is facing a critical competition from Gautemaja in the International market.
Uses of Lemon Grass:
1. The chief constituent of the oil is the citral. It is the starting material for the preparation of important ionone viz. A – Ionone, used in flavors, cosmetics and perfume and P – Ionone- used in the manufacture of synthetic vitamin A.
2. Oil has bactericidal, insect repellent and medicinal uses.
3. The spent grass is a source of good cattie feed and can be converted into good silage.
4. Spent grasses are also useful for the manufacture of card boards and papers or as fuel.
Climate and Soil:
The plants are hardy and grow under a variety of conditions. The most ideal conditions are a warm and humid climate with, plenty of sunshine and rainfall of 250-280 cm per annum, uniformly distributed. Regarding the soil, it can be grown from poor soils, in the hill slopes. Soil pH ranging from 4.5 to 7.5 is ideal. As it has good soil binding nature, they can be grown as vegetative cover over naked, eroded slopes.
Varieties of Lemon Grass:
The Medicinal and Aromatic Plants Research Station, Odakkali (Kerala) and CTMAP, Lucknow have developed improved strains viz. OD-19 and SD-68 respectively as a result of breeding. The important features of these varieties are given below:
Oil recovery per cent on dry weight
1,2 to 1.5
1,2 to 1:5
These two improved varieties are now recommended for wide cultivation. Recently the RRI, Jammu has developed hybrid strain CKP-25 by crossing C. khasianus and C. pendulus which is capable of yielding 50 % and 140 % moire oil yield than RRL-16 and OD-19 respectively.
The soil should be well pulverized for forming the seed bed and it should be a raised bed one. Leaf mould and farm yard manure are also added to the soil while forming the bed. 15-20 kg of seeds are required for raising seedlings for one hectare. Seeds are sown in lines drawn at 10 cm interval mthe beds and -covered with cut grass materials when the seedlings are about 2 months old or, about 12 to 15 cm high, they are ready for transplanting.
The land is cleared of the underground vegetations and pits of 5 cm cube are made at a spacing of 15 x 19 cm. Splits from old clumps can also be used for propagations.
Manures and Fertilizers:
The Aromatic Plants Research Station, Odakkali (Kerala) recommended 100 kg of N/ha. Under North East conditions, application of 60 kg N, 50 kg P and 35 kg K is recommended per hectare.
Harvesting of Lemon Grass:
Lemon grass comes to harvest 90 days after planting and subsequently it is harvested at 50-55 days interval.. The grass is cut 10 cm above the ground level and 5-6 cuttings can be taken in a year subject to the climatic conditions. Depending upon the soil and climatic conditions, the crop can be retained in like field for 5 to 6 years.
On an average 25 kg of oil can be obtained from first year per hectare plantation and about 80 to 100 kg of oil per year from 2nd to 6th year if well maintained.
In North India, Jammu lemon grass (C. pendulus) is cultivated under irrigated condition as a source of citral. The cultural practices are almost similar to East Indian lemon grass. It is propagated exclusively by slips which are planted on flat beds. A spacing of 50 x 50 cm is adopted. A dose of 260 N, 80 kg P205 and 120 kg K20 per hectare is recommended in 3-4 split doses. The crop responds to irrigation especially during hot summer months.