Cymbopogon winterianus (Java Citronella) finds extensive use in perfumery and is an important source of high grade aroma. Oil of Java citronella is a raw material for manufacturing aromatic chemicals such as citronellal, hydroxy citronellal, ester of geraniol and is therefore considered more important. This oil is mainly used in manufacturing of soaps, cosmetics and mosquito repellent creams. The oil is found to be effective against certain micro and macro organisms. The deoiled grass is used in mulching, as fuel in distilling the oil and manufacture of rough paper boards. This multicut crop provides around 3 to 4 cuttings with an essential oil yield of about 200 kgs from one hectare.

It requires hot and humid climate in tropical areas. It requires abundant moisture and sunshine for its growth. Well distributed rainfall ranging from 200-250 cm and high atmospheric humidity influence the plant growth, yield and quality of oil favourably. The growth of citronella is reported to get restricted when grown on higher altitudes above 400 m, resulting in lower yields.

Javagrass grows best in sandy loam soils. Heavy clayey soils and light sandy soils are not suitable for this crop. It cannot withstand the water stagnation condition. The ideal pH range is 5.0-7.0. Fertility management is important for higher productivity. The land is prepared to fine tilth. Organic P and K fertilizers are mixed into the soil at this stage. In plains, ridges are made 60 cm apart. Apply 25-30 tonnes FYM or well decomposed cow-dung mixed with the soil, at the time of last ploughing. Planting is done in the month of February-March under irrigated conditions while July-August for North-Eastern regions, at a spacing of 60x30 cm.

Citronella is propagated by splitting the clumps of vigorously growing 8-12 months old plant. The clump is gently dug out and separated into number of slips containing 2 tillers/slip. The fibrous roots and dry leaves are trimmed off at 25-30 cm height before planting. One-year old clump, on an average, gives about 50 slips.

The slips are planted at a spacing of 50x40 or 60x30 cm line to line and plant to plant. One slip is inserted in each hole and later filled with loose soil and firmly pressed keeping the slip vertical. The soil moisture is maintained till the crop establishes.

It should be done within a month. 50,000 slips are required to plant one hectare area.

For poor and medium fertility soil, NPK @150:60:60 kg/ha/year and 20-25 ton well decomposed FYM (Farm Yard Manure) or 10-15 ton vermicompost properly mixed in the field during preparation, should be applied. Nitrogen should be applied at 4 equal splits in the first year; first application at about one month after planting followed by first weeding and rest 3 splits after each harvest. In subsequent years, the basal dose may be applied along with the first dose of N. N as urea is top dressed soon after the regenerated crop is established and thereafter once in every two months.

Javagrass requires sufficient moisture for good growth and yield of herb. When there is no rain, irrigation, once in 10-15 days, will be required. For undulating areas, sprinkler irrigation is suggested.

Javagrass plants are susceptible for weed competition during the first month after plantation. This problem is more severe in rainy season. The plants should be kept weed free for 60-75 days for better growth. Weeds are removed either manually or through herbicides.

Diseases

Most important disease is leaf blight or Curvularia leaf blight caused by Curvularia. This can be controlled by application of mancozeb (0.2%).

Insect-pests

During dry season the crop may be affected by yellowing and crinkling disease (due to mites). The emerging leaves become wrinkled and pale. It may fail to open and the part may die. This may be controlled by spraying a mixture of Docofol (Kelthane) @ 2 ml/lit and Ethion (Tafethion, 50 EC) @ 1 ml/lit along with a wetting agent like Triton AE or Enditron AE @ 0.5 ml/lit. In the subsequent years stem borer and in rainfed condition termite may infest the crop. These can be controlled by applying Furadan @ 20 kg/ha or by spraying 0.5 % Dimethoate 400 to 500 kg Neem oil cake. The crop sometimes may show yellowing of growing leaves indicating a mixed deficiency of Zinc, Molybdenum and Sulphur. Two or three foliar sprays of a complete micro-nutrient mixture at fortnightly intervals are sufficient to combat the deficiency.

First harvesting, after 4-5 months from planting and in subsequent second or third year, after 3 months interval. Harvesting is done 6"-8" above the ground level. Harvesting is done by sickle and cut at 15 cm above the ground. Cutting close to the ground results into mortality of the plant.

It takes around 3-4 hours to distil the oil from the herb in field distillation units.

The crop yield is around 20-30 tonnes biomass from one hectare. The average oil recovery is 1%. Hence the oil yield is about 200-250 kg/ha/year. A crop under average management should not yield less than 200 kg oil/ha/year.

Cost of cultivation : Rs. 1,00,000/ha/year

Gross return : Rs. 2,20,00/ha/year (considering a minimal annual yield of 200 kgs)

Net profit : Rs. 1,20,000/ha

Only in areas where well distributed rains occur throughout the year, otherwise citronella is not recommended in rainfed areas.

Slips can be multiplied upto 30 to 40 times after one year.