MEDICINAL AND AROMATIC CROPS (2+1)

Cultivation

Soil
The plant has been found to grown well under varying soil conditions but sandy loam soil with abundant organic matter is the most suitable. Heavy clay and sandy soils are not conducive to the good growth of this plant. Citronella thrives well in a wide range of soil pH ranging from 5.8 to 8.0. However, a pH of around 6.0 is the most suitable. The plants are reported to grow well at altitudes between 1000-1500m.

Climate
Citronella thrives best under tropical and subtropical conditions. It requires abundant moisture and sunshine for its good growth. However the distribution of rainfall is important rather than the total amount. Well distributed rainfall ranging from 200- 250cm and high atmospheric humidity appears to influence the plant’s growth, yield and quality of oil favourably. In areas where the rainfall is low the plant can be grown with supplementary irrigation.

Land Preparation
The land is brought to a fine tilth by ploughing and harrowing and the field is laid out in 6m x 6m size beds, providing irrigation channels. Ridges and furrows are made at 60cm intervals.

Propagation
Citronella flowers profusely in South India at higher altitudes and sporadically in the plains of the North and North – eastern regions. Viable seeds, however, are not formed because of irregularities in meiosis and therefore the species can be propagated only by vegetatively. The slips are taken from healthy, vigorously growing young bushes. The bush is gently dug out and separated into a number of slips and each slip contains 1-3 tillers. The fibrous roots and leaves should be trimmed off the slips before planting. It is observed that one year old clump on an average gives about 50 slips.

Planting
The slips are planted in May- June when they establish well in this region. Late planting, particularly after July, sometimes results in heavy casualty. The slips are planted at a distance of 60cm x 60cm apart. However in areas where the soil is very fertile and the climatic conditions support luxurious growth spacing of 90cm x 90cm may be followed. It is better if the slips are planted on ridges to avoid water –logging. The field should be irrigated immediately after planting, if there are no rains within the next 24 hours.

Manures and Fertilizers
In the red laterite soil of Karnataka and other Southern States where the plant grows through out the year 10t of FYM is applied. A fertilizer dose of 80-120 kg N, 80 kg P2O5 and 40kg K2O is given. Nitrogen is applied in 4 equal split doses, the first about a month after planting and then after each harvest at an interval of about 4 months. The CIMAP, Lucknow, has recommended a spray of 0.5% Fe through ferrous sulphate + Citric acid to check the spread of chlorosis.

Irrigation
Citronella requires sufficient moisture for good growth and yield of leaves. In the areas where the annual rainfall is about 200-250cm, well distributed over the year and humidity is high, supplementary irrigation is not necessary. In the drier months, however, irrigation may be provided and this increases the yield. Under Karnataka conditions about 8-10 irrigations are required in the dry period.

Interculture
Citronella plantations should be kept weed –free. When the plants have established themselves and grown into bushes the problem is not that severe. However in newly established plantations and after each harvest, weeds spring up in the inter-row spaces and weeding is essential.