Conditions for Growth of Rubber:
i. Rubber tree is a fast growing tall tree acquiring a height of about 20 to 30 metres.
ii. Rubber tree needs a hot and humid climate with temperature ranging between 25 °C and 35 °C and the annual rainfall of about 300 cm.
iii. The rainfall should be well-distributed throughout the year. Dry spells and low temperature are harmful for rubber trees. Daily rainfall followed by bright sunshine is ideal for its growth.
iv. Deep, rich and well-drained loamy soil, at an elevation of about 400 metres above the sea level, provides ideal conditions for the growth of rubber trees.
v. Cheap and adequate supply of labour is needed.
Methods of Cultivation:
The land is first cleared of forests and then levelled properly.
a. The seeds of the rubber tree are first planted in raised nurseries.
b. When the seedlings are about one year old, they are planted in rows in the main estate with a gap of about nine metres between them.
c. The area around the rubber tree is kept free from weeds and other unwanted plants. Leguminous crops are planted between the seedlings to prevent soil erosion.
d. A rubber seedling may take about 7 years to mature and produce latex. The cover crop can provide income to the farmer during this period.
e. The fertilizers are regularly applied and the plants are protected from pests and diseases.
The trees are regularly tapped to get the latex. Skill and practice are required to tap a rubber tree. The work on the plantation starts early in the morning and is completed before the mid-day rains.
a. The tapper makes a cut about 2 mm deep and about 11/2 metres above the ground, which slants downwards.
b. Latex is collected in a metal cup. The workers, after completing the tapping work, collect the latex from the cups into large buckets.
c. A skilled worker can tap up to about 300 trees in a day. Tapping of trees is generally done on alternate days. It is avoided on rainy days.
d. The fresh latex must be protected from the sun. It should be taken to the rubber processing unit immediately.
The latex from the rubber tree must be processed before it becomes hard.
a. The latex is thickened by adding formic acid and then converted into large blocks.
b. The rubber blocks are pressed through roller to squeeze out water and convert them into sheets.
c. The rubber sheets are dried either in the open or in smoke houses. This is done to preserve them.
d. The fully dried sheets are inspected, graded and finally packed in bales either for sale in domestic market or for export.
Areas of Rubber Production:
India is the fifth largest rubber producing country in the world, after Malaysia, Indonesia, Thailand and Brazil. India produces about 7 lakh tons of rubber, which is about 4 per cent of the total world’s production.
Kerala is the largest producer of natural rubber in India. Other important producers are Tamil Nadu, Karnataka and Andaman and Nicobar Islands. Kerala produces about 6 lakh tons of rubber, which is more than 80 per cent of the total rubber production in India. The main rubber producing districts of Kerala are Kottayam, Kollam, Ernakulam and Kozhikode.