More than 36,000 articles ranging from giant Truck tyres to small bushes are manufactured from rubber. The commercial source of natural rubber is Hevea brasiliensis, which is introduced in India in the year 1902 and planted in Kerala. Even though it is a tropical tree, it grows well in the soils of N.E. states.
The tyre industry consumer nearly 85% of the natural rubber produced in India and there is an ever- increasing demand for rubber. The basic requirement and a brief package of practices for growing of Rubber is as below.
Rubber is grown in literate or loamy soil, mostly in slope and undulated land or slightly high elaborated flat land where there is no possibility of water stagnation, and having well drainage facilities.
Rubber plants can be successfully grown up to the elevation of 450 metre from mean sea level.
RRIM 600, RRII-105 and GT1 are the recommended clones.
Usually bud grafted plants are planted in polythene bags (poly bag nursery) and after well established, plants are transplanted to the main field which will reduce the immaturity period. Growth will be uniform and causality in the main field will be less.
Preparation of land:
Clearing operation may be done during the month of January-March. A light burning after felling of trees and drying may be done to ensure the destruction of light bush wood and branches of tree.
Lining of spacing:
Recommended planting distance for flat and slightly undulated area:
4.60m x 4.60m (15'x 15')
4.90m x 4.90m (16'x 16')
Undulated and hilly land:
6.10m x 3.00m (20'x 10')
6.70m x 3.40m (22'x 11')
In undulated and hilly land contour lining and terracing is recommended.
Pitting & Refilling:
Pitting is necessary to private favourable condition for the early establishment and growth of young plants. The standard pits recommended are 90x90x90 or 75x75x75cm size. Refilling of the pits should be done with top soil, organic manure and phosphatic fertilizer.
Planting and stand per hectare:
Planting is done during the month of May to August depending upon the rainfall. Bud grafted stumps can be planted directly in the field. In case of planting with polybag plant, a hole of the same size of polybag has to be digged in the centre of the refilled pit. The polybag plant is to be placed in the hole cutting the bottom of the polybag. A vertical cut is made in the bottom half of the polybag and blank space is filled with soil and remove the polybag carefully to avoid disturbance of the soil around the plant. Usually 450-500 plant can be planted in one hectare.
The plantation should be well protected with strong fencing to protect the plants from cattle or wild animals. The plant base of 1m radius should be kept clean and free from weeds. Leguminous cover crop can be established which have multiple advantages. Regular manuring with NPK mixture of recommended dose should be done twice a year. During drought, mulching and white washing should be done. The holding should be protected from fire by providing a fire belt or fire live along the boundary.
If timely maintenance is done, plants will get matured within 6-7 years of planting and will be ready for tapping. To start tapping the plants should have attain a girth of 50cms.