Botanical name: Hevea brasiliensis.
Family: Euphorbiaceae, which includes plants such as cassava, castor bean, and poinsettia.
Chromosome numbers of rubber: The chromosome number of Hevea brasiliensis (rubber) is 2n=36. This means that the cells of rubber plants have 36 chromosomes, with two sets of 18 chromosomes each. The diploid number of chromosomes in rubber was first determined by cytogenetic studies in the early 20th century.
1. Climatic Conditions:
Rubber requires a hot and humid climate, with an average temperature of 27-34°C and annual rainfall of 2000-3000 mm. It can be grown in areas with a temperature range of 10-40°C, but temperatures below 16°C can be detrimental to growth.
2. Suitable soil:
Rubber requires well-drained, deep soils that are rich in organic matter. The soil pH should be between 4.5 and 6.5. Sandy or clay soils are not suitable for rubber cultivation.
3. Propagation:
Rubber trees are usually propagated by budding or grafting onto rootstocks. Budding is the most common method, and it involves the insertion of a bud into the bark of a seedling or a mature tree.
4. Planting:
The best time for planting rubber is during the rainy season. The seed rate is about 3-5 kg per hectare, and the spacing between trees is about 6m x 6m.
5. Irrigation:
Irrigation is essential from the day of sowing until the plants are established, after which the trees can be watered every 7-10 days.
6. Manures and fertilizers:
Rubber trees require regular applications of nitrogen, phosphorus, and potassium. The recommended dose is 150 kg N, 30 kg P2O5, and 150 kg K2O per hectare per year.
7. Training and pruning:
Rubber trees require training to maintain a straight trunk, and pruning is necessary to remove damaged or diseased branches. The first pruning is done when the tree is about 3 years old.
8. Variety names:
There are several varieties of rubber, including RRIM 600, PB 86, GT 1, and PR 107.
9. Maturity indices:
Rubber trees usually take about 6-7 years to mature and start producing latex. The maturity of the tree is indicated by the girth of the trunk, which should be about 50 cm or more.
10. Harvesting and yield:
The latex is harvested by making incisions in the bark of the tree, and collecting the latex in cups. The latex is usually harvested every 2-3 days, and each tree can produce up to 1-2 kg of latex per day. The yield of rubber varies depending on several factors, including the age of the tree, the variety, and the management practices.
