Rubber (The wheel of modern civilization) brasiliensis Scientific name: Hevea brasiliensis
Family: Euphorbiaceae
Origin
Rubber is originated from Brazil.
Clones
Clones are group of plants produced by vegetative propagation from single plants. Base Based d on the the type type of moth mother er tree tree from from whic which h the the clon clonee is deriv derived ed they they are are classified as... a. Primary clone (e.g. GT-1, PR-07, PB-28/29 PB-28/29 etc.) etc.) b. Secondary Secondary clone clone (e.g. (e.g. RM 600, 600, PRII 105, 105, RRII-203 RRII-203 etc.) etc.) c. Tertia Tertiary ry clon clonee (e.g. (e.g. PRIM 703) 703)
Species
Para rubber - Hevea brasiliensis Assam rubber - Ficus elastica Ceara rubber – Manihat glaziovii Panama rubber – Costilla elastica Logos milk rubber – Funtumia Funtumia elastica
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Production technology Climate
Rubber is a tropical quick growing tree.
Optimum temperature requirement is 25 to 28°C.
2000 to 3000 mm rainfall is suitable.
It requires bright sunshine.
Soil
The The rubb rubber er tree tree is adop adopte ted d to grow grow in a wide wide rang rangee of soil soils. s. Soil Soil must must be pulverized, deep, rich in organic matter, well drained, acidic soils of red lateritic loam with a pH ranging from 5-8 is suitable.
Propagation
Mainly by seeds but can also be done by •
Bud wood
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Budded stumps
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and advanced planting materials like polybag plants, maxi stumps etc.
Planting system
The planting systems adopted in rubber are square, rectangular, or triangular. The square and triangular systems result in well balanced crown and root systems.
Plant spacing
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The planting density varies with different situations. Usually a planting density of 420 to 445 budded plants per hectare is recommended. This is increased to 445 to 520 plants per hectare in case of seedlings. For budding, In hilly areas 6.7×3.4 m In flat areas 4.9×4.9 m For seedlings, In hilly areas 6.1×3.0m In flat areas 4.6×4.6 m Planting
For new planting jungle clearing with felling of trees has to done first. Pits are usually dug to the size of one cubic meter and are filled f illed with soil and compost. Planting time
Planting should be done in the month of June- July. After care a. Cove Coverr ccro rop ps
Cover crops form an important ground cover in rubber plantations to prevent weed, weed, soil soil erosio erosion, n, conser conserve ve soil soil moistu moisture, re, temper temperatu ature re and add organi organicc matter to the soil. b. We Weed ed cont contro roll
Weed control should be done when and as necessary. Weed control can be done manually or or using herbicides like paraquat (2.25L (2.25L /ha), 2,4-D (1.25 kg/ha) c. Ferti ertillize izers
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After 4 years of planting a dose of 40g N, 90g P 2O5 and 90g K 2O per plant should be applied. In the 1 st and 2nd year one third and two third of the full dose should be applied. Diseases •
Abnormal leaf roll
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Powdery mildew
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Shoot rot
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Leaf spot
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Black rot
Pests •
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Melay bug Scale insect
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Bark feeding caterpillar
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Termite
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Slug and snail
Harvesting Tapping •
Tapping is the process of controlled wounding of rubber tree during which thin shavings of bark are removed r emoved leading to flow of latex.
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The tapping cut should have a slope of 25-30 0 to the horizontal zone.
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Tapping depth should be less than 1mm close to the cambium since more latex vessels are concentrated near the cambium.
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•
Tapping should be done early in the morning as late tapping reduces the exudation of latex.
Tapping systems
3 systems a. Th Thee her herri ring ng bone bone
It is a method in which oblique cuts are made which alternate with each other and open on either side of the vertical cut or line. These oblique cuts may be on both sides of the line or on only one side. b. Th Thee spi spira rall cu cutt
The spiral cut may be •
Half spiral
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Full spiral
The half spiral may have the spiral cuts on one side of the vertical line or on both sides. The half spiral method is generally adopted. c. The V cut
Two slanting cuts are made like the two arms of a ‘V’, which meet at the lower end where latex receiving cup is fitted.
Yield
The latex yield vary with the •
Clone
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Age of the trees
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Fertility of the soil
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Climatic condition 5
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Skill of the tapper
In Bangladesh about 5.3 quintals per hectare.
Processing of rubber
Processing of rubber involves 3 steps: a. Coag Coagul ulat atio ion n
The fresh latex is diluted with water and stained through a sieve to remove barks, fiber etc. Then it is poured into shallow trays. The latex is then acidif acidified ied.. Formic Formic acid acid (0.5%) (0.5%) or acetic acetic acid acid (1%) (1%) is genera generally lly used used for coag coagul ulat atio ion. n. The The quan quanti tity ty of acid acid depe depend ndss on the the amou amount nt and and type type of anticoagulant used, the duration of coagulation, the season and the nature of latex.
b. Rolling
After coagulation, the coagulum is removed from the pan and thoroughly washed in running water. Then rubber sheets are rolled either in a hand or power operated roller to a thickness of 3 mm to remove excess water, dissolved impurities, protein, regin, carbohydrates etc.
c. Smok Smokin ing g and and dr dryi ying ng
After rolling rubber sheets are placed in a smoke house. Here the sheets are dried gradually to avoid the formation of blisters. Sheets thus dried are called RSS (Ribbed smoked sheet). The temperature in the smoke house has to maintain in the range of 40-60 0c. The sheets are spread on wooden or bamboo rods placed on trolleys which move on a central rail track in a large 6
tunnel type smoke house. Drying of sheets take four to six days in a smoke house.
Then sheets are graded, cut into suitable sizes and packaging is done. Grading is done based on •
Colour
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Transparency
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Presence off mould
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Oxidized spots
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Blisters
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Bubbles
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Dirt
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Sand
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Degree of drying
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