Rubber production
Land preparation
Rubber tree belongs to the natural order Euphorbiaceae. This tree is sturdy, tall and quick growing. It has a well-developed tap root and laterals. The leaves are trifoliate, with long petioles. Flowers are unisexual, small and fragrant. Staminate flowers are small and numerous. Pollination is by insects. Latex vessels are present in all parts of the tree except in the wood. https://www.indiaagronet.com/horticulture/CONTENTS/Rubber.htm
Rubber requires a well-drained land that has a deep water table (deeper than 100 cm). land should be gentle sloppy/undulating to rolling terrains. Areas with big trees, or in second growth forest should have the under growth cleared first to enhance cutting of bigger trees. Cut into logs the large trees and remove these from the site. Cut and heap the smaller trees found along the expected rows of rubber. In cogonal areas, remove the cogon grass completely since it can hinder the growth of rubber. In hilly areas where cultivation is difficult, remove the cogon along the rubber rows only, prepare the land following contour lining and note that land terracing is highly recommended. While in flat but cultivated areas, plough the area twice before laying out. http://cagayandeoro.da.gov.ph/wpcontent/uploads/2013/04/RUBBERPRODUCTION-GUIDE.pdf
Climatic and soil requirements
Rubber demands in its climatic requirements. The regions lying within 100 latitudes on either side of the Equator is highly suitable for rubber cultivation. It requires a temperature ranging from 200 to 300C with a well distributed rainfall of 200-250cm over the year. It comes up in plains and also in slopes of mountainous regions ranging from 300-800m above sea level. This specific climate is available only in Kanyakumari district, Tamil Nadu and Kerala, which constitute the traditional area. It thrives well in deep well drained acidic soils of red lateritic loams or clayey loams with a pH varying from 4.5 to 6.0 https://www.indiaagronet.com/horticulture/CONTENTS/Rubber.htm (ideal pH is 5.5) and a well aerated soil (30%). An atmospheric humidity of 80% with moderate wind and top soil containing plenty of organic matter.
Varieties of rubber
Rubber Research Institute of Malaya, Rubber Research Institute of India, kottayam and other institutes have developed clonal varieties. These clones are broadly classified into three categories viz., primary, secondary and tertiary, based on the method adopted for the development of their mother trees. When mother trees are selected from existing seedling populations of unknown parentage and are multiplied vegetatively to give rise to the clones, they are called primary clones. When the mother trees clones and are then multiplied vegetatively, they are known as secondary clones.
| S/n | Name | Parents | Characters |
| 1 | TJIR – 1 | Indonesian clone, Yield 930 kg/ha per year, Susceptible to phytophtora, Oidium and pink disease. | |
| 2 | G.T.1 | Indonesian clone, Yield 1360 kg/ha year, Tolerant to phytophthora, pink disease and brown bast. | |
| 3 | G.I.1 | Malayasian clone, Yield 1130 kg/ha year, Susceptible to brown bast, possess drought tolerance. | |
| 4 | P.B. 86 | Malayasian clone, Yield 1130 kg per ha/year. | |
| Secondary clones | |||
| 5 | PRIM-600 | TJIR-1 x P.B. 86 | Developed by Rubber Research Institute of Malaya (RRIM). Yield 1317kg/ha/year, Susceptible to phytophthora and pink disease. |
| 6 | RRIM. 628 | TJIR.1x RRIM.527 | Yield 1051 kg/ha/year, Susceptible to brown bast, poor yielded during summer. |
| Tertiary clones | |||
| 7 | RRIM – 703
|
RRIM.600xRRIM.500 | Yield 1725 kg/ha/year, Susceptible to brown bast and wind damage. |
Seeds
Propagation through seed is practised to raise seedlings for rootstock purpose or to raise polyclonal seedling progenies. Seeds normally ripen during July-September in South India. As the viability is very short (8 weeks), they are to be sown immediately raised beds of river sand of 1m width and of convenient length are formed and the seeds are sown in a single layer toughing one another and pressed firmly with the surface of the seed just visible above. Nursery may be protected from direct sun by providing a temporary shade. Regular watering is attended to maintain the moisture in the beds. Seeds start germinating within 6 to 10 days. Such raise seedling stumps or at 60x90cm or 60x120cm to raise bud wood nursery or stumped budding. Otherwise, sprouted seeds can be directly planted in the field.
Budding
The scions of a particular clone are maintained in the bud wood nursery by planting the budded stumps or by budding the clone on the seedlings in situ at nursery. Budded stump often refers to the budded plant whose scion shoot is cut very close to the budding zone leaving few dormant buds in the scion shoot. On the other hand, if the root stock is cut as a stump and budding is done, usually green budding at four to five months’ stage, then it is known as stumped budding. When the bud wood nursery plants are one-year-old, about 1m of usable bud wood can be obtained. The bud wood is cut when at least 1m of brown bark has developed. The immature green portion should be removed to a point about 1m below the terminal bud, leaving the leaf stalks in position. The bud wood may be cut off about 15cm at the base, leaving a few dormant buds to develop into bud shoots for the subsequent season. Two such sprouting shoots may be allowed for next year, from one metre shoot, 15 to 20 buds may be obtained.
Modified forked method is followed and is done during April-May, when the weather is not dry or wet. Two types of budding techniques are practiced. Brown budding is done by using buds taken from bud wood of one-year growth on to a stock plant of ten months old. Green budding on the other hand involves young green bud wood and stock. Bud wood of 6-8 weeks old is used on stock seedlings of 2 to 6 months old.
Recently, polybag plants are raised as such plants reach tapping stage quickly. Black polythene bags of 60 x 30 cm with 400 gauge are filled with topsoil alone along with 25g of rock phosphate. Green budded stumps are planted in these polybags and the scions are allowed to develop 2 to 3 whorl of leaves.
https://www.indiaagronet.com/horticulture/CONTENTS/Rubber.htm
Management practices
Fertilizer application
Normally rubber plants respond very well to organic matter and fertilizers. 10 to 12 kg of well rotten organic manure and 225 grams of rock phosphate should be applied to each plant pit while preparing the piit as basal application. This dosage iss recommended up to 4th year of planting. In case of soils having magnesium deficiency, a fertilizer mixture of 10:10:4:1.5 of N: P2O5: K2O: MgO at 100, 400, 500 and 400 kg per hectare should be applied during the 1st, 2nd, 3rd and 4th year of rubber planting.
In case of magnesium rich soils, a fertilizer mixture of 12:12:6 of N: P2O5: K2O at 85, 340, 430 and 340 kg per hectare during the 1st, 2nd, 3rd and 4th year of rubber planting.
Intercropping
This will generate good revenue during the first two years of cultivation. The suitable intercrops in rubber plantation are like ginger, turmeric, tuber crops, vegetables, pineapple, banana and medicinal or herbal plants.
Cover cropping
This is very helpful in sloppy regions to prevent soil erosion. This also helps in enhancing the soil fertility and controls the weed growth along with soil temperature. Intercropping like leguminous crops will help in nitrogen fixation in the soil.
Weed control
Weeding is usually carried out manually or chemically or through combination of both. The main weeds commonly foundin rubber plantation are Axonopus, Paspalum, Digitaria, Mikania, Sida, Pennisetum etc. as a pre emergence application, chemical herbicides like Alachor, Diuron and Simazina should be applied to control the weeds. Herbicides like Paraquat and Glyphosate can be applied in the post emergent stage.
Pest and diseases
Scale insect, termite, mealy bug, cockchafer grub and mites are the main pests in rubber plantation. The following are the control measures:
Scale insect: spray malathion at 50 EC 2 ml/litre of water
Mealy bug: spray fish oil rosin-soap 25g/l
Termite: Drench the soil at plant base with chlorpyriphos 20 EC 2 ml/l of water.
Cockchafer grub: drench the soil at plant base in the affected area with chlorpyriphos 20 EC 2ml/l of water.
Mites: Spray sulphur at 50 WP at 2g/l of water.
Rubber tree is subjected to many diseases like abnormal leaf fall, secondary leaf fall, Bird’s eye spot, Leaf spot, Powdery mildew, pink disease, patch canker or bark cankers, dry rot, stump rot, collar rot or charcoal rot and brown root disease are the main disease found in rubber farming. http://www.agrifarming.in/rubber-plantation/
When to Plant
Newly purchased or existing rubber trees require occasional transplanting into a new container to promote continued growth. Rubber trees will eventually outgrow their container as they mature in height and width. Growing root systems may expand to the point that they become overcrowded in their current container, which if left unaddressed may stunt the rubber tree’s growth. Top-heavy rubber trees are likely to tip over and sustain injuries. Transplant rubber trees if possible in late winter or early spring when the trees are dormant or just beginning to produce new growth to minimize shock. Plant rubber trees into containers 2 inches larger than the size of their current pots to allow adequate room for future growth. Always select containers with holes in the bottom for proper drainage. Untreated clay containers are porous and draw moisture from the soil, requiring shorter periods between wettings. Therefore, treated clay or plastic containers work better. Rubber trees grow best in rich, fertile soils that are well-draining. A good growing medium for rubber trees contains 3 parts potting soil, 1-part sand, and 1-part peat moss.
Planting
Proper planting procedures are important to minimizing transplant shock and setting the tree up for continued healthy growth. Lightly moisten the potting soil with a spray nozzle attached to a garden hose. Fill the container one-third full with soil. Tip the rubber tree on its side and carefully slide the tree’s root ball out of the pot. Prune off any broken, damaged or mushy roots with a pair of pruning shears. Spread the bottom roots gently outward and place the tree upright into the new pot. Back fill the pot with soil, tamping the medium down around the roots. Repeat this process until the soil level is even with the soil level at the top of the root ball, which should be 1 to 2 inches below the top of the pot. http://homeguides.sfgate.com/process-planting-rubber-trees-27634.html
The choice of planting distance, largely depend on the topography of the area and possibility of planting intercrops.
| Topography | Distance (m) | No of tress |
| Hilly (contour sloping) | 9.0 x 2.5 | 444 |
|
Flat or Undulating |
8.0 x 2.5
10.0 x 2.0 8.0 x 3.0 5.0 x 4.0
|
500
500 416 500 |
|
Avenue system |
6.0 x 3.0
7.0 x 3.0 12.0 x 2.0 |
555
476 416 |
Lay-out in Flat Lands
Rows of rubber are usually set at east-west orientation to obtain maximum exposure to sunlight. Steps:
- The longest straight boundary line along the east-west orientation is made as convenient base line.
- Measure and determine the 900 angle using the 3, 4, 5 meters on both ends of the base line.
- Establish the distance between the rows and the rubber plants within the row following the line as indicated by the 90o.
- Measure the distances between plants along the row in the succeeding row until the lay-out of the whole area is completed.
- Determine the distances of rubber plants between the rows following the line as indicated by the 90o in the other end of the base line.
Lay-out on Hill Areas
Contour lining is highly recommended on hilly areas of more than 200 gradients as mentioned earlier, by marking the planting in level lines across the slope. A line of average slope is selected dividing the slope, a frame is used.
After the lay-out the contour lines along the slope, cutting of the planting terrace is done. Terraces are necessary on hilly lands to prevent soil erosion and also for convenience in tapping. To establish a this, the soil is cut away 1.0 – 1.5 m back to the hill from the planting guide stick with a drop of 25-50 cm to the back of the terrace.
Establishing a Terrace by Cutting the Soil
Holing
Size and shape of the hole depends largely on the soil condition and planting materials. In fertile and soft soils, hole shall be 25-30 cm in diameter and 40-45 deep. In poor and hard soils, bigger holes are required from 40-45 cm diameter to 50-60 cm deep. If possible, holing must be done few days before planting.
Planting
A planting material of a second leaf storey with fully expanded, dark green and mature top whorl leaves will be used. Planting will be done during rainy months. Plant the budding according to sizes. Bigger plants should be planted first followed by smaller ones.
Steps
- The bottom of the bag should be completely removed first before placing in the hole.
- The planting material is carefully placed in the hole and with the sharp knife, cut the plastic bag vertically starting from the bottom going up.
- Pull the plastic sleeve and backfill with fertile soil.
- In compacting the backfilled soil, it should be in a slight manner to allow air circulation within the soil particles.
http://cagayandeoro.da.gov.ph/wpcontent/uploads/2013/04/RUBBERPRODUCTION-GUIDE.pdf
Tapping
This stage is attainable at seven years provided they possess the required girth of the trees. Seedling must attain a girth of 55cm at a height of 50 cm from the ground. In the case of budded trees, the girth should be 50 cm at a height of 125 cm from the bud union. Tapping is the periodical removing of thin slices of bark to extract rubber latex. Tapping is done by skilled men. While tapping the depth should be 1mm close to cambium without any damage to it, otherwise callus formation will take place causing swellings. Tapping has to be done on a slope of 300 to the horizontal zone in the case of budded trees and 250 in the case of seedlings. Tapping is done early in the morning, as late tapping will cause reduction in the flow of latex. In the early morning the turgor pressure in the latex vessels is high and rapid flow of latex occurs.
Yield/Harvest
In rubber plantation, yield depends on the method of propagation. In any method, usually yield increases year by year. the yield reaches peak after 14 to 15 years of planting. An annual average yield of rubber is about 375 to 400 kg/ha from seedlings tree. In budded plants, an average yield of 800 – 1000 kg/ha can be obtained. http://www.agrifarming.in/rubber-plantation/
Processing
The latex that flows out from the rubber trees on tapping is channelled into a container, generally coconut shell cups, attached to them. Latex collected in coconut shell cups in transferred to clean buckets, two to three hours after tapping. The latex which gets dried up on the tapping panel (tree lace) and the collection cups (shell scrap) also form a part of the crop and are collected by the tapper in baskets just prior to tapping. The latex spilt including overflows on the ground (earth scrap), when gets dried up, is also collected once in a month. Normally 10-20 % of the total crop constitute the tree lace, shell scrap and earth scrap. Rubber can be processed and marketed as Preserved latex concentrates: The latex is collected in the storage tank, from there it is brought to a centrifuge machine, rotating at 1440 rpm. Due to the centrifugal action, liquid portion comes out. The upper layer, the concentrated latex, is collected and brought to bulking tank and mixed with chemical and packed in drums. 60% rubber is present in it. Skim latex is taken to another tank and sulphuric acid is added and coagulated and milled to get skim crepe. It is of poor quality while the concentrated latex fetches very higher price. Dry ribbed sheet rubber: Anti-coagulants (solutions of ammonia, formalin or sodium sulphite) are added to the cups to prevent the coagulation of latex before it reaches the factory. The latex so collected is bulked and then strained to remove the impurities. It is then diluted to a standard consistency of 12-13% rubber. Special hydrometers like metrolac, latex meter are employed to measure the percentage of rubber. After dilution, the latex is strained through a 60 mesh screen for the second time. Then it is poured into the special coagulating tanks or aluminium pans which is divided into many compartments by thin aluminium sheets and acetic acid or formic acid to use for coagulation. Slow coagulation produces a soft rubber, which is easy to work on the rollers. The acid is to be added quickly and mixed thoroughly with the surface of rubber sheets. After coagulation, rubber sheets are repeatedly washed several times with changes of water and passed through hand or power operated rollers. In the roller excess water and dissolved impurities are pressed and squeezed out. The surface of the rollers may be either smooth or grooved or zig zag or straight or diamond pattern, its impression is normally left on the surface of the sheets when they come out of the press. These sheets are hung in shade for two to three hours for dripping in a dust free place. They are then taken to smoke houses for thorough drying. Smoking of rubber sheets is done to dry the sheets properly and to avoid formation of blisters. In the smokehouse, the sheets are smoked at a low temperature of 48-500C with fairly high humidity during the first day subsequently during 2nd to 4th day the temperature being 680C with low relative humidity. They are taken out, graded and packed. Such products are known as smoked sheets or dry ribbed sheet rubber. Various grades of rubber sheets are RMA IX, RMA-1, RMA-2, RMA-3, RMA-4 and RMA-5. High grade rubber sheets are clear, free from blisters, translucent and of a golden brown colour and fetch a better price. Dry crepe rubber: When coagulum from latex or any form of field coagulum after necessary preliminary treatments is passed through a set of creping machines to get crinkly, lace-like rubber called crepe rubber after drying. Various grades of crepe rubbers are EPC super 1 X, EPC1X, EPC2X, and EPC3X. https://www.indiaagronet.com/horticulture/CONTENTS/Rubber.htm
