Rubber plantation

The Amazon rubber industry collapsed almost overnight. In 1876 the English botanist Henry Wickham shipped 70,000 Hevea seeds to the Royal Botanic Gardens in London. New strains of Hevea were developed that produced three to four times as much mbber and were more disease-resistant than their wild Amazonian cousins. Soon, seedlings were sent to Malaya, Java, and other islands of the East Indies. Thirty-five years later, rubber plantations on these islands took control of the industry. 

The rabber industry changed again when the Japanese captured the East Indian rubber plantations during World War n. The resulting shortage of rabber prompted an intensive research program to produce synthetic rubber. Today, more than 2 million tons of synthetic rabber is produced each year in the United States. Natural rubber is still produced in the tropics, but its importance pales compared to the glory days of the Brazilian rabber plantations. 

Neoprene, Carothers first practical invention, was made reluctantly, as a kind of side issue to his scientific investigation of polymers. Synthetic rubber was of great commercial interest. The car-happy United States used half the world s natural rubber, and demand had outstripped the supply from wild rubber trees in the Amazon. Price fluctuations on British rubber plantations in Southeast Asia provided further incentive for the development of synthetic substitutes. Du Pont had been trying without success to... 

On a rubber plantation, the tree population per acre. The initial stand is sufficient to allow for losses due to disease and provides a final stand of 90-100 trees per acre. 

The cutting of terraces on rubber plantations situated on hilly areas, with the object of preventing the loss of top soil during heavy rain. Terylene... 

Whereas, at the beginning of the thirties, polystyrene had been the driving force in the styrene monomer and polystyrene fields, this development was soon reversed. Under Germany s efforts to become self-sufficient there was a much bigger demand for styrene monomer for the manufacture of synthetic rubber than for polystyrene. As early as 1938 approximately 2500 t of styrene monomer was produced in Ludwigshafen for the newly commissioned rubber plants. When the Allies were cut off from their Asian rubber plantations in the Second World War, the U.S.A. followed suit with large styrene monomer capacities for the manufacture of rubber. Thus there were big capacities for styrene monomer available by 1945 for other uses. 

Wellman, F. L., Condition of Hevea Rubber Plantations in E1 Recreo, and... 

Following the Japanese blockade of exports from the natural rubber plantations of Malaysia, the United States established the Rubber Reserve Program, a crash program... 

Chemical weed control in sugarcane may have started in Hawaii. Sodium arsenite was first used in rubber plantations in 1913, but its most lasting impacts occurred in the sugar industry. At that time the Hawaiian industry was spending 750000 to 1 million annually for hand hoeing, but growers learned that they could apply sodium arsenite at 5.5kg/ha in 380L of water and achieve weed control at one-fourth the cost. 

White latex drips out of cuts in the bark of a rubber tree in a Malaysian rubber plantation. 

On a global scale, success of rubber plantations in diverse areas such as Malaysia and southern Brazil have drastically altered the price of natural rubber, making extractive rubber production less lucrative... 

For example, all these factors have operated in Amazon. Even during the rubber boom of the late 19 th Century colonization was primarily confined to locations on the riverbank which could be reached by boat. It was calculated that completion in 1912 of the Madeira-Mamore railway line of 364 km cost one life for every sleeper laid (de Oliveira, 1983). We now know much more about tropical diseases, but the problems are far from being solved (da Costa Linhares, 1983). Failure in exploitation may be due to unexpected reasons. The well-funded rubber plantation of the Ford Motor Co. (Fordlandia) established near Santarem in the 30 s failed by 1944 primarily because of fungus disease and an insect parasite. This was not a problem with the isolated trees of natural rubber in the jungle, but under plantation conditions the trees were close enough together for the infection to pass from one to another. At that time no effective pesticide treatment was available. 

Synthetic latex polymers got their first main push during WWI when the Allies blockaded Germany, cutting her off from the South American rubber plantations. It got its second big push in WWII when Japan occupied the South East Asian plantations. Today, manufacture of synthetic latex polymers is a 13 billion industry of which 5.5 billion is from the 604 million gallons of paint made annually. The paint manufacturing industry in 1993 employed 58,200 people in 800 to 900 plants. The average costs of a gallon of latex paint in 1993 were 9.15 wholesale and 13.25 retail. 

At lower rates it is used as an experimental herbicide in several crops, in pastures, established alfalfa, banana plantations, orchards, forests, rubber plantations, flax and hemp. 

Dimefuron is a pre- and postemergence herbicide of high activity. At a rate of 4 kg active ingredient/ha it has a total effect, and it is very persistent at this rate. At a rate of 0.5-1.0 kg it selectively controls most of the annual broad-leaved and grassy weeds, with the exception of a few cruciferous weeds, in cereals, dormant alfalfa and legumes. Higher (2-3 kg) doses can be used in cotton, tea, cocoa, sugar cane and rubber plantations. 

Today s by far predominant application of AS2O3 is raw material for the production of wood preservatives. The main product is chromated copper arsenate (CCA). As this is very effective, it is difficult to replace it with other substances, but in a number of countries its use is already forbidden. The USA and Malaysia (for rubber plantations) are still the largest consumers, but stricter regulations because of occupational and environmental problems makes the future market situation risky (Crund and Hanusch... 

Rubber trees are affected by a number of diseases involving roots, stems, and leaves. However, effective control measures have been evolved for all these diseases, except the South American Leaf BUght, caused by the fungus Microcyclus ulei, which has caused extensive damage to rubber plantations in South America. Fortunately Asia and Africa are free from this disease... 

Natural rubber (NR) is one of natural polymers produced by a number of tropical countries Indonesia, Malaysia, Thailand, Sri Lanka etc. Indonesia, with about 2.6 Million Ha of rubber plantation, producing about 1.3 Million tonnes of NR annually. It was a subject of investigation long before the second WW,from the process of producing a raw NR which should meet a standard of quality to the process of producing rubber goods. 

Materials High ammonia type centrifuged natural rubber latex from Pasir Waringin Rubber Plantation. FTP XI, West Jawa, lndone.sia was used (Table 1). Carbon tetrachloride and normal butil acrylate were used as sensitizer. Nocract 300 was used as antioxidant. All the chemicals were technical grade without further purification. 

Table 1. Specification of natural rubber latex from Cikumpai rubber plantation, produced in September, 1989.

All other industrial coimtries remained content with natural rubber. Its qualities were still better overall. However, all was to change during the Second World War, when almost all the rubber plantations in South-Eastern Asia were occupied by the Japanese. This encouraged the search for new methods of synthesizing rubber, especially in the United States and Canada. Soon, the world production of artificial rubber caught up with and, by the 1960s, had surpassed the production of natural rubber. 

As rubber plantations are currently expanding to new areas under drier climatic conditions than traditional ones (north-eastern Thailand, Mato-Grosso in Brazil, north-western India), the performance of rubber trees under water stress has become a major issue. Two main traits are to be considered performance (the ability to transfer water and grow under water stress) and resistance (the ability to avoid damage and survive under water stress). Performance mainly relies on the conductivity of the hydraulic system from root to leaf, whereas resistance mainly relies on susceptibility to cavitation, leading to embolism, within xylem vessels. Stomatal closure occurs to avoid severe cavitation. Hence, differences in susceptibility to cavitation among rubber clones are likely to induce differences in resistance to severe water stress. 

P. Thaler, M. Verdier, O. Roupsard, A. Chantuma, P. Siripornpakdeekul, P. Kasemsap and K. Sangkhasila, Partitioning of water flux in rubber plantations. Estimation of tree transpiration by sap flow measurement. International Workshop on Flux Estimation over Diverse Terrestrial Ecosystems in Asia - AsiaFlux Workshop, Chiang Mai, Thailand, 2006, p. 30. 

The marketed product is a racemate, although only the (L)-form inhibits glutamine synthase. [11] The broad-spectrum herbicide Basta finds application against annual and perennial broad-leaved weeds and grasses on railway tracks, in fruit plantations, vineyards, oil and rubber plantations and for ornamental plant cultivation. It is also applied pre-emergent in vegetables. The major use of... 

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