Rubber Cultivation

Van Iterson, Intern, Assoc, Rubber Cultiv, Netherland Indies Comm,... 

The original habitat of the rubber tree in the Amazon valley is situated within 5° latitude and at altitudes less than 200 m. Naturally, the trees evolved in this environment prefer warm and humid weather [9]. The climatic conditions suitable for optimum growth of rubber trees include an annual rainfall of not less than 2000 mm, evenly distributed without any marked dry spell, a maximum temperature of 29-34°C and a minimum of 20°C or more, high atmospheric humidity of around 80% with moderate wind, bright sunshine amounting to about 2000 hours per year at the rate of six hours per day throughout the year [10]. Rubber needs a well-drained, fairly deep, loamy soil with a pH value of 4.5-6.0. South East Asia is particularly suitable for rubber cultivation as are countries in West Africa. Although not ideally suited, rubber is now successfully cultivated even up to latitudes of 25° in countries such as India and China. 

In Southeast Asia the ambitious expansions of oil palm plantations in the tropical areas have made this region by far the main palm oil producing region in the world outdistancing natural rubber cultivation as the key agro resource in Malaysia (Figure 9.1.4). 

Originally from China, Rhus vernicefera has been under cultivation in Japan since the sixth century AD. The latex is collected in the same way as the rubber plant Hevea brasiliensis. The product is known as urushiol, which consists mostly of dihydric phenols of structures (Fig. 6) and is used as lacquers. 

Roy Choudhury N., Bhowmick A.K., and De S.K., Thermoplastic natural rubber. Natural Rubber Biology, Cultivation and Technology (Sethuraj M.R. and Mathew N.M., eds.), Elsevier, New York, 1992. Elliot D.J., Natural rubber systems. Development of Rubber Technology 3 (Whelan A. and Lee K.S., eds.). Applied Science, New York, 1982. 

Natural rubber obtained from cultivated trees as opposed to that obtained from trees growing wild in the jungle. The size of a plantation varies from the large estate of several thousand acres down to the smallholdings of a few acres worked by the owner and his family. Such smallholdings produce a significant proportion of the world s NR output. 

Natural rubber obtained from trees growing wild and not cultivated in either plantations or native small holdings. The output of wild rubber is now insignificant. 

Sethuraj. M R, and NM. Mathew Natural Rubber Biology, Cultivation, and Technology, Elsevier Science. New York, NY, 1992. 

In 1906, she moved to Dorking to work for 3 years with J. B. Wilson, an accomplished pharmacist and a cultivator of medicinal plants. She passed the Major examination in 1909, after which she became a research assistant at the Pharmacy School with Henry Greenish, studying components of quinine. Having been recommended by Arthur Crossley,63 Borrowman subsequently left the School s laboratories and took up a better-paying appointment as Research Chemist in the London laboratory of the Rubber Growers Association of Malaya and Ceylon. 

The increase in the production of the synthetic indigo has decreased the cultivation of the indigo plant, especially in India where the land formerly used for this purpose is now used for other crops such as rubber, turmeric, hemp, cotton, etc. 

The latex of milkweeds and other species in the family Asclepiadaceae can be used to make a natural rubber. During World War II, when supplies of rubber from Asia were not readily available in North America, research was undertaken to see whether this strategically important material could be obtained from milkweeds under cultivation. However, the yields of rubber were too small to make this enterprise worthwhile. 

National Academy of Sciences (1977). Guayule An Alternative Source of Natural Rubber. Washington, D.C. Jojoba Feasibility for Cultivation on Indian Reservations in the Sonoran Desert Region. Washington, D.C. 

Note Olefinic (isoprenoid) hydrocarbons are produced by a number of plants, notably Hevea brazi-lietisis (rubber), guayule, and various members of the Euphorbiaceae family. Current research on the latter group indicates that they could be used as a source of liquid fuels and chemical feedstocks by genetic modification of the plants and control of then molecular constitution. It is estimated that oil obtained by large-scale cultivation of such plants, which grow well in semi-arid environments, could become economically competitive with petroleum within a few years. 

Sethuraj MR, Mathew NM (1992) Natural rubber biology, cultivation and technology in crop science. Elsevier, Amsterdam... 

Natural rubber is obtained from the juice present in various trees and shrubs which grow best in tropical countries. On account of the importance of rubber commercially the trees which yield it are grown systematically on plantations formerly the supply was obtained from natural forests. The intensive cultivation of rubber trees has had a marked effect in lowering the price and insuring a steady supply of rubber. 

Keywords Natural rubber, Hevea brasiliensis, cultivation, modification, primary processing, manufacturing techniques, pneumatic tyre, non-tyre products, vulcanization, green commodity... 

P.S.Rao and K.R.Vijayakumar, "Climatic requirements" in M.R.Sethuraj and N.M.Mathew, eds. Natural Rubber Biology, Cultivation and Technology, Elsevier Science Publishers, Amsterdam, 1992. 

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