Tropical plantations

Atraton. Atraton was one of the first methoxytriazines developed for commercial use and was marketed in the early 1960s for weed control in tropical plantations. However, it was only sold for a few years and then dropped because of poor control of perennial weeds, such as cogongrass. Atraton also was used alone and in mixtures with other herbicides on roadsides and railway tracks in Europe and in the United States. 

Uses herbicide, rice, grass, tropical plantations Trade names Setoff (Ciba)... 

Cuevas, E., and A. E. Lugo. 1998. Dynamics of organic matter and nutrient return from litterfall in stands of ten tropical plantation species. Forest Ecology and Management. 112 263-279. 

Vogt, K., H. Asbjomsen, A. Ercelawn, F. Montagnini, and M. Valdes. 1997. Roots and mycotihizas in plantation ecosystems. In Management of Soil, Nutrients and Water in Tropical Plantation Forests, eds. E. K. S. Nambiar, and A. G. Brown.(ACIAR/CSIRO/CIFOR. ACIAR, Canberra, Australia), pp. 247-2(16. 

In coimtries that had no access to the tropical plantations of rubber trees, especially in Russia and Germany, scientists tried to work out how to make sjmthetic rubber from available raw materials. The studies were a success. They foimd a way of making sjmthetic rubber from butadiene and in the 1930s production started. It worked out well, S5mthetic rubber was satisfactory, and looked very similar to natmal rubber. 

Uses Preemergence and postemergence herbicide for control of some annual grasses and broad-leaved weeds in com, fallow land, rangeland, sorghum, non-cropland, certain tropical plantations, evergreen nurseries, fmit crops and lawns. 

Rubber, natural (India rubber, Caoutchouc) n. An amorphous polymer consisting essentially of ds-1,4-polyisoprene, obtained from the sap (latex) of certain trees and plants, mainly the Hevea brasiliensis tree. The material is shipped from tropical plantations in one of two primary forms latex, usually stabilized and preserved with ammonia and centrifuged to remove part of the water or sheets made by milling the coagulum from the latex. Natural rubber has very high molecular weight and is usually masticated to reduce the molecular weight and improve processability. A major use is sidewalls of automotive tires. 

It is over three centuries since cinchona bark came into use in European medicine, and no other natural drug has had so much written about it. There are the stories, sometimes legendary, of its discovery by Europeans, vigorous early discussions of its therapeutic value, the destruction of the S. American cinchona trees to meet the demand for bark, the labours of botanical explorers in collecting seed for the formation of plantations, the establishment and development of these plantations in Ceylon, India and Java, the competition between them, the gradual emergence of Java as the world s most important source of supply of cinchona bark, and the development of the manufacture of quinine sulphate in Europe, the United States and the Tropics. ... 

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. 

In tropical and subtropical regions, fruits also contribute to the p-carotene supply. The mango, one of the most consumed tropical fruits, showed a wide range of carotenoids, especially p-carotene contents, depending on cultivar, plantation weather conditions, and degree of ripening (Table 4.2.1). Fresh fruits and pro-... 

Veldkamp E, Keller M (1997) Nitrogen oxide emissions from a banana plantation in the humid tropics. J Geophys Res 102 15889-15898... 

In the Far East, on the whole, the most troublesome hevea rubber diseases are root decays. It is commonly realized (4, 11, 35, 36, 40, 42, 43, 45) that, left unchecked, rubber root rots would have very soon destroyed commercial production of plantation rubber in the Orient. There is no tree crop that has had its many root rot diseases given such thorough study as has rubber. E. W. Brandes, R. D. Rands. Theodore J. Grant, E. P. Imle, and John B. Carpenter agreed that these troubles have been of practically no concern in tropical America. Langford (19) found little root rot trouble in his considerable observations specifically on rubber in the Western Hemisphere. 

Practically all the coffee planted commercially comes from seed, except in the rather limited Robusta-growing region of Java where grafted plants are used. Coffee seeds are planted in seedbeds and are treated in about the same way all over the tropics. The mature and apparently healthy fruits are selected and the seeds are pressed out, washed and dried in the shade, and planted rather soon, because coffee seed viability is lost within a comparatively short while. Handled in this manner, the chances are lessened that coffee diseases will be carried by seeds. However, it has been proved experimentally that infected plants can be produced from seeds contaminated with both the coffee Colletotrichum and the coffee Cercospora from either field material or artificial inoculation. This contamination is probably not uncommon in plantation practice and thus far it is not of extreme importance. The Hemileia rust is probably not carried on the seed (93). The American leaf spot is not carried on seed (97). 

PCP was developed primarily for use as a wood preservative but has also been used as an herbicide on pineapple and sugarcane plantations. It has also been employed as a molluscicide against schistosomiasis, a severe human parasitic disease prevalent in much of tropical Asia, Africa, and South America (Hutzinger et al. 1985). The major contaminant of commercial PCP is OCDD, which may be present at concentrations between 500 and 1,500 mg/kg (ppm) (Dobbs and Grant 1979 Miller et al. 1989a). PCP may also contain mixed isomers of HxCDD and HpCDD (Pereira et al. 1985). It is currently registered as a restricted-use pesticide for use as a wood preservative (Sine 1990). 

In comparison, the average tree consumes only 1 ton of COz in a lifetime, and an acre of rainforest consumes about 500 tons yearly. When agribusiness, the ethylene industry, or pulp and paper corporations turn forests or rainforests into farmland, they also destroy an effective consumer of COz. The world s fastest-disappearing forests are in Indonesia, where they are cut down either to make paper pulp or to be replaced by palm oil plantations. Palm oil is mostly used to make biodiesel fuels. Tropical deforestation not only results in COz emissions (20% of the global total), but it also poisons the rivers. 

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