ABSTRACT
The world requirement of elastomers has been estimated at between 14 and 17 million metric tons. If the 43% share of natural rubber is to be sustained, world production of natural rubber would be not less than 6 million mt. For optimum growth and yield, rubber (Hevea brasiliensis) plants require an evenly distributed annual rainfall of 2000-3000 mm. In areas where rainfall is lower or unevenly distributed, trees become stunted with crooked trunks and lower branches. Potential yields when nutrients needed are fully met. Yield is a result of the combination of soil factors, suitability of clones, and proper nutrition. Nutritional disorders of hevea rubber can be diagnosed either by the observation of visual symptoms, or by soil and plant tissue testing. The visual method of diagnosing a deficiency is entirely qualitative. However, growth may be severely retarded before the actual visual symptoms are visible and it may often be too late for remedial action.
