Gums, Resins, 



294 



[April, 1910. 



force. The tree lias exceeded the most 

 sanguine expectations regarding its pro- 

 ducing capacity and vigour of growth. 

 A few fortunate planters who laid down 

 areas with this tree before this period 

 have beeu the first to reap their reward. 



About 750 acres had been planted with 

 Hevea in Ceylon previous to the year 

 1899. Now at least 180,000 acres are 

 under rubber in the island, either pure 

 or planted amongst tea and cacao. 

 Ceylon, though the pioneer, has had to 

 give place to the Malay States in respect 

 to area and yield. Planters soon saw 

 an excellent opening for Para-rubber 

 cultivation there. The soil and climate 

 have been found especially suitable for 

 the rapid growth of this tree, and the 

 success already achieved is phenomenal. 

 The premier company, Selangor, formed 

 in 1899, paid a dividend of 75 per cent, 

 for 1908 and is calculated to have earned 

 one of 250 per cent, for the year just 

 closed. Such extraordinary profits are 

 of course partly due to the high market 

 price of raw rubber at the present time, 

 but partly also to increased output. No 

 estate, as yet, has reached its full pro- 

 ducing capacity. 



Over 300,000 acres are now under Para- 

 rubber in the Malay States. Its culti- 

 vation has also extended to Java, 

 Sumatra, Borneo, etc. At least 600,000 

 acrej must now be planted with Hevea 

 in the Middle East. 



Attention in certain quarters has been 

 l^edirected to Ceara rubber (Manihot 

 Glaziovii).* As this small tree will grow 

 on dry ground where Hevea would not 

 flourish, and as it produces good caout- 

 chouc at an early age, it may perhaps 

 become of some importance as a source 

 of cultivated rubber, It is being plant- 

 ed largely in German East Africa, 

 Nyassaland, and the Zanzibar Protecto- 

 rate. 



Rambong rubber (Ficus elastica) has 

 received from the Dutch in Java con- 

 siderable cultural attention in the past, 

 and where growing now on any estate 

 the trees are a valuable asset, as the 

 rubber when well prepared commands 

 a price only a little lower than fine Para. 

 It is, however, likely to be replaced 

 gradually by Hevea. Its banyan nature 

 is a drawback to easy tapping, and in 

 other respects it is inferior to Hevea, 



The only other arborescent form of 

 possible value for cultivation seems to 



•Three other species of Mai ii hob (M, Dicho- 



lonia, M. heptaphylla and M. pianhyensh) are 

 now attracting attention as rubber plants. It 

 is too early yet to decide as to whether any of 

 (hem may be superior to M. Gliziovii for 

 cultivation. 



be Funtumia elastica of* tropical Africa. 

 Attempts to grow it, however, have not 

 met with much success, and Hevea is 

 being introduced into West Africa in 

 its stead. 



The Landolphias are unlikely to be- 

 come a cultivated source of India rubber 

 as they are climbers (lianesj of slow 

 growth. 



Experience all points to Hevea brasi- 

 liensis as the best tree for culti- 

 vation. Manihot may take its place in 

 drier tropical regions. Castilloa, Ficus, 

 and possibly Funtumia might be useful 

 as subsidiary sources, and be grown as 

 trees in protective belts on estates. 



General Cultivation. 



It is not within the scope of this 

 article, nor is it within the writer's pro- 

 vince, to deal in a complete manner with 

 the general cultivation of the Para-rub- 

 ber tree. However, as this is a crop of 

 a special and novel kind, a few remarks 

 respecting its peculiarities and the pro- 

 blems it offers for solution may not be 

 without interest. 



Close v. Wide Planting.— Hevea, is a 

 forest tree, and its cultivation might 

 therefore be deemed a branch of forestry 

 and so conform to the rules of sylvicul- 

 ture ; but timber production is not the 

 aim, hence close planting with the ob- 

 ject of producing long straight poles is 

 not necessarily the best means of grow- 

 iug this tree. 



As the latex (rubber milk) is obtained 

 fiom the bark of the trunk, the main 

 purpose to be striven after is the pro- 

 duction of as large an area of bark as 

 possible in a given time. Farther, since 

 the greatest yield of latex is from the 

 basal part of the trunk, thus making 

 tapping above six feet, as a rule, inadvis- 

 able, it would seem expedient to grow 

 the tree so as to throw the main in- 

 crease of girth into the basal six to ten 

 feet of bole. In sylviculture the great 

 length of unbranched stem is secured 

 at the expense of its thickness. As soon 

 as the maximum height has been reach- 

 ed, thinning is commenced, in order to 

 give room for a greater development of 

 leaf-canopy to hasten the increase in 

 girth. In rubber cultivation, however, 

 thickness rather than height of trunk 

 is desired from the beginning, so the 

 trees must be planted much wider apart 

 than appertains in ordinary forestry, in 

 order to afford room for an early and 

 ample production of foliage. 



The first areas laid down with Para 

 rubber were planted with trees ten feet 

 apart, roughly 400 to the acre. It be- 

 came evident in a few years that the 



