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The Supplement to the Tropical Agriculturist 



Again, the humble dimensions of the Mani- 

 toba tree, I am convinced, are a factor in its 

 favour from a cultural point of view, for it 

 attains to a size exactly suited for close plan- 

 ting. In the great Hevea (Para rubber) planta- 

 tions under cultivation in the East, close plan- 

 ting is systematically resorted to with the object 

 of forcing early crops which are available from 

 young trees of limited size, for numbers collec- 

 tively far more than compensate for the pro- 

 duction of rubber per acre from full grown trees 

 widely planted. As a matter of fact, big trees are 

 stated in the East to be an encumbrance. 



The number of trees usually planted in the 

 East run from 100 to 200 per acre, sometimes 

 more. The number of Manicoba I advocate to 

 be planted is 1,200. I estimate that 1,200 trees 

 per acre (exclusive of certain returns in the 

 fourth year) will yield 600 lb. of rubber in the 

 fifth year ; and at least the same quantity an- 

 nually thereafter for a long period of years. In 

 msnyrich Manicoba zones I computed thenurn- 

 ber of wild trees at more than 100 per acre, some 

 25 per cent being tappable trees, most of the re- 

 mainder saplings, the forest growth of which is 

 sluggish as compared with cultivation. It may 

 be observed that a wild tree occasionally yields 

 one pound of rubber at a tapping, but the aver- 

 age is far less. One of the advantages, a subsi- 

 diary advantage, to accrue from cultivation is 

 that of systematic control of the cropping by a 

 special staff of workers, for the itinerant collec- 

 tors of wild rubber cannot always bo counted on. 



I detected in the Manicoba forests several 

 distinct varieties of this tree, and on enquiry I 

 found that one particular variety was recog- 

 nised as being richer in latex than others. The 

 varieties are distinguished by colour, size and 

 lobe formation of the foliage which latter are 

 remarkably vigorous in cultivated plants. The 

 uncultivated trees are sparsely furnished with 

 foliage. I have had considerable experience 

 with regard to the effects of soil on rubber 

 plants. Apart from the large plantation of 

 Virgen rubber which I established in Columbia, 

 I planted experimentally more than quarter of 

 a century ago, both in Jamaica and in Columbia 

 many plants of Ceara, a nearly related species 

 of Manicoba. Furthermore, I introduced to 

 Jamaica many plants of Para rubber, Castilloa 

 and Virgen rubbers. Unfortunately, until re- 

 cently, no attention has been pa'd to their pro- 

 pagation in that colony. 



The Hevea (Para rubber) is indigenous to 

 another part of Brazil. In addition to th«' 

 boundless tracts of country throughout which 

 it is dispersed, it ie a large tree. It furnishes 

 in a wild state most of the rubber found in 

 commerce. But the natural resources of the 

 forest gradually dwindle. This is the tree for 

 cultural purposes that has claimed the attention 

 of the capable planters of the East with far- 

 reaching consequences. The species flourishes 

 in conditions of soil and climate the converse 

 of those requisite for the humble Manitoba tree. 

 Hence, the latter species can never be culti- 

 vated side byside.with its great Amazonian rival. 



Supplementary to my foregoing account of 

 this species of rubber, I think it is important to 

 cite from, and append hereunto, an interesting 



article in the Kew Bulletin, No. 2 1908, on this 

 subject, which, inter alia, contains much infor- 

 mation supplied by Mr O'Sulhvau Beare, H B, 

 M.'s Consul at Bahia, to tvhom I had a letter of 

 introduction from the Governor of Jamaica : — 



In the year 1906, Dr. Ule, a German botanist, 

 who visited Bahia, named the Jequie Manitoba 

 Manihot dichotama. 



" The Jequie Manigoba is undoubtedly a new 

 and distinct species of Manihot, and it must not 

 be confounded with the Manihot of Cearea 

 Manihot Glaziovii. 



" This discovery is a matter of much import- 

 ance, not only to this State but also for the rub- 

 ber trade in general, inasmuch as the rubber 

 obtainable from the Jequie Manigoba when 

 properly prepared, would seem to be equal in 

 quality to the best product of the Para region. 



"The season for extracting the latex from the 

 Jequie Manicoba extends from August to 

 March. The latex possesses the valuable pro- 

 perty of coagulating spontaneously when ex- 

 posed to the air, and it requires no acid or 

 artificial coagulant of any kind. 



"A planter, established in the .lequie district, 

 recently prepared a considerable quantity of 

 rubber obtained from Manicoba trees growing 

 wild in that neighbourhood, and despatched it 

 to New Fork. The consignment was classified 

 in the New York market as being equal to the 

 best Para rubber, and it fetched one dollar 

 twenty cents (5s.) per lb." 



In addition to Manihot dichotama, two distinct 

 aud nearly related rubber-yielding species of 

 Manicoba were found by Dr Die, "the one 

 growing on the mountains of the right 

 bank of the Rio San Erancisco, and the 

 other confined to the country at some 

 distance from the left bank, occurring especially 

 in the adjoining State of Piauhy." . . . These 

 two species are described under the names of 

 M. heptaphylla and M. piauhyensis. 



My examination of this species of rubber,- 

 M anihot dichotama, in its native habitat, set forth 

 in my preceding account shows that I am im- 

 pressed with the remarkable possibilities of this 

 rubber yielding, plant, thus having arrived at 

 the conclusion that, under cultivation, it is des- 

 tined to rank in productiveness, per acre second 

 to none. It therefore seems obvious that 

 some confusion has arisen in the publication 

 of a paragraph in the " Kew Bulletin," 

 wherein this species as regards its rubber- 

 yielding capacities is undoubtedly mis- 

 represented. A comparison is made with this 

 and the two other allied species, namely, M. 

 hctaphytta and M. piauhyensis. In this compari- 

 son it is stated that the yield of rubber per tree 

 under cultivation for the two latter actually ex- 

 ceeds the yield for M. dichotama five-fold? Thus 

 "the yield of rubber from a single tree of M. dicho- 

 tama in one year can be reckoned at from 100-200 

 grammes." And, the annual yield of rubber for 

 single trees of M. piauhyensis is from 500-1,000 

 grammes." Said paragraph is here subjoined: — 



"Plantations. — At present the plantations 

 of M. dichotama are rather young and only the 

 oldest are ready for tapping ; but from the two 

 other species, which have been known longer, a 

 satisfactory amount of rubber is now being 

 brought on to the market. In the plantations 



