54 



THE INDIA RUBBER WORLD 



[October 1, 1919. 



HARBOR ON SUMATRA'S WEST COAST. 



Pulau Bay, a few miles south of Benkulan, on the west coast 

 of Sumatra, has heeii known for over 250 years as the safesi 

 harbor on that coast, and is famous as the "the bay of Selebar," 

 the town from which the pepper came. A good many years ago 

 a big Arab sailing junk sank at the entrance to the harbor and 

 blocked it. Now efforts are to be made to remove the obstacle 

 because the harbor is close to rubber and fiber plantations. 

 There is. moreover, water-power near at hand. 



BROWN BAST ON TAPPED HEVEA. 



BROWN B.\ST is the most wide-spread and injurious plague of 

 plantation rubber in the Far East, and is therefore being 

 investigated in the laboratories of Ceylon, Malaya, Southern 

 India and the Dutch East Indies. The disease and its effects 

 are described by Professor T. Fetch in a leaflet issued by the 

 Ceylon Department of Agriculture. 



Brown bast attacks the cortex of Hevea, apparently only in 

 trees that have been tapped. The tree runs dry, the lapping 

 cut ceasing to yield latex, either wholly or partially, and in the 

 latter case the latex coagulates on reaching the dry part and 

 blocks the cut, so that later latex runs down the stem of the 

 tree instead of along the cut to the vertical channel. This dis- 

 eased cortex is a yellowish gray, dotted with brown spots and 

 streaks ; it may also be sodden and watery. In well defined 

 cases a brown line runs along the cut very near the cambiuin. 



If let alone, the tissue outside the brown line may dry up, 

 forming a scale which, when it pulls off or is removed, leaves 

 a thin layer of laticiferous cortex, one or two millimeters thick, 

 that is speckled or thin and develops nodules. Or else no scale 

 appears, yet the nodules develop under the surface just the 

 same. Then the tree cannot be tapped. 



The final effect of brown bast is to form nodules or burrs 

 which interfere with or stop the flow of latex. These are a 

 secondary feature of the disease ; if they did not develop it 

 would not be so serious. The disease may attack the whole 

 tree or vital parts or may appear on a portion only of the cortex. 

 Nodules also appear in the cortex that are not formed by brown 

 bast. 



Three methods arc employed to get rid of brown bast by 

 removing the diseased cortex to the depth that is necessary. 

 These are : stripping ; scraping ; after which the spot is painted 

 with Brunolinum plantarium, in which Professor Fetch has great 

 faith, and tarring. Trees that are badly afifected had better be 

 destroyed. 



As to the nature of the brown Ijast, scientific men still differ. 

 A few still believe that it is a fungus or other microorganism 

 which carries infection. Rands, who was an advocate of this 

 theory, seems to have changed his opinion materially. In April 

 he held that "brown bast is an accentuated condition of gum 

 secretion, probably resulting from response of the tree to the 

 present methods of tapping." On the other hand7 in January, 

 1919, the mycologists Belgrave, Perry and Richards reported that 

 they had been unable to discover any microorganic cause for the 

 disease. 



W. Bobilioff in the "Archiev voor de Rubber Cultmir" for 

 May sums up the case in reporting his experiments. The disease 

 either is caused by infection or is a physiological phenomenon. 

 Investigators have been unable to discover the microorganism 

 that could carry it or to produce the infection by putting sound 

 bark in contact with the diseased. Bobilioff experimented with 

 trees on which he tried excessive tapping, and brought on the 

 disease at once. His explanation is that brown bast is formed 

 by drawing the latex from the bark and the cause therefore 

 is purely physiological. The brown degenerate substance gave 

 the principal reactions for lignine ; so he holds that it is not yet 

 proved that it is a gum, as Rand asserts. Harrison connects it 



with wood pulp. The slightest trace of brown bark could be 

 detected by a phloroglacin reaction, which colored the spot red. 

 The severity of the disease depends on the general physiological 

 condition of the trees. 



Agriculturists, as contrasted with laboralury men, advise giving 

 the trees a rest, in the first place, then, that the soil be manured 

 and drained, etc. They suggest that trees be raised from seed- 

 lings instead of cuttings, as those are believed to be less subject 

 to disease, and tapping be improved so as not to wound the 

 trees so severely. .'Ml seem to agree that tapping and the condi- 

 tion of the tree have more tu do with the disease than possible 

 infection. 



PLANTING RUBBER IN WEST DUTCH BORNEO. 



Br /. IV. Evans. 



SAY "Dutch East Indies" to an .\merican rubber man and 

 he thinks of Java, Sumatra and a few islands of compara- 

 tively slight importance. But only an exceptionally well-in- 

 formed man would think of West Dutch Borneo. Concerning 

 that region as a field for the rubber man, next to nothing is 

 known. It is generally understood that there is considerable 

 coconut growing along the coast from Paloh to Pontianak, 

 but that's about all. 



Rubber cultivation has grown enormously in West Borneo 

 during the last ten years, and the only reason why the fact 

 is not known and the opportunity not recognized is that almost 

 none of the rubber estates are owned by Europeans or Ameri- 

 cans. Almost 90 per cent of the rubber plantations are in the 

 hands of Chinese, Malays, and Japanese. 



The reason why so little European or American capital has 

 found its way to the rubber cultivation of West Borneo is that 

 the region has been a field for irresponsible speculation. Sound 

 investors have been afraid to go in there because various es- 

 tates were opened up either by people who knew nothing about 

 rubbc and the conditions in Borneo, or by people who formed 

 syndicates purely for speculation, and got from under as soon 

 as their object was accomplished. 



In consequence of such fast and loose methods the country got 

 a bad name which it was far from deserving, for the condition 

 of soil, climate, labor, and transportation are such that exten- 

 sive and profitable rubber cultivation is perfectly practicable 

 there, and the field is new. 



Borneo, as a field of rubber, compares favorably with the 

 East coast of Sumatra, the Straits Settlements, the Federated 

 Malay States, and even Java. As to climate, indeed, it is es- 

 pecially suitable. Rain falls there in right proportion all the year, 

 and there is no dry season such as Java has to contend with. 

 That the soil is excellent is shown by the rapid growth of 

 trees and the large yield of latex. 



Here are some production figures from one estate in West 

 Dutch Borneo which was badly run, and so neglected, and which 

 suffered so much from the wild boar that it might have been 

 expected to produce poorly. Seven-year-old trees which were 

 planted too close and had never been thinned, produced as a 

 yearly average 3.6S pounds per tree. Compare that with the re- 

 sults from 7 to 9-year-old trees elsewhere In Malacca the 

 average annual yield per tree is 2.42 to 3.41 pounds; in Ceylon, 

 .77 to 1.65 pounds; in West Java, 2.42 pounds; on Sumatra's 

 East Coast, 3.98 pounds on choice estates, and 2.97 pounds on 

 average estates. 



By contrast, there is an exceptionally well-kept Chinese-owned 

 estate in Sambas, a locality in West Dutch Borneo where the 

 trees were well spaced, and the yield for 6 to 7-year-old trees 

 amounted to 5.28 pounds per tree a year. 



Contrary to the general impression, labor conditions in West 

 Borneo compare favorably with those in the Federated Malay 



