August, 1909.] 



tions in Java and Sumatra, where 

 fungus diseases, of which the most fre- 

 quent is caused by Corticium javanicum, 

 Zimm. (called in Malay "Djamoer 

 Oepas"), attack principally those trees 

 on which the desired branching has been 

 produced naturally, and those on which 

 it has been induced by human agency. 



" This terrible disease, which Dr. 

 Bernard has written about, seems in fact 

 to originate, for preference, in the axils 

 of branches where rainwater lodges, and 

 to spread afterwards in all directions. 

 Under the shade of a crowded plantation 

 where the air is constantly humid, fungi 

 develop with extreme ease. It is certain 

 that their spores, falling in a favourable 

 situation, on a wound incompletely 

 healed, grow very rapidly, and cause 

 immediate injury to the trees. 



"If these observations are correct, 

 the branching of the stem ought to be 

 induced with as little pruning as pos- 

 sible. With this object, I have cut off all 

 the leaves of several young heveas, 

 about fifteen months old and four metres 

 high, leaving only the buds arising from 

 the terminal crown, thus giving the 

 tree the appearance of a long switch. At 

 the end of a month young shoots ap- 

 peared in the axils of the old leaves. 

 These shoots, the future branches of the 

 tree, have the advantage of being 

 arranged at irregular distances suffici- 

 ently far apart. 



"The terminal crown, alone, produces 

 too many branches, and some of them 

 must be suppressed; but at this stage 

 the tissues are so young that cicatri- 

 sation is very rapid, and does not permit 

 the development of the terrible Corti- 

 cium, which appears rather on stems 

 with wood already formed or in course 

 of formation. 



"Among the trees experimented upon, 

 some which possessed leaves scattered 

 along the whole length of the stem in- 

 stead of being grouped in false whorls 

 were intentionally chosen ; for trees of 

 this type, which expand with the greatest 

 readiness, removal of the leaves appears 

 very suitable, The result sought by 

 Mr. Wright, i-e-, the increase of the cir- 

 cumference of the stem in consequence 

 of the iucrease of the foliage, is here 

 equally attained while a presumed source 

 of danger is avoided. 



" Personally, I do not believe that 

 there is any great advantage in inducing 

 branching before the end of the second 

 year. At that time, the majority of 

 heveas branch of their own accord, and 

 it would be sufficient then to induce it in 

 those which proved refractory. Finally, 

 up to the present it is scarcely decided 

 that, as a producer of rubber, a dwarfed 



tree has any real advantage over one 

 which has not been dwarfed (rabattu). 



" P.S. -In addition to these interesting 

 observations, M, de Ryckman has for- 

 warded an excellent photograph of a 

 plot of heveas which nave been treated 

 by defoliation ; these young trees are 

 perfectly shaped, and their branching 

 is not less symmetrical than that of 

 trees in Ceylon, made to branch by 

 pollarding, of which we have been per- 

 mitted to see photographs.— Editor, 

 Journal d'Agric. Tropicale." 



To the above may be added the follow- 

 ing extract from the Continuation Report 

 on the Kambe Rubber Plantation, Ran- 

 goon, by Lt. -Colonel J. A. Wyllie: — 



"As the young trees come on, they will 

 require pruning to encourage develop- 

 ment of the crown and stem, and to 

 check too rapid upward growth. This 

 can best be carried out by simply nipping 

 off the terminal bud when the tree has 

 attained a height of anything from six 

 to fifteen feet. A tree of fifteen feet that 

 has not been pruned is, as a rule, suffi- 

 ciently flexible to allow of its being bent 

 down within reach of the operator. This 

 is what is known as thumb-nail pruning, 

 but may of course be done with a knife or 

 a pair of scissors if preferred. The oper- 

 tion may subsequently be extended to the 

 top lateral shoots, and a bushy growth 

 of the whole crown produced. Some 

 trees have a habit of sending out 

 lateral shoots all down the stem, which 

 should be discouraged severely by means 

 of pruning. The best type of tree for 

 practical purposes is one forking about 

 five feet (sic) from its base, as the tap- 

 ping area is thus likely to be larger 

 than in the case of a single stemmed 

 tree." 



Evidently the idea of thumb-nail prun- 

 ing has been regarded more seriously 

 in other countries than in Ceylon- It 

 would be interesting to know whether 

 any large areas have been treated in 

 this fashion in Ceylon, and where the 

 photographs alluded to were taken. It 

 is certainly not a common practice, as 

 the authors quoted appear to think. 

 The objection taken by M. Ryckman— 

 that parasitic fungi readily develop in 

 the forks of* trees because of the flow 

 of rainwater over them, and the conse- 

 quent disintegation of the bark,— was 

 privately urged in 1906, but, in the 

 absence of any enthusiastic adoption 

 of the proposed system, it was not con- 

 sidered worth while to press the matter 

 further. Corticium javanicum is fairly 

 common in Ceylon, but its effect is not 

 so terrible as it appears to be in Java 



