Gums, Resins, 



116 



that may, on further observation, require Modifications ; for instance, the system 

 of manuring based on the alleged rate of root growth, the cultivation of catch 

 crops, green manuring, &c. 



Yours faithfully, 



Colombo, January 26th. W. A. De S. 



VIII. 



Sm,— This question of pollarding young Hevea trees, or thumb-nail pruning 

 them, which is being discussed so vigorously in your columns, is not only full of 

 interest but it is also of no little importance to many planters. For if, as is claimed, 

 it makes a difference of one year before the trees are ready for tapping, that- means 

 a great deal to many of us ; and the subject is worthy of the lengthiest discussion 

 in your paper— only, letters should be writen to the points discussed and not in 

 the frenzied style of " Pollard Rubber," who apparently had a bad head that 

 morning, or a touch of liver if he wrote at night. Mr. Wright says bud-pruning 

 the young tree stops growth in height and encourages girth, so that the tree 

 attains a size fit for tapping— i.e., 20 inches at 3 ft. from base— one year in advance 

 of others. From this one naturally concludes that the whole question of " when 

 to tap " depends upon the girth of the tree alone ; and if a tree attains 20 inches in 

 three years, it could then be tapped. Has age nothing to do with time for tapping ? 

 Is not the latex in young trees far inferior to those of maturer age ? Consequently, 

 if you tap at 4 — 5 years the percentage of caoutchouc is less, and the analysis of it 

 will show a far higher percentage of resin and proteids. Does Mr. Wright con- 

 tradict this? If not, how does he reconcile his advice to bud-prune young trees 

 with these facts ?— f or he is encouraging the production of inferior rubber, which 

 we want to avoid in Ceylon. I quite understand, and I fully believe that this 

 pruning process will develop the girth of the tree considerably, therefore it may 

 be advisable to do it. But I should suggest at the same time that tapping be not 

 commenced until the trees are of an age fit to be tapped, as well as of a size. On 

 this point I refer to Mr. Wright's book, and I find he refers to Johnson (author 

 of " Para Rubber ") who goes by size and not age ; while Dr. Weber goes rather 

 by age. Now, judging by his book on rubber Mr. Johnson is no authority to go 

 by, and I have read more stuff of practical use to planters in the Ceylon Observer's 

 columns than in all Johnson's 100 pages. Further, we have Ceylon men with far 

 more experience of rubber cultivation than anyone outside the place, and I think 

 most of our leading rubber men would go on age plus size rather than size alone, 

 and even on age alone rather than size alone. 



As a further point to strengthen my argument, referring again to Wright's 

 book, rubber from 2-year-old trees was "sickly and snapped when slightly stretched, 

 it was obviously unfit for sale." Parkin, he says, holds same opinion, and Stanley 

 Ai'den, of the Straits, has shown that the rubber from 3$ to 4-year-old trees is 

 decidedly inferior. Ergo, size alone won't do. How then will Mr. Wright modify 

 his advice ? But there is a good deal more in all this than appears on the surface. 

 Reading the analyses of rubber from different aged trees on page 48 of Wright's 

 book, I find the six analyses given, from two-year old to 30-year old trees, differ 

 mainly in the percentage of proteids, while the amount of caoutchouc in each 

 differs little, especially from four years upward. From six years to twelve years 

 they all have roughly 94 per cent, pure rubber ; but why do the 30-year old trees 

 give only 93 per cent, rubber, and 1 per cent, more proteid ? Another point on 

 which some of us would like Mr. Wright's explanation. 



There are further points on which I am still a bit puzzled, but we must 

 finish this pruning matter first. One more question before I finish— does bud- 

 pruning offer any invitation to disease ; does the scar grow over as the tree grows, 

 or will it form a wide and increasing, roughly healed cicatrice ? Does the thumb- 



