7 



Saps and Exudations. 



age, and the results from Monaragala, Dumbara, Kalutara, and Matale do, I am 

 glad to say, support the original idea. In the first place I want to remind you of 

 the tendency of Para rubber plants to produce tall, woody stems with whorls of 

 foliage one above the other and to impress upon you the fact, known to all horti- 

 culturists, that growth in height may be checked and that in girth increased. The 

 energy of the plant, used in the production of high, bulky, woody tissues, may be 

 directed to the production of the same maternal in the base of the stem and to that 

 of branches bearing foliage. The success of the pruning experiment depends upon 

 checking the formation of high wood and increasing the foliage. The leaves of a 

 plant are of vital importance and are the organs wherein the food supplies are 

 elaborated. If you repeatedly remove the leaves or diminish their numbers the 

 production of food supplies is seriously affected and the increase in circumference of 

 the stem is reduced. We have some cuttings of Dadap, planted two years ago, 

 which, on account of the leaves having been hand-pruned every month, are of 

 the same thickness today as when they were first planted. In the same way one 

 may state that an increase in foliage increases the rate of food manufacture and 

 therefore provides the materials necessary for the stem to grow at a quicker rate. 



FORKING AND FOLIAGE. 



It is necessary to first prove what happens when the terminal bud is 

 removed by the thumb-nail or the knife. If you examine a Para rubber plant, ten to 

 fifteen feet high, you will notice that the upper part of the stem is green ; this is the 

 part which will throw out numerous lateral branches if the growth in height is 

 stopped by removal of the terminal bud. If, as has often been done in the Straits 

 and Ceylon, the whole of the green wood and foliage is cut away, the probability is 

 that the remaining stump will only throw out a single shoot and you will be no 

 better off. The result which follows careful removal of the terminal bud is best seen 

 in the photograph I have here. (See plate A.) This photograph shows two plants of 

 exactly the same age, grown from seeds from the same parent. In one case the 

 plant has been allowed to grow into the usual long and slender stem, and, when I left 

 Peradeniya, had only three whorls of foliage. The other tree, about four months 

 ago, had its terminal bud removed by thumb-nail pruning, and being unable to grow 

 in height, has thrown out ten lateral branches. The result is the straight-stemmed 

 tree has still only one growing point at the apex of the stem, whereas the pruned 

 one has ten, and from each are produced whorls of foliage. Though the pruning 

 was only done recently, fhe plant so treated has no less than 200 fully-developed 

 leaves, whereas the one which has been allowed to grow in its own way has only 

 about 50 leaves. That, gentlemen, is within four months. The food-producing 

 capacity of the pruned tree, as far as the foliage alone is concerned, is now four 

 times as great as that of the straight-stemmed one, and it stands to reason that 

 the basal part of the pruned tree will grow at a quicker rate. The operation itself 

 is a gentle one and does not partake of anything so drastic as the cutting away 

 of the upper part of young or old trees. The lateral branches each produce their 

 own whorls of foliage as though they were members of separate trees, and as they 

 tend to grow more or less upwards may themselves require pruning at intervals of 

 three or six months. If there is anyone who doubts the effect of pruning the 

 terminal bud, I need only ask him to consider what happens when he primes his 

 tea bushes for the first time. As an example of a system of pruning the following 

 will serve our purpose ; the tree may be thumb-nail pruned when twelve feet high 

 and two branches allowed to develop, one on either side ; in about one-and-a-half 

 month's time those two lateral shoots will be a little over a foot each in length, 

 and can be again pruned and half-a-dozen shoots allowed to grow from each ; in 

 four or five months' time these shoots will be from four to six feet in length and 

 may be finally pruned at the apex and allowed to develop as many branches as they 



