Gums, Resins, 



r, 



[Jan. 1907. 



the age of the felled and remaining trees, or with the difficulty with which the root 

 rot fungus actually commences on Para rubber stumps. On most estates the root 

 ungus is transmitted from the roots of trees other than rubber, which ramify in 

 the soil and reach the rubber roots no matter how widely the latter may be planted. 

 It has been questioned, in view of the fact that the roots of jak and cotton trees, 

 etc., traverse a greater distance than that between any two rubber plants as at 

 present planted, whether the difference in distance between Para rubber trees 

 planted ten and fifteen or twenty feet apart appreciably affects the spread or 

 distribution of the root fungus- It cannot be doubted that the closer the roots the 

 greater is their liability to catch whatever fungus is in the soil, but as against such 

 a disadvantage has to be set the advantage of the produce obtained even allowing 

 that the roots are not removed but left to decay. 



If it can be proved that the excessive tapping of intermediate trees and the 

 removal of their root stumps is calculated to aid in the spread of diseases, then the 

 system here outlined must not be in any way encouraged, but until such has been 

 established, the system deserves consideration. As matters stand at present, where 

 most of the rubber has been closely planted, it will be necessary to adopt some 

 process of thinning-out, if the Para rubber trees are to receive the soil and light 

 which their gradually increasing size will demand. 



Permanent Wide Planting. 

 The third possible system is that of permanent wide planting, by which is 

 meant that no thinning-out or intercrops of any kind shall be entertained and the 

 trees be planted at a distance sufficient to last for the whole of their lives ; assuming 

 that such trees will be tapped from the time they are 20 inches in eh'cumference, a 

 distance of twenty feet or over may perhaps be designated as wide planting. A 

 distance of twenty feet apart may not appear to be a very wide one, but it is taken as 

 the minimum in the system under discussion ; it may be completely covered by the 

 roots and foliage of untapped trees when 20 years old, but we have no evidence of 

 the demand which regularly tapped trees of such an age will make. 



Briefly stated the advantages of permanent wide planting are that the trees 

 are never interrupted in their growth ; they attain the maximum size in 

 the minimum period of time ; thicker, shorter and better yielding trees are 

 obtained ; collecting and other operations are simplified ; diseases will probably 

 not spread as rapidly and can be more easily controlled. The disadvantages 

 associated with wide planting are that there is a deplorable w T aste of soil until the 

 ground is covered ; there is a serious reduction in the available tapping area during 

 the first ten or fifteen years ; the fewness of the trees enhances the loss occasioned by 

 the death of a single tree ; and interplanting of such a property can only with 

 difficulty be carried out. 



The interruption in growth among closely-planted Para rubber trees is one 

 of the greatest disadvantages attendant on close-planting, and the freedom from such 

 of first importance when the trees are more widely planted. But to argue 

 that trees because they are more widely planted will attain the maximum size 

 in the minimum period is apt to be misconstrued into meaning that the trees 

 always grow more vigorously and at a quicker rate ; it should be clearly understood 

 that there is an average incremental rate of growth above which most Para rubber 

 trees do not develpo, and a maximum annual average increase of five to six inches in 

 stem circumference is indicated by trees of varying age and planted at widely dif- 

 ferent distances. The largest thirty-year-old tree at Henaratgoda, neglected and 

 grown on poor soil, has a circumference of only 109| inches, and the average of such 

 trees, planted at relatively wide distances does not exceed 75 inches— an incremental 

 circumferential growth of 2f to 3f per year for each of thirty years. No one for a 



