November, 1912.] 



THINNING OUT HEVEA ESTATES. 



In an article on the above subject, the India Rubber Journal for Oc- 

 tober, 1912, says that in regard to the number of trees per acre Ceylon pre- 

 fers to have the largest. Gentlemen connected with plantation work in the 

 East have different opinions regarding planting distances, and in Malaya 

 there is a general consensus of opinion that the number of permanent trees 

 per acre should be 90 to 100. Mr. Harrison points out that it is not advisable 

 to thin out to less than 115 to 120 in view of the inevitable loss that may be 

 sustained from storms and diseases. Estates on good soils may be thinned 

 down to 70 trees per acre. In Malaya and Sumatra the distance favoured 

 appears to be 20 by 20 feet. 



On good soils where no intercrops are cultivated one could not go far 

 wrong in planting 20 by 20 feet. If intercrops are cultivated then rubber 

 trees should be planted about 30 by 20 feet. 



Though there is difference of opinion on the subject of reducing the 

 number of trees per acre, many agree in thinning out the bad and weak 

 trees on uneven plantations and cutting out every alternate row on very 

 even estates. In thinning out by the careful method of selection it 

 is suggested that the backward trees, those with large burrs or those 

 which have been badly tapped, should be selected for removal. Care 

 should betaken to uproot those which have the shortest lives before them. 

 A selection should be first made of the permanent trees rather than the 

 weakest in order that the former may be retained and the latter destroyed 

 on a regular system. 



Lastly, about 100 trees should be aimed at permanently in average 

 soil, a lower number in good soil and a higher number in poor soil ; (2) thin- 

 ning out should be done by the removal of backward or weak trees, and 

 not cutting out every alternate row ; (3) where money is badly needed, 

 rubber should be extracted from the stumps before the bad trees are 

 removed. 



The following are areas under crop according to the Memoranda issued 

 by the Department of Agriculture, Bombay :— 



How to Thin out Estates. 



CROP AREAS IN BOMBAY". 



Cotton. 



Acres. 

 1,409,000 

 2,614,000 



British Districts 

 Native States 



Sugarcane. 



British Districts 

 Native States 



13,000 

 23,000 



Groundnuts. 



British Districts 

 Native States 



110,000 

 63,000 



Sesamum. 



206.000 

 450,000 



63.000 

 5,000, 



