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to walk between the trees. In addition to the cost of labour there 
are the following' items : fewer cups, spouts, wire, etc., are required, 
and a smaller labour force with its attendant expenses in line 
accommodation, recruiting expenses and hospital charges. This 
applies mainly to estates employing Indian labour. In the ease of 
estates which employ Chinese labour it will generally be found 
that the coolies work at a given rate per lb., this rate is governed by 
the amount of rubber a cooly can reasonably be expected to collect. 
To illustrate this we will suppose that a Chinese cooly expects to 
get 70 cents per diem ; most planters have found that the number of 
trees a cooly can tap well has its limitations, and though, of course, 
every estate has its “star” tappers the capacity of the average 
Chinese cooly is, say, 450 trees. If then the trees are yielding at the 
rate of 6 lbs. dry per annum, a cooly tapping 450 trees can get a daily 
average of 8 lbs. which at 9 cents per lb. will give him the required 
wage ; if, however, the trees are yielding at the rate of 3 lbs. he would 
have either to do twice the task or the rate would have to be 
increased. 
Both these cases are possibly exaggerated, but if allowance is 
made for a slightly higher task in the case of closely planted trees 
and also a slightly higher yield per tree it is still very obvious that 
a closely planted estate is less economical to work. 
Effect of Thinning Out on Disease. 
Another point which most certainly should not be lost sight of 
is the effect of thinning out on plant sanitation. This is so closely 
connected with disease and pest work that I intend merely to call 
your attention to it. 
Diseases which are giving the most trouble at the present time 
can be divided into three heads, the worst being (1) branch disease, 
Corticium mlmonicolor , (2) stem disease, bark canker, and (3) 
root disease, Poria hypolateritia, Ustulina zonata. It is obvious 
that the stronger the plant the better its chances of recovery if 
attacked, in cases of branch and stem diseases if given proper 
treatment the effect of sunlight will greatly accelerate the cure. To 
prevent root disease the destruction of all butts and roots of rubber 
trees thinned out is essential and cannot be too strongly insisted 
upon. With proper precautions the mortality in old clearings should 
not be great, records from an estate with rubber about 12 years old 
show a loss of ’8 per cent, during the past two years. We now 
come to the debatable question of how it should be done. 
PART II. 
Young Clearings. 
• The days of 10 ft. by 10 ft. planting have passed and most 
estates are now planted 20 ft. by 20 ft., or avenue planting 
14 ft. by 28 ft. or 15 ft, by 30 ft. Let us take a normal 
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