25 



to walk between the trees. In addition to the cost of labour there 

 ai'e the following items : fewer cups, spouts, wire, etc., ai-e 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 case of 

 estates which employ Chinese labour it will genei-ally 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 coui'se, 

 every estate has its " star " tappei*s the capacity of the avei'age 

 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 

 avei-age of 8 lbs. which at 9 cents per lb. will give him the required 

 wage ; if, however, the ti'ees are yielding at the rate of 3 lbs. he would 

 have either to do twice the task or the i-ate would have to be 

 inci"eased. 



Both these cases ax-e 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 Thinnino 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 thi-ee heads, the woi'st being (I) branch disease, 

 Corticmm salmonicolor, (2) stem disease, bark canker, and (3) 

 root disease, Poria hyj)olateritia, JJstulhia zonata. It is obvious 

 that the stronger the plant the better its chances of recovery if 

 attacked, in cases of bi*anch and stem diseases if given proper 

 treatment the effect of sunlight will gi-eatly accelerate the cure. To 

 pi-event i-oot disease the destruction of all butts and roots of rubber 

 ti*ees 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 aboiit 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 Clbaeings. 



The days of 10 ft. by 10 ft. planting have passed and most 



estates ai*e 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 



