46 



the gardens covered the same ground every fortnight. 



In such a case the weeds cannot seed and the expen- 

 diture on weeding per acre is very low, especially when 

 the plant is well grown. This experience is comfirmed 

 in Java with the so-called "djoetoel-system" which is 

 employed on well cleared gardens. 



It is essential, by careful management, to control the 

 work in the plantations, in order to see that each field 

 gets its turn every fortnight. 



Working with absolutely clean gardens, has, therefore, 

 the advantage that it is cheap; a second advantage is 

 that the Hevea, with such upkeep, gets on splendidly. 



A third advantage is, that it facilitates the control oi 

 the upkeep of the garden and noxious plants like lalang 

 get no opportunity of getting a foot-hold in the plantation. 



The advantages are not however, all on one side. 

 On sloping lands where the soil is not under cover 

 plants some amount of wash takes place, whereby, the 

 best part of the soil is lost, as well as a part of the 

 roots of the rubber trees (see fig. 8). 



It is time something was done to prevent this, by means 

 of surface drains, but this remedy is not wholly sufficient 

 in hilly lands. 



b. Partly cleaned gardens. On steep lands which are 

 much exposed to wash, part of the weeds are sometimes 

 left, only the lalang and other noxious weeds being taken 

 away, plants like Passiflora foeiida, Mimosa pudica and 

 other harmless weeds are retained, and somtimes even 

 cultivated. The gardens must be kept as systematically 

 as the clean weeded ones. It is necessary to point 

 out that under this system, full control of upkeep is 

 not possible and there is always the danger that lalang 



