287 



Allowing weeds to grow among the rubber and consume 

 both plant food and moisture can be shown to markedly lessen 

 the rapidity of growth of the trees in the plantation. In 

 Ceylon, the case of weeding is on a different footing to that 

 which exists on the large majority of estates in the Federated 

 Malay States. In the former country the cultivation to some 

 extent of the soil by weeding is in itself of value, as the soils are 

 often packed on the surfa.ce and prevent the free passage of air 

 and water, the pulling of weeds and scraping the surface is tillage 

 which benefits the rubber trees. In the rubber-growing districts 

 of Malaya the soils generally are of so porous and friable a 

 character that the partial cultivation which weeding gives, is of 

 little or no value. On undulating or steep lands the 

 disadvantages of constantly disturbing the surface, causing the 

 loss of top soil during heavy rainfall, is very marked, and the 

 difficulty of making efficient drains is increased by the fact that 

 each rainfall means the introduction into the drains of large 

 quantities of silt. 



. . The cost of weeding is becoming a very serious charge, and 

 js m fact the heaviest item of expense during the period 

 °eiore trees can be tapped. In the second, third and fourth year 

 °n some estates weeding cannot be efficiently done for much 

 un der $ 2 per month per acre. Thus on a 1,000 acre clearing, 

 weeding causes a very large annual expense, in some years 

 amounting to a charge of over $20,000. 



The relatively high cost of weeding has led some planters to 

 abandon weeding, or to weed only partially, either a space round 

 each tree or a strip down the line. In these cases the growth of 

 grass and other weeds is checked by regular cutting. 



That the presence of grass and other weeds retards to some 

 Jwent the rapid growth of young rubber can be demonstrated, 

 °« the fact that on many estates where this treatment has been 

 Practised the trees are growing vigorously and yielding well, leads 

 P eters to consider the damage done by weeds as not sufficiently 

 6 eat to justify the cost of their extermination. 



ohi T he , position in the Federated Malay States is that the only 

 col of wee ding in rubber estates is to prevent the harmful 

 ^Pe.t.tion of useless plants among the trees. If, however, a 

 amnn 1S ? roved to be not useless but advantageous to the trees 

 lie ^ 18 S rowin S' then its removal is neither necessary 



trib e ^ egUminous P. lan ts, i.e., of the Clover, Pea, Crotolaria 

 KvwT 1 * £ nar acterised by the presence of bacteria in their roots, 

 beinf "f What is ca "ed symbiotic relationship, i.e., both organisms 

 caui „ .^ual service to each other. These bacteria, which 

 * no( lules on the roots, absorb free nitrogen from the air, and 



