537 



Weeding on most of the rubber estates in the Federated Malay 

 States is the item costing most annually. This sum is spent on labour, 

 and represents in many cases 70 per cent or more of the total labour 

 of the estate. 



The object of the rubber planter is to obtain as quickly as he can 

 vigorous trees of as large a girth as possible, at the smallest cost, and 

 in order to effect this he keeps his fields as clear of weeds as possibl 9 

 and so allows the rubber tree to have all the moisture and plant food 

 available in the soil. 



That clean weeding will show a better result in the growth of the 

 rubber trees than allowing all and any weeds to grow continuously, 

 can no doubt be proved. In Perak, however, some of the estates from 

 want of money or shortness of labour have not been able to keep their 

 plantations clear of weeds and have abandoned weeding. In some 

 cases the weeds are checked by being regularly cut, but in others 

 nothing at all has been done to eradicate or discourage the weeds. 



The growth of trees on such places is somewhat poorer than trees 

 in similar conditions which have been kept free from weeds, bnt the 

 vigour and girth of the trees where the weeds have been allowed to 

 grow is not so markedly different as the disciples of clean weeding 

 would expect to see. 



The belief in clean weeding is a tradition handed down from Eng- 

 lish farming to tea and coffee planting in the East, good farming is 

 associated with absence of weeds. In Europe, the farmer of cereals 

 and other crops does not practice the method of using certain plants 

 as a substitute for weeds. There are various reasons why clean weed- 

 ing in such crops is a good policy in Europe, but annual crops have to 

 be treated differently fromtpermanent cultivations, and the conditions 

 of labour, cultivation, plant growth and especially climate are entirely 

 different in the tropics from those in temperate climates and conse- 

 quently methods have to be modified. 



The objections to clean weeding in rubber cultivation in the Feder- 

 ated Malay States and removal of all protection from the surface of the 

 soil, are that it allows a large amount of percolation, of heat radiation 

 and of evaporation of moisture, also that heavy rainfall on all but flat 

 surface always results in the constant removal of very large quantities 

 of top soil, which are either carried away in streams or transferred to 

 the drains. It is not easy to estimate the loss that takes place in 

 tropical climates where soils are allowed to remain exposed and fre- 

 quently scraped. An immense amount of plant food is continually also 

 lost through percolation and drainage, the greater part of this is absorb- 

 ed by the roots of any plants growing on the surface, and when the 

 leaves and stems of these plants are cut this is to a great extent 

 returned to the soil. 



With the soil protected from the rays of the sun the conditions of 

 moisture and temperature are most favourable to the development of 

 bacteria which are responsible for the liberation of plant of food. In 

 clean weeded land the top two inches or more of soil are, because 'of 

 admission of heat and light, made impossible for feeding roots and the 

 preparation of food for them. When the ground is covered this surface 

 layer is kept moist and useful for the feeding roots. A considerable 



