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no artificial aids to get rid of excess of water the structure allowing 
water to percolate freely while not being to loose to partially retain it. 
Drainage is a factor the importance of which the planter has 
learnt by experience. If the soil is water-logged and consequently not 
sufficiently aerated rubber roots will not grow vigorously. 
He has still to learn the advantages of protecting his soil from sun 
and rain or rather the disadvantages of exposing it to these inimical 
influences. His drains are made chiefly to decrease the loss of surface 
soil after rain but if lie will cover his land with a beneficial weed the 
only drains that will be necessary will be those on flat land which pre- 
vent the land becoming waterlogged. 
Nearly all the expenses of draining are thus saved and a sum of 
from $1/- to $4- per acre in order to permanently establish a protective 
plant which will obviate the necessity for drains on sloping land and 
at the same time encourage the root growth of his rubber trees, can readily 
be afforcftxl, especially as it means a cessation of all expense in regard 
to weeding attending to drains. 
Millions oi dollars have been spent on keeping the land on which 
rubber is growing exposed and probably three-quarters of the labour force 
have been used in carrying this out. Hundreds of thousands of tous 
of top soil, which can never be replaced and the value of which as plant 
food is immense have been washed off clean weeded estates. 
Is this expenditure of money and labour and sacrifice of top soil 
necessary in order to get, the most rapid and vigorous growth of rubber 
trees ? This is a problem which any planter can solve himself. Let 
him the next time he is opening a cleaning sow or plant a selected green 
manure Crotakuia, M sensitive plar?t) Vigna, DcsmocUmi &c., or 
even Passi flora foctida (passion flower) directly the burning is finished 
and see that it is established so that the grouWl is never exposed to 
the sun and the rich top soil which is left behind wlhen jungle is burnt 
is not immediately washed off. Let him plant bis r dibber in this and 
compare its height and girth and general vigour with cthe growth of 
rubber trees of equal age in his clean weeded clearings, and ± have no 
doubt that he will be convinced that the labour and money s^ent on 
clean weeding is not a sound commercial investment. 
If be establishes bis selected plant at once there is no fear V>f 
lalang that bug bear of the rubber getting admission. 
During the past three years I have been making observations as to 
rubber which for various reasons has been allowed to remain in weeds 
or has had other plants growing with it which tend to protect the soil 
from sun and rain'. In cases where the weed is lalang the benefit 
of the protection of the soil is to a great extent counteracted by the 
damage done by this, the worst of all the weeds of Malaya. 
Lalang forms a close mat of roots which absorb a great of deal 
of rain and dew, the loaves of the plant do not protect the soil nearly 
ap well as almost any other plant, being all arranged vertically and thus 
giving as little shade as possible. I have found the surface temperature 
in lalaug to be some eight to ten degrees higher than in other weeds 
sensitive plant, passion flower &c., on similar soil. 
Even where lalang is the weed the hindenmee to the rapid growth 
of the rubber is not so marked as believers in clean weeding would 
