As already intimated, the usual method of eradication of areas of lallang is by thorough digging, and the exposure of the strong root system to the sun. As a matter of interest it may be noted that recently some success has been obtained by another method[1] on areas which one may have in view for planting at some future date.
[1] “Eradication of Lallang,” W. P. Handover, The Planter, Vol. I., No. 1, August, 1920.
It consists in the employment of Mimosa gigantea, which eventually smothers the growth of lallang.
The seeds are sown broadcast, in drills, or in pockets, amongst the lallang. In the course of about three months it overtops the grass and proceeds to travel. At this stage the whole mass is pressed down, and the pressing is repeated at regular intervals. Under favourable conditions, in about twelve months, an impenetrable mat has been formed, which gradually forms a good mulch. When it is desired to remove the Mimosa, the mass (pressed down) is cut and rolled up like a carpet. Cleared in this manner, the area then needs regular weeding, in order to check the development of any stray lallang shoots. In actual practice it was found that the cost of this method was approximately two-thirds that of the usual digging method.
Green Cover Plants.—Some years ago it was quite common to find green cover-plants employed on estates with the primary idea of minimising weeding costs. With most of these it was found later that their value was not real, and that they harboured diseases, and pests. Moreover, when they were removed, it was often found that an abundant crop of lallang and weeds resulted.
There can be no question that certain plants can be employed with advantage, not only in the control of weeds, but also by reason of benefit to the soil in which they are established. These plants are leguminous, and their use is restricted almost entirely to young areas, inasmuch as they will not continue to grow when shade becomes marked. Of those best known in modern practice might be mentioned Tephrosia candida (Boga bean), Centrosema Plumerii, and Dolichos Hoseii (Sarawak bean).
Typical Young Clearing, with Timber.
Young rubber plants in foreground. Two of these are easily distinguishable, both with small crowns of leaves.