February, 



165 



Miscellaneous. 



germination takes place at irregular 

 intervals, producing a succession of 

 weeds, which must be repeatedly 

 destroyed before the time of flowering, 

 if the weeding is to be permanently 

 successful. The process of examin- 

 ation can be accelerated to a certain 

 extent by tillage, which leads to the 

 immediate germination of a la rge pro- 

 portion of seeds, and must be followed 

 as before by repeated weeding. 



Weeds which have other methods of 

 reproduction besides that of seeding are 

 even more difficult to deal with. Many 

 weeds of the worst class are perennial. 

 The well-known Lalang, or illuk grass 

 (Imperata arundinacea), for example, 

 has strong underground root stocks, 

 which extend far and wide in the soil. 

 Small pieces broken from the creeping 

 rhizomes by ploughs or other implements 

 are often spread abroad in the land, and 

 may grow into individuals as strong as 

 the original plants from which they were 

 derived. The attempt to dig out the 

 illuk, unless carried out with the most 

 extreme thoroughness, may therefore 

 merely lead to an increase of the 

 nuisance. 



Continual mowing down and removal 

 of the green parts of a plant of this 

 kind will tend to weaken it materially, 

 although illuk itself is very resistant to 

 such treatment. Nevertheless, repeated 

 pulling up of the shoots as fast as they 

 appear must necessarily result in the 

 exhaustion of the stored food, and 

 effectually prevents the manufacture of 

 more, since it is in the leaves that the 

 production of food takes place. 



Land infected with illuk, which is 

 not required for immediate cropping, 

 can most easily be dealt with by growing 

 some other plant which is able success- 

 fully to compete with it. Such a plant 

 is the common climbing weed Micania 

 scandens, which, however, ceases to be a 

 weed in this connection whilst it is being 

 employed for a useful purpose. Several 

 other climbing plants can be used in a 

 similar manner, their only necessary 

 qualification being that they should 

 themselves be easy to exterminate when 

 the battle with the illuk has ended in 

 their favour. In 3ome cases at least 

 these creeping plants are able to destroy 

 the illuk grass by climbing over it and 

 weighing it down to the ground with 

 a mass of heavy green foilage, which 

 cuts off the illuk from air and light and 

 leads to the final extermination of the 

 more virulent weed, The creepers 

 themselves are afterwards comparative- 

 ly readily amenable to the ordinary 

 operations of (weeding. 



Another weed which is found parti- 

 cularly difficult to exterminate is the 

 Oxalis, which infests some up-country 

 tea estates. Apparently this weed does 

 not at present affect the yields of the 

 tea bushes very greatly, but there can 

 be no doubt that it removes, temporarily 

 at least, a large proportion of the 

 manure intended for the tea. The 

 Oxalis is propagated by vast numbers of 

 minute bulbils, which, on account of 

 their earthy colour and minute size, are 

 quite impossible to extract completely 

 by the most careful hand weeding. The 

 policy of smothering by a vigorous creep- 

 ing plant is not applicable on a tea 

 estate, as the tea would be smothered as 

 well as the weeds, and would probably 

 fare worse than the Oxalis, which is 

 itself a shade-loving plant. The only 

 method I have heard of which is found 

 to be at all effective is to dig out the 

 plant, root and all, with the earth 

 intact, and burn plant and earth to- 

 gether. But this is a method which can 

 obviously only be applied when the 

 weed is confined to a small area. 

 , I do not know whether the experiment 

 has been made of attempting to shoke 

 out the Oxalis by growing some such 

 plant as Orotalaria amongst the tea. 

 Since the mulch of Orotalaria leaves and 

 stems obtained in this way by cutting 

 before the time of flowering is known to 

 be of the utmost benefit to the tea, 

 there could be no harm in making the 

 attempt, although it is impossible to say 

 whether the Oxalis would be exter- 

 minated or only benefited like the tea 

 by the additional supply of nitrogen. 



In setting one weed to kill another 

 in this way considerable discretion is 

 required in order that the remedy may 

 not turn out to be worse than the 

 disease. Thus, the suggestion was made 

 some . time ago to introduce Tithonia 

 diversijolia— the common yellow sun- 

 flower of our roadsides and railway 

 embankments — into some parts of South- 

 ern India. The suggestion was made by 

 a forest officer, who had heard from a 

 high authority that this plant was a most 

 effective agent for exterminating lan- 

 tana. Now, this happens to be perfectly 

 true ; but I have never heard of any 

 agent which will in its turn effectively 

 exterminate the sunflower when it is 

 once established. And I would here 

 point out that the climber Micania 

 scandens, alluded to a little time ago, is 

 itself a troublesome weed iu many 

 instances, and should never be intro- 

 duced except for the express purpose of 

 destroying a worse weed &uch as illuk. 



Indeed, there is no royal road to 

 the eradication of weeds, We are 



