Miscellaneous. 



166 



[February, 1910. 



constantly being asked to recommend 

 some less laborious process than baud 

 weeding, whicb will prove equally- 

 effective, but it is very seldom that sucb 

 a recommendation can be made. The 

 method of spraying with some poison, 

 such as sodium arsenite, seems to be 

 effective with some kinds of weed, but 

 it leaves others almost untouched, and 

 it must be repeated over and over again 

 as more seeds germinate or as fresh 

 shoots arise from the buried portions of 

 the plants. The great objection to all 

 such methods is that the poison from 

 the spray is very liable to fall alike upon 

 the cultivated plant and upon the weed, 

 and the successful manipulation implies 

 an amount of skill, which, combined 

 with the original cost of the necessary 

 apparatus, makes it very doubtful 

 whether the method can compete 

 successfully with the ordinary mechan- 

 ical operations. 



On level ground a great deal can be 

 done with the ordinary machinery of 

 cultivation — ploughs and harrows of 

 various kinds — and this fact is at last 

 beginning to be recognized in several 

 parts of Ceylon. We have found on the 

 Government Experiment Stations that 

 by the use of modern machinery an 

 amount of labour can be saved, which 

 very soon pays for the first cost of the 

 necessary apparatus. A good plough 

 which turns the soil completely over so 

 as to bury the weeds at a depth of a 

 few inches causes the immediate destruc- 

 tion of innumerable plants. A large 

 proportion of the weeds so buried are 

 completely stifled and are unable to 

 make their way again to the surface. 



On soil which has been already 

 loosened by ploughing we find the 

 disc harrow an invaluable implement, 

 although its use is more limited than 

 that of the plough, inasmuch as it can 

 only be used when the soil is compara- 

 tively dry. The disc harrow, therefore, 

 cannot be used in moist paddy fields, 

 whereas the plough works best in 

 comparatively moist soil. This imple- 

 ment churns up the whole surface of the 

 ground to a depth of two or three inches, 

 and as it works very rapidly, covering 

 three or four acres in a day, it can be 

 sent over the ground again and again, 

 destroying each crop of weeds as fast 

 as it arises. We have also other imple- 

 ments adapted for working between the 

 rows of standing cotton and other crops, 

 and although some of these may appear 

 complicated at first sight, there can be 

 no doubt that they have a very marked 

 effect in the direction of saving labour 

 weeding. 



After all, prevention is better thau 

 cure. Let me quote the words of Dr. 

 A. J. Ewart, writing upon the subject 

 of the weeds of Victoria :— " It is not too 

 much to say that no new plant should 

 be introduced to this State, and ntft 

 even in a private garden, if there is any 

 chance of its spreading, unless an official 

 report upon its capacities for good and 

 evil has been obtained, and unless the 

 jeport is a favourable one. Although 

 the annual loss due to weeds is difficult 

 to estimate, owing to its generalized 

 and diffuse character, there can be no 

 doubt that if suitable regulations had 

 been in force fifty years ago, the country 

 would now be saved an annual loss of 

 several hundred thousand pounds." 

 Australia is well known to be a country 

 particularly susceptible to the rapid 

 spread of introduced weeds, and legis- 

 lation now exists directed against more 

 thau 100 varieties of these pests, as com- 

 pared with a single "proclaimed plant" 

 in Ceylon — the Avater hyacinth. Never- 

 theless, our own list of undesirable 

 aliens is not a short one, and a com- 

 paratively small amount of misdirected 

 energy would suffice to lengthen it 

 materially. 1 need only mention as 

 examples : — 



Lantana aculeala, introduced as an 

 ornamental plant soon after 1824; the 

 Tithonia diversifoiia, or wild sunflower, 

 which was only introduced as a garden 

 plant as recently as 1851, and probably, 

 I am afraid, spread from Peradeniya ; 

 Mimosa pudica, the sensitive plant, also 

 introduced from America ; and the 

 Oxalis already alluded to, which ig 

 originally a native of the United States. 

 Happily the inhabitants of Ceylon are 

 becoming cautious of casual acquaint- 

 ances from the outside world of plants, 

 and I have not heard of the recent intro- 

 duction of any serious pest in spite of 

 our freedom from special legislation. 



There has recently been some discus- 

 sion in the local press as regards the 

 uses of weeds. As I have already 

 pointed out, it would simplify matters 

 a good deal if the term "weed "were 

 confined to plants when and where they 

 are useless, or at least where the dis- 

 advantages of their presence outweigh 

 the advantages ; and if the rule were 

 made to apply some other term to plants 

 which are grown or allowed to grow for 

 a specific purpose. 



Plants which are weeds under certain 

 circumstances, may under other circum- 

 stances have the following recognised 

 uses : — 



1. The use as nitrogenous plants grown 

 for the purpose of enriching the soil in 

 this most important element. 



