608 NOXIOUS WEEDS 



from seeding. Persistent cutting down of the leaves and stems has 

 been found effectual in Ceylon in exterminating such pestiferous 

 weeds as the Sensitive Plant and the Tithonia (Mexican Sun-flower), 

 which is so troublesome along the Railway. The same effect may 

 be obtained by placing a layer of mana-grass or other covering 

 over the affected ground. An old maxim which shows the im- 

 portance of preventing weeds from seeding is that, 

 One year's seeding, 

 Is seven years' weeding. 



In some cases, as in Coconut cultivation, it is possible to keep 

 down weeds by means of grazing cattle, which also benefit the 

 land by their manure. 



Poison weed-killers. Destroying weeds by means of poisons 

 or weed-killers is not practicable amcng crops, except perhaps on 

 young clearings. BAMBER recommends arsenate of soda for killing 

 out weeds on young Rubber clearings, when it is impossible to 

 eradicate these by ordinary means. For roads, paths, railway 

 tracts, tennis-courts, compounds, etc., poison weecl-killers can, 

 however, be effectually applied. Of commercial weed-killers, 

 there are various kinds, some in powder form, others in liquid. 

 Those consisting of compounds of carbolic or arsenic are the most 

 effective, but other substances, as sulphate of copper, kerosene, 

 common salt, etc., are also sometimes used for the purpose with 

 more or less success. Arsenate of soda has in some cases been 

 found effectual in destroying troublesome weeds, and MR. BAMBER, 

 Government Chemist, has recommended it against "link" 

 (Imperata arundinacea) and u Nut-grass" or " Kori grass," (Cypenis 

 rotundus), two of the most noxious weed-pests in Ceylon. Where 

 a commercial weed-killer is not available, any of the following 

 simple mixtures may be employed : (i) Mix 1 oz. carbolic acid with 

 one gallon water, and apply through the rose of an ordinary water- 

 ing can. (2) Take one part kerosene to three of boiling water, and 

 emulsify with soap. (3) Dissolve one pound common salt in one 

 gallon of boiling water, and apply as hot as possible through the 

 rose of a watering pot, at the rate of one gallon to every two 

 square yards of weedy surface. (4) Take 9 Ib. white arsenic and 

 3 Ib. washing soda, boil in one gallon of water till dissolved. For 

 use, add half pint of solution to one gallon of water. In using 

 poisonous weed-killers, gloves should be worn to prevent contact 

 with the skin ; care should be taken to keep the solution clear 

 of clothes and boots, whilst going too near grass verges, plant- 

 edgings, etc., must also be avoided. 



