and Magazine of the Ceylon Agricultural Society,— May, 1910. 



473 



CHEMICAL SPRAYS FOR WEED, 

 INSECT, ETC., DESTRUCTION. 



We have received a very neatly drawn up 

 circular from the Acme Chemical Co., Limited, 

 Tonbridge, Kent, giving a general idea of the 

 methods they recommend for the destruction of 

 weeds, insects, and fungi. They submit that 

 the only effective method of ridding land of 

 weeds, especially Lalang Grass, is to attack the 

 roots with a solution of Arsenite of Soda. Where 

 the roots are not more than a foot below the 

 surface, and the soil is fairly loose, the solution 

 will find its way to the roots if the ground is 

 well and carefully sprayed. If the grasses and 

 weeds have boon cut down and removed, and 

 the surface so cleared that there will be no 

 waste of solution upon the rubbish lying about, 

 a good dressing at the rate of 25 gallons to 70 or 

 80 square yards (that is SO by 1) will be sufficient 

 to kill the roots without taking them up ; the 

 time chosen for application is when the ground 

 is moist with dew. Tho ground should be well 

 sprayed once, and then again before it has time 

 to dry, one dressing following the other whilst 

 the ground is wet. If the roots are more than 

 a foot down it may be- necessary to fork them 

 up or to loosen the ground so that the solution 

 can easily penetrate to them. It is stated that 

 to destroy young Lalang by forking costs at 

 least about $30 per acre, whereas the cost of 

 Arsenite of Soda of sufficient strength to accom- 

 plish this more effectually upon an acre of 

 ground would only cost about $13 (1 dollar = 2s. 

 4d.) c.i.f. Port Swettenham, Singapore or 

 Penang. The time occupied in sprayiDg the 

 solution over an acre would take three men, 

 with a fairly good distributing apparatus, from 

 three to four hours. There may be cases where 

 from the nature of the ground, or the fact that 

 the Lalang is so deeply rooted that it has to be 

 dug up and the roots taken away and destroyed, 

 but even in such cases many broker, pieces of 

 root are bound to be scattered over the surface. 

 These will grow again if not destroyed. One 

 spraying would be sufficient to destroy these 

 pieces of broken roots, thereby using just half 

 the quantity of solution. 



Ants or any other vermin feeding on vegetable 

 matter in the soil would also be destroyed. 



Another preparation manufactured by the 

 Acme Chemical Co., Ltd., is " Fumerite " a 

 non-poisonous preparation which when mixed 

 with the soil gives off a gas most deadly to 

 insects and especially to ants. The fumes 

 permeate the soil for a considerable distance 

 around if the surface is beaten down fairly close 

 after the powder has been put in the earth. 

 The fact that white ants work in tunnels makes 

 this powder very effective against those insects. 

 The fumes collect in the galleries and complet- 

 ly exterminate the insects. If the powder is 

 put near the roots without actually touching 

 them the fumes will travel through the soil 

 without doing harm ; ants and other insects 

 living in the soil or among the roots are never- 

 theless killed. Its action is very quick in warm 

 and moist soils, and for a long time it will 

 continue to be very objectionable to insects. 

 In the course of a couple of months it will 



become exhausted, but the residue is a good 

 plant food. They strongly recommend its use 

 against the attack of ants on young plantations, 

 and they give full instructions in the circular 

 how to use it both in young plantations and in 

 older plantations. This powder is mixed with 

 from 100 to 200 parts of soil, and is very cheap. 



"Anti-Fungi Powder" is a non-poisonous 

 powder cotaining the active properties of the 

 Bordeaux Mixture ; it does not scorch or injure 

 foliage. In many situations where it is difficult 

 to use liquid fungicides this powder is most 

 useful, and in any case it is cheaper to use than 

 the liquid. It has been used with good effect 

 against fungoid diseases on Hops, Tomatoes, etc. 



"Arsenate of Lead Paste" is a poisonous 

 preparation which destroys all biting and leaf- 

 eating insects, such as caterpillars and beetles. 

 It may be mixed with Bordeaux Mixture or 

 Solution of Sulphate of Copper, and so act as an 

 insecticide and fungicide. Of all arsenical 

 washes Arsenate of Lead is best to use because 

 of its being more easily mixed. It is held in 

 suspension much longer than Paris Green, and 

 the scorching noticeable after using Paris Green 

 never occurs when Arsenate of Lead is used. It 

 also adheres to leaves better than most washes. 

 1 lb. is sufficient for 25 gallons of water, and 

 as it is only necessary to slightly wet the leaves 

 it is an economical wash. On cotton plantations 

 it has been customary to use quantities of Paris 

 Green Powder, but owing to the uncertain effect 

 of Paris Green, its scorching of the foliage, and 

 danger to natives inhaling the poisonous dust, 

 Arsenate of Lead Paste, in solution, is quickly 

 taking its place. 



The Acme Chemical Co., Ltd., manufacture 

 chemicals for agricultural and horticultural use, 

 and are specialists in insecticides, fungicides, etc. 



We hear that a copy of this circular has been 

 sent to all rubber plantations, and if planters 

 will write them explaining any difficulties, they 

 will be happy to give them the benefit of their' 

 many years' experience in combating the attacks 

 of insects, diseases of plants, and destruction 

 of weeds. 



If spraying machines or powder distributing 

 machines are required, on being supplied with 

 particulars of the work the machines are to 

 accomplish, the nature of the ground over which 

 they have to work, etc., they will be glad to 

 send particulars and quotations. 



THE UTILITY OF GHALK. 



BY MR. JOHN HUGHES. 



Agricultural Analyst for Herefordshire. 



The value of freshly burned lime for agri- 

 cultural purposes has been recognised from 

 a very remote period, also the utility of the 

 application of chalk, which consists of lime 

 combined with carbonic acid, has also been 

 recognised by practical farmers. But the 

 conditions of soil and climate which should 

 determine respectively when the highly caustic 

 or quick lime, and when the mildly caustic 

 chalk should be applied have not been re- 

 cognised as they should be. In the first 

 place quick lime when properly burned and 



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