THE 



and Magazine of the Ceylon Agricultural Society. 

 BLEEDING 



193 



COCONUT STEM 

 DISEASE. 



and 

 When 

 the lime 



IMPORTANT ADVICE FROM THE GOVERNMENT 

 MYCOLOGIST. 



Sir,— Will you kindly publish the recipe for 

 " Bordeaux Mixture," with the accompanying 

 details and suggestions for treatment of the 

 stem bleeding disease : — 



Bordeaux Mixture. 



(1) Dissolve 6 lb. of copper sulphate in 25 

 gallons of water. This is best done by putting 

 the copper su'phate in a coarse bag and sus- 

 pending it in the water. 



(2) In another vessel put 6 lb. of fresh 

 lime, and add water slowly, say a quart at first, 

 and when this disappears, another quart, 

 so on, until a smooth paste is obtained, 

 this is done, add water to bring 

 solution up to 25 gallons. 



(3) When the copper sulphate is dissolved 

 and the lime milk is cool, mix them by pouring 

 them slowly together into another barrel, thus 

 making 50 gallons of Bordeaux Mixture. 



(4) Wooden or earthenware vessels must be 

 used throughout. Iron or tin vessels make the 

 mixture worthless. 



A stronger solution may be made by reducing 

 the water to 12£ gallons in each case instead 

 of 25 gallons. The mixture should not be made 

 stronger than this. 



A barrel fitted with a pump and mounted 

 on wheels is cheaper and more effective 

 on coconut estates than the knapsack 

 sprayers used in cacao disease. The Deeming 

 barrel pump is recommended. The Bor- 

 deaux Mixture is only used to prevent -in 

 fection. It is quite useless to spray diseased 

 trees without cutting out the diseased parts. 

 The fungus is inside the tree, and cannot be 

 reached by any external wash. 



Cutting out Diseased Parts. 

 All the pieces cut out must be collected and 

 burned. If left on the ground, tho fungus 

 will grow on them luxuriantly, and there will 

 be far more danger of the disease spreading 

 than there was before the tree was cut. A 

 piece of sacking spread fiat at the base of the 

 tree will save some of the trouble of collecting. 

 Where Bordeaux Mixture is being used the 

 ground round the diseased trees should be 

 lifjhlly sprayed after they have been treated, 

 in order to destroy the fungus on any chips 

 which may have beon overlooked. 



When all the diseased tissue appears to have 

 been cut out, cutting should be continued up- 

 wards and downwards for about an inch. This 

 is especially important in dealing with young 

 trees, because in soft tissues the diseased tissue 

 thins out to an imperceptible thread and then 

 expands again. 



Bleeding does not occur until three months 

 or longer after the tree has been infected. It is 

 probable, therefore, that when the tree is first 

 treated some infected spots will be overlooked 

 because they are not bleeding. These will begin 

 to bleed later. The trees must, therefore, be 

 examined periodically. A mallet and a broad 

 chisel are the best tools for general use. The 

 long chisel used by Tamil coolies for cutting 

 out red beetle is excellent, and can be used 

 without a mallet. 



Scorching the Wodnd. 

 If the torch used to scorch the wound is too 

 large, it will damage the surrounding parts of 

 the stem. A rag wrapped round the end of 

 a stick or iron rod for a length of about two 

 inches is sufficient. It should be dipped in 

 the oil, and then lighted and passed over the 

 cut surface. Kerosine is better than coconut 

 oil. The main object is to dry the cut. surface 

 so that the tar will adhere properly. The tar 

 should be applied hot; it waterproofs the 

 wound and prevents decay as well as reinfection. 

 Liquid fuel does not prevent the entrance of 

 fungi and is not permanent. On large estates 

 it would be more economical to scorch the 

 wound with a blowpipe lamp such as is used 

 by painters to remove paint from woodwork. 

 One which burns kerosine should be selected. 



Notes on some Suggested Remedies. 

 Cutting a hole in the tree may diminish the 

 bleeding, but it cannot stop the growth of the 

 fungus : the latter continues to grow without 

 giving so much indication of its presence. It seems 

 to be forgotten that the fungus attacks the tree 

 first and the bleeding is a secondary feature. If 

 the hole is cut through the diseased patch, it 

 provides a better exit for the spores of the 

 fungus : if it is cut through the sound part of 

 the stem, it provides a place where the disease 

 can attack the tree more easily. Either way 

 it is bad. 



A bag of kainit hung round the tree has no 

 effect until the kainit dissolves and reaches 

 the ground. Then, it has only a manurial 

 value and might just as well have been applied 

 to the soil at first. A solution of kainit trick- 

 ling down the stem does not affect the fungus 

 in the slightest degree. 



