292 



The Supplement to the Tropical Agriculturist 



Mr. Petch :— Tar is better, something that is 

 waterproof is desirable. 



Mr. Felsinger .-—The effect of carbolic acid is 

 felt deeper. 



Mr. Petch:— If it goes deeper than tar there 

 is a decided disadvantage. In the coconut 

 tree, unfortunately, if you make a hole, it does 

 not fill up through growth. In cacao or rubber 

 it is otherwise. So if you make an opening in 

 the coconut tree you must make the surface 

 impervious to water. Cyllin or carbolic acid 

 or anything similar will not make it water- 

 proof. 



Mr. Felsingeb :— What about a mixture of 

 carbolic and tar ? The effect should be better. 

 The carbolic would work on particles of 

 diseased matter left and the tar act as a water- 

 proof coat. 



Mr. Petch : —The mixture would be too 

 expensive. You do not want to kill the tissues ; 

 and you use tar to prevent water effects. 



Mr. Felsinger : — Carbolic will kill the fungus. 



Mr. Petch :— If you get at it. But you cut 

 out the fungus and apply tar. 



Mr. F. J. de Mel :— Can this fungus grow on 

 jak trees ? 



Mr. Petch : — It thrives on sugars. The bleed- 

 ing on jak trees is not caused by this fungus. 



Mr. F. J. de el : — It is very much like this. 



Mr. Petch : — It is the result of decayed bark : 

 and is a well-known phenomenon on other 

 trees. It is not caused by the fungus which 

 grows on the coconut palm. It is a different 

 thing altogether. 



Mr. F. J. de Mel : — Different treatment 

 is required ? 



Mr. Petch :— I have not heard of any treat- 

 ment in any country for such a bleeding disease. 



Mr. F. J. de Mel : — Is it safe to leave it alone? 



Mr. Petch : — Not if you are growing it for 

 the timber. If so 



Then Tar the Wounds. 

 But if you are growing it for the fruit or for 

 ornamental purposes you may leave it alone. 



Mr. F. J. de Mel :— Will the fungus spread to 

 other trees ? 



Mr. Petch : — It is a disputed point alto- 

 gether whether the things you get in that liquid 

 will do so. 



In reply to a question of Mr. W. Dias Bandara- 

 nayake, Mr. Petch remarked that the coconut 

 stem fungus would grow on dead sugarcane. 

 They could grow it in a solution of sugar. 



Mr. Bandaranayake referred to the bleed- 

 ing disease of mango trees reported from India. 



Mr. Petch:— That is quite different from this. 

 You have a definite mixture of organisms in the 

 sap that exudes from the jak and mango trees. 



Mr. Felsinger :— In your opinion carbolic 

 acid is effective in killing the fungus ? 



Mr. Petch :— If you are quite certaiu that it 

 will go to every portion of diseased tissue you 

 can be happy. 



Mr. Felsinger :— The application of carbolic 

 will benefit the diseased tree ? 



Mr. Petch :— If you are sure it will travel in 

 the wood it will be effective. But here you are 

 working in the dark. It would not get through 

 the tissues. 



Mr. Felsinger :— To what extent will it 

 penetrate ? 



Mr. Petch :— That I cannot say. 



Mr. G.S. Schneider:— I wish to know whether 

 the spores would be wind-borne or carried by 

 insects. 



Mr. Petch :— The spores are deep inside the 

 tree and do not come out till the bleeding stage 

 is reached. Then they corne in the liquid which 

 is thick and sticky. I do not think the wind has 

 any chance of carrying the spores. They will be 

 conveyed by anything that settles and moves 

 about on the coconut trees— insects, rats, 

 squirrels or men who climb the trees. 



Mr. Schneider :— The fungus begins inside 

 the trunk ? 



Mr. Petch : — It works in from the outside 

 through cracks in the bark. 



Mr. Schneidkr : — I have been to three large 

 estates about a fortnight ago and saw more 

 diseased trees near the bungalows than further 

 afield. 



Mr. Petch : —There is more tendency for the 

 disease to spread in some places. In some places 

 there is more disease round mills than in other 

 parts. I may be able to explain that but not to 

 make a suggestion. 



Mr. Schneider : — Coming down from Chilaw 

 the other day I noticed a large number of fires on 

 plantations. 



Mr. Fetch : — There has been a suggestion 

 that you should burn tar in plantations. If the 

 disease is due to insects, that might work, but 

 being a fungoid disease inside the stem of the 

 tree you cannot rrevent it by burning tar 

 Or Making Bon-Fires on Estates. 



Mr. Schne'Der :— Except to the extent of kil- 

 ling insect carriers. 



Mr. Petch :— Yes. But that is rather remote. 



