and Magazine of the Ceylon Agricultural Society, 



491 



COCONUT STEM DISEASE AND THE 

 DISAGREEMENT OF DOCTORS. 



April 15th. 



Dear Sir,— During the discussion that fol- 

 lowed Mr. Petch's lecture on the Stem Disease 

 at the Public Hall, Mr. Petch is reported to 

 have said, in reply to Mr. G S Schneiders 

 question : — " 1 wish to know whether the spores 

 would be windborne or carried by insects ";— 



Mr. Petch The spores are deep inside the 

 treo and do not come out till the bleeding stage 

 is reached. Then they come in the liquid which 

 is thick and sticky. 1 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 :— Coming down from Chilaw 

 the other day I noticed a large number of fires 

 on plantations. 



Mr. Petch : — Thero 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 prevent it by burning tar. 



To a layman, Dr. Butler seems to hold a con- 

 trary opinion or is it that the bleeding disease 

 in Travancore ie not the same as ours, but is a 

 variety of it ? 



Dr. Butler — on the coconut palm disease in Tra- 

 vancore— said:— "A coconut disease, similar in 

 many respects to the Travancore disease, has re- 

 cently engaged attention in Ceylon. It has been 

 attributed by the Government Mycologist, Ceylon, 

 to a fungus known as Thielaviopsis ethaceticus, 

 well known as the cause of the 'pine-apple 

 disease' of sugar cane. A similar fungus occur- 

 red with such regularity on the cut stems of 

 coconut palms wherever examined in Travancore, 

 that the likelihood of its being the cause of the 

 disease appeared considerable. Further investi- 

 gation showed that this is not the case. The 

 fungus though allied to the cause of 'pine-apple 

 disease,' is a distinct species of Thielaviopsis. 

 It occurs equally on healthy and diseased palms 

 and on all or most of the Indian species, being 

 common on coconut, areca, palmyra and date. It 

 is found on cut surfaces of roots, stem and 

 crown and appears freely on split arecanuts that 

 are perfectly healthy. Hence its spores must be 

 very widely distributed on the surfaces of palms, 

 and in the air in palm growing tracts. As it lends 

 itself eminently to rapid dissemination, this fact 

 alone would be enough to put it out of court 

 as a cause of the disease, for the progress of the 

 latter is extremely slow. Even more definite evi- 

 dence is fortunately available. It occurs equally 

 freely on palmyra ami date palms at Pnsa 

 where no serious palm disease is known. It has 

 also been encountered in Sylhet on areca palms, 

 in the Godavari on palmyra and coconut, and 

 on date palms from Said. In none of these 

 areas is there a similar disease to that in Tra- 

 vancore. Further, slabs of the stem of diseased 

 coconut palms in Travancore were cut out with 

 a red hot knife, under asceptic precautions and 

 incubated. These did not give risb to any fun- 

 gus when kept from exposure to the air, though 



when uncovered they quickly showed a charac* 

 teristic growth of Thielaviopsis. Henco what- 

 ever be the cause of the Ceylon disease, the palm 

 Tliiel.aviopsis is a perfectly harmless fungus in In- 

 dia, so far as is at present known, and certainly 

 has nothing whatever to do with the Travancore 

 disease." 



The italics are mine. I am not writing criti- 

 cally, but enquiringly. Is the Thielaviopsis, 

 which so high an authority as Dr Butler says 

 is " perfectly harmless '' in India, the same fun- 

 gus as is doing damage to coconut trees 

 in Ceylon, or is it a harmless variety of it ? Will 

 Mr Petch kindly enlighten us ? — Truly yours, 



B. 



COCONUT PALM CULTIVATION 

 AND SALT. 



Mr. Petch has kindly responded to our en- 

 quiry by sending us the following copy of re- 

 ports of American agricultural experiments in 

 the Philippines which, we suspect, will take 

 every intelligent coconut cultivator in Ceylon 

 completely by surprise : — 



Philippine Bureau of Agriculture. — Farmer's 

 Bulletin No. 8.— The Coconut. 



"Upon suitable coconut soil — i.e., those that 

 are light and permeable — common salt is posi- 

 tively injurious. In support of this contention 

 I will state that salt in solution will break up 

 and freely combine with lime, making equally 

 soluble chlorides of lime which, of course, 

 freely leach out in such a soil and carry down 

 to unavailable depths these salts, invaluable as 

 necessary bases to render assimilable most plant 

 foods. And that, on this account, commercial 

 manures containing large amounts of salt are 

 always to be used with much discretion, owing 

 to the danger of impoverishing the lime in the 

 soil. 



Finally, so injurious is the direct application 

 of salt to the roots of most plants that the in- 

 variable custom of trained planters (who, for 

 the sake of the potash contained, are com- 

 pelled to use crude Stassf urt mineral manures 

 which contain large quantities of common salt) 

 is to apply it a very considerable time before 

 the crop is planted, in order that this dele- 

 terious agent should be well leached and washed 

 away from the immediate field of root activity. 



That the coconut is able to take up large 

 quantities of salt may not be disputed. That 

 the character of its root is such as to enable 

 it to do so without the injury that would 

 occur to most cultivated plants I have pre- 

 viously shown, while the history of the coco- 

 nuts' inland career, and the records of agri- 

 cultural chemistry, both conclusively point to 

 the fact that its presence is an incident that 

 in no way contributes to the health, vigour, or 

 fruitfulness of the tree." 



The Philippine Journal of Science Vol. 1. No. 1. 



"The Coconut and its Relation to the Pro- 

 duction of Coconut Oil " by H S Walker. 



P. 59. — " Chemically the results of these ana- 

 lyses show very little difference between the 

 soils near the shore and those further inland. 

 The latter, contrary to what would be supposed, 



