COCO-NUT AND OTHER PALMS 201 



A number of explanations have been offered to 

 account for the disease. Dr. Carlos de la Torre and many 

 other writers believe that it is due to scale insects ; 

 Mr. Wm. Fawcett expressed the opinion that it was 

 due to an organised ferment ; Mr. August Busch believed 

 it was due to Pestalozzia palmarum ; while Prof. F. S. 

 Earle, Prof. Wm. T. Home, Dr. Erwin F. Smith, and 

 the writer are all of the opinion that it is of bacterial 

 origin. 1 



Associated with the disease are many fungi, such 

 as Pestalozzia, Diplodia, Aspergillus, Penicillium, 

 Rhizoctonia, and others, but experimental work has 

 shown that they do not cause the disease. 



No satisfactory remedies have been devised, but the 

 following suggestions have been offered, and, in fact, 

 are being followed in some parts of the West Indies. 



(1) Cutting and burning the tops of all affected trees ; 



(2) burning out the loose fibrous materials from the 

 tops of all slightly affected trees ; (3) spraying the 

 slightly affected trees with Bordeaux mixture ; (4) the 

 establishment of wind-breaks ; and (5) the selection of 

 seeds from healthy trees. However, in order to meet 

 with any degree of success, it is necessary to follow the 

 disease very closely and prevent its spread as much 

 as possible. It is far better to destroy an affected tree 

 than to allow the disease to spread to the neighbouring 

 healthy trees. 



Leaf Disease. This disease is said to be due to 

 the fungus, Pestalozzia palmarum 2 (Cooke), and is 

 more or less common on the coco-nuts throughout the 

 East Indies, Ceylon, Travancore. and in Trinidad and 

 Cuba. It is also said to occur on tea and other plants. 

 It appears as little, transparent, whitish spots near the 

 tips of the young leaves. These spots gradually increase 

 in size and frequently run together, thus forming 



1 The latest studies upon this subject by John R. Johnson ("The History 

 and Cause of the Coco-nut Bud-rot," U.S. Dept. of Agric., Bureau of Plant 

 Industry, Bulletin No. 228) seems to prove that this disease is due to Bacillus 

 coli (Escherich, Migula). 



2 Diplodia epicocos is frequently found on the leaves in connection with 

 the P. palmarum. 



