C6C0NUT PLANTER'S MANUAL. 33 



the hole' which should be left open for at least a year. There is no 

 chance of treatment by internal application of fungicides. 



There is no difficulty in distinguishing between bud rot and root 

 disease. In the former case the central spike withers first, in the 

 latter the outer leaves wither first. 



Stem Disease. — This is the common bleeding disease which for a 

 time caused great alarm amongst planters, and is the subject of a 

 voluminous report by Petch, who, however, does not attach much 

 importance to it. There may be cases of actual death, but these ai'e 

 comparatively few. The appearance of the bleeding spots which exude 

 a viscid liquid is too familiar to need minute description. In spite of 

 the cutting out of affected parts any effect of the disease on the crop does 

 not appear to be appreciable. The fungus responsible for the disease 

 (Thielaviopsis ethaceticus) is parasitic on the sugarcane in which it 

 causes the ' Pineapple disease." The diseased part should be completely 

 cut out till all discoloured tissue is removed. This can be conveniently 

 done by means of a 1-inch chisel and mallet, care being taken to 

 slope the lower end of the cut to allow water to flow away. The 

 excised tissue must be burnt. The exposed inner tissue should 

 then be protected by a coating of hot coal tar after scorching 

 the wound by means of a lighted torch of rags dipped in kerosene 

 oil. The disease is propagated by spores from tree to tree, and this 

 transference may be affected in many ways such as by coconut-pluckeis, 

 ants, squirrels, etc. The spores on being lodged in the cracks usually 

 found on the stem would penetrate it and start the disease, and 

 fresh spores would again be brought to the surface by the liquid that 

 exudes from the diseased patch. Often the patch may be a small one, 

 but when treatment is being carried out it is frequently found that 

 the disease is very extensive underneath, and requires considerable 

 excision. 



Nut-fall. — This phenomenon was fully investigated by Mr. C. 

 H. Gadd, Assistant Government Mycologist, Ceylon, who has summa- 

 rised the result of his latest observations as follows : — 



The fall of nearly full grown, but immature, nuts from the coco- 

 nut palm has hitherto been regarded as being primarily due to fungus 

 attacks. The failure to find a causative organism always associated 

 with the disease has given rise to the view that its cause may in some 

 cases be purely mechanical, or due to adverse physiological or environ- 

 mental conditions. 



