88 ENEMIES AND REMEDIES. 



susceptible to the effects of wood smoke, and may be 

 easily driven off or destroyed by the smoke of ordinary 

 wood or grass fires. 



Canker, or Bark Disease. — Is a disease of the Coffee 

 plant which has created great havoc in Africa and other 

 countries of the East, and which causes an annual loss 

 of about one per cent, of the trees of Jamaica and other 

 West India Islands. The first symptoms is the withering 

 of a secondary or tertiary branch, when it will be found 

 that the bark under the primary branches is decayed and 

 blue-mouldy, the blue mould gradually extending down- 

 wards over the whole stem ; a tree once attacked never 

 recovering, but dying in a few months. All soils and 

 situations seem liable to this disease, the trees beginning 

 to suffer when about six years old. Though the mould 

 is the proximate cause of death, the ultimate cause 

 is undoubtedly due to some unfavorable external 

 condition. 



The opinions of experienced planters as to what 

 this may be are various, being generally attributed to 

 neglect of cultivation, to unstability of climate and to 

 a want of sufficient depth of soil. All may be practically 

 right, but the last seems the most probable, and is the 

 reason given for it in many countries. Rot, grubs, rats 

 and squirrels are accounted for in the following manner: 

 " Rot," or the blacking and withering of the young leaves 

 and shoots, is due to wet and cold, and may be cured by 

 good drainage and mulching. Grubs of a large and 

 yellow kind, destroy the tap-roots of the plants, cattle- 

 manure being a fertile source of them, must be well- 

 limed. Rats, squirrels, grasshoppers, ants and spiders 

 collectively do considerable mischief, and should be 

 exterminated whenever possible. 



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