DISEASES OF CACAO 89 



gives rise to the white mildewy appearance, but also that 

 containing the resting spores, as these are capable of 

 remaining dormant for long periods under unsuitable 

 conditions for growth, on or under the ground, and of 

 afterwards producing the disease again when falling on 

 suitable surroundings. 



It should be remembered, however, that there is no 

 radical cure for this disease, any more than there is for the 

 treatment of the well-known potato disease, and that the 

 treatment must perforce be either of a preventive character 

 or by selection methods in order to obtain a class or strain 

 of trees which is immune to its attack ; in the same way 

 as has been adopted for control of the potato disease in 

 Europe and America. Bordeaux mixture used as a spray 

 will undoubtedly serve to destroy the conidia, but the 

 disease, being internal, and these being regularly ex- 

 pelled day after day for a long period, the impracticability 

 of the method of spraying is demonstrated, as it cannot 

 reach the interior of the pod, and therefore cannot harm 

 the internal growth, which will continue again and again 

 to expel the reproductive organs shortly after any spraying 

 that may be applied. This point should be well understood 

 by cacao planters, as there are not wanting those who 

 for trade purposes will advocate the use of sprays imder 

 circumstances similar to those just described, which will 

 not only fail but will discredit the application of sprays 

 where they might be applied to considerable advantage. 

 Therefore, no practice other than that of total destruction, 

 as recommended by the celebrated Russian mycologist, 

 Tubeuf, can be absolutely efiEectual for exterminating the 

 disease. The best control is obtained by the careful 

 destruction of the pods ; the burying of pods containing 

 the resting spores is only hiding it for a time, as the disease 

 will again appear when any of the resting spores are 

 liberated. Fermentation at a high temperature appears 

 to be, on the whole, the best means of destruction of the 

 pods, especially if a free use of lime is made when making 

 up the heaps or tanks for the purpose. The ordinary 



