86 CACAO 



circles. The disease can be at any time reproduced on the 

 half-ripe or full-grown pods from this cultivation. 



Fortunately, there are several saprophytic fungi which 

 cover up and appear to destroy the conidia of Phytophthora, 

 and besides these I have noticed a small mite or Acarus 

 which completely destroys the whole growth of the parasite 

 from the exterior of the pods. These are probably to be 

 regarded as natural enemies of the fungus, and may help 

 in no uncertain way to prevent its spread. It is quite 

 certain that we are facing no new enemy, but one which 

 has long been present, and one which we have not much 

 cause to fear if proper measures are adopted to secure 

 the destruction of infected material. Persons possessing 

 a microscope may compare the material from infected 

 pods with the drawing of the fungus on the opposite page, 

 which is taken from an illustration in ITartig's work on the 

 diseases of plants, and is reproduced together with others 

 from the Kew Bulletin by Mr. Massee. 



It has been found that this disease is largely propagated 

 in the decaying material from the opened pods when left 

 upon the field, as the disease is always more noticeable 

 in the vicinity of such heaps, and one of the first measures 

 to be adopted is that all such material must be moved 

 away or destroyed. 



The effect of this disease upon the cacao bean in itself 

 is shown by an experiment made on account of its being 

 asserted that the beans in the interior were not deteriorated 

 by the presence of the fungus in the outside of the pod. 

 It was found that samples of diseased and healthy beans 

 fermented and dried under exactly the same conditions 

 differed materially in weight. In the experiment made, 

 432 beans from healthy pods weighed one pound, but it 

 took 565 beans from diseased pods to make that weight, 

 which is a loss of nearly 25 per cent. 



Phytophthora first appears to the unassisted eye as a 

 delicate white mould on the surface of the part attacked, 

 which allows it to be readily distinguished from " Brown 

 rot." The conidia, or reproductive bodies, are ovate, or 



