DISEASES OE CACAO 79 



80-82 contains most of those which have appeared to this 

 date, but it may be that on further search more will be 

 brought to light. There are, of course, many of the well- 

 known mould fungi which have not been included on 

 account of their practically harmless character. Notes 

 and comments occurring to the writer follow each numbered 

 species appearing in the Table, which are given as showing 

 what each disease can effect, and affording further in- 

 formation on the methods of control which have been found 

 of service. It is to be distinctly understood, however, 

 that there is in all probability no more disease present 

 now than in previous times, but what is present is better 

 known and understood, and the planter is better able to 

 control its spread by adopting methods which have been 

 found successful. 



No. 1. " Black Pod " (Phytophthora omnivora, De 

 Bary). — This disease has been formerly discussed in the 

 Bulletin of the Botanical Department, Trinidad (1899). 

 It was then shown by the present writer to be due to a 

 parasitic fungus known as Phytophthora omnivora, De Bary, 

 a well-known relative of that causing the potato disease. 

 This fungus is specially known in Europe by the attack 

 it makes upon young beech seedlings and many other 

 plants, both in the open air and when grown under glass. 

 It is nearly allied to a fungus called Pythium de Baryanum, 

 which causes a like destruction among seedling plants, 

 generally known as " damping off." Both fungi are 

 essentially lovers of moisture, and do but little destruction 

 in dry weather. Phytophthora reproduces itself in several 

 different ways, and its oospores are capable of lying 

 dormant for as long as four years without losing their 

 vitality. Hartig on " Diseases of Trees," 1894, p. 45 : 

 " Its conidia (such as are formed on the surface of a cacao 

 pod), are capable of being blown by the wind, or conveyed 

 by animals, insects, or men." Tubeuf, in his work on the 

 "Diseases of Plants," 1897, p. 116, says: "Preventive 

 measures against the whole group of fungi to which 

 Phytophthora belongs consist in the destruction by burying 



