F. C. VON FABER : Die Krank. und Parasit. des Kakao- 

 baumes, S. 197, 1909. 



Phytophthora sp. has been reported to cause a blackening 

 and decay of fruits of the Para rubber plant in the Malay 

 States. 



RIDLEY : Agric. Bull, of the Straits and Federated Malay 

 States, Vol. V., No. 11, 1906, p. 397. 



PERONOSPORA TRICHOTOMA, Massee. 

 (Disease of Colocasia). 



Colocasia esculenta, the tubers of which yield an impor- 

 tant food, is known in Barbados as " eddoe," in Jamaica 

 as "coco," and in Trinidad as "tania." The disease was 

 described by Mr. Massee in 1888, having been reported to 

 occur on " cocos " in Jamaica in that year. The tubers of 

 the plant are the parts affected. When the disease is in 

 its incipient stages the cut surface of a tuber shows a 

 number of bright yellow spots on it, the spots corres- 

 ponding with the vascular bundles. Later, the spots 

 become brown or blackish and the intermediate portions of 

 the tuber are tinged brown, shewing that the fungus has 

 spread to the ground-tissue separating the vascular 

 bundles. The fungus effects an entrace at a wounded 

 surface, usually where the skin of the tuber has become 

 broken. 



Conidia are produced superficially on the tuber, and 

 the oospores are formed in the decaying tissues. Destruction 

 of the diseased tubers (by burying or burning) is recom- 

 mended ; a rotation of crops would also, no doubt, prove 

 to be advantageous in combating the disease. 



Diagnosis: — Mycelium thick; haustoria clavate ; 

 conidiophores fasciculate, 2-3 times dichotomously divided; 

 conidia small, obovate or subglobose, 12 by 10 microns, 

 oospore globose, epispore brown with anastomosing ridges, 

 35-40 microns in diameter. 



Massee : Journ. Linn. Soc. XXIV., p. 45, 1888. 



PERONOSPORA CUBENSIS, Berk, and Curt. 



(Cucumber Mildew.) 



In addition to the cucumber the fungus attacks melon, 

 squash, pumpkin, etc. A delicate white mould forms on 



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