Tlie J)ie-I)ack Disease of Cacoa trees and tlie 



„Brown rot" of Cacoa Fruits, caiised by 



Diplodia cacaoicola. 



by 



A. E. DE JONGE and A. W. DROST. 



With Plate VIII and IX. 



Introduction. 



The dying off of cacoa trees-not as a resuit of old âge, 

 but in plantations which are still fairly young, often by 

 groups and sometimes in such large numbers, that whole 

 fields had to be written down-has repeatedly been observed 

 in Surinam. It is only in the last few years, however, 

 that more attention bas been paid to this dying off, and 

 that it has become a subject of study. In this way it 

 was found that this dying off was not always due to the 

 same disease, but that it had to be attributed to the 

 attack of différent parasites. For instance the „canker" 

 which sometimes occurred in a destructive manner, was 

 caused by a Spicaria'); the so-called „leaf disease", 

 which has also caused much damage from time to time, 

 was recognized as due to Thrips. 2) 



1) A. E. de Jonge. Recueil des Travaux botaniques néerlan- 

 dais. Vol. VI, 1009. 



2) Inspeclie van den Landbouw in West-Indie. Verslag over het 

 jaar 1906. p. 11. 



Recueil des trav. bot. Néerl. Vol. VI. 1909. 16 



