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on pods, although fruits of feeble trees, or of trees placed 

 in unfavourable conditions, may perhaps sometimes be 

 attacked by it primarily. Finally tlie expérimenta show, 

 that, in the case of fruits also, tlie fungus probably only 

 pénétrâtes througli wounds. 



Combative measures. 



It follows from the above that Di/plotlia is a wound 

 parasite. That it can penetrate directly into living tissue, 

 was never observed by us in the field, and may be 

 doubted. 



The loss of pods, which arises through „brown rot" is 

 presumably small and very likely only occurs in the case 

 of fruits which hâve been wounded in some way or other. 

 In the case of the branches also we consider the fungus, 

 as was painted out above, to be a secondary wound parasite 

 which only attacks the branches after they hâve been 

 damaged by some cause or other. The primary cause is 

 a différent one, and that primary cause the planters 

 must reckon with in the first place, when combating the 

 die-back disease. There is only one pièce of advice which 

 can be given for the protection of cacoa trees against 

 the die-back disease : keep your trees in a strong, healthy 

 state of cultivation and be on your guard against the 

 diseases mentioned on page 8. 



In Surinam the fight against the witches' brooms disease 

 will hâve to be carried on first, in order to counteract 

 the loss of trees by the die-back disease. 



A second and also very important cause which faveurs 

 the spread of the disease, is Thrips. Of late years Thrips 

 has been recognized as the primary cause of the loss of 

 large plantations of cacao trees in conséquence of the 

 die-back disease. Thrips chiefly attacks weak and unheal- 

 thy trees; with their mouths they make numerous small 



