DISEASES OF COCONUT 189 



Sporangia develop abundantly on material transferred to a 

 moist chamber, and chlamydospores and oospores occur in 

 cultures. The sporangia are decidedly more globose than in 

 P. palmivora, with a narrower papilla and less tendency to 

 break away with a stalk. 



The fungus agrees with P. parasitica Dastur, described on 

 castor oil and Vinca in India. It also agrees with P. terrestria 

 Sherbakoff, on tomato fruits in Florida, which is probably 

 synonymous. 



Control. 



Attempts at control by cutting out diseased leaves and 

 by the use of Bordeaux mixture or Bordeaux paste have not been 

 successful. More promising results have been obtained by 

 packing banana or coconut trash round the affected limbs 

 and firing it. 



Stem-Rot. 



Stem-rot occurring in local patches on trees of any age is 

 a matter of some concern in Trinidad and Tobago. A similar 

 trouble has been noted in Grenada. In the typical form of the 

 affection the outward sign of its presence is the exudation of a 

 liquid which runs for a little way down the rind and dries to 

 a reddish-brown stain. Removal of the rind reveals a patch of 

 sodden tissue with an early tendency to yellow or reddish dis- 

 coloration followed by browning as decay progresses. 



The starting point of the rot is frequently a cut arising from 

 the habit of pickers and others of using the stem as a cutlass 

 rack, or from weeding near the base of the tree. The affection 

 also arises in many cases in connection with the natural cracks 

 common in the rind. 



In old and hardened trees the rot spreads little and is not 

 of much account, but in the softer wood of younger trees severe 

 injury may occur and eventually result in death. This may be a 

 matter of months or of several years according to the extent and 

 number of the attacks and the susceptibility of the tissues. 



The disease is at present under investigation in Trinidad, 

 where it is very common in some districts and rare in others. 

 A small-celled yeast appears to be general in the affected tissues 

 and F. Stell has recenHy obtained cultures of Thielaviopsis 

 from the spots. 



A small amount of gumming is often associated with the 

 typical affection as above described, but other cases occur 

 where a verv profuse exudation of gum from cracks all over the 

 affected patch is the most prominent symptom. The internal 

 appearances are similar, but the relationship of the two types 

 is not known. 



T. Fetch has described under the name stem-bleeding disease 



