40 



THE COCO-NUT 



CHAP. 



yellow, first at the tips, and then gradually all over the leaflets. 

 These dry up, blacken, hang down from the "cabbage," and 

 often remain for a considerable time before they are shed. 



The petiole partly or completely breaks. Sometimes 

 the outermost, sometimes some other cycle of leaves is 

 first to wilt. 



After the yellowing of the leaves, trees bearing a good crop 

 of nuts as a rule gradually shed most if not all of them, 

 irrespective of their size and state of development, and the 

 flowers subsequently produced do not set. In fact, it is possible 

 for a person to pick out with certainty trees that are diseased, 

 before any yellowing of the leaves is noticed, by carefully 

 looking at the condition of the leaves and at the latest flowers 

 that are being put forward. 



The general appearance is similar to that produced by 

 drought. Petioles of badly diseased trees, after they 

 fall to the ground, almost always show a large number 

 of minute ruptures of the epidermis. The first point of 

 attack appears to be where the petiole merges into the 

 sheath. The fungus bears hyaline, unicellular spores, 

 capable of germinating in this state, but these at full 

 maturity become two-celled and brown. Patouillard 

 classified it as a Botryodiplodia. 



The roots of the same trees always have a fungus, 

 which destroys the cells of the cortex. This fungus has 

 not been seen to fruit, but is believed to be the same as 

 that which attacks the petioles. The wood in the trunk is 

 reddish in the parts connecting w r ith diseased roots and 

 petioles. As the trees die with the symptoms of drought, 

 and in some cases diseased roots were found on trees 

 with sound petioles, it is believed by Stockdale that it 

 is by attacking the roots that the fungus does most 

 serious injury. In the Guapo and Cedros districts 

 " three or four months is usually the time that inter- 

 venes between the first external symptoms to the death 

 of the tree, and usually within another three months a 

 ring of diseased trees is noticed around the dead stump. 

 In Mayaro the disease is much less prevalent, and the 



