130 



From experiments previously mentioned there can be no doubt 

 as to the fungoid nature of the disease and measures for combat- 

 ing its ravages will be considered later. The spread of the disease 

 certainly appears to be influenced by the age and condition of the 

 plants and therefore improved cultural methods are of paramount 

 importance. 



29. The primary damage done by this fungus has been seen 

 to be the destruction of the cells of the internal tissues of the 

 leaflets. This destruction continues if the conditions are favour- 

 able for the fungus, and gradually the leaf-area of the plant is 

 reduced. Under extremely favourable conditions, many of the 

 leaves become entirely destroyed through the mycelium from a 

 large number of disease-spots spreading throughout the whole 

 of the interior of the leaf. When such happens, the whole of the 

 leaf-area of the plant is destroyed, the terminal bud falls over, and 

 the tree eventually dies. 



At other times large numbers of disease-spots are scattered 

 about the leaves but not in sufficient quantities as to cause the death 

 of the plant. These spots, however, have been rendered, through 

 the destruction of the chlorophyll of the leaf, useless to the plant 

 and, therefore, the plant becomes gradually weakened. 



To the planter, the most important of the checks is that given 

 to flower development. Less flowers are produced and finally the 

 diseased condition of the trees become marked in the shortness of 

 the crop of nuts. Again food is cut off from the development of 

 nuts, their size diminishes, and their saleable value becomes 

 reduced. 



It has been noticed that in some instances the shortage of crop, 

 etc., can be traced directly back to the damage done by the leaf- 

 fungus. In some cases where the " diseased spots " are few in 

 number little damage was noticed, nor do they seem to increase 

 until the conditions become unfavourable to healthy growth of the 

 host plant. 



It would appear, therefore, that this fungus is a weak parasite 

 and is only capable of doing appreciable damage when the con- 

 ditions are extremely favourable for its development. 



The fungus that is present on coco-nuts in Java is also a weak 

 parasite and there the damage seems to be limited to young plants 

 just after being planted out, when they are sending out roots in 

 search of food for themselves after having used up all the stored 

 material of the endosperm of the seed. Therefore if the condi- 

 tions are such as to promote healthy, vigorous growth in the coco- 

 nuts, the fungus may be overcome and its attack, for the time at 

 least, thrown off. 



30. The distribution of this fungus appears to be fairly general, 

 for it has been noticed to a limited extent in Cocorite, Laven- 

 tille, Guapo, Mayaro (one estate) and Icacos districts, but it is 

 probable that only in the last two is it doing any appreciable 

 damage. In Icacos three or four acres of diseased trees were 

 noticed and the manager of the estate reported that their death 

 was very rapid. As a rule, within four months after the tips of 



