336 DISEASES OF CROP-PLANTS 



" As in the case of the mango, the fungus also attacks leaves, 

 and causes a certain amount of defoliation." 



Date Palm. 



Leaf Disease. 



The date palm is everywhere subject to infestation with a 

 parasitic fungus Graphiola Phcenicis, Poit. of unknown affinities. 



The fructifications are based on small yellow or brown spots 

 on both sides of the leaflets and on the rachis. They consist 

 of single or grouped black cups of carbonaceous texture, up to 

 I mm. in diameter, from the interior of which project con- 

 spicuous buff-coloured cottony tufts, thickly powdered with 

 light yellow pollen-like spores. 



Each infection appears very narrowly localized, but their 

 number progresses with the age of the leaf, so that old leaves 

 are very heavily infested. 



The writer is not acquainted with the results of any attempt 

 at control. 



The same or similar species occur on certain other kinds of 

 palms. 



Pomes Stem-Rot. 

 The fungus Fonies australis Fr. has occurred on the stems 

 of living date palms in St. Kitts, associated with a process of 

 failure ending in death. The same fungus has been seen on dead 

 palms in Grenada. 



Grape-Vine. 



Anthracnose. 



Anthracnose of the grape-vine caused by the fungus Gloso- 

 sporium ampelophagum has been met with in Barbados. The 

 disease is well distributed throughout Europe and America. 

 Leaves, berries and shoots are attacked. The spots produced 

 are of the bird's-eye type, consisting of a pale centre with a brown 

 or reddish border. On the shoots they are elongated in the 

 direction of the axis, and sometimes by affecting the cambium 

 give rise to small cankers. The fungus closely resembles other 

 species of Gloeosporium ; the conidial measurements given are 

 5-6 X 2.5-3.5 rnicrons. 



Repeated spraying with Bordeaux mixture is a fairly satis- 

 factory means of control, but needs to be aided by the pruning 

 out as far as possible of the diseased shoots and the removal 

 of infested leaves and fruit 



Powdery Mildew. 

 The Oidium stage of an Erysiphaceous fungus, in all pro- 

 bability Uncimda necator (Schw.) Burr., a general pest of the 



