TROPICAL FRUITS 



193 



upon the trunk of the tree, are the first signs of attack. 

 Upon the leaves, the knots are always small, particularly if 

 they are numerous. Upon the small twigs the knots 

 attain the size of a garden pea, while upon the trunk they 

 become 2-3 cm. or more in diam- 

 eter and finally destroy the tree. 

 The disease was noticed in Cali- 

 fornia in 1893 and appears to be 

 confined to a very small range. 



Peacock leaf spot (Cycloconium 

 oleaginmn Cast). — According to 

 Bioletti this disease is very prev- 

 alent in certain regions of Cali- 

 fornia, occasionally causing the 

 leaves to turn yellow and injur- 

 ing the appearance of the fruit. 

 Usually it does but little harm. 

 Spots 2-4 mm, in diameter occur 

 upon the leaves. They are com- 

 posed of concentric rings of differ- 

 ent colors, giving them somewhat 

 the appearance of the spots on 

 a peacock's tail feathers. The 

 spots on the fruit are smaller and 

 more decidedly l^rown in color. 



The use of Bordeaux mixture checks the trouble. 



Sooty mold. See citrus fruits. 



