86 



JOUENAL OF AGRICULTURE OF P. R. 



lowed by a rapid production of the corky outgrowths so character- 

 istic of the disease. On the fruit these corky outgrowths, wartlike 

 in appearance, vary much in size and shape, often running together, 

 or occurring in such numbers as to cover a large percentage of the 

 surface of the infected fruit. At times ])lateau-shaped areas are 

 produced, of an inch or more in diameter, irregular in shape, and 

 marked by the dying of the epidermis and its breaking up into 

 silver\^ scales. Again it may take the form of ridges, conical eleva- 

 tions, or other shapes. 



The corky areas are dull brown in color in some instances, but 

 very commonly are a dull red with bi-own margins. This latter 



s t a g e occurs 



where tlie dis- 

 ease is espe- 

 cially virulent, 

 the ridge and 

 plateau condi- 

 tinii l> e 1 n g 

 m ore oft e n 

 noted in in- 

 stances where 

 hut little dis- 



FiG. n. — Citrus scab on full- 

 grown lemon. 



ease is present. Fig. 12. — Young grapefruit 

 ^, . , . (lefornied Ijv citrus seab. 



This latter is 



the type found on oranges. 



Young fruit are frequently much distorted, assuming triaagular or 

 ether peculiar shai)es. Those most distorted fall to the ground soon 

 after attack. Tt may be noted that a larger i)erccntage of scabbed 

 fruit fall than of normal ones. Infected fruit remaining tend to 

 regain their nonnal slia])e by subsequent growth, and as there is 

 no increase in size of the initial infections, the great increase of 

 the surface areas of the fruit gives all appearance of a partial re- 

 covery or "cleaning up" from the disease. This, of course, is not 

 what takes place, but merely means that there has been no further 

 spread of the scab areas. 



Leaves are frequently distorted, the same corky areas ai)pear- 



