80 



JOUENAL OF AGRICULTURE OF P. R. 



is ordinarily a saprophyte or weak wound parasite, except in certain 

 instances as will be noted hereafter. 



Leaf spots. 



On the leaves the spots produced are medium to deep brown, 

 finally gray, in color with definite margins, circular to irregular 

 in shape, and up to an inch and often more in diameter, even at 

 times involving the entire leaf. The spots commonly have a charac- 

 teristic zoned appearance, due to the production of tlie numerous, 

 minute, fruiting pustules in concentric lines. The appearance of 

 the spots is practically the same on both surfaces of the leaf. Repro- 



FiG. 9. — Anthraenose spots on leaves of lemon seedlings. 



duction is brought al)()nt by means of the minute spores produced 

 in great numbers ni the sporodocliia or fruiting pustules. 



In a great majority of cases anthrac nose leaf spots will be found 

 in connection with scale infestations, they being particularly al)iin- 

 dant on old leaves infested by purple scale. They are also commonly 

 found on leaves partly consumed bj^^ biting insects, infection having 

 occurred along the injured margins. Occasionally in contrast to 

 this type of occurrence, cases will ])e found where no other initial 

 injury is present. In one instance a large grapefruit tree was noted, 

 apparently normal, except that a large percentage of the leaves was 

 badly affected with anthraenose spots. 



