Tropical Fruits 145 



some weedy Rubiaceous host, is widely present through the 

 Old World. It was introduced into Porto Rico some years 

 ago, but prompt recognition and effective action by the 

 Porto Rican Experiment Station exterminated it in the 

 Western Hemisphere. 



Viruela {Stilhella flnvida (Cke.) Kohl). — This is the most 

 serious coffee disease of the Western Hemisphere, causing 

 circular, decayed, tan-colored leaf-spots, leading to rapid 

 defoliation. 



Leaf-spot (Cercosporn cojfeicola B. & C). — Numerous, 

 circular, brown spots occur, causing leaf-fall. The fungus 

 grows also on the berries. Other leaf-spot fungi are Col- 

 letotrichum, Gloeosporium, Anthostomella, Henderson ia and 

 Rhabdospora. 



Leaf -rot " (Corficium koleroga (Cke.) v. Hohn.). — The 

 causal fungus grows on the stems, leaves, and fruit, spread- 

 ing as a smooth, tissue-like, whitish film. Rot of the affected 

 parts follows. 



Stem-disease (Necator decretus Mass.). — Minute orange 

 spots are produced. 



Root-rot due to various fungi is destructive. 



FIG 1*'*' 



Fruit-rot (Colletotrichum carica S. & H.). — This disease, 

 first described in 1909, produces sunken, rotten, more or less 

 circular fruit spots, nearly always covered with a white 

 mass of fungous mycelium. As the spots grow older they 

 bear numerous pustules of the salmon-pink color characteris- 

 tic of the spores. 



The amount of damage caused is very great by reason 

 of premature falling of the fruit, at times destroying the 

 whole of the crop. 



Infected fruit should be gathered and destroyed and 

 the bushes should be given a dormant spray and two or more 

 applications of Bordeaux mixture when in foHage. 



Rust (Phjsopella fid (Cast.) Arth.). — This rust does 



