MARKET DISEASES OF FRUITS AXD VEGETABLES 39 



CONTROL MEASURES 



For the control of avocado scab, spraying with bordeaux mixture is 

 recommended. 



(See 70, 113, lid, 116, lJfi.) 



Bananas 



ANTHRACNOSE 



(GJocosporium musarum Cke. and Mass.) 



OCCURRENCE, SYMPTOMS, AND EFFECTS 



Anthracnose occurs in all parts of the world where bananas are 

 grown. It is occasionally destructive to banana plants in the field but 

 is usually confined to the fruits and does very little damage even to 

 them except when they are ripe. Although the disease may develop on 

 bananas in transit from the Tropics and in ripening rooms at ter- 

 minal markets, it is not usually important as a cause of decay and 

 waste until after the fruit has passed into the hands of the retailer 

 and the consumer. Many so-called overripe bananas in grocery and 

 fruit stores are merely- in an advanced stage of anthracnose, at least 

 so far as the skin is concerned. 



Anthracnose may develop first on the short stems by which the 

 individual bananas are attached to the main stalk, and it spreads from 

 them to the adjacent peel at the attached end of the fruit. At such 

 places it shows as a brown discoloration, which slowly darkens to 

 black as the affected areas enlarge. The disease may also appear on 

 any part of the peel, first as very small brown spots and later, "when 

 these enlarge and darken, as black spots an inch or more in diameter. 

 If the fruit is held for a considerable time after ripening, the spots 

 may coalesce so completely that all of the peel becomes diseased and 

 blackened. Eventually there is noticeable decay of the edible portion 

 of the fruit. Tip rot caused by Gloeosporium develops in ripening 

 rooms when the fruit begins to turn yellow, its occurrence there being 

 the result of a spreading of the fungus from diseased flower remnants 

 to the adjacent peel. 



Under conditions where the air is moist and the temperature fairly 

 high, decayed spots on bananas take on a whitish, hoary appearance, 

 with the black color showing through. This condition is produced by 

 a superficial growth of the anthracnose fungus and is one of the most 

 characteristic symptoms that the disease exhibits. 



At about the time when blackening occurs, sometimes earlier, the 

 affected areas begin to show a pink color, due to the production of 

 pink masses of spores. On large spots it frequently happens that 

 only the younger spore masses around the outside are pink while the 

 older ones toward the center are gray or even black. 



The only condition with which anthracnose is likely to be confused 

 is the blackening caused by bruises. The two can usually be dis- 

 tinguished, however, by noting the presence or absence of the symp- 

 toms described above, i. e., pink spore masses, a superficial growth of 

 white mold, and decay extending into the edible portion of the fruit. 



CAUSAL FACTORS 



Banana anthracnose is caused by the fungus Gloeosporium mvsarum, 

 which is represented by a number of different strains in different 



