market diseases of fruits and vegetables 47 



Papayas 



anthracnose 



{ColletotricHum gloeosporioides Penz.) 



Anthracnose is the most important and widespread decay of 

 papayas on the market. It also affects the leafstalks, blossoms, and 



very young fruit, causing them to drop. Lesions on the mature 

 papaya usually appear first in or near the fleshy stem. They occur 

 as >aucerlike depressions in which for a short period the skin remains 

 normal or is but slightly deeper in color. The spots develop rapidly 

 and may coalesce to cover the entire fruit before it is fully soft. As 

 they enlarge, the lesions become gray to black in the centers and are 

 often covered with a scaly wax composed of dried latex. The de- 

 cayed tissue is shallow, fairly firm, and may be readily lifted from 

 the surrounding healthy fle>h. Under moist conditions pink spore 

 masses are produced from fruiting bodies in the older part of the 

 lesion. 



OoUetotrichum gloeosporioides. the fungus that causes the disease, 

 also causes anthracnose of citrus fruit (p. 3), avocado (p. 35). and 

 mango (p. 45). Papaya fruits may be infected at any stage in their 

 development and are particularly susceptible as they approach ma- 

 turity. However, most of the infections do not become visible until 

 the fruit begins to soften. 



Bordeaux mixture and other fungicides when applied frequently to 

 the fruits and sterns have been found helpful in controlling the 

 disease. Attempts to control the decay by dipping the fruit in 

 fungicidal solutions after harvesting have not been successful. 



(See 8, 103, 11^ 12^) 



Pineapples 

 black rot 



(CeratostomeUa paradoxa <De Seyn.) Dade 12 ) 



OBBENCE, SYMPTOMS. AND EFFECTS 



Black rot. sometimes called soft rot. water blister, or water rot. is 

 found in all commercial pineapple-growing regions of the world. It 

 attacks all parts of the plant in the field, but it is of chief importance 

 on ripening fruits during transit and marketing periods. Losses 

 of from 3 to 5 percent in stock from Cuba and Puerto Rico because 

 of the decay are ordinarily experienced by dealer.- on the Xew York 

 market, and under conditions favorable to the disease, losses in transit 

 may mount to over 25 percent. All commercial varieties are suscepti- 

 ble to the decay. The Red Spanish variety, which constitutes the 

 bulk of the fruit shipped from Cuba and Puerto Rico, is considered 

 one of the most resistant. 



On the leaves of the plant in the field the disease appears as small 

 water-soaked spots, which soon dry and become light gray. Plant- 

 ing material may be affected with decay, which begins at the cut made 

 in removing it from the parent plant and develops rapidly through 

 the root-prochicing area, causing this to disintegrate. Decay of the 



ii:. Endoconidiophora paradoxa <De Seyn. i Dnvidson. 



