MISC. PUBLICATION 49 8, U. S. DEPT. OF AGRICULTURE 



Citrus fruits— Continued. p 



Oranges — Continued. -rage 



Blue mold and green mold rots 19 



Brown stain (scald) 21 



California red scale 22 



Chewing-insect injury 22 



C itrus rust mite russeting 22 



Coloring-room injury 23 



Creasing 24 



Exanthema (ammoniation) 24 



Florida red scale 26 



Freezing injury 27 



Fumigation injury 28 



Granulation 29 



Gray mold rot 29 



Heat injury 29 



Melanose 30 



il spotting (oleocellosis) 30 



Orange tortrix injury... 30 



Pitting 30 



Puffiness 30 



Purple scale 30 



Scab 30 



Sclerotium rot 31 



Septoria spot and stain 31 



Spotting and scarring 31 



Spray injury 32 



Stem-end rot 32 



Stylar-end rot 32 



Thorn injury 33 



Thrips injury 33 



Trichoderma rot 34 



Water spot 34 



Watery break-down 35 



Other subtropical fruits 35 



Avocados 35 



Anthracnose (black spot) 35 



Other subtropical fruits— Continued. ^ 



Avocados— Continued. .rage 



Blotch (cercospora spot) 36 



Dothiorella rot 36 



Flesh darkening 37 



Rhizopusrot 37 



Scab 38 



Bananas . 39 



Anthracnose 39 



Chilling injury 40 



Fruit spot 41 



Figs 42 



Alternaria spot 42 



Black mold rot 42 



Blue mold rot 43 



Cladosporium spot 43 



Gray mold rot 44 



Rhizopus rot 44 



Soft rot (endosepsis) 44 



Splitting 45 



Sunburn 45 



Mangoes 45 



Anthracnose 45 



Olives 46 



Low- temperature injury.. 46 



Sulfur dioxide injury 46 



Papayas 47 



Anthracnose 47 



Pineapples 47 



Black rot 47 



Brown rot 49 



Internal break-down 50 



Pomegranates 50 



Gray mold rot 50 



Heart rot... 50 



Sunburn. 61 



Literature cited 51 



INTRODUCTION 



Market diseases of fruits and vegetables are those that develop dur- 

 ing the process of marketing. This process should be understood to 

 include the harvesting, grading, and packing of the crop, its trans- 

 portation to market, its storage at shipping point or at the market, 

 and the various handling operations required to move it from the 

 wholesale dealer to the retail store and the ultimate consumer. Dur- 

 ing any of these operations the product may be subjected to conditions 

 that impair its appearance and food value and render it liable to 

 attack by decay-producing organisms. 



The fruits discussed in this publication, like all other fruits and vege- 

 tables, are susceptible to invasion by bacteria and fungi at bruises and 

 skin breaks. Hence, it is of prime importance that they be handled as 

 carefully as possible at all times. Clipper cuts, fingernail scratches, 

 injuries caused by packing-house machinery, packing bruises, damage 

 caused by rough handling in transit and on the market are all sources 

 of danger, especially if the places where the fruit is packed, or stored, 

 or offered for sale are not kept free of rotting fruit and other infectious 

 material. These, as well as insect injuries, must all be considered b} r 

 anyone attempting to judge the storage or shipping quality of the 

 fruit or its ability to hold up well until it is consumed. 



Temperature and humidity have a direct effect on the development 

 of decay in fruits. They should have the critical attention of those 

 who wish to ship or store fruits and of those who attempt to determine 

 why a given lot, at any stage in the marketing process, shows decay or 

 other deterioration. Too low temperature may freeze the fruit, or it 

 may cause only chilling injury; subtropical fruits are particularly sus- 

 ceptible to such injury. Too* high temperature favors decay and may 



