MARKET DISEASES OF FRUITS AND VEGETABLES 17 



excrescences. Other varieties of limes are reported to be immune to 

 the disease. The common anthracnose of citrus, including limes, is 

 caused by a less actively pathogenic organism, which does not produce 

 the corky fruit spots characteristic of lime anthracnose. 



Lime anthracnose occurs as a blossom blight, a leaf spot, and a die- 

 back of tender twigs as well as corky spots on the young fruit. Leaves 

 and twigs as they near maturity and fruits after they are three-fourths 

 inch in diameter become immune to attack. If the fruit is severely 

 infected when very young it may fall from the tree. At first the spots 

 on the fruit are a water-soaked" brown and slightly sunken, but later 

 they become flesh color with the formation of raised corky scabs. 

 Frequently the fruit becomes distorted and cracks through the spot, 

 exposing the juice sacs below. The affected areas do not enlarge 

 after the fruit is picked, but secondary organisms may enter through 

 the cracks and cause decay. Occasionally the scabby excrescences may 

 fall away from spots leaving a rough slightly sunken scar. The dis- 

 ease on the fruit may have somewhat the appearance of citrus scab, 

 but there need be no confusion because the latter has not been found 

 on the Key variety of limes. 



CAUSAL FACTOES 



The disease is caused by the fungus Gloeosporium limetticolum, 

 which is peculiar to the Key lime, not having been found on other 

 species of Citrus. It lives from year to year on affected twigs and 

 leaves. 



CONTROL MEASURES 



Although the disease may be controlled with lime sulfur or bordeaux 

 mixture, spraying is rarely done on the Florida Keys because of the 

 difficulty of getting spray machines into the groves and because so 

 many applications are necessary if all of the flushes of new leaves, 

 twigs, and fruits are protected. The sparing use of nitrogenous fer- 

 tilizers or their application at a time that will not produce flushes of 

 tender growth during the wet seasons when infection is most severe is 

 an important control measure. 



(See 38, 43, 53, 88.) 



BLUE MOLD AND GREEN MOLD ROTS 



(See Oranges. Blue Mold and Green Mold Rots, p. 19, and pi. 6, 

 B and C.) 



FREEZING INJURY 



[ See Oranges, Freezing Injury, p. 27, and pi. 16, A-C.) 



OIL SPOTTING (OLEOCELLOSIS) 



(See Lemons, Oil Spotting (Oleocellosis), p. 14. and pi. 11, A 

 and B.) 



RIND BREAK-DOWN 



Both Key (Mexican) and Tahiti (Persian) limes are subject to a 

 conspicuous spotting or collapse of the rind during transit and stor- 

 age. Affected areas occur on any part of the fruit but are more com- 

 mon on the sides than at the stem and stylar ends. Because large areas 



466977°— 42 2 



