MARKET DISEASES OF FRUITS AND VEGETABLES 29 



the color of the uninjured rind, but later they turn brown to almost 

 black (pL14,*7uid-J9). 



Fumigation injury is not often seen on the market, and when it does 

 appear it is likely to be in the form of small, inconspicuous spots or 

 pits that might be mistaken for small scars or for pits resulting from 

 other causes. 



(See £?, 1U-) 



GRANULATION 



The dryness resulting from freezing on the tree has been discussed 

 in the section on freezing injury (p. 27). Dryness may occur, how- 

 ever, when there has been no possibility of freezing, and it is then 

 to be regarded either as a varietal peculiarity or the result of condi- 

 tions under which the fruit was grown. This kind of dryness is 

 known as granulation. It is found in all citrus-producing regions. 

 Valencia oranges harvested late in the season or from young trees even 

 in early or midseason are very likely to show it, particularly in the 

 large sizes. In Florida, drought favors the development of granula- 

 tion; in California, granulation sets in earlier in the season if there 

 has been a lack of irrigation. Thomson Navel oranges and the larger 

 sized Washington Xavels grown in Florida are likely to show granula- 

 tion no matter when they are harvested. In both these orange varie- 

 ties the granulated condition appears sometimes throughout all of 

 the pulp of affected fruits but more often only in the upper or stem- 

 end portions. Even in fruits affected only at the stem end the granula- 

 tion as seen in cross section affects all of the pulp and not merely small 

 spots in two or three segments, as so often happens in freezing injury. 



In tree-frozen fruit the juice sacs collapse, wither, and separate 

 from each other and from the segment walls. The fruit is soft and 

 light in weight. In granulated fruit the juice sacs do not separate 

 from each other or from the segment walls; they remain turgid, the 

 juice being displaced by solid matter that is yellow to grayish white 

 in Florida fruit and grayish white in California fruit. Such fruit 

 feels firm but is light in weight. 



(See 18, 19, 20, Jfi.) 



GRAY MOLD ROT 



(See Lemons, Gray Mold Rot, p. 13, and pi. 10, A.) 



HEAT INJURY 



Citrus fruits are sometimes injured by heated washing solutions 

 or by heated dye solutions used in the "color-added" process, especially 

 when the fruit is immersed in the dye (pi. 12, C). The first symptom 

 is the collapse of the oil vesicles accompanied by a strong orange odor 

 if the fruit is stored in a closed room, probably due to distillation of 

 oil. Eventually the injury shows as a brown area around the stem 

 or as isolated brown patches or streaks elsewhere on the fruit. In 

 both types the affected area is slightly sunken and the outer surface 

 of the rind frequently has a collapsed or dried-out appearance and 

 finally becomes hard and leathery. In early stages the fruit is softer 

 at places where the injury occurs than at places where the rind seems 

 normal. 



