

MARKET DISEASES OF FRUITS AND VEGETABLES 21 



59° there is some checking that amounts to about 5 or 6 days extension 

 of the time during which the fruit can be marketed at a profit. At 50° 

 the first really satisfactory checking is obtained with a further exten- 

 sion of the safety period by 5 or 6 days. At temperatures between 40° 

 and 45° the growth of both molds is so slow as to be practically negli- 

 gible during the ordinary commercial handling period for citrus fruit. 

 Blue mold can develop very slowly at low temperatures that more 

 completely inhibit green mold. 



COXTEOL MEASURES 



The control of blue mold and green mold rots depends first of all 

 on careful handling throughout the harvesting, packing, and market- 

 ing processes, in order to keep the fruit as free as possible from skin 

 breaks and bruises. For the control of green mold it is highly desir- 

 able to treat the fruit with a borax solution as described under Grape- 

 fruit, Stem-end Rot (p. 7) . The blue contact mold not only is not con- 

 trolled by the borax treatment but often is actually increased by it. 

 The reason for this is thought to be that when green mold is practi- 

 cally eliminated by the use of borax, blue mold has a free field and 

 progresses more rapidly than if the green mold were present (43) . 



Holding the fruit at temperatures between 40° and 45° F. gives 

 good control of green mold and blue mold rots. The storage tempera- 

 ture of 32° to 34° recommended for oranges and sometimes desirable 

 for grapefruit will usually hold the rots in check during the period 

 for which these fruits can safely be stored. Grapefruit stored at 45° 

 to 55° may suffer some damage from these rots, but it is in less danger 

 of being damaged by pitting than if stored at 36° to 40°. Blue mold 

 rot is markedly checked by maintaining the coloring-room tempera- 

 tures between 80° and 85°. (See p. 24.) 



Fruit that is to be shipped to market should be precooled promptly 

 after being packed or placed in the refrigerator car. Refrigeration in 

 transit is necessary except during the winter months in order to prevent 

 the development of decay. 



(See 9, 42, 43, U, £*, U, 92, 96, 117, 139, 141, 143.) 



BROWN STAIN ( SCALD ) 



The terms "brown stain" and "scald" have been used to refer to what 

 is apparently the same disease, namely, a superficial and fairly uniform 

 browning over relatively large areas of the rind (pi. 12, E). The 

 disease stands out in marked contrast to all forms of pitting because 

 of the extent of the areas affected and the fact that they are never as 

 much or as sharply depressed as in pitting. In mild and typical cases 

 the rind is firm, but in severe cases it may become spongy and soft. 

 The color of the affected rind is seldom as dark as that found in severe 

 pitting. Brown stain is practically always worse on overmature, 

 highly colored fruits. 



Brown stain is a disease that affects oranges while under refrigera- 

 tion. It is much more common on fruit held at 32° F. than on that 

 held at higher temperatures, but it has been found to a greater or less 

 degree on fruit held at temperatures as high as 40°, particularly if 

 subjected to air-blast refrigeration. 



(See 23.) 



