18 CIRCULAR 2 7 8, U. S. DEPARTMENT OF AGRICULTURE 



is prevalent, this disease is likely to be the determining factor ; it will 

 generally be advisable to use a comparatively low temperature range 

 (32° to 34° ) . On the other hand if the fruit is grown in regions where 

 stem end rot is not prevalent, the limiting factors are likely to be 

 storage pitting and watery break-down, which develop most seriously 

 at temperatures of 40° or lower. For fruit from these regions a 

 temperature of 45° to 55° is satisfactory, and the more rapid develop- 

 ment of undesirable high color and the increase in blue mold and green 

 mold rots at the higher temperatures have not been found as objec- 

 tionable on such fruits as the pitting that results from storage at lower 

 temperatures. 



Sound fruit that is not overmature or likely to suffer from stem 

 end rot can usually be held for 6 weeks without serious spoilage at 

 the higher temperature ranges mentioned above, and this storage 

 period can sometimes be doubled with satisfactory results. Weak or 

 overmature fruit requires close watching from the time it is removed 

 from the tree, regardless of storage conditions. 



The percentage of stem end rot in Florida and Texas grapefruit 

 will be greatly reduced if the fruit is properly treated with borax or 

 sodium metaborate, pulled from the tree instead of being clipped 

 (98), and precooled before being shipped. The disbuttoning that 

 may occur during handling and packing is also effective in reduc- 

 ing loss from stem end rot. As compared with stem end rot, blue 

 mold and green mold rots are relatively less important on Florida 

 grapefruit in storage. Stem end rot is not known to occur on 

 California and Arizona fruit. 



(See 11, 21, 77, 78, 79, 97, 98, 99.) 



Grapes 

 vinifera 



. (Temperature, 30° to 31° F. ; relative humidity, 85 to 90 percent) 



Large quantities of the European or vinifera grapes, grown princi- 

 pally in California, are stored every year. The most important of the 

 varieties stored are Emperor and Ohanez (Almeria). Olivette de 

 Vendemian, Malaga, Sultanina (Thompson Seedless), Cornichon. and 

 Alphonse Lavallee (Ribier) are also occasionally stored. All of these 

 have low freezing points, lower in fact than that of any other im- 

 portant fruit, largely because of their high sugar content. Although 

 for most varieties there is no danger of freezing injury at tempera- 

 tures as low as 28° F. (H), they are usually held at temperatures of 

 30° to 31°. At low air velocities a humidity of 85 percent prevents 

 excessive wilting of stems and berries without favoring the formation 

 of mold growth. At air velocities of 100 to 150 feet per minute a 

 humidity of 90 percent is desirable ( 57) . 



California grapes for cold storage are packed in kegs or drums in 

 sawdust or in various types of lidded lugs with or without sawdust. 

 Good results are usually obtained, although if the fruit or the sawdust 

 is damp at packing time or becomes so in storage there is danger of 

 damage by mold. Mold may develop also if the grapes have been 

 handled carelessly and if there are numerous cracked or loosened ber- 

 ries scattered through the pack. Varieties differ in keeping quality. 



