HANDLING APPLES FROM TREE TO TABLE 9 



and Rome Beauty, red bud sports of these varieties have been eagerly 

 sought and largely substituted wherever possible. Many large plant- 

 ings of the original varieties will doubtless remain in heavy production, 

 however, and will continue to pose problems of color, dropping, and 

 overmaturity. Use of hormone sprays, which prevent dropping of the 

 fruit, meets the problem of slow coloring only in part, because of the 

 danger that apples thus held on the tree to color may become too far 

 advanced in maturity or may be fully ripe at time of picking. An early 

 picking of the fruit of advanced maturity so that it does not become 

 overmature would then be desirable. Careful sorting during packing 

 may also be desirable in order to remove fruit of advanced maturity, thus 

 maintaining the storage quality of the pack. Overmature apples are 

 particularly susceptible to water core, soft scald, internal breakdown, 

 and Jonathan spot and are more subject to stem punctures, bruising, 

 and other mechanical injuries through which blue mold infection takes 

 place. Blue mold entering through lenticels is also more likely to infect 

 overmature apples than those picked at proper maturity. 



Storage Temperature 



The life processes of apples that have to be considered in the successful 

 storage of the fruit after harvest are essentially chemical, and, as with 

 other chemical processes, the rate at which they proceed depends largely 

 upon the temperature at which they can be carried out, that is, upon the 

 temperature of the apples. Apples freeze at about 28.5° F. (27); hence, 

 it is necessary to keep them above this temperature. In practice, stor- 

 age temperatures of 30° to 32° have been found most satisfactory {22). 



Magness' and others (16) found that the rate of respiration largely 

 governs the rate of ripening and softening of apples in storage. They 

 found that at 40° F. this rate is approximately twice as rapid as at 32°; 

 at 50° it is almost double that at 40°; and at 70° it is about twice as fast 

 as at 50°. At 30°, on the other hand, 25 percent more time is required 

 for apples to ripen than at 32°. These results emphasize the importance 

 of quickly cooling apples to the minimum safe temperature for storage; 

 the apples will ripen as much in 1 day at 70° as they will in 10 days at 30°. 

 Holding apples at 70° for only 3 days after harvest thus will cut off about 

 a month of their potential storage life at 30°. If 30° storage is not im- 

 mediately available, every opportunity should be taken to cool the fruit, 

 such as stacking it in the shade and providing good ventilation, especially 

 at night (fig. 2). The same principle applies after storage. It is therefore 

 inadvisable to remove from cold storage at one time more apples than 

 can be used or marketed before they deteriorate seriously. It must also 

 be remembered that after storage the span of life remaining for the 

 fruit is much shortened, and, as the end point is uncertain, the gamble 

 in holding at warm temperatures is much greater. 



Cooling the fruit means the transfer of heat from the fruit to the sur- 

 rounding air. The effectiveness of the cooling depends on the difference 

 between the temperature of the air and that of the fruit and the rate at 

 which the air moves over the fruit. In common storage, cooling is 

 accomplished by transferring heat from the fruit to the outside air. 

 A good ventilating system intelligently operated is necessary to make 

 this method efficient; the vents should be opened when the outside air 

 temperature is lower than that of the fruit and closed when conditions 



