582 EXPERIMENT STATION KECOKD. 



for 2 vt'arH in different ai)|)l('-.<,M(i\vin<,' sections of the country to detcrniinc the l)est 

 methods for harvesting and Vceepinj; aj)i)les in cold storaire. Al)Out 180 varieties of 

 a])i)K's taken from localitit-s in Kansas, IMissouri, Illinois, Micliitran, West Virfrinia, 

 North Carolina, Delaware, Maine, Massachusetts, and New York have been nseil in 

 the investigation. 



Preceding the detailed results of the experiments a discussion is given of the infiu- 

 ence of cold storage on the apple industry, the function f)f cold storage, principles of 

 mechanical refrigeration, and statistics of the extent of the cold-storage warehouse 

 industry in this country. The specific i)rol)lems investigated were the effect of the 

 degree of maturity at harvesting time on the keeping quality of the fruit, the effects of 

 delaved storage, and of storing at different temi)eratnres. In addition, the inHuence 

 of different kinds of packages, wrapping of fruit, soil and cultural conditions, fruit 

 from young rapidly growing trees and from old trees, etc., on the keejMng qualities 

 of the fruit in cold storage were investigated; as well as the effects of all the above 

 factors on the development of apple scald during and after the removal from cold 

 storage. The keeping qualities of about 180 varieties of apples used in the test are 

 given in comparative notes. 



As regards the best time to pick apples for storage, the results indicate that they 

 should have reached full growth and high color before harvesting, but still be firm 

 and hard when picked. Such fruit equals in keeping quality, and often surpasses, 

 partially colored or less mature fruit. It is superior to such fruit in flavor and tex- 

 ture, more attractive in appearance, more saleable, retains its flavor longer, and is 

 less subject to apple scald. Overripe fruit deteriorates rapidly unless placed in cold 

 storage soon after picking. 



In experiments with some unusually large Tompkins King and Sutton apples 

 picked from rapidly-growing young trees, the fruit that was but three-fourths colored 

 kept much better than fully colored fruit. When examined in February fully 

 colored Tompkins King showed 28 per cent of physiological decay, while lighter- 

 colored fruit from the same tree, picked and handled in the same manner, showed 

 but 10 per cent of decay. In another instance small, mature fruit from older slower- 

 growing trees kept well until the middle of Aj^ril; while the commercial limit of 

 fruit from young rapid-growing trees in cold storage was sometimes 3 months shorter. 

 Late varieties of fruits may be picked when they are l^eginning to mellow, provided 

 they are handled with great care and stored immediately in a temi:)erature of 31 to 

 32° F. As a further protection, however, such fruit should be wrapped and stored 

 in boxes. 



As a means of securing better-colored fruit, pruning to let sunlight into the tree is 

 suggested. Cultivation and cover crops which tend to vigorous growth and lighter- 

 colored fruits may be withheld in part or the orchard seeded down until the desired 

 condition is obtained. More uniform grades can be secured by picking ti-ees over 

 several times. This is especially desirable in the case of a specialist working up a 

 fancy trade in apples. 



Relative to the effects on keeping quality of delay in placing fruit after picking in 

 cold storage, the authors found that W'hen the weather at picking time was cool there 

 was no apparent injury from delaying the storage of a large number of varieties of 

 apples 2 weeks after they were picked. With warmer weather, however, a delay of 

 2 weeks seriously injured the keeping quality of the fruit. Rhode Island Greening, 

 Tom]jkins King, and Sutton apples picked when the temperature averaged about 

 62° F., and stored within 3 days, kept firm until the following March without rot or 

 scald; while fruit from the same trees not stored until 2 weeks after picking was 

 badly scalded or decayed by January 1. "None of the immediate-stored fruit was 

 scalded or decayed by the first of February, but the delayed Sutton and Rhode 

 Island Greening apples were soft and mealy, and one-third were scalded at that time, 

 while nearly 40 per cent of the delayed Tompkins King were soft and worthless. 



