f BULLETIN 587, U. S. DEPARTMENT OF AGRICULTURE. 
been possible to obtain an exact history of each box stored and also 
a record of the soil in which it was grown, the condition of the trees, 
and the cultural methods pursued. 
Although the investigations have been comprehensive in scope, so 
many factors affect the behavior of fruit in storage that the data 
obtained are still too limited to justify a complete report or definite 
recommendations with reference to all the factors involved. Cer- 
tain important practices, however, have been shown to have such a 
consistent and important bearing on the successful storage of north- 
western apples that it is believed advisable to present to the industry 
at this time the data obtained. No attempt is made to discuss all 
phases of the problem. The discussion is limited largely to those 
factors of first importance to the industry on which it has been pos- 
sible to secure reliable and consistent data over a period of four 
years. 
The data given cover in most cases the seasons 1911-12, 1912-13, 
1913-14, and 1914-15. 
OUTLINE OF EXPERIMENTS. 
(1) A determination of the influence of maturity at time of pick- 
ing on the keeping quality of the more important varieties grown in 
the Northwest. 
Two pickings from the same trees were made 20 days apart. Fre- 
quently an additional pick was made between these two. The first, 
or immature, pick was made at the beginning of the commercial 
picking season for the variety. The last, or mature, pick was made 
20 days after the first, usually a few days later than the last com- 
mercial picks. These lots, comparable in every other respect, were 
stored immediately at a temperature of between 31° and 32° F. All 
fruit was stored in Portland, Oreg. Careful inspections were made 
four times during the winter, beginning in all but the early varieties 
about the first of January and continuing at intervals approxi- 
mately six weeks apart. One-fourth of each lot was taken out of 
storage at each withdrawal, inspected, and held in an ordinary ware- 
house room for 10 days. It was then inspected again and discarded. 
The temperature of the fruit during these 10-day periods varied with 
the season and climatic conditions, but was usually between 50° and 
60° F. 
(2) A study of the effect of delaying the storage of certain 
important commercial varieties on their behavior in storage. 
For this purpose several boxes of a variety were picked and packed 
at the same time. Half of each series was placed in cold storage as 
soon as possible, usually not more than two days from the time of 
picking; the other half was held two weeks in a grower’s or shipper’s 
warehouse before being placed in cold storage. The first lot was 
