6 BULLETIN 1104, U. S. DEPARTMENT OF AGRICULTURE, 
EXPERIMENTAL WORK. 
Previous to the time the present writers took up the work on 
internal browning considerable attention had been given to obtain- 
ing individual tree records from a number of orchards in the 
Pajaro Valley. This work has been continued and modified in some 
respects. Most of the work has been confined to orchards on the floor 
of the valley, but sufficient data have been obtained from trees grow- 
ing at higher elevations, in the so-called mountain orchards, to} 
establish a definite contrast in the susceptibility to internal brown-|_ 
ing of the two types of fruit. In addition fruit from a number of 
individual Yellow Newtown trees in the Yakima and Wenatchee 
Valleys of Washington and in Albemarle County in Virginia have 
been shipped to Watsonville and held in storage for comparison 
with the locally grown fruit. In this experimental work some at- 
tention has been given to the Red Pearmain variety, but for the most 
part the investigations have been confined to the Yellow Newtown, 
because of its greater commercial importance. ‘Trees under obser-. 
vation have been marked by numbered indestructible metal tags. 
At picking time the desired quantity of fruit from each tree has 
been packed in commercial apple boxes and the boxes marked with 
the tree and orchard number. After picking, the fruit practically 
always has been placed in cold storage within 24 to 36 hours. 
The fruit from the various orchards was picked each year at the | 
time when the commercial harvesting was in progress in the par- 
ticular orchards, and an attempt was made to gather apples from 
all parts of the tree, so that each box represented as nearly as pos- 
sible a uniform sample of the crop on the tree. Usually, when only 
a record of internal browning was wanted, a single box was all that 
was taken from a tree. If it was desired to compare the effect of | 
various storage temperatures on fruit from a certain tree or if 
larger quantities were wanted for experimental work, the required 
quantity was picked and carefully mixed before packing, in order 
to insure as far as possible a uniformity of fruit throughout the | 
entire number of boxes. 
During the progress of the investigations with which the present 
writers have been concerned, more or less continuous records have 
been obtained from a total of about 150 trees. During that time 
about 800 boxes of fruit have been carefully examined, and for the 
most part a record of the internal browning in each individual apple 
has been made. 
The fruit has usually been left in storage until May or June, to 
allow the maximum development of internal browning. At the time 
of inspection the apples were examined as soon after removal from 
storage as possible, and in no case was the fruit taken from storage 
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