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L161— O-1096
Precooliag Rail
SKipmertts of
NOIS
w
special reference
to the use
of ventilated packages
by
J.W.Lloyd
Bulletin 455
University of Illinois
Agricultural Experiment Station
CONTENTS
PAGE
PLAN OF THE TESTS 512
EQUIPMENT USED AND METHOD OF MAKING
TESTS 512
RESULTS OF 1935 TESTS: LIMITED TO PRECOOLING
PERIOD 517
Ventilated vs. Standard Packages, Both With Standard
Liners 517
Ventilated Packages Without Liners vs. Standard Packages
With Liners 519
Fruit Loaded on a Cool Day 523
Fruit Loaded on a Hot Day 523
RESULTS OF 1937 TESTS: CARS FOLLOWED TO TER-
MINAL MARKETS 526
Ventilated vs. Standard Packages Under Standard
Refrigeration 526
Ventilated Leigh Tubs vs. Standard Tub Bushels 529
Ventilated Packages and Liners vs. Standard Packages
and Liners 532
Standard vs. Ventilated Round-Bottom Baskets With
Ventilated Liners 536
GENERAL DISCUSSION OF RESULTS 540
COMMERCIAL PRACTICES IN 1938 541
SUMMARY 542
CONCLUSIONS 544
LITERATURE CITED.. .544
Urbana, Illinois May, 1939
Publications in the Bulletin series report the results of investigations made by or
sponsored by the Experiment Station
PRECOOLING RAIL SHIPMENTS
OF ILLINOIS PEACHES
With Special Reference to Use of Ventilated Packages
J. W. LLOYD, Chief in Fruit and Vegetable Marketing
TESTS concerned with the refrigeration of eight carloads of
Illinois peaches — four in 1935 and four in 1937 — are reported
in this bulletin. The rapid cooling of peaches in ventilated
packages had been demonstrated by experiments in 1933 and 1934
under controlled laboratory conditions, but it seemed advisable to make
further tests in refrigerator cars in order to determine how well this
type of package was adapted to carlot shipments. Furthermore it was
considered desirable to observe the combined effect of forced air circu-
lation, salt, and ventilated packages on the rapidity with which peaches
can be cooled after they are loaded into refrigerator cars.
Earlier experiments by this Station4* had shown that in a refrig-
erator car handled under standard refrigeration the temperature of
peaches packed in standard bushel baskets and having an initial
temperature of about 72° F. was reduced about 24 degrees during the
first 48 hours the car was in transit. In other tests, in which electric
fans were used to increase the air circulation in refrigerator carloads
of fruit, there was much greater uniformity of fruit temperatures
thruout the load and more rapid cooling of the entire lading while
the fans were in operation.6* The addition of salt to the ice in the
bunkers also hastened refrigeration.4*
In the laboratory tests5* referred to above, the most rapid cooling
took place in ventilated bushel baskets with wide cracks between the
staves. Peaches packed in this type of ventilated basket without any
liner cooled down to 50° F. in less than 6 hours, or in less than half the
time required for the contents of a standard lined tub bushel. Other
workers2* have shown that for safe carriage the temperature of
peaches should be reduced to 50° F. as quickly as possible. It is reason-
able to assume that with rapid cooling, peaches could be allowed to
become more mature and of better flavor before picking.
The author acknowledges the assistance of S. W. DECKER, M. P. GEHLBACH,
and V. A. EKSTROM in the procuring of data for this publication.
*These figures refer to literature citations on page 544.
511
512 BULLETIN No. 455 [May,
PLAN OF THE TESTS
Plans for conducting the tests reported herein were started during
the 1935 Illinois peach shipping season, and arrangements were made
with one of the package manufacturers to make up a special order of
ventilated packages for use in the tests, since baskets of this type were
not carried in stock at that time.
Before fans for this work had been procured, it was learned that
two different companies operating precooling equipment were seeking
business at Illinois peach shipping points. Contacts were made with
shippers considering the use of this service, and arrangements were
finally made to conduct tests with a number of carloads. In each test,
one half (one end) of the car was loaded with peaches packed in
ventilated baskets and the other half with peaches packed in standard
tub bushel baskets or standard round-bottom bushel baskets. Previous
tests had shown that refrigeration is practically the same at similar
points in opposite ends of refrigerator cars, provided lading, package
types, and loading system are similar in the two ends of the car.4*
Tests were undertaken in a number of cars in 1935, but various
contingencies arose which rendered the results in several of the cars
unreliable, such as failure of the fans to work properly, unloading part
of car to fill truck orders, exhaustion of a large part of the ice supply
in bunkers before the precooling period was completed, and unusual
delay in completing loading of car. Therefore only four cars included
in the tests made in 1935 are reported herein.
The Illinois peach crop in 1936 was too limited in volume to war-
rant undertaking any commercial precooling tests. In 1937 tests were
resumed. These included only four cars, but in each test the car was
followed thru to the terminal market. Temperature readings were
made enroute and the fruit was inspected upon arrival. Results of the
tests on the four cars in 1935 and the four cars in 1937 are included in
the present report.
The Elberta variety was used in the 1935 tests. In 1937 three cars
were loaded with Elberta and one with the Red Bird variety.
EQUIPMENT USED AND METHOD OF MAKING TESTS
Precooling Equipment. — The equipment of the two companies fur-
nishing the precooling service used in these tests was entirely different.
One type consisted of electric fans approximately 18 inches in diameter
mounted on motors to be connected with the power-and-light circuit at
the packing shed. One fan was placed at each end of the car directly
1939]
PRECOOLINC. ILLINOIS PEACHES
513
FIG. 1. — ELECTRIC FAN IN POSITION AT END OF CAR
Precooling by means of this type of equipment involves the use of salt with
the ice in the bunkers.
opposite the center of the opening between the body of the car and
the top of the ice bunker (Fig. 1). A baffle of fabricated wood covered
with canvas closed all the opening at the top of the bunker except the
portion occupied by the fan.
The fans used in different tests with this first type of precooling
equipment differed somewhat in type, some being multiple-bladed and
others single-bladed. One of the most satisfactory was a single-bladed
propeller fan with a half-horsepower motor, rated at 3450 r.p.m. This
was operated on 220 volts, alternating current. Each fan was set so as
to draw the cold air out of the top of the ice bunker and force it down
upon the load and toward the center of the car. Thus air currents
were set up which were directly opposite to those which normally occur
in a refrigerator car loaded with fruit.6* Of course the velocity of the
air currents generated by the fans was very much greater than the
ordinary rate of air movement in a refrigerator car.
When operating the above type of precooling equipment, salt was
added to the ice in the bunkers after the loading of the car with fruit
was completed and usually just before the fans were started. Some-
times more salt was added later.
514
BULLETIN No. 455
[May,
The other type of precooling equipment employed was much more
elaborate. Each precooling unit was self-contained and furnished its
own power. It was mounted on a motor truck chassis and could be
parked beside a refrigerator car on any team track and put into opera-
tion, all power required being furnished by the truck motor (Fig. 2).
When this machine was used, the ice in the bunkers had no relation to
the cooling of the fruit. The portable refrigeration plant itself fur-
*
FIG. 2. — PORTABLE PRECOOLING PLANT MOUNTED ON TRUCK CHASSIS
The truck motor furnishes the power for operating this refrigeration plant,
which can be parked beside a refrigerator car on any team track.
nished the cold air which was forced into the car above the load thru
the upper part of the doorway at one side of the car. After circu-
lating thru the load it was drawn back into the machine thru an open-
ing near the bottom of the false door that was fitted into the doorway
of the car. A heavy canvas, perforated in certain areas, covered the
center part of the load to aid in forcing the cold air toward the ends
of the car.
Types of Packages and Liners. — The ventilated packages used in
the 1935 tests were round-bottom bushel baskets each having 20 cracks
approximately %-inch wide at the top and gradually tapering until at
the bottom the basket was solid (Fig. 3). These were compared with
standard tub bushels or with standard round-bottom bushel baskets in
the different tests. Paper liners were used with both ventilated and
standard packages in all except one of the tests made in 1935. Each
liner used in 1935 had 21 round holes {Y\ inch) arranged in two rows
located at one- fourth the distance from the top and from the bottom.
In 1937 ventilated Leigh tubs (Fig. 4) were used as the ventilated
1939]
PRECOOLING ILLINOIS PEACHES
515
FIG. 3. — VENTILATED ROUND-BOTTOM BASKET (left) AND
STANDARD TUB BUSHEL (right)
The three-hoop ventilated basket shown here is a more rigid package than
the two-hoop ventilated basket, which was used in all but one of the tests in
which round-bottom baskets were employed.
FIG. 4. — VENTILATED LEIGH TUB (left) AND VENTILATED TUB
BUSHEL (right) USED IN TESTS
These two packages were quite extensively used for shipping Illinois
peaches in 1938.
FIG. 5. — Two TYPES OF LINERS USED IN 1937 TESTS
The new type of ventilated liner (left), with 80 holes, was used in all of the
1937 tests. It is a vast improvement over liners with 21 or 18 holes (right) which
were in common use commercially in 1937 and were used in the 1935 tests.
516 BULLETIN No. 455 [May,
package in two of the tests, ventilated tub bushels in the third, and
ventilated round-bottom baskets in the fourth. In 1937 a new type
of liner was used which provided more thoro ventilation than any
available in 1935. The new liner contained 80 holes, each H/^ inches
long and 1/2 inch wide (Fig. 5). Some of the standard liners in general
use in 1937 contained only 18 holes, and these were not very well
distributed (Fig. 5).
Equipment for Determining Temperatures. — Sixteen thermocouples
were used in each car in 1935. Four were placed in the air and 12 were
inserted in the fruit. Positions of the thermocouples in cars precooled
with the fan type of equipment are indicated in Fig. 6. When the
THERMOCOUPLES
T/
T* Aft A A • K A A A * A A A • A A JTl
FIG. 6. — POSITIONS OF THERMOCOUPLES IN TEST CARS PRECOOLED WITH
FAN TYPE OF EQUIPMENT IN 1935
Twelve thermocouples were inserted in the fruit, while 4 recorded air
temperatures.
T HER MOM E TERS
FIG. 7. — POSITIONS OF THERMOMETERS IN TEST CARS IN 1937
Eight thermometers indicated temperatures of the fruit in different parts of
the car, while 4 indicated air temperatures.
truck type of precooler was used thermocouples were placed to record
the temperature of the air as it entered the car and as it left, instead of
recording the temperature at the bottom of the ice bunkers.
In placing a thermocouple in a fruit, the point was inserted in such
a way that it grazed the side of the fruit pit and then passed a short
distance into the flesh. Under this arrangement the temperature read-
ings were those of the flesh in the immediate vicinity of the pit. In each
instance the thermocouple was inserted in a fruit as near the center of
1939] PRECOOLING ILLINOIS PEACHES 517
the package as was expedient ; usually the fruit selected was in the third
layer from the top, and in the third ring or center fruit of that layer.
For determining the temperatures in 1937, electrical resistance
thermometers were employed except in one of the tests. Twelve
thermometers were used in each car, 4 in the air and 8 in the fruit, at
positions indicated in Fig. 7. The same method of inserting the
thermometer points in the fruit was employed as with the thermo-
couples, and the position of the selected fruit in the package was
essentially the same. The baskets of fruit in which temperatures were
taken were always in the third row from one side of the car.
Arrangement of Packages in Car. — All cars of peaches were loaded
3 packages high, 6 wide, and 21 to 22 long, depending upon the length
of the car.
RESULTS OF 1935 TESTS: LIMITED TO
PRECOOLING PERIOD
Ventilated vs. Standard Packages, Both With Standard Liners
In Car A, loaded at Ozark, Illinois, August 10, 1935, a comparison
was made between the rate of cooling of peaches packed in standard
tub bushels and in ventilated round-bottom baskets, both equipped
with standard liners and facing pads. The fan type of precooler was
used. Two hundred pounds of salt was added to the ice just before the
fans were started. After the fans had been operating 1 14 hours, 2,000
pounds of ice and 100 pounds more of salt were placed in the bunkers,
which were not as well filled with ice as they should have been at the
time precooling started. The fans were shut off for 15 minutes during
this icing and salting. Operation was continued for 81/2 hours from the
start, except for the 15 minute shut-off, mentioned above, and another
shut-off of 30 minutes to allow a switch engine to move the car 6^i
hours after the start.
Rapidity of Cooling. — Temperature readings were taken ten times
during the test. The readings for the fruit in each type of package are
given in Table 1, together with the total drop in temperature during the
8y£-hour period, and the air temperature at lower bunker openings and
above the load.
The 15-minute shut-off of the fans and opening of the bunkers for
reicing after the precooling equipment had been operating for 1}4 hours
seriously interfered with the progress of the precooling. Every ther-
mometer in the car registered higher at the end of the second hour
than at the end of the first hour. Shutting off the fans toward the
518
BULLETIN No. 455
[May,
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1939]
PRECOOLING ILLINOIS PEACHES
519
end of the precooling period, while the car was being switched, did not
affect the temperature so much.
The cooling of the fruit was distinctly more rapid in the ventilated
packages and in the top layer of packages of both types. The more
rapid cooling of the top layer, compared with the bottom layer, was
due to the reversal of the air currents in the car while the fans were
50
FIG. 8. — PROGRESS OF COOLING OF PEACHES IN STANDARD AND IN
VENTILATED PACKAGES IN CAR A
Cooling was distinctly more rapid in the ventilated packages. Standard
liners and facing pads were used in both types of packages, and the fan type
of precooler was used.
operating. If the temperature reductions in the baskets in both layers
are averaged, the fruit in the ventilated packages shows a decline of
25.8 degrees and that in the standard packages only 18.4 degrees. The
progress of the cooling in the two types of packages is shown in Fig. 8.
Ventilated Packages Without Liners vs. Standard
Packages With Liners
In Car B, tested at Kinmundy, Illinois, August 29, 1935, a com-
parison was made between the rate of cooling of peaches packed in
standard round-bottom baskets with standard liners and those packed
in ventilated round-bottom baskets without any liners. The fan type of
precooling equipment was used. Two hundred pounds of salt was
520
BULLETIN No. 455
[May,
added to the ice in the bunkers just before the fans were started. No
additional salt was used. The fans were operated without interruption
for 6 hours.
Marked Differences in Rapidity of Cooling. — Because of the cool
weather prevailing when the peaches loaded in this car were harvested,
the temperature of the fruit at the time precooling started was much
lower than in Car A. Hence the rate of cooling was slower.5* However,
70
FIG. 9. — RAPIDITY OF COOLING OF PEACHES IN UNLINED VENTILATED BASKETS
AND IN LINED STANDARD BASKETS IN CAR B
The difference in rate of cooling in the two types of packages was un-
doubtedly accentuated by the absence of liners in the ventilated baskets. The fan
type of precooler was used.
the difference in rate of cooling in the standard baskets and the venti-
lated baskets was extremely marked, the average drop in temperature
of the fruit in the ventilated baskets being nearly three times as great
as that of the fruit in the standard baskets (15.7° F. against 5.7°).
Here again the temperature of the fruit in the top layer of packages
was reduced more rapidly than that of the fruit in the lower layer
(Table 2).
The difference in temperature drop in the two kinds of packages
was undoubtedly accentuated by the absence of any liners in the
ventilated packages, the circulating cold air thus having freer access
to the fruit in those packages.5* The temperature of the fruit in both
top and bottom layers of the ventilated packages was reduced to a safe
carrying degree within the 6-hour precooling period. The relative
rapidity of cooling of fruit in the two types of packages is indicated in
Fig. 9.
PRECOOLING ILLINOIS PEACHES
521
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1939]
PRECOOLING ILLINOIS PEACHES
Fruit Loaded on a Cool Day
523
The portable type of precooling plant mounted on a truck chassis
was used for precooling Car C, loaded at Cobden, Illinois, August 13,
1935. The day the fruit was harvested and packed the weather was
cloudy and fairly cool, so that the temperatures of the fruit at time of
loading were not very high. The precooler was operated only 21/4
hours, in accordance with the commercial practice of the company.
Temperature readings were continued for an hour after the precooler
was disconnected from the car.
Portable Precooler Was Effective. — During the hour after the pre-
cooler was detached, the temperatures of the fruit near the center of
the baskets continued to decrease rapidly on account of the transfer
50
FIG. 10. — COOLING OF PEACHES LOADED ON A COOL DAY, CAR C
The portable type of precooling plant used on this load rapidly reduced
the temperature of the fruit in both types of packages, tho the fruit in the
ventilated baskets cooled considerably faster than in the standard baskets. Both
types of baskets were equipped with standard liners.
of heat between the different rows of fruit in the package.5* During
the 3}4-hour cooling period the average drop in temperature of the
fruit in the standard tub bushel baskets was 11.9 degrees, while in the
ventilated round-bottom baskets it was 16.1 degrees (Table 3 and
Fig. 10). Standard liners were used in both types of package.
Fruit Loaded on a Hot Day
Car D, tested at Cobden, Illinois, August 16, 1935, was loaded
with fruit packed during a day when the temperature was high, the
524
BULLETIN No. 455
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1939]
PRECOOLING ILLINOIS PEACHES
525
outside thermometer registering 94° F. at 4 p. m., the time at which the
loading was completed. A temperature reading was made at this time,
but the precooling machine, which was of the same type as that used
for Car C, did not start operating until 4:45. The next reading was
made at 5 p. m., after the machine had been operating for 15 minutes.
No reading was made just before the machine started.
After the loading had been completed and the car closed, and
previous to the starting of the machine, the refrigerative effect of the
ice in the bunkers was operative for y\ hour. The precooler was
operated for 2i/4 hours. Thus a total of 3 hours elapsed from the time
the first reading was made until just before the precooler was stopped.
Temperature readings were continued for 1^4 hours after the pre-
cooling machine was detached from the car, making a total period of
hours during which temperature records were taken.
60
FIG. 11. — COOLING OF PEACHES LOADED ON A HOT DAY, CAR D
Fruit at high initial temperature was cooled very rapidly by the portable
type of precooling plant, but this was especially true of the fruit in the venti-
lated packages. Standard liners were used in both types of packages.
Marked Differences Between Packages. — Again, the fruit in the
ventilated packages cooled much more rapidly than that in the standard
packages, the difference in rate of cooling being somewhat more marked
than in Car C. This greater difference may have been due to the higher
initial temperature of the fruit in Car D. The average drop in the
temperature of the fruit in the standard tub bushel baskets during the
4^4 hours was 12.7 degrees, while that of the fruit in the ventilated
round-bottom bushel baskets was 21.1 degrees (Table 4 and Fig. 11).
Both types of packages were equipped with standard liners.
526 BULLETIN No. 455 [May,
RESULTS OF 1937 TESTS: CARS FOLLOWED TO
TERMINAL MARKETS
In the tests conducted in 1935 there was no opportunity for
determining the ultimate effect of the precooling, either by temperature
readings while the fruit was in transit or by inspection of the fruit upon
arrival at destination. Plans for the tests in 1937 therefore provided
for following each car, taking temperature readings at transfer and
reicing stations, and inspecting the condition of the fruit when the
car was opened in the terminal market to which it was shipped. Cars
were purposely selected that were to be billed to points at considerable
distance, so that the real effect of differences in temperature of fruit
at the end of the precooling period might have a chance to manifest
itself.
In the 1937 tests fruit temperatures were determined at eight points
in each car (Fig. 7).
Since practically a week's time is required to prepare a test car,
conduct the precooling operations, follow the car thru to market, await
the unloading of the car so the temperature-recording equipment could
be taken out, and drive back to the producing region, it was decided to
make one test on Red Bird peaches before the opening of the Elberta
shipping season, so as to run at least four tests while Illinois peaches
were available.
As a result of the favorable outcome of the tests of ventilated
packages in 1935 (a preliminary report of which was presented at the
meeting of the Illinois State Horticultural Society in December of that
year3*), several peach growers in the state had provided themselves
with ventilated packages for part of their shipments in 1937. Arrange-
ments were made with certain of these growers for conducting tests on
some of their cars. The orchardist with whom arrangements were
made for testing the car of Red Bird peaches and one car of Elbertas
had provided himself with a supply of ventilated Leigh tubs (Fig. 4),
which he expected to use for shipping most of his fruit. Accordingly
these Leigh tubs were used as the ventilated package for comparison
with standard tub bushel baskets. A new type of ventilated liner,
commercially available in 1937 (Fig. 5), was used in both types of
package in the test with Red Bird peaches.
Ventilated vs. Standard Packages Under Standard Refrigeration
Car E, loaded with Red Bird peaches at Cobden, Illinois, on July 5,
1937, was followed thru to Detroit, Michigan. Since no precooling
1939] PRECOOLING ILLINOIS PEACHES 527
TABLE 5. — PROGRESS OF COOLING OF RED BIRD PEACHES IN STANDARD AND IN
VENTILATED PACKAGES IN DIFFERENT LOCATIONS IN CAR E, 1937
(Car was shipped from Cobden, Illinois, to Detroit, Michigan, under standard
refrigeration without precooling. Eighty-hole liners were used in all packages)
Time elapsed (hours)
Start
2X
Chicago
22
Detroit Drop in
44 K 2^ hrs.
Drop in
22 hrs.
Standard tub
(Temperature of fruit, °F.)
Lower layer
Basket 2
. 66.0
65.4
59.9
54.0
.6
6.1
Basket 8
. . 75.4
71.6
61.8
3.8
13.6
Average
. . 70.7
68.5
60.8
2.2
9.8
Top layer
Basket 2
. 65.7
64.2
57.1
53.4
1.5
8.6
Basket 8
.. 72.9
72.6
59.9
57.1
.3
13.0
Average
. . 69.3
68.4
58.5
55.2
.9
10.8
Average, both layers
. . 70.0
68.4
59.7
54.8
1.5
10.3
Ventilated (Leigh) tub
Lower layer
Basket 2
76.0
58.3
42.0
40.1
17.7
34.0
Basket 8
. . 89.8
77.8
57.4
12.0
32.4
Average
. . 82.9
68.0
49.7
14.9
33.2
Top layer
Basket 2
. 83.4
81.6
52.1
49.7
1.8
31.3
Basket 8
. . 84.6
81.6
59.9
56.5
3.0
24.7
Average
.. 84.0
81.6
56.0
53.1
2.4
28.0
Average, both layers
. . 83.4
74.8
52.8
48.8
8.6
30.6
(Temperature of air)
At bottom of bunker, standard ....
. 52.8
43.8
35.7
35.7
At bottom of bunker, ventilated . . .
.. 51.5
42.0
35.7
36.0
Above load,1 standard
.. 71.9
68.0
56.5
55.6
. . • •
Above load,1 ventilated
71.3
60.8
51.2
50.6
•Fifteen inches above load, 3 feet from bunker.
equipment was available at Cobden before the beginning of the Elberta
season, the car was shipped under standard refrigeration without pre-
cooling. Both standard and ventilated packages were used.
Temperature readings were made soon after the car was closed
following the completion of the loading. Another reading was made
2^2 hours later, shortly before the car left the shipping point. The
next reading was made in Chicago 22 hours after the original reading;
and the final reading was made in Detroit 44^ hours after the first
reading (Table 5).
Temperature Reductions Previous to Shipment. — Owing to differ-
ence in time of loading, the temperature of the fruit in the standard
packages was much lower than of that in the ventilated packages at the
time the first reading was made. During the first 2i/i hours of refriger-
ation the drop in the temperature of the fruit in the standard packages
was slightly more than 2 degrees in the lower layer of baskets and
slightly less than 1 degree in the top layer. The drop in temperature
of the fruit in the ventilated packages during this 2i/2-hour period was
14.9 degrees in the lower layer and 2.4 degrees in the top layer. This
shows the rapidity with which refrigeration may start in the ventilated
528
BULLETIN No. 455
[May,
packages in the lower layer directly accessible to the cold air emerging
from the bottom of the bunker and drifting toward the center of
the car.
Temperature Reductions in Transit. — The further influence of the
two types of packages upon rate of refrigeration is well indicated by
the reduction in temperature during the 22-hour period which elapsed
by the time the car reached Chicago. The average drop in temperature
of the fruit in the lower layer of standard packages during the period
was 9.8 degrees, while that in the top layer was 10.8 degrees, or an
average of 10.3 degrees for both layers. The drop in temperature of
the fruit in the lower layer of ventilated packages during the same
period was 33.2 degrees, while that in the top layer was 28.0 degrees,
or an average of 30.6 degrees for both layers. Altho the average
temperature of the fruit in the ventilated packages at the start was
13.4 degrees higher than that of the fruit in the standard packages, it
was 6.9 degrees lower at the end of the 22-hour period (Fig. 12).
Even tho allowance is made for the differences in temperature at the
start, there is a wide margin in favor of the ventilated packages in
reference to rapidity of refrigeration of the fruit contained.
40
FIG. 12. — COOLING OF PEACHES IN STANDARD AND IN VENTILATED
PACKAGES UNDER STANDARD REFRIGERATION, CAR E
This car was shipped from Cobden, Illinois, to Detroit, Michigan, without
precooling. Refrigeration was much more rapid in the ventilated packages.
Eighty-hole liners were used in both types of packages.
1939] PRECOOLING ILLINOIS PEACHES 529
Temperature and Condition of Fruit at Destination. — By the time
the car reached Detroit one thermometer had become displaced. Leav-
ing out of consideration the corresponding thermometer in the other
end of the car, the average temperature of the three baskets of fruit
in the standard packages was 54.8° F., while that in the ventilated
packages was 48.8° F., a difference of 6 degrees.
Inspection in Detroit 44i/i hours after the car was loaded at Cobden
showed the U. S. No. 1 peaches to be in good firm condition except
for a trace (about 1 percent) of brown rot in the fruit in the standard
packages. There was no decay apparent in the No. 1 peaches in the
ventilated packages. A few baskets of Utility grade peaches in venti-
lated packages, that had been put in to fill out the car, showed 7 per-
cent brown rot.
Ventilated Leigh Tubs vs. Standard Tub Bushels
Car F, loaded with Elberta peaches at Cobden, Illinois, on August
13, 1937, was precooled and billed thru to Bay City, Michigan. The
precooling was done with the portable truck type of precooler. The
peaches in one half of the car were packed in ventilated Leigh tubs
while those in the other end were packed in standard bushel tubs. The
new type of ventilated liner, with 80 holes, was used in both types of
packages. The condition of the fruit in both types of containers was
"hard" to "firm" at the time of loading. Loading was completed and
the car closed at 11:40 a. m. The bunkers were practically full of ice
at this time. A temperature reading was made at 1 p. m., and the car
was opened for attaching the precooling equipment at 1:10. Actual
precooling was started a few minutes later, and the machine was con-
tinued in operation for 3 hours.
Temperatures During Precooling. — During the 3-hour precooling
period the temperature of the peaches in the standard packages near
the center of the car dropped very rapidly (18 degrees in the lower
layer and 25 degrees in the top layer). The drop in temperature of
the fruit in the same type of packages near the end of the car was
very much less (7.8 degrees and 9.2 degrees in lower and top layers
respectively). On the other hand there was much less variation in the
amount of drop in temperature of the fruit in ventilated packages in
different positions in the car. In the lower layer the difference in
temperature of the fruit in the package near the end of the car and
near the center was only 2i/2 degrees. In the top layer the difference
was greater, the drop being 20 degrees in the basket near the center
of the car and 12.2 degrees in the basket near the end of the car.
530
BULLETIN No. 455
[May,
There was thus much better distribution of the refrigeration in the
ventilated packages, even tho the average drop in temperature was only
slightly greater (Table 6).
Temperatures in Transit. — Half an hour after the above readings
were made, the car was "pulled" by a switch engine and attached to the
fast fruit train. The bunkers were seven-eighths full of ice at this
time. The car was billed for Bay City, Michigan, with instructions
not to reice.
The next temperature reading was made in Chicago 22 hours after
the initial reading. By this time the temperature of the fruit in the
standard containers in different parts of the car was much more nearly
equalized.
Temperature readings were made at Grand Rapids, at Saginaw
(two readings), and finally at Bay City 68 hours after the original
reading at Cobden. The drop in the temperature of the fruit in the two
types of packages during the first 48 hours is shown graphically in
Fig. 13.
90
42
FIG. 13. — COOLING OF PEACHES IN STANDARD AND IN VENTILATED
PACKAGES IN CAR F, PRECOOLED BUT Nor REICED
This car was precooled and billed thru to Bay City, Michigan, without
reicing. It was in transit for 68 hours. The temperatures during the first 48
hours of the 68 in which the car was in transit are shown here. Temperatures
of fruit in different parts of the car and in the two types of packages tended
to become equalized as the end of the journey approached. Eighty-hole liners
were used in both types of packages.
PRECOOLING ILLINOIS PEACHES
531
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532
BULLETIN No. 455
[May,
Temperatures at Destination. — When the car arrived at its destina-
tion, the bunkers were nearly half full of ice, and there was no apparent
difference in the amount of ice in the two bunkers. The temperature
of the fruit in the top layer of packages was nearly uniform thruout
the length of the car, including both types of packages. The tempera-
ture of the fruit in the lower layer of packages was, for each type of
package distinctly lower than that in the top layer. The average
temperature of the fruit in the ventilated packages was only slightly
lower (1^/2 degrees) than that of the fruit in the standard containers.
Condition of Fruit at Destination. — Within a few minutes after the
temperature reading in Bay City, the car was opened and about one-
third of the peaches were unloaded. The peaches were firm and in good
market condition at this time with the exception of a very small per-
centage that showed rot. The fruits from one package of each type
of container taken from corresponding positions in the car were
TABLE 7. — DEFECTIVE PEACHES IN STANDARD AND IN VENTILATED CONTAINERS
ON ARRIVAL IN MARKET AT BAY CITY, MICHIGAN: CAR F
Kind of package
Number of
fruit in
package
Brown rot
Bruised peaches
Standard tub bushel
178
198
No.
3
1
perct.
1.68
.50
No.
6
4
perct.
3.37
2.02
Ventilated (Leigh) tub
counted out and very carefully examined. Of the 178 peaches in the
standard container 3 showed brown rot and 6 showed shipping bruises.
Of the 198 peaches in the ventilated package only 1 showed brown rot
while 4 showed shipping bruises (Table 7). Altho the percentage of
damaged peaches was small, there appeared to be some advantage in
favor of the fruit shipped in the ventilated packages.
Ventilated Packages and Liners vs. Standard Packages and Liners
Car G was loaded with Elberta peaches at Ozark, Illinois, on
August 20, 1937, and precooled with the fan type of precooling equip-
ment. One half of the car was loaded with peaches packed in venti-
lated tub bushels and the other half with peaches packed in standard
tub bushels. The new type of ventilated liner was used in the venti-
lated containers, and the old type of liner (with much less ventilation)
was used in the standard containers.
Loading was started at 12 m. and was completed at 2:45 p. m. The
1939] PRECOOLING ILLINOIS PEACHES 533
car had been fully iced before it was received at the siding, but more
ice was added at 12:30 p. m. to completely fill the bunkers. The car
was closed at 2:50 p. m. and the precooling equipment was put into
operation at 2:52. At 3:30 p. m. the ice bunkers were opened and 200
pounds of salt was placed over the ice and chopped in. Precooling was
continued until 7:50, a total period of 5 hours. The equipment was
removed and the car sealed at 8 p. m.
This car was billed out under standard refrigeration for Buffalo,
New York. Temperature readings were made at Bluford and Neoga,
Illinois; at Frankfort, Indiana; Bellevue, Ohio; and finally at the Food
Terminal in Buffalo, New York.
Reicing took place at Bluford, Frankfort, and Bellevue. The
elapsed time from the start of precooling until delivery of the car at
its destination was 63 hours.
Drop in Temperatures During Precooling. — At the time precooling
started, the average temperature of the fruit in the ventilated tubs was
3.3 degrees higher than that of the fruit in the standard tubs. At the
end of the 5-hour precooling period the average temperature of the
fruit in the ventilated tubs was 12.3 degrees lower than that of the
fruit in the standard tubs. In the bottom layer cooling was more rapid
in the package near the bunker than in that toward the center of the
car in both types of package. In the top layer cooling was about equally
rapid in the standard containers in both positions, but was more rapid
in the ventilated package toward the center of the car (Table 8).
Temperatures in Transit and at Destination. — When the reading
was made at Bluford 21 1/2 hours after the loading had been completed,
the difference in temperature of the fruit in the two types of packages
was less marked than at the close of the precooling period. At this
time the average temperature of the fruit in the ventilated packages
was 52.5° F., while that of the fruit in the standard packages was 56.7°
F. The temperature of the fruit in both types of packages continued
to decline until the car was delivered at its destination, when the aver-
age temperature of the fruit in the ventilated packages was 44.0° F.
and that of the fruit in the standard packages was 46.0° F.
The progress of cooling of the fruit in each type of package during
the first 48 hours is graphically presented in Fig. 14.
Condition of Fruit at Destination. — The peaches were inspected
upon arrival by two inspectors, one a representative of the consignee
and the other a representative of the railway company. Fifty peaches
were taken out of each basket inspected. All inspected baskets were
from the top layer in the car. Results of the inspection are shown in
534
BULLETIN No. 455
[May,
)
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1939]
PRECOOLING ILLINOIS PEACHES
535
Table 9. Both inspectors stated that the fruit seemed to be in a little
better condition in the ventilated packages. The amount of brown rot
or of "decay" was too small to warrant any definite comparisons on
these points. Likewise, there was little difference in the percentage of
"soft" peaches in the two types of packages.
40
42
FIG. 14. — COOLING OF PEACHES IN STANDARD AND IN VENTILATED
PACKAGES IN CAR G DURING FIRST 48 HOURS
This car was followed thru to Buffalo, New York, which was reached in
63 hours. Undoubtedly the new type of liner was an important factor in the
extremely rapid refrigeration of the fruit which took place in the ventilated
packages during the precooling period. An 18-hole liner was used with the
standard packages.
TABLE 9. — DEFECTIVE PEACHES IN STANDARD AND IN VENTILATED CONTAINERS
ON ARRIVAL IN MARKET AT BUFFALO, NEW YORK: CAR G
Kind of package
and position
Brown rot
"Decay"
Soft peaches
Standard tub
4th from end
No.
1
None
None
1
None
None
None
None
None
pent.
.66
None
No.
None
None
None
None
None
None
2
None
2
perct.
None
1.00
No.
2
None
2
4
1
5
None
None
6
perct.
2.66
3.00
At Quarter-length
Near middle of car. . . .
All 3 baskets
Ventilated tub
3d from end
At quarter-length
Near bunker
Near middle of car .
All 4 baskets
536 BULLETIN No. 455 [May,
Standard vs. Ventilated Round-Bottom Baskets
With Ventilated Liners
Car H, loaded with Elberta peaches at a siding near Irvington,
Illinois, on August 27, 1937, was followed thru to its destination in
Burlington, Vermont. Half the car was loaded with peaches packed in
standard round-bottom bushel baskets and half with peaches packed
in ventilated round-bottom baskets. The new type of ventilated liner
was used in both types of packages. The bunkers were completely
full of ice when loading of the car started at 2:30 p. m. The first
reading was made at 5 p. m. after the thermometers had been in place
about half an hour. The car was switched from the loading track to the
Centralia ice yard, and arrived at the ice track at 9:45 p. m. A tempera-
ture reading was made just before the car was opened at 10 p. m. to
install the precooling equipment, which was of the fan type. Ice was
added at 10: 15 p. m., in the amount of 3,200 pounds, to fill the bunkers ;
and 200 pounds of salt was placed on top of the ice.
The precooler was started into operation at 10:30 p. m. and was
continued in operation until 4:30 a. m., a period of 6 hours, during
which readings were made once an hour.
Average Temperature Reduction Previous to Shipment.- — During
the 5 hours after the first temperature reading was made and before the
salt was put in or the fans were started, the average drop in tempera-
ture of the fruit in the standard baskets was 6.3 degrees while that of
the fruit in the ventilated baskets was 9.3 degrees even tho the tempera-
ture in the ventilated baskets at the start was 5.9 degrees lower than
in the standard baskets. During the 6 hours the precooler was in
operation the average temperature of the fruit in the standard baskets
was reduced 13.7 degrees and that of the fruit in the ventilated baskets
16.1 degrees.
During the 11 hours after loading and previous to shipping, the
average temperature of the fruit in the standard baskets was reduced
20 degrees and that of the fruit in the ventilated baskets 25.5 degrees,
thus increasing the difference in temperature between the two lots to
11.4 degrees, and leaving the average temperature of the fruit in the
standard baskets at 65.2° F. and that of the fruit in the ventilated
packages at 53.8° F. at the close of the precooling period (Table 10).
Temperature Reductions in Different Layers. — During the first 5
hours, while the normal cooling effect of the ice in the bunkers without
forced air circulation or salt was operative, the fruit in the lower layer
of packages cooled more rapidly than that in the top layer of the same
type of package. As soon as the precooling equipment was put into
1939]
PRECOOLING ILLINOIS PEACHES
537
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I i
BULLETIN No. 455
[May,
HOURS
FIG. 15. — COOLING OF PEACHES IN TOP AND BOTTOM LAYERS OF
PACKAGES IN CAR H DURING FIRST 11 HOURS
Cooling was much accelerated when the precooling equipment started opera-
tion 5 hours after loading. Immediate change in rate of cooling of fruit in the
top layer of packages was apparent. The new type of 80-hole liner was used in
both types of packages.
operation, the temperature of the fruit in the top layer began to drop
more rapidly than that of the fruit in the lower layer, and the more
rapid cooling of the top layer was maintained to the end of the pre-
cooling period (Fig. 15). This illustrates the point that precooling by
forcing a blast of cold air over the top of the load of fruit reduces the
temperature of the fruit which is normally the hottest and least affected
by the normal flow of cold air from the bottom of the ice bunkers.
Thus more uniform refrigeration thruout the load of fruit is eventually
effected.
Treatment of Car in Transit. — The precooling equipment was
removed and the car sealed at 4:45 a. m., August 28. At 5:30 a. m.
the bunkers were again filled with ice, 2,800 pounds being used. The
car was billed out under standard refrigeration to Burlington, Vermont.
It was reiced at Harvey, Illinois; Port Huron, Michigan; and St.
Albans, Vermont. Temperature readings were made at Champaign
and Harvey, Illinois; at Port Huron, Michigan; Mimico, Ontario;
and upon arrival at Burlington, Vermont.
Temperature Reductions in Transit. — The reading in Champaign
was made 28 hours after the initial reading at the loading point. At
PRECOOLING ILLINOIS PEACHES
40
FIG. 16. — COOLING OF PEACHES IN STANDARD AND IN VENTILATED
PACKAGES IN CAR H DURING FIRST 48 HOURS
Precooled and shipped under standard refrigeration to Burlington, Vermont,
this car reached its destination 91 1/2 hours after the initial temperature reading.
The fruit arrived in firm condition. The 80-hole ventilated type of liner was
used in both types of packages.
this time the average temperature of the fruit in the standard baskets
had been reduced to 53.4° F. and that of the fruit in the ventilated
baskets to 48.0° F. In the reading at Port Huron 48 hours after the
original reading, the average temperature of the fruit in the standard
baskets was found to be 47.4° F. and that of the fruit in the ventilated
baskets 44.7° F. The progress of cooling of the fruit during the
48-hour period is graphically presented in Fig. 16.
The difference in temperature between the two lots of fruit became
less and less as time went on until the final reading at its destination,
when the fruit in the standard baskets had attained a temperature
lower than that in the ventilated baskets. This was 91 1/2 hours after
the initial reading.
Condition of Fruit at Destination. — One hour after the last reading
was made, the car was opened and the condition of the peaches noted.
Fifty peaches were taken from each of four packages examined.
Inspection of these samples resulted in the data given in Table 11. The
amount of brown rot and number of soft peaches were too small in
both types of packages to warrant any comparison. In one of the
540
BULLETIN No. 455
[May,
TABLE 11. — DEFECTIVE PEACHES IN STANDARD AND IN VENTILATED CONTAINERS
ON ARRIVAL IN MARKET AT BURLINGTON, VERMONT: CAR H
Kind of package
Brown rot
Bruised peaches
Soft peaches
Standard basket
Basket 1
No.
None
None
None
None
1
1
percl.
None
1.00
No.
2
2
4
6
1
7
perct.
4.00
7.00
No.
2
2
None
percl.
2.00
None
Basket 2
Ventilated basket
Basket 3
Basket 4
ventilated baskets there were more and in the other less bruised
peaches than in either of the standard baskets. The peaches in general
were firmer and greener in the ventilated packages than in the standard
packages.
GENERAL DISCUSSION OF RESULTS
The outstanding feature in nearly all the tests just reported was
the much more rapid reduction in the temperature of the fruit in the
ventilated packages than in the standard packages. As was to be
expected, the initial temperature of the fruit in the different cars and in
different parts of the same car had a decided influence upon the rate of
cooling, which varied considerably in the different tests and in differ-
ent parts of a load.
When the fan type of precooler was used, there was usually a
greater drop in the temperature of the fruit in the top layer of packages
than in that of the lower layer, during the time the precooler was in
operation. This was due to the forcing of the cold air directly upon
the top layer, where, under normal conditions in a refrigerator car
temperatures are likely to be highest. When the portable precooling
plant was used, there usually was not much difference in the average
drop in the temperature of the fruit in the top and bottom layers, but
there was a tendency toward a greater drop near the center of the car,
especially in the top layer.
Vagaries in rates of cooling in the same parts of different cars were
doubtless due to differences in the adjustment of the precooling equip-
ment and in details of operation.1*
In general, more thoro precooling could have been attained if the
equipment had been operated for a longer time on each car, and if a
lower air temperature had been maintained during the cooling period
than was maintained in most of the cars included in the tests.
1939] PRECOOLING ILLINOIS PEACHES 541
After the close of the precooling period the temperature of the
fruit continued to decline, but the differences between the temperatures
in the different types of packages tended to diminish. However, the
favorable effect of the more rapid early cooling of the fruit in the
ventilated packages was shown in the firmer condition of the fruit
upon arrival in the terminal markets.
COMMERCIAL PRACTICES IN 1938
No test shipments in the precooling of peaches were made by the
Illinois Experiment Station in 1938; but an effort was made to ascer-
tain to what extent precooling of peaches was practiced by Illinois
shippers that season, and also the extent to which ventilated packages
were used in marketing the peach crop.
Precooling. — Personal contacts with peach growers during the 1938
crop movement and consultation with operators of commercial pre-
cooling equipment revealed that a number of Illinois growers handling
large volumes of peaches had nearly all their rail shipments precooled.
The charge for precooling was $12.50 to $25 a car.
Equipment for precooling had been further improved for the 1938
season ; and this, together with the experience of previous years, made
more efficient precooling possible. Some operators of precooling equip-
ment tried to get the temperature of the fruit down to 40° F., as
recorded by a thermometer inserted into a fruit near the center of a
basket in the top layer of baskets near the car door. To attain this
temperature, precooling practices were varied to meet specific condi-
tions. For example, the quantity of salt was varied from 200 to 400
pounds to the car, the amount depending upon: (1) the initial tem-
perature of the fruit, (2) the outside air temperature, (3) the amount
of ice in the bunkers, and (4) the time available for precooling before
the fruit train would arrive to pick up the car.
One of the companies operating the fan type of precooler pre-
ferred to have at least 8 hours in which to precool a car, but because
of late loading of the car or early movement of the train on which
shipment was desired, they were sometimes obliged to do the work in
4 hours. When this occurred, more salt had to be used, and even then
the desired temperature was not always attained. In fact, unless all
conditions were favorable, the temperature of the fruit at the end of
the precooling period was more likely to be in the neighborhood of
50° F. than 40° F. In the report to the shipper the precooling com-
pany recorded the initial and final temperature of the fruit, the amount
of salt used, and the length of time the precooler was operated.
542 BULLETIN No. 455 [May,
Ventilated Baskets. — The use of ventilated baskets for shipping
peaches had become an even more common practice in Illinois in 1938
than the precooling of rail shipments of this product. An incomplete
survey made in southern Illinois during and shortly after the peach
movement showed that 22 shippers used 128,201 ventilated bushel
containers in the marketing of their peaches. The survey covered the
operations of 126 growers, who marketed 460,002 bushels of peaches
in 1938. Thus the ventilated packages used represented 28 percent of
the total packages used by the growers included in the survey. Three
years previous the only Illinois peaches shipped in ventilated packages
were those included in the tests by the Experiment Station. The cost
of ventilated packages and the new type of liners was practically the
same as that of standard packages and the old type of liners.
SUMMARY
Refrigeration tests with eight carloads of Illinois peaches in 1935
and 1937 are reported herein. The effects of two different types of
packages — ventilated and standard — on the rapidity with which the
fruit cooled were studied, half of each car being loaded with ventilated
packages of fruit and half with standard containers. A special type of
ventilated liner, not available in 1935, was used in the 1937 tests.
Four of these cars were observed only during the precooling period,
and four were followed thru to their destinations. In the latter tests
the condition of the fruit was observed when the cars were unloaded.
The precooling equipment was of two types. One consisted of
electric fans (with accessories) which forced cold air from the ice
bunkers thru the load of fruit. With this type of cooler, salt was added
to the ice in the bunkers to reduce the air temperature. The other
type of cooler consisted of a portable refrigeration plant mounted on an
auto-truck chassis.
The results of the 1935 tests, which covered only the precooling
period, may be summarized as follows:
1. The temperature of the fruit in the ventilated packages
equipped with standard liners was reduced 25.8 degrees in 81/2 hours,
while that of the fruit in the standard packages with standard liners
was reduced only 18.4 degrees. (Car A)
2. The temperature of the fruit in ventilated baskets without any
liners was reduced approximately three times as much during a 6-hour
precooling period as that of the fruit in the standard baskets equipped
with standard liners. (Car B)
1939] PRECOOLING ILLINOIS PEACHES 543
3. In a car precooled with a portable refrigeration plant, the
temperature of the fruit in the ventilated packages dropped 16.1 de-
grees in 3f4 hours, while that in the standard packages dropped only
11.9 degrees. The day was fairly cool and the temperature of the fruit
not very high at the start. Standard liners were used in both types of
package. (Car C)
4. In a car loaded on a hot day, when the outside temperature
was 94° F., the drop in the temperature of the fruit in the ventilated
packages during a 4^-hour refrigeration period was 21.1 degrees,
while in the standard containers it was only 12.7 degrees. The pre-
cooling equipment was of the same type as that used for Car C just
mentioned. ( Car D)
The results of the 1937 tests, in which each car was followed thru
to the terminal market and temperature readings were made enroute,
were briefly as follows:
1. In a car loaded with Red Bird peaches, and shipped under
standard refrigeration without precooling, the temperature of the fruit
in the ventilated packages was reduced 30.6 degrees in 22 hours ; while
that of the fruit in the standard packages was reduced only 10.3
degrees. The new type of 80-hole liner was used in both types of
packages. (Car E)
2. In a car precooled with the portable truck type of cooler, the
average reduction in fruit temperatures in 3 hours was nearly the
same in both the ventilated and the standard containers, both of which
were equipped with the new type of ventilated liner. However, the
amount of temperature drop in the fruit in the ventilated packages in
different parts of the car was much less varied than it was in the
standard packages. ( Car F)
3. In a car precooled with the fan type of precooling equipment,
the temperature of the fruit in ventilated tub bushels equipped with
the new type of ventilated liner dropped 26.1 degrees in a 5-hour pre-
cooling period, while in the standard tub bushels equipped with the
standard type of liner the drop was only 10.5 degrees. (Car G)
4. In a car in which precooling equipment was not installed until
5 hours after loading was completed, the temperature of the fruit in
ventilated baskets equipped with the new type of ventilated liner was
reduced 9.3 degrees by the effect of the ice in the bunkers ; while in the
standard baskets with the same type of liners the temperature dropped
only 6.3 degrees. During the next 6 hours, while the precooler (fan
type) was in operation, the fruit in the ventilated packages showed
544 BULLETIN No. 455
a further temperature drop of 16.1 degrees and the fruit in the
standard packages a drop of 13.7 degrees. (Car H)
5. Variations in the rate at which the peaches in the different
tests cooled (both in 1935 and in 1937) were attributable partly to
differences in the initial temperature of the fruit and partly to differ-
ences in the operation of the precooling equipment.
6. The peaches in both types of containers in the 1937 tests
carried thru to their destinations in excellent market condition, tho the
fruit in the ventilated packages was usually slightly firmer. The
amount of brown rot and other decay was too small to warrant
comparison.
That precooling of rail shipments of peaches and the use of venti-
lated containers are coming into favor among Illinois growers was
indicated in contacts made with 126 growers in 1938. A number of
those handling large volumes of peaches were precooling nearly all their
rail shipments; and ventilated packages were used for marketing
approximately 28 percent of the Illinois peach crop, according to an
estimate based on interviews with these 126 growers, who marketed
nearly half a million bushels of peaches in 1938.
CONCLUSIONS
1. Precooling is worthy of adoption as a general practice for rail
shipments of Illinois peaches.
2. For rapid precooling, the fruit should be packed in ventilated
containers equipped with the new type of ventilated liners.
3. Even for rail shipments of peaches that are not precooled, the
use of ventilated packages is warranted because of the more rapid
refrigeration which these packages permit.
LITERATURE CITED
1. ALLEN, F. W., and McKiNNON, L. R. Precooling investigations with deciduous
fruits. Calif. Agr. Exp. Sta. Bui. 590. 1935.
2. BROOKS, CHARLES, and COOLEY, J. S. Temperature relations of stone fruit
fungi. Jour. Agr. Res. 22, 451-465. 1921.
3. LLOYD, J. W. Precooling in relation to the marketing of Illinois fruits. Trans.
111. State Hort. Soc. 69, 225-235. 1935.
4. - and NEWELL, H. M. Observations on the refrigeration of some
Illinois fruits in transit. 111. Agr. Exp. Sta. Bui. 334. 1929.
5. — and DECKER, S. W. Factors influencing the refrigeration of pack-
ages of peaches. 111. Agr. Exp. Sta. Bui. 418. 1935.
6. NEWELL, H. M., and LLOYD, J. W. Air circulation and temperature conditions
in refrigerated carloads of fruit. 111. Agr. Exp. Sta. Bui. 381. 1932.
6050— 6M— 16623
JiSKTuRiMU
445-457 1938-39
C002
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