OILED PAPER AND OTHER OILED MATERIALS IN THE 
CONTROL OF SCALD ON BARREL APPLES 1 
By Charles Brooks and J. S. Cooley, Pathologists, Office of Fruit-Disease Investi¬ 
gations , Bureau of Plant Industry, United States Department of Agriculture 
INTRODUCTION 
Scald is one of the serious storage and 
market diseases of apples, and is par¬ 
ticularly bad on the fruit that is stored 
in barrels. The barrel package is a 
tight one and its bulk of fruit relatively 
large, with the result that the apples 
cool more slowly than those in smaller 
and more open packages and also have 
less opportunity for the elimination of 
moisture, odors, or other waste prod¬ 
ucts. In addition to this, a number of 
the varieties that are usually packed in 
barrels are naturally susceptible to 
scald and several of them are largely 
grown in the more southern orchard 
sections where picking and packing 
often begin while the weather is warm. 
These various conditions have made 
scald a particularly serious problem in 
the storage of barrel apples. The 
present paper gives a report of experi¬ 
ments in the use of oiled paper and 
other oiled materials for the control of 
scald in the barrel package. 
HISTORICAL 
Investigations looking to the control 
of apple scald extend over the last 
quarter of a century. They have de¬ 
veloped a number of methods of re¬ 
ducing the disease and several of these 
have been put into practice to an extent 
to be of material value to the apple 
industry. 
The first definite contribution in the 
study of scald was made in 1903 by 
Powell and Fulton (16). 2 They found 
that mature fruit scalded less than 
immature, and well-colored apples less 
than poorly colored ones, that less 
scald developed at a storage tempera¬ 
ture of 31° to 32° F. than at a tempera¬ 
ture of 36° F. or higher, and that delays 
in reaching storage were extremely 
favorable to the development of the 
disease. 
Following this pioneer investigation 
no extended study of scald was made 
for a number of years. In 1904 (If) 
and again in 1909 (5) Beach pub¬ 
lished notes supporting the results of 
Powell and Fulton and in 1913 Greene 
(12) reported further supporting evi¬ 
dence. Greene found, however, that 
apples often scalded less in good cellar 
storage than in cold storage and that 
apples that were delayed in reaching 
storage sometimes scalded less than 
those that were stored immediately. 
Ramsey, McKay, Markell, and Bird 
(19) in 1917 obtained results on the 
northwestern box apples similar to 
those of Powell and Fulton on the 
eastern barrel apples. Their investi¬ 
gations covered a period of four years 
and their experimental data gave 
conclusive proof that bad scald could 
be greatly decreased by picking the 
fruit at proper maturity. Apples that 
were delayed two weeks in reaching 
storage usually developed consider¬ 
ably more scald than those that were 
stored immediately and less scald 
developed in 32° F. storage than in 35° F. 
storage. They made withdrawals from 
storage at intervals of four to six weeks 
and reported data showing the pro¬ 
gressive development of scald during 
the storage period. 
Brooks and Cooley (6) (1917) and 
Brooks, Cooley, and Fisher (7) (8) (9) 
(10) (1919), (1923) found that im¬ 
mature apples scalded much worse 
than mature ones but that the mature 
ones might scald earlier in the storage 
season than the immature ones. Apples 
from heavily irrigated trees scalded 
worse than those from trees receiving 
more moderate irrigation. The rate 
of development of scald increased with 
a rise in temperature up to 15° or 20° C. 
(59° or 68° F.) but no scald occurred at 
25° or 30° C. (77° or 86° F.). Scald 
was not due to the shock from the 
change of temperature on bringing the 
apples out of storage, but largely to 
the conditions that prevailed during 
storage. Delayed storage without ven¬ 
tilation resulted in increased scald but 
1 Received for publication June 4, 1924—issued-January, 1925. 
2 Reference is made by number (italic) to “ Literature cited,” pp. 134-135. 
Journal of Agricultural Research 
Washington, D. C. 
( 129 ) 
Vol. XXIX, No. 3 
Aug. 1, 1924 
Key No. G-412 
