Denmark 
CA storage trials in Denmark are reported by Dullum and Rasmussen (20) in 
some detail and summarized for the 8th International Congress of Refrigeration 
by Rasmussen (81). A number of the apple varieties in Denmark responded most 
favorably to a gas mixture of 8 to 10 percent CO» and 11 to 13 percent 0» at 
39° to 40° F, Jonathan may show some CO injury under these conditions and 
Boikin and Bramley's Seedling may develop scald. Belle de Boskoop and Cox's 
Orange Pippin are injured by CO, concentrations much above 5 percent so for 
these varieties a mixture of 5 percent CO, and 2 to 3 percent 05 at 39°" £0 40s 
F, is suggested. 
The Netherlands 
The gas storage conditions in use in the Netherlands are similar to 
those of Denmark, Van Hiele (101) details these conditions as being 10 percent 
COj and 10 percent 0, for Bramley's Seedling and Golden Delicious; 5 percent 
COp and 4 percent 0» for Cox's Orange Pippin; and 7 percent CO, and 13 percent 
O02 for Jonathan, All of these to be stored at 4.5° C. (40° F.). 
Norway 
Of five varieties tested by Lanfald (44) in Norway, the variety Filippa 
responded most favorably to CA storage. The best storage conditions for this 
variety were 5 percent CO, with 3 percent 0, at °C... G3.8° F.). His, nesules 
with Gravenstein, Bramley's Seedling, and James Grieve were not striking. The 
atmospheres tested did retard ripening, but the occurrence of scald and brown 
core largely offset the beneficial effects. 
United States 
A December 1961 issue of the International Apple Association's Special 
Letter (2) lists eight varieties of apples in CA storages in the United States. 
In order of decreasing volume these varieties were McIntosh, Delicious, Newtown, 
Jonathan, Rome, Northern Spy. Golden Delicious, and Stayman. These varieties 
are stored in atmospheres that range from 1.5 to 5 percent CO, and 2.5 to 3.5 
percent 05. Specific recommendations for the varieties and conditions in their 
areas may be found in publications by Smock (88), Van Doren (100), Southwick 
and Zahradnik (92) and Dewey, et al. (18). Research to establish these CA 
requirements has been carried out by a number of investigators, 
Smock (86) at one time recommended an atmosphere of 5 percent CO» and 2 
to. 3) percent .0>. at 40° F, for the CA storage of McIntosh. In 9 out of 10 years 
these conditions entirely prevented the development of brown core (core brown- 
ing, core flush), a low temperature disorder of McIntosh. Smock later (88) 
revised this to 38° to 40° with the 0) level unchanged but with a CO, level of 
2 to 3 percent for the first month to be followed by the 5 percent level. This 
change in the CO) level was to avoid the occasional external cO, injury that 
may occur during the early storage period when the fruit is apparently more 
susceptible to external injury. Southwick and Zahradnik (92) have not found 
Massachusetts McIntosh to be injured by the 5 percent level of C09, and they 
suggest this concentration throughout the storage period. 
88 
