May, 1922] BERGMAN — • WATER-RAKING OF CRANBERRIES 249 
berries from the same bog, stored under the same conditions, as shown in 
tables I and 4, that the extent of injury is not the same in all varieties. 
In table i, comparing MetalHc Bell and Bennet Jumbo, which were from 
the same grower and were examined at essentially the same time (November 
23-25), it is seen that the Metallic Bell shows a greater percentage of 
spoilage than the Bennet Jumbo. A similar relation is indicated by the 
comparison of water-raked varieties examined at Minneapolis November 
12-15 and also between Searles Jumbo and Howes examined December 
9-1 1. In this case the test was a severe one, as the berries were under water 
from three to five days before being raked. Prolific and Bennet Jumbo 
were injured worse than Searles Jumbo, Howes least of all, and Early Black 
about the same as Searles Jumbo. 
Causes of Spoilage in Water-raked Cranberries 
The spoilage of water-raked cranberries is due to two causes: fungous 
rots and smothering. The fungi which are important in causing storage 
rots are present on the bogs and may gain entrance into the berries before 
they are picked. Having gained entrance, the fungus may remain inactive 
indefinitely, at least without any external manifestation of its presence, 
and then become active and result in the decay of the berry. It is possible 
also that infection may occur under certain conditions after the berries are 
picked. However this may be, it is well known that methods of handling 
and of storage are very important in determining the amount of spoilage. 
Spoilage from smothering is not confined to water-raked berries. It 
may be caused by various conditions, as indicated by Shear and associates 
(4, p. 4). With the exception of smothering as a result of flooding, the 
conditions under which it occurs are the same for water-raked as for dry- 
raked berries. The length of time during which cranberries may be kept 
flooded without injury by smothering is determined by the oxygen content 
of the water and by the rate of respiration of the berries. The oxygen 
content of the water used for flooding Wisconsin marshes has been found 
to be generally low. For this reason injury by flooding is particularly 
apt to occur unless care is taken to prevent it. The causes of this oxygen 
deficiency will not be considered here. Some of the factors concerned have 
been indicated elsewhere (i) and will be treated more fully in another paper. 
With reference to the rate of respiration, attention may be called to 
the age of the berries at the time of flooding in relation to the degree of 
injury sustained. Green cranberries are the first to suffer from smothering 
when flooded. This is well illustrated by the percentage of spoilage in 
partly colored and in fully colored water-raked berries as shown in table 3. 
A similar difference in the extent of injury between early-raked (not fully 
colored) and late-raked (fully colored) berries in storage at Minneapolis 
is shown in table 4. In order to avoid any effect of difference in treatment 
after picking, the comparison is limited to Searles Jumbo examined De- 
