Dec. 3. 1917 
Temperatures of Cranberry Regions and Plant Growth 527 
during the first half of September, a considerable portion of rotten 
berries which had yielded chiefly G, cingulata. Apparently at tempera¬ 
tures favoring its growth the more rapidly growing G. cingulata had 
obscured the F. putrefaciens. Cranberries of the same variety but of 
superior keeping quality from another bog showed a somewhat similar 
relation. Of the berries which rotted at o° and io° C. over 90 per cent 
yielded only F . putrefaciens . Of those rotting at 20° C. about 30 per 
cent yielded only F. putrefaciens , while the remainder showed fungi 
belonging to five different genera. 
That this may happen on a large scale seems to the writer to be indi¬ 
cated by the relations of the two fungi in Massachusetts, where Fusi - 
coccum putrefaciens , though known to occur on the early varieties, is 
especially common as a storage-rot of late berries, making the greater 
part of its growth at 
temperatures well be¬ 
low the optimum for 
the growth of such 
fungi as Glomerella cin¬ 
gulata. It must not be 
supposed that the com¬ 
petition is solely or 
even perhaps chiefly 
between these two 
fungi. The relations 
must be very much 
more complex than 
this and may be fur¬ 
ther confused by the susceptibility of some varieties of cranberries to 
certain fungi. These fungi are, however, taken as representative of 
different classes, within each of which there is great variation and 
undoubtedly competition. The fifth column in Table IV gives the ratio 
between the index for G . cingulata and that for F. putrefaciens at the 
different stations, the index for the latter being considered unity in each 
case. These ratios, which are shown graphically in fig. 3, may be taken 
to represent in a rough way the relative amounts of heat available for 
the two fungi in each locality and indicate to some extent the relative 
amount of competition to which F. putrefaciens is subjected. Where this 
ratio is high, as in New Jersey, fungi having temperature relations similar 
to G. cingulata predominate. Where it is low, as in Wisconsin and 
Massachusetts, F. putrefaciens apparently becomes more abundant. 
Fig. 3. —Curves of the ratios of the index for Glomerella cingulata to 
that for Fusicoccum putrefaciens . 
WISCONSIN AREA 
The temperature efficiency index of Grand Rapids, Wis., is between 
those of the two New England stations, and during the growing season 
the rainfall of the three localities is similar. One would then expect the 
fungus diseases common in the Massachusetts cranberry region to be 
found also in Wisconsin, and this is generally the case. 
23716°—17 -6 
