92 



MASS. EXPERIMENT STATION BULLETIN 198. 



Table III. — Most Important Fungi causing Storage Rot of Cranberries 

 at Massachusetts State Experiment Bog, East Wareham, 1917. 



[Figures indicate per cent of total spoiled berries infected with each,] 



' E.stimated from outside temperature and from temperature of same room during the same 

 periods of the previous year. 



As in 1916 Sporonema is the least important of the four, and is found 

 chiefly on the Early Blacks. Phomopsis is again more common on the 

 Early Blacks, and Glomerella on the Howes; indeed, the contrast is more 

 striking in 1917 than in 1916. During both 'years Phomopsis and Glomer- 

 ella are more abundant early in the season, while Fusicoccum is rare early 

 in the storage period and becomes more abundant later. The most un- 

 usual feature presented by the results is the very great abundance of 

 Glomerella on Howes during 1917, and the relative scarcity of Fusicoccum. 



So far as is now known infection by the various fungi causing decay 

 of cranberries generally occurs before the berries are picked. That the 

 development of the fungus is often delayed for some time is evident from 

 the data here published, when it is recalled that in every case only appar- 

 ently sound fruit was used for the storage test. The conditions necessary 

 for the further development of a fungus already in the fruit or attached 

 to the outer epidermis as a spore or appressorium are not yet determined. 

 That it is not entirely a matter of condition of the berry is apparent 

 from the fact that end rot, for example, becomes abundant on the 

 Howes as soon as on the riper Early Blacks; and that it is not a matter 

 of temperature appears (see Table IH) from the fact that berries kept at 

 20° C. showed no marked difference in this respect from berries kept at 

 lower temperatures. 



