MASS. EXPERIMENT STATION BULLETIN 198. 



FUNGI STUDIES. 



BY BERT A. RUDOLPH AND H. J. FRANKLIN. 



Relative Prevalence of Fungi causing Rots of Cranberries at 

 Different Periods during the Storage Season. ^ 



Decay of cranberries in storage has been reported to be caused by more 

 than ten species of fungi. The study of these storage rots and their con- 

 trol is comphcated by the fact that the fungi causing them vary greatly 

 in their relative abundance during different seasons. Moreover, berries 

 from the various bogs within a given region are often found to be affected 

 with different fungi, and there is apparently some difference in varieties 

 on the same bog. Finally, in any given lot of berries there seems to be a 

 more or less definite succession among the fungi causing decay during the 

 storage period. The present paper deals especially with the last-men- 

 tioned point. 



The plan of work in 1916-17 was as follows. Twelve storage boxes (1 

 bushel capacity) were filled with Early Black cranberries from a uniform 

 area on the station bog at East Wareham, Mass., and placed in storage 

 in the basement of the screen house, together with a similar lot of Howes. 

 Beginning September 27 quart samples of sound berries were selected 

 weekly from each variety and stored for two weeks in quart cans (which 

 were closed but not sealed) at room temperature, after which they were 

 sorted, and the berries which had rotted during the two weeks were sent 

 to Washington. Here at least 60 cultures were made^ from each lot of 

 rotten berries by sterilizing the outside of the berry by immersing for five 

 minutes in mercuric chloride solution (1-1000) and transferring a portion 

 of the pulp to culture media by means of sterUe forceps. In case fungi 

 developed which did not fruit readily on the culture medium first used, 

 subcultures were made on oat, beef, glycerine and corn-meal agar. 

 1 In the work of the season of 1917-18 the method was modified in several 

 particulars. Closed cans were abandoned in favor of open boxes for the 

 storage of the selected sound berries, the interval between tests was four 



1 The work summarized in this paper forms a part of the study of the spoilage of cranberries 

 after harvest, which is being carried on jointly by the Massachusetts Agricultural Experiment 

 Station and the United States Department of Agriculture. For further information on this 

 general subject see Mass. Agr. Exp. Sta. Buls. Nos. 168 and 180, and U. S. Dept. Agr. Bui. No. 

 714. 



2 The fungi were all cultured and identified by Rudolph, whose enlistment in the navy late 

 in 1917 prevented the completion of the work planned for that season. Mr. Rudolph was at that 

 time scientific assistant, fruit disease investigations, Bureau of Plant Industry. 



