826 



Journal of Agricultural Research 



Vol. VI, No. 21 



were wrapped separately in sterile paper. Each half -bushel lot was then 

 placed in a tin box which had first been sterilized. Half -bushel lots of 

 each variety thus prepared were placed in cold storage at temperatures 

 of o° and i.i° C. Half -bushel lots of each variety were prepared in the 

 same manner and placed in the incubator room as a check. Check 

 lots in which the tubers were treated in the same manner but not inocu- 

 lated were also placed in the incubator room and in cold storage at tem- 

 peratures of d° and i.i° C. Table III gives the results of these tuber 

 inoculations under the different storage conditions, showing the tem- 

 peratures of the incubator chambers, the incubator room, the rooms in 

 the cold-storage plant during the period of storage, and the condition of 

 the inoculated tubers at the end of the storage period. In Table III the 

 incubator chambers are designated by numbers i to 10 and the cold- 

 storage rooms as A and B. All of the uninoculated checks remained 

 sound. 



Table III. — Results of potato-tuber inoculations under different storage conditions 



It is evident from the results obtained that powdery dryrot will not 

 develop at temperatures below 2 C. At temperatures ranging from 2 

 to 4 (35 to 40 F.) the amount of decay will be slight, especially if the 

 storage rooms are kept fairly dry and well ventilated. 



INFLUENCE OF HUMIDITY ON THE DEVELOPMENT OF POWDERY 



DRYROT IN STORAGE 



It has often been observed in storage cellars which were comparatively 

 dry and well ventilated that the losses from powdery dryrot were much 

 less than in damp, poorly ventilated cellars. The writer has been in cel- 

 lars where practically every bruised tuber was from one-third to nearly 

 totally decayed. Such cellars have invariably been exceedingly damp 



