REPORT OF THE CRANBERRY SUBSTATION. 109 



2. Five pounds in 10 gallons of water applied June 1. This killed all the diseased 

 shoots and hurt the uprights little. 



3. Five pounds in 10 gallons of water applied May 31. This killed all the 

 diseased shoots and reduced the prospective crop more than 50 per cent. 



4. Ten pounds in 10 gallons of water applied May 29. Tliis killed all the 

 "rose bloom" shoots and hurt the uprights but little. 



5. Twenty pounds in 10 gallons of water applied May 29. This killed all the 

 diseased shoots and injured the uprights severely. 



These experiments suggest that the sulfate may be used to combat the 

 disease successfully if applied at a right strength often enough to prevent 

 the infected shoots from developing to the condition in which they give 

 off spores. To be thorough enough this treatment might necessitate the 

 sacrifice of the crop of the season in which it was used, and also, by de- 

 stroying the bud-bearing tips of the new growth, that of the next year. 

 As fresh spores were found on the diseased growths on May 20, 1918, 

 the spraying, if tried, should be begun fairly early in the season. 



The station bog was completely flooded June 3, 1918, and the water 

 was held forty-four hours. The "rose bloom" shoots turned dark and 

 shriveled soon after the water was let off, just as the}^ did after the 1917 

 flooding. It seems from this that such submergence can be relied on to 

 destroy these growths. 



The diseased shoots were well developed and plentiful on the station 

 bog on May 18, 1918, but they did not seem to be giving off spores then. 

 The winter buds in the tips of the cranberry uprights were enlarged but 

 not opened at all at the time, and therefore probably were not in condi- 

 tion to receive a new infection from the spores of the disease. The in- 

 fected axillary buds apparently develop earlier than the healthy terminal 

 buds. 



These obsei-vations and the effect of the June fioodings on the "rose 

 bloom" growths suggest that where water supplies are adequate the 

 disease may be controlled by letting off the winter water about May 20 

 and flooding again for from two to three days when the terminal buds are 

 developed to the point of breaking open. This treatment would allow the 

 diseased, spore-producing shoots to grow, but would destroy them before 

 the new cranberry growth developed enough to become susceptible to in- 

 fection. 



The writer has never j^et found "rose bloom" very prevalent on a bog 

 that was regularly reflowed after picking. 



Table 3 compares the experience had with Early Black and with Howes 

 cranberries which were left unpicked and subjected to the long (September 

 29 to October 13) after-picking flooding in 1917 with that had with berries 

 of the same varieties picked before the flowing from vines near those 

 bearing the submerged fruit. The Early Black berries decayed remark- 

 ably in the water, the main fungus causing the rot, as determined by Dr. 

 Shear, being Sporonema oxycocci Shear. The Howes fruit picked after 

 the flooding, however, showed less decay than that gathered and stored 

 before it, this probably being due to a considerable development of "end- 



