REPORT OF CRANBERRY SUBSTATION FOR 1914. 99 



ing for the control of fungous diseases on the Cape bogs will seem im- 

 practicable until some non-injurious substitute for the Bordeaux can be 

 found. Doubtless, some bogs are occasionally so badly infested with 

 fmigous diseases that spraying would be advisable even if it did cause 

 considerable injury. Diseases appear to be so much more prevalent 

 in New Jersey than they are on the Cape bogs that spraying should 

 probably be generally adopted there in spite of the possibihties of its 

 doing damage. 



The "ring-worm" trouble (commonly so-called by the growers because 

 it was formerly supposed to be the result of some insect's work) was 

 given some study. The vines die in a small patch at first and, the center 

 recovering, the affected area gradually becomes circular. These patches 

 persist for years, the vines on the outer side of the rim dying every season, 

 while recovery takes place on its inner side, the circle thus growing larger 

 j'early and preserving its form if not interfered with by a ditch or some 

 other obstruction. Both Dr. Shear and the writer for some time have 

 believed this trouble to be due to a fungous disease. Insects e\'idently do 

 not cause it. This year evidence has come to hand which appears to go far 

 toward proving that fungi are at the bottom of the trouble. On Sept. 24, 

 1910, the writer visited some bogs in Plymouth, belonging to Mr. Henry 

 J. Thayer of Boston, and found them more badly marked with "ring- 

 worm" patches than any other bog he has ever seen. Moreover, it had 

 been with Mr. Thayer a trouble of long standing, for the "rings" varied 

 in size from mere beginnings to circles 25 or 30 feet in diameter. He 

 thought it was caused by some insect, but decided to trj^ spraying with 

 Bordeaux mixture on the chance that it might be a fimgous trouble. He 

 si^rayed twice in 1911, three times in 1912, three times in 191.3, and twice 

 in the present year, before the writer visited his bogs again on July 4. 

 The change since 1910 was verj^ striking, the "rings" having in most cases 

 entirely or nearly disappeared, and no new dying of the vines being 

 apparent. Mr. Thayer thought his spraying had caused the improve- 

 ment, and it evidently had. His results seem to help prove the char- 

 acter of the "ring- worm" trouble. It should be stated, however, that 

 in all of his spraying after the season of 1911 Mr. Thayer used commercial 

 "Bordo Lead" with a little Paris green instead of straight Bordeaux 

 mixture. 



Early in July, a North Carver grower sent in some vines seriously affected 

 by an unfamiUar disease. Specimens were forwarded to Dr. Shear, and 

 he found the trouble was one which had been known for a long time in 

 Wisconsin, but which had never been previously reported from any other 

 cranberry-growing section. The Wisconsin growers commonly call this 

 disease "false-blossom." There is, however, an entirely different trouble 

 known as "false-blossom" (hypertrophy caused by Exobasidium sp.) by 

 the Cape Cod growers, and to distinguish between the two, the new 

 disease will be called "Wisconsin false-blossom" in this report. It is 

 characterized by an abnormally profuse branching of the vines and a 



