6 BULLETIN 444, U. S. DEPARTMENT OF AGRICULTURE. 
The disease appears to have originated in Wisconsin, but has 
become established in Massachusetts, New Jersey, Oregon, and 
Washington by transplanting diseased vines. 
The cause is not known. No evidence has yet been obtained to 
indicate that it is produced by insects or fungi. 
It is suggested that the disease may be due to unbalanced nutri- 
tive conditions. 
The disease is perpetuated from year to year in plants reproduced 
vegetatively from diseased plants, not only in bogs where the trouble 
originated, but also under somewhat more favorable conditions of cul- 
tivation in localities in which the disease was unknown previously. 
Observations made by Mr. Malde in Wisconsin and by a grower in 
Oregon seem to indicate that the offshoots from plants affected with 
false blossom tend to recover and become normal when transplanted 
and grown under optimum soil and moisture conditions. 
To overcome the disease, optimum conditions for growth should be 
provided, including good drainage, clean culture, and pruning. 
Where diseased plants are numerous, the bog should be scalped 
and replanted with healthy vines. 
To prevent the further spread of the disease only vines known to 
be absolutely free from it should be planted. 
