232 MASS. EXPERIMENT STATION BULLETIN 180. 



Bog Management. 



Prof. H. B. Scammell has recently reported ' a destructive visitation of 

 the fall army worm (Laphygma jrugi-perda S. & A.) this year on widely 

 separated cranberry bogs in New Jersey following closely, and evidently 

 somehow caused by, the removal of the winter-flowage in mid-July. This 

 insect feeds on a variety of plants, but has not heretofore been known as a 

 cranberry pest. As its frequent outbreaks, which start in the southern 

 States, sometimes reach as far north as Canada, by the spreading of the 

 successive broods of strong-flying moths, in a single season, though it is 

 unable to endure the winter in the north, there is gi'ound for fearing that 

 midsummer removal of the winter-flowage may more or less regularly 

 invite serious trouble from this insect on Cape Cod as well as in New Jer- 

 sey. This unexpected development must be regarded as a possible com- 

 plication in connection with certain phases of the biennial cropping system 

 suggested by the writer in last year's report (page 46). 



Late holding of a deep winter-flowage is sometimes dangerous. This 

 flowage was started off from a bog in Assonet, Mass., on June 10, its with- 

 drawal being completed on the 11th. When the writer visited this bog on 

 June 30 the vines seemed completely dead where the flowage had been 

 deepest (5 feet deep), whereas they showed no injury, aside from the re- 

 tarded seasonal development of growth, where the water had been shal- 

 lowest (2 feet deep), their leaves having been well retained and appearing 

 green and healthy. Where the water had been deepest the leaves were all 

 off, the buds at the tips of the uprights were gone, and the vines were 

 brittle and showed no green in the break when broken off. There was a 

 complete gradation from this condition to that where the flowage had been 

 shallowest, corresponding with the variation in elevation. 



Part of the vines on this bog were set out in the spring of 1914, and part 

 in the spring of 1915, strips of both plantings running from the lowest to 

 the highest parts of the bog. The writer is informed by the manager that 

 the one-year sets where the flowage was deep finally recovered somewhat, 

 but that the two-year plantings were killed entirely. 



A large bog in Rochester, Mass., the winter-flowage of which ranged in 

 depth from 4 feet to nothing, had this flowage held until May 31 this sea- 

 son. This is an old bog, with vines well established. Where the water was 

 deepest the leaves all came off, leaving the uprights alive but bearing only 

 the terminal bud. On the other hand, there was no abnormal falling of 

 the leaves where the water was shallow. As on the Assonet bog, there was 

 a complete gradation in the injury corresponding with the variation in the 

 depth of the flowage. 



A new 60-acre bog at Assonet, Mass., was flowed on the night of May 31, 

 the vines being completely submerged for forty-eight hours, the water 

 ranging from 3 feet to a few inches in depth, and averaging about 2| feet. 



» Proc. 47th Ann. Meet, of the Amer. Cranb. Grow. Assoc, p. 11, January, 1917. 



