62 MASS. EXPERIMENT STATION BULLETIN 150. 



sonal development of the root system of most plants begins fairly early 

 in the spring and is nearly coincident with the development of the por- 

 tions of the plant above ground. Recent investigations ' by Professor 

 Coville, of the Bureau of Plant Industry of the United States Depart- 

 ment of Agriculture, have shown that with the blueberries, which are 

 closely related to the cranberry, there is no new root growth until the plants 

 have developed both their leaves and their blossoms. If this is also the 

 rule in the development of the cranberry, it may have a rather vital bear- 

 ing on the practices to be observed in the flooding and irrigation of cran- 

 berry bogs. A lot of vines have already been potted in earthen pots 

 for this and other studies, and it is planned to pot more in glass pots, so 

 that the growth of the root system may be directly observed in all its 

 stages and in all seasons. 



NOTES ON THE WATER OF CRANBERRY BOGS.^ 



Since 1910 the experiment station has been studying the properties and 

 movements of the water in cranberry bogs, in order to determine the 

 probable losses of fertility in the drainage water, because the bogs are 

 generally flooded throughout the winter and sometimes for brief periods 

 during the summer, as a protection against frost and insects. 



The problem of fertilizing cranberry bogs to improve the crop is com- 

 phcated by this periodical fiowage and drainage. Many cranberry 

 growers think that fertilizers are wasted if applied to the bogs, while actual 

 field experiments in Massachusetts, New Jersey and Wisconsin have 

 shown a positive benefit by a light top-dressing of soluble chemicals, 

 namely, nitrates, superphosphates and potash salts. 



The small experimental cranberry bogs in which the studies have been 

 made were devised by Director Brooks, who has described them fully 

 elsewhere.' It is deemed sufficient for this article to say that each bog is 

 contained in an upright cylinder 24 inches in diameter and 48 inches in 

 depth, constructed of glazed sewer tile bedded in concrete. Each bog 

 is connected by a brass pipe passing through the concrete, with a smaller 

 cylinder of similar construction, 6 inches in diameter and of the same 

 depth as the bog. The small tile corresponds to the drainage ditch in the 

 field, and is provided with an outlet and stopcock 12 inches below the 

 level of the surface of the bog. By means of the smaller cylinder the bog 

 can be drained or irrigated at will, and the depth of the water-level below 

 the surface can be observed at any time. 



At the approach of winter the bogs are fitted with galvanized iron rims 

 cemented in place with an asphaltum cement, by which the water-level 

 over the bogs may be raised to a height of about 12 inches. To prevent 

 freezing and bursting the cylinders the entire set of bogs is covered with a 



1 Experiments in Blueberry Culture," by Frederick V. Coville, 1911. Bulletin No. 193 of the 

 Bureau of Plant Industry, United States Department of Agriculture. 

 = By Fred W. Morse. 

 3 Proc. Soc. Promotion Agri. Sci., 1911, pp. 23-28. 



