REPORT OF CRANBERRY SUBSTATION FOR 1914. 115 



The elevation of the surface of the peat around these holes averaged 

 roughly about 98.59. There was, therefore, a drainage in the peat of con- 

 siderably over 9 inches in less than nine hours, at the middle of the section, 

 at a distance of 44 feet from the nearest ditch. This shows that the 

 horizontal movement of water through the peat of cranberry bogs is a 

 very rapid one, if conditions at the station bog are representative. 



Root Development. 



A study of the seasonal development of the root growth of the cran- 

 berry was begun in a rough way and produced some interesting results. 

 As stated in last year's report. Professor Coville, of the Bureau of Plant 

 Industry of the United States Department of Agriculture, has found 

 that the root development of blueberries, rather closely related to the 

 cranberry, is very sluggish. This is also found to be true of the cranberry, 

 though apparently not to so great an extent. On the fungous plots of 

 the station bog this year there was practically no new root development 

 until after the vines had bloomed, and most of the new growth came after 

 blossoming time on the bog as a whole. The new roots were found, how- 

 ever, to start fairly early on bogs which are not winter flowed, some new 

 growth being discovered on well-sanded portions of such bogs as early 

 as May 7. 



The winter flowage was let off from the station bog on May 5, and no 

 new roots could be found on it on May 7. On May 26, a considerable 

 growth of new rootlets had already taken place near the surface, but 

 the lower roots showed no new development whatever. A season's root 

 growth on cranberry bogs evidently begins, therefore, at the surface 

 of the sand, where the roots have the most air and heat. In examinations 

 made later in the season new roots were finally found deeper down in 

 the bog, but the conditions that favored the starting of development 

 near the surface evidently continued to have their influence more or less 

 throughout the period of growth, causing the greater part of the season's 

 root growth to be developed within two or three inches of the surface. 



The degree of drainage does not seem to affect the new root develop- 

 ment in the first part of the season (before the 1st of June), except that 

 when the water table is so high (within three or four inches of the surface) 

 that it makes the surface sand soppy the new rootlets are distinctly larger 

 and more succulent than when they grow under dryer conditions. 



Studies of the Mycorhiza fungi on cranberry roots were begun in a rough 

 way, with the idea of first finding out, if possible, whether there is any 

 great difference in the abundance of these fungi present in different sorts 

 of bogs, attention being given particularly to comparisons between flowed 

 and dry bogs, old bogs and new plantings, and vines growing on "hard 

 bottom" and on "peat bottom." While this investigation has not ad- 

 vanced far enough to justify definite conclusions, it is apparent that 

 different bog conditions have a considerable bearing on the abundance 

 of these fungi. 



