EXPERIMENTAL WORK WITH CRANBERRIES. 



67 



During 1912 it was noticeable that some bogs evaporated much more 

 rapidly than others; but the actual differences were not determined. In 

 the fall, before putting on the sheet-iron rims, it was necessary to cut off 

 the vines which extended over the wall of the tile, and also to cut out some 

 of the surplus growth within the bog area. These prunings were dried 

 and weighed, and were found to vary much. There also appeared to be 

 some relationship between the weight of prunings and the rate of water 

 movement in the bogs, which was to be expected, since transpiration should 

 increase with the development of the vines. 



Therefore in 1913 a careful record was kept of the amounts of water 

 removed from individual bogs as drainage water in the spring and the 

 quantities of irrigation water added during the summer. The results, 

 together with the weight of vines removed the previous fall, are given in 

 Table 3, as follows: — 



Table 3. — Relation between Drainage, Irrigation and Vine Growth. 



The bogs are arranged so that the unfertilized ones, 6, 10, 11 and 14, 

 head the columns, followed by 2, 3 and 7 with no nitrogen, while 1, 4 and 5 

 receive nitrogen in nitrate of soda, and 8. 9, 12, 13 and 15 are dressed with 

 complete fertilizers, including nitrates. 



It will be noted that neither nitrogen nor other fertilizers were respon- 

 sible for large vine growth, but that in 12 out of 14 bogs having vine 



* Water applied to surface of bog. 



