194 THE STRAWBERRY IN NORTH AMERICA 



Klondike that is ten days earlier; a variety adapted to 

 the hot climate of the Imperial Valley, California; a 

 William Belt that is more resistant to leaf spot ; a variety 

 that has the qualities of color, firmness, acidity and pro- 

 ductiveness that make it especially valuable for canning. 

 The way in which a strawberry breeder should direct 

 his efforts toward a specific object is illustrated by the 

 work of N. E. Hansen and C. C. Georgeson. The winters 

 in northern Minnesota, North and South Dakota, Mani- 

 toba and Saskatchewan are so severe that most of the 

 common varieties winter-kill outright, even under a 

 heavy mulch. Others are not killed, but are so weakened 

 that the stand is poor and the yield light. In 1899 and 

 1900 N. E. Hansen, of the South Dakota Experiment 

 Station, began work to produce " varieties that will be 

 hardy without winter mulch or protection of any kind." 

 The Dakota prairie strawberry, a form of F. virginiana, 

 was crossed with some of the hardiest of the standard 

 sorts, including Princess, Warfield, Enhance, Van Deman, 

 Beder Wood, Bisel, Seaford and Glen Mary, which were 

 found hardy in about the order named. The prairie 

 strawberry does not winter-kill but it is defective in other 

 respects, especially in size, and in multiplicity of runners. 

 Efforts were made by Hansen to improve the native berry 

 by making selections of pure seedlings as well as by cross- 

 ing it with good varieties. The result was a number of 

 seedlings that are able to endure forty degrees (F.) below 

 zero without being mulched; but they are so small in 

 berry that they are of value only where the standard 

 varieties winter-kill. This work is being continued with 

 the wild strawberry of Alaska, which has larger fruit than 

 the prairie strawberry. The work of C. C. Georgeson, 

 at the Alaska Experiment Station, is another illustration 



