226 THE STRAWBERRY IN NORTH AMERICA 



Why varieties run out. Varieties that have been 

 in cultivation a long time and, apparently, have become 

 less vigorous and productive than when introduced, are 

 said to have "run out." Strawberries run out more 

 quickly than other fruits because of the shorter interval 

 between generations. Fifty years ago, when most 

 growers were beginning to find the Wilson less responsive 

 than it had been, it was thought that no variety of straw- 

 berry could be expected to last longer than twenty-five 

 years, even under the most favorable care. It was argued 

 that it is natural and inevitable for a variety to gradually 

 decline and that the only solution is to have a succession 

 of new sorts coming forward to replace the exhausted old 

 varieties. This theory has been effectually disproved. 

 J. M. Smith, of Green Bay, Wisconsin, grew the Wilson 

 profitably long after it had run out elsewhere. The 

 Longworth still is a profitable commercial variety in Cali- 

 fornia, although seventy-five years old. Several varieties 

 over one hundred years old are grown in England and are, 

 apparently, just as valuable today as when introduced. 

 There is no limit to the life of a variety if it has good care. 



The chief cause of running out is neglect. At the time 

 when growers were mourning the decline of the Wilson, 

 they were fruiting then* beds for six to twelve years, with- 

 out annual renewal. Not only was the vigor of the plants 

 seriously impaired, but, also, the beds became full of seed- 

 lings. " At this time we have but few beds of pure Wilsons 

 in this State," declared J. L. Budd of Iowa in 1876. "If 

 some known variety be not mixed with it, its own seedlings 

 are annually produced." Some prominent varieties have 

 declined and eventually disappeared because of their 

 susceptibility to disease; the Hunn was ruined by leaf 

 blight. Most varieties are lost because nurserymen 



