HAEDINESS IN SUCCESSIVE ALFALFA 

 GENERATIONS 



L. R. WALDRON 

 Dickinson, North Dakota 



In 1908 .Mr. Charles J. Brand, of the Department of 

 Agriculture, inaugurated an experiment in alfalfa to de- 

 termine, among other things, the relations that different 

 strains of alfalfa have to the cold of severe winters. The 

 writer aided in this investigation. 



For this purpose 68 regional strains of alfalfa were 

 assembled from the various alfalfa regions of the world, 

 many of them being foreign in immediate origin. The 

 alfalfas were planted in hill and drill rows, and during 

 the season of 1908 the rows were thinned so that accurate 

 countings could be made. There were in the neighbor- 

 hood of 80 plants to each strain. The winter of 1908-09 

 was particularly severe to alfalfa, and as a consequence 

 most of the strains were sadly deleted. 1 



Twelve of the 68 strains were entirely killed, no living 

 plants remaining. Twenty-eight of the strains killed out 

 over 90 per cent., and over 60 per cent, of the strains 

 killed out over • 80 per cent. There were but 3 of the 68 

 strains that killed out less than 10 per cent. The killing 

 of the American alfalfas was severe as indicated by the 

 fact that the 9 strains from Utah killed over 90 per cent., 

 while the 3 Montana strains killed over 65 per cent. 



The hardier strains were those of more recent foreign 

 origin. Two strains of the Grimm alfalfa had an aver- 

 age killing of less than 5 per cent., thus being the hardiest 

 in the nursery. Neglecting the 12 strains that killed out 

 entirely, the average killing of the nursery amounted to 

 77.51 per cent., using each strain as a unit. 



'Charles J. Brand and L. E. Waldron, "Cold Eesistance of Alfalfa and 

 Some Factors Influencing It," Bulletin 185, Bureau of Plant Industry, 

 U ' S - Department of Agriculture. 



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