PLANS OF EXPERIMENTS. 17 



In the following; paojes are given in detail the data concerninji^ each 

 of the strains experimented upon, special attention being given to the 

 hairless Orel clover. 



PLANS OF EXPERIMENTS, ORIGIN OF SEED, AND METHODS OF 



PROCEDUJIE. 



For the present experiments about thirty regional varieties " of 

 red clover seed were secured from as many domestic and foreign 

 sources. Each station and individual cooperator has been furnished 

 with a series including from 16 to 21 of these strains, and these are 

 being grown side by side, in most cases on acre plats, under as nearly 

 uniform conditions as possible. The varieties came from sources 

 having a great diversity of climatic and soil conditions and methods 

 of cultivation, and are now being grown under a range of conditions 

 representing scarcely less diversity than those under which they 

 originated. Twenty States are represented in the whole experiment, 

 but of this number it is proposed to deal here only with those localities 

 where the promising Russian variety before mentioned is being 

 grown: ^linnesota, North Dakota, South Dakota, Nebraska,. Indiana, 

 Ohio, and Ontario. 



The circles on the sketch map of the United States (fig. 1) show 

 the approximate location of each of the stations, while the crosses 

 indicate the general region of each State from which the strains of 

 known American origin were secured. 



In the case of domestic varieties, every effort was made to secure 

 seed that had been grown in the region of origin for a period of years 

 and whose ancestry could as a consequence be followed to some extent. 

 In most instances the American strains used are directly traceable to 

 the identical field which produced them, and soil samples have been 

 secured for examination and comparison with the soils into which 

 they were transplanted. In the present bulletin only those varieties 

 grown in comparison with clover No. 16, the promising Russian 

 variety, will be discussed. All of the seed used in the work was 

 secured by the Office of Seed and Plant Introduction and Distribu- 

 tion, the foreign seed through Dr. E. A. Bessey and that of home- 

 grown varieties through the writer. 



a The term "variety" is not used in its strict botanical significance, but is employed 

 to designate seed from more or less widely separated sources. 



5164— No. 95—06 3 



