10 BULLETIN 430^ U. S. DEPARTMENT OF AGRICULTURE. 



number of varieties in the nursery than m the plats. Only the 

 data obtained from the plat tests are reported in this paper. All 

 rate-of-seeding and date-of-seeding experiments have been con- 

 ducted on field plats. 



SIZE AND ARRANGEMENT OP PLATS. 



In 1913 and 1914 tenth-acre plats were used in varietal, rate-of- 

 seeding, and date-of-seeding experiments. Tlie plats were 2 by 8 

 rods, or 33 by 132 feet, arranged hi series of 67 plats. The plats in 

 each series were separated by 5-foot alleys and the series of plats 

 were separated by 20-foot roadways. Thus each plat was bordered 

 on each side by a 5-foot alley and on each end by a 20-foot road. 

 Li 1915 the plats used were a thirtieth and a twentieth of an acre, 

 being 11 by 132 feet and 16.5 by 132 feet, respectively. The thir- 



FiG. 4.— Farmers' round-up on the Cheyeniie Experiment Fann, Archer, Wyo. Each year the 

 fanners in the community visit the station and inspect the experimental work. (Photograph lent 

 by the Office of Dry-Land Agriculture Investigations.) 



tieth-acre plats were separated by 18-inch alleys and the twentieth- 

 acre plats by 30-inch alleys. Thus the thirtieth-acre plats were 

 bordered on the sides by 18-mch alleys and on the ends by 20-foot 

 roads. The twentieth-acre plats had 30-inch alleys on each side 

 and 20-foot roads on each end. The long dimension of the series 

 extended east and west, while that of the plats extended north and 

 south. The series are designated by the letters A to M. The plats 

 are numbered from 1 to 67, inclusive. 



REPLICATION OF PLATS. 



In 1913 the winter wheats were grown in dupHcate tenth-acre plats. 

 The spring wheats and other spring cereals were grown in single 

 tenth-acre plats. In 1914 all winter and spring cereals were grown 

 in single tenth-acre plats except a few spring-wheat varieties, which 



