32 



BULLETIN 976, U. S. DEPARTMENT OF AGRICULTURE. 



6-inch spacing to 65.3 per cent in the 18-inch spacing. The maxi- 

 mum, 72.7 per cent, was produced in 1917 from a stand of 32.7 

 inches of row space to the plant. A low percentage of suckers was 

 produced by all rates of seeding in 1918. 



The number of stalks bearing heads varies widely between the 

 spacings in some seasons. The number or percentage of headed 

 stalks usually increases as the stands decrease. This is especially 

 true for the poor seasons of 1916, 1917, and 1918. 



The best total crop yields were produced in 1915, and the poorest 

 in 1918. The highest yield, 11,710 pounds, was from the 6-inch spac- 

 ing in 1915; and the lowest, 1,080 pounds, from the 12-inch spacing in 

 1918. The highest grain yield does not always accompany the high- 

 est total crop yield. Seasonal conditions at and following heading 

 largely govern the grain yield. Favorable seasons are conducive to 

 high grain yields from thick stands, while thin stands have the advan- 

 tage in unfavorable seasons. In the favorable season of 1915 the 

 highest grain yield was from a stand having 8.8 inches of row space 

 to the plant. In the poor seasons of 1916, 1917, and 1918 the highest 

 yields were produced by stands with 6 to 7 inches of row space to the 

 plant. A study of the average yields for a series of years is essential 

 to determine the rate which will give the best results under average 

 conditions. These are presented in Table XVI. 



Table XVI. — Annual and average yields of Dawn kafir in rov:s spaced 3h feet apart in 

 the spacing experiments at the Amarilla Cereal Field Station during the 6-year period 

 from 1914 to 1919, inclusive. 



[In the statement of yields per acre the bushel is rated at 60 pounds.] 





Yields per acre. 



Average yields per acre. 



Row space per plant. 



1914 



1915 



1916 



1917 



1918 



1919 



3 years, 

 1915, 

 1917, 

 and 

 1919. 



4 years, 



1915 to 



1918. 



5 years, 

 1914, 

 1915, 

 and 



1917 to 

 1919. 



5 years, 

 1914 to 

 1916, 

 1918, 

 1919. 



6 years, 

 1914 to 

 1919. 





Bu. 



8.7 

 18. 5 

 18.7 

 19.0 



Bu. 

 60.2 

 69.0 

 68.3 

 62. 7 

 55.5 



Bu. 

 1.0 



5.8 

 3.8 



Bu. 

 14.8 

 12.2 



17.8 

 26.8 



Bu. 

 0.7 

 1.8 

 .7 

 3.3 



Bu. 

 38.8 

 25.4 

 32.3 

 32. S 

 29.7 



Bush. 

 37.9 

 35.5 



Bush. 

 19.2 



Bush. 

 24.6 

 25.4 



Bush. 

 21.9 



Bush. 

 20.7 









25.2 

 24.3 







37.8 

 37.3 



21.9 



27.1 



23.2 



21 to 26 inches 















The annual and average acre yields from the six spacings are shown 

 in Table XVI. The first or thick rate has a stand in the different 

 years with 6 to 7 inches of row space to the plant. The second rate 

 has a stand with 8 to 10 inches of row space to the plant. This rate 

 is omitted in 1916, and the 11 to 12 inch stand is missing in 1917. 

 The 15 to 19 inch stand continued through the 6-year period, but the 

 21 to 26 inch stand obtains only in three years. In order to get com- 

 parisons of all rates it is necessary to strike averages for a 3-year, a 

 4-year, two 5-year, and a 6-year period. In the 3-year average, 



