10 



BULLETIN 943, U. S. DEPARTMENT OF AGRICULTURE. 



No summer-fallow land was found in the winter-wheat districts, 

 and in the spring-wheat areas only a small percentage of the crop 

 area was summer-fallowed. 



The area devoted to flax production was also limited. 



The miscellaneous crops consisted principally of potatoes, millet, 

 spelt, and clover and timothy seed. 



CLIMATE. 



Although wheat is grown in localities in the United States having 

 widely different climates, it is a cool-weather crop', and produces the 

 largest yield of best quality where cool, moderately wet weather 

 prevails during the growing season and dry, sunny weather during 

 the ripening period. Wheat is not generally a safe crop where the 

 mean annual precipitation is less than 15 inches. In the districts 

 of densest production (North Dakota and Kansas) the annual pre- 

 cipitation ranges from 18 to 32 inches. Where the rainfall exceeds 

 45 inches a year wheat does not thrive, principally because rust and 

 fungus diseases are more prevalent there than in less humid districts. 



The distribution of the rainfall is as important as the total amount. 

 For instance, in Ford County, Kans., in 1918, the total rainfall was 

 normal, but the average yield of wheat for the county was only 3 

 bushels per acre. This low yield was due mainly to the small amount 

 of rainfall during the months of April, May, and June; in June it 

 was only one-fourth inch; and for the three months but 4.5 inches, 

 as compared with a normal rainfall of about 8 inches for these months. 



Table IV shows the average yearly precipitation for all districts 

 visited, as compared with the total rainfall for the year 1919: 



Table IV. — Mean annual rainfall for districts visited. 



Kegion. 



Weather station. 



Annual average. 



1919 



SPRING WHEAT. 



North Dakota: 





From 1910 to 1918 



From 1909 to 1918 



From 1892 to 1918 



From 1881 to 1918 



From 1915 to 1918 



From 1896 to 1918 



From 1860 to 1918 



From 1889 to 1918 



From 1890 to 1918 



From 1878 to 1914 a 

 From 1890 to 1918 



From 1891 to 1918 



From 1880 to 1918 



From 1890 to 1918 



Inches. 

 20.20 

 17.87 



20.64 



23.65 

 18.47 



20.32 

 22.70 

 31.16 



38.63 

 41.26 

 36.68 



24.84 

 28.85 

 16.62 



Inches. 

 25.32 





New Salem 



13.68 



South Dakota: 



Melette 



21.41 



Minnesota: 





23.75 







21.18 



WINTER WHEAT. 



Kansas: 



Dodge City 



13.70 







19.88 







31.46 



Missouri: 





36.12 













35.11 



Nebraska: 



Holdredge 



25.83 







33.42 







18.95 









a No record taken after 1914. 



