CEREAL EXPEEIMENTS AT JUDITH BASIN SUBSTATIOISI". 



9 



Table IX gives the dates of the last spring and first fall frosts and 

 the number of days in the frost-free period in each year from 1909 to 

 1915, inclusive. 



The longest frost-free period was 150 days, in 1909, and the shortest 

 82 days, in 1910. The latest frost in the spring was on June 4, in 

 1911. The average date of the last frost in the spring is May 20. 

 The earliest frost in the fall in the seven years occurred on August 23, 

 in 1910. The average date of the first frost in the fall is September 

 13. The average length of the frost-free period in the seven years is 

 116 days. 



Table IX. — Dates of killing frosts, the last in spring and first in fall, with length of 

 frost-free period in each year from 1909 to 1915, inclusive, at the Judith Basin sub- 

 station, Moccasin, Mont. 



[Data from the records of the Biophysical Laboratory of the Bureau of Plant Industry.] 



Year. 



Last in 

 spring. 



First in 

 fall. 



Frost-free 

 period. 



Year. 



Last in 

 spring. 



First in 

 fall. 



Frost-free 

 period. 



1909 .... 



May 15 

 Jiuie 2 

 June 4 

 May 12 

 May 19 



Oct. 12 

 Aug. 23 

 Sept. 15 

 Sept. 15 

 Sept. 9 



Days. 

 150 

 82 

 103 

 126 

 112 



1914 



1915 



May 12 

 May 16 



Sept. 12 

 Sept. 11' 



Days. 

 123 



1910 



118 



1911 



Average 





1912 



May 20 



Sept. 13 



116 



1913 









THE JUDITH BASIN SUBSTATION. 



LOCATION. 



The Judith Basin substation is located 2 miles west of the town of 

 Moccasin, in Fergus County, Mont., in the central part of the Judith 

 Basin and about the geographical center of the State. The latitude 

 is about 47° N., and the longitude 109° 45' W. The substation farm 

 is section 16, township 15 north, range 14 east. A branch of the 

 Great Northern Railway from Great Falls to Billings passes through 

 one corner of the station section. 



DESCRIPTION. 



The station farm consists of 640 acres. One corner of the farm is 

 creek bottom and the remainder is level, tillable bench land. About 

 320 acres are under cultivation and the rest is used for pasture. The 

 elevation at the substation is 4,300 feet. Figure 3 gives a view of the 

 substation buildings in 1915. 



It is believed that the results obtained at Moccasin are appUcable 

 to the whole of the Judith Basin and in a general way to the 20,000,000 

 acres of dry land throughout the State, where the annual rainfall and 

 its distribution are the chief factors limiting crop growth. 



SCOPE OF THE EXPERIMENTS. 



The experiments with cereals may be divided into two groups, 

 plat tests and nursery tests. A general view of the plat and nursery 

 is shown in figure 4. The plat experiments consist of varietal, 



