CEREAL EXPERIMENTS AT JUDITH BASIN" SUBSTATION. 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 fail 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 
fail. 
Frost-free 
period. 
1909 
May 15 
June 2 
June 4 
May 12 
May 19 
Oct. 12 
Aug. 23 
Sept. 15 
Sept. 15 
Sept. 9 
Days. 
150 
82 
103 
126 
112 
1914 
May 12 
May 16 
Sept. 12 
Sept. 11 
Days. 
123 
118 
1910 
1915 
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 applicable 
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, 
