8 BULLETIN 1481, U. S. DEPARTMENT OF AGRICULTURE 
PLOT EXPERIMENTS 
During the period from 1911 to 1925, inclusive, 55 strains of fall- 
sown oats, representing about 11 more or less distinct varietal types, 
were grown in duplicated twentieth-acre or triplicated fortieth-acre 
field plots at the Arlington Experiment Farm. A number of these 
strains were tested for only short periods and were then discarded. 
Only the data from the varieties which have been grown continuously 
since 1911 and those which have been added in later years and have 
been continued to date are presented in this bulletin. Data obtained 
on varieties of minor importance are not presented. The data on 
the varieties discarded with the ending of the 1923 season have 
been published by Taylor (9, p. 9). 
In Table 2 are given annual and average acre-yield data of 26 
varieties and selections®* of fall-sown oats grown at the Arlington 
Experiment Farm for two or more years during the 15-year period 
from 1911 to 1925, inclusive. 
Of the 26 varieties on which data are presented in Table 2, only 
2 were grown for the entire period. These were Winter Turf (C. I. 
No. 431) and Culberson (C. I. No. 273). The average acre yield of 
the former was 52.1 bushels and of the latter 50.3 bushels. In 10 
years Winter Turf outyielded Culberson; in 5 years Culberson gave 
the better yields. The average yield of Culberson was 1.8 bushels 
less than that of Winter Turf. 
In 9 of the 15 years the average yields of each of these two varieties 
exceeded 50 bushels per acre, and in 6 years one or both of them 
yielded in excess of 60 bushels per acre. In 4 years the average 
yield of the two varieties was Jess than 40 bushels per acre, in 2 of 
which, 1912 and 1920, especially light crops were harvested. To 
summarize, in 15 years 9 good to excellent crops, 4 fair crops, and 2 
very light crops were harvested. 
During the Jast 15 years the average acre yield of fall-sown oats 
in the varietal experiments at Arlington has increased steadily. A 
comparison of the yields obtained from the same variety shows con- 
siderable change. During the first five-year period from 1911 to 
1915, inclusive, the average yield of the two varieties, Winter Turf 
and Culberson, was 42.5 bushels per acre; whereas in the second 
five-year period from 1916 to 1920 the average yield of these two 
varieties was 49.1 bushels per acre, an increase of 6.6 bushels. In 
the last five-year period, 1921 to 1925, inclusive, the average increase 
yield was 19.6 bushels greater than that for the first five-year period and 
13 bushels greater than for the second five-year period. The average 
yield for the five-year period from 1921 to 1925 for these two varieties 
was 62.1 bushels. 
Several factors probably have contributed to this result. Soil 
conditions have improved on the Arlington Experiment Farm, owing 
to the continued use of commercial fertilizers, stable manure, and 
green-manuring crops. This has resulted in increased soil fertility 
and consequent higher acre yields. Natural selection also may have 
been partially responsible for increased yields. The older oat vari- 
eties are by no means homozygous, but contain numerous distinct 
strains. In growing a variety “continuously under severe winter con- 
3 All Cereal Investigations (C. I.) numbers and Georgia station numbers in this and succeeding table$ 
followed by dash and additional numeral or numerals indicate selections of the varieties named. 
