NORTHERN GREAT PLAINS FIELD STATION, 1913-1922 67 
The results from the flax varietal experiments in the years 1914— 
1916 show what may be expected of flax on breaking under favorable 
conditions. The results from the flax varietal experiments from 1917 
to 1922, inclusive, indicate what may be expected of flax on old land 
under exceptionally dry conditions. The average acre yield of all 
varieties on breaking during 1914, 1915, and 1916 was 14.8 bushels. 
The average acre yield of all varieties grown on old land in the years 
1917 to 1922, inclusive, was 4.1 bushels. The season of 1921, when 
the crop was a total failure, is included in this average. 
The average acre yields of five varieties for the 6-year period from 
1917 to 1922, inclusive, were as follows: Reserve (C. I. No. 19) 
4.5 bushels; Damont (C. I. No. 3) 4.3 bushels; North Dakota Resist- 
ant No. 52 (C. I. No. 8) 4.0 bushels; North Dakota Resistant No. 114 
(C. I. No. 13) 3.9 bushels; and, Primost (C. I. No. 12) 3.8 bushels. 
The large-seeded varieties, Reserve and Damont, again yielded better 
than the small-seeded varieties, North Dakota Resistant No. 114 
and Primost. 
A rate-of-seeding experiment similar to that on breaking was con- 
ducted on old land during the years 1917-1921. On account of the 
dry seasons, the differences in yield were not large enough to be signifi- 
cant. The results indicate, however, that on a loose seed bed on old 
land slightly better yields may be expected from seeding 25 pounds 
per acre than from less. 
Experiments on the date of seeding flax on old land have indicated 
the advantage in dry seasons of giving the land thorough cultivation 
with a disk harrow before seeding, in order to destroy weeds, espe- 
cially the Russianthistle, which is the worst weed in the dry-land 
area. Plats disked twice or three times at intervals of two weeks 
between cultivations and sown May 15 or June 1 were more free 
from weeds and the yield of seed was higher than from plats disked 
only once and sown April 15 or May 1. 
experiments with flax grown continuously on the same land have 
indicated that North Dakota Resistant No. 114 can be depended 
upon to produce a crop on flax-sick soil. 
Investigations with flax canker have indicated that excessive heat 
will girdle the plants at the soil line, causing them to fall over and 
die. This subject is treated fully in Department Bulletin No. 1120." 
Flax varieties obtained from many parts of the world have been 
grown in nursery rows and classified according to height, earliness, 
type of plant, resistance to wilt, yield of seed, and other charac- 
ters. These nurseries have furnished valuable material for breeding 
new flax varieties. 
FLAX AND CEREAL MIXTURES 
Experiments in growing flax in mixture with wheat, oats, and barley 
were carried on in 1917 and 1918. A fair yield of the mixed crop was 
obtained in 1917. In 1918 the flax was a failure both in mixture and 
where sown alone. The mixture of flax with Marquis spring wheat 
gave better results than the mixture of flax with oats or, barley. 
The yield of the mixed crop in 1917 was 1.5 bushels of flax plus 9.9 
bushels of wheat, as compared with 7.2 bushels of flax alone and 
13.3 bushels of wheat alone. 
14 Reddy, C. S., and W. E. Brentzel. Investigations of heat canker of flax. U.S. Dept. Agr. Bul. 
1120, 18 p., 4 fig., 5 pl. 1922. (Literature cited, p. 17-18.) 
4 
