40 BULLETIN 878, U. S. DEPARTMENT OF AGRICULTURE. 
Marquis of 18.8 per 'cent during the same station years. Although 
a high-yielding variety in seasons of rust epidemics, the D-5 wheat 
is only a fair yielder when rust is not a factor. Arnautka (C. I. No. 
1493) shows a higher percentage of rust than Kubanka (C. I. No. 
1440), the Arnautka haying only 5.7 per cent less rust, while the 
Kubanka had 10.8 per cent less rust than Marquis. Two pure-line 
selections of these varieties, Arnautka (C. I. No. 4064) and Kubanka 
No. 8 (C. I. No. 4063), have each a higher percentage of rust infection 
than the original unselected varieties mentioned above. Kubanka 
(C. I. No. 1516), from which the Acme variety was selected, shows 
slightly less rust infection than Kubanka (C. I. No. 1440). In 1919, 
Golden Ball proved to be somewhat resistant. Owing to the limited 
data the rust infection of the Mindum variety of durum wheat is not 
shown in Table XVII, but this variety is known to be much more 
resistant than Arnautka. The Pierson and Buford have the highest 
percentage of infection of all durum varieties shown in Table XVII, 
BUSHEL WEIGHT. 
The bushel weight of all varieties of wheat at the 11 stations has 
been determined nearly every year by the use of a standard test 
kettle. The weights have varied according to seasonal conditions. 
In the northern half of the Great Plains area the frequency of 
drought, hot winds, rust, and scab has resulted in shrunken kernels 
having low bushel weights during most of the years. 
The average bushel weight of 38 'varieties of spring wheat grown 
in the northern half of the Great Plains area is shown in Table 
NVTII. 
The average bushel weights of spring wheats, as shown in Table 
XVIII, are practically all less than the standard weight of 60 pounds 
per bushel, and nearly all less than the weights for the No. 1 grade- 
In experiments covering 57 station years in the northern half of 
the Great Plains, the average bushel weight of Marquis has been 56.3 
pounds. At Highmore, S. Dak., in 1916, the weight of Marquis was 
only 42 pounds, owing to the rust epidemic, but at Newell, S. Dak., 
in 1915, a very favorable season, Marquis had a bushel weight of 
62.5 pounds. 
None of the common spring varieties in the Fife and Bluestem 
groups had a higher bushel weight than Marquis, and Ruby was the 
only variety in these groups which had a weight equal to that of 
Marquis. Preston in 52 station years had an average weight of 57.4 
pounds per bushel, or 1.4 pounds heavier than Marquis. The differ- 
ences in bushel weight in either class of wheat shown in Table XVIII 
are due almost exclusively to differences in plumpness. Nearly all 
of the common varieties which were heavier than Marquis were 
slightly earlier and awned and evidently more evasive of drought 
and disease. 
