HARD RED WINTER WHEATS IN DRY AREAS 39 
The average percentages of stem-rust infection on 23 varieties of 
wheat in comparison with Kharkof are shown in Table 21. Kharkof 
wheat shows an average stem-rust infection of 9.2 per cent in 12 
station years, during which the degrees of rust infection varied from 
0 to 25 per cent in different years. Most of the hard red winter 
varieties did not differ greatly from Kharkof in average rust infec- 
tion. Kanred during seven station years showed an average infec- 
tion of 6 per cent less than Kharkof. Less than five observations 
were made on the other varieties which had less rust than Kharkof. 
Kanred apparently is the most rust-resistant wheat grown in these 
experiments. 
Of the soft red winter wheats, Buffum No. 17 showed only a 
slightly higher rust infection than Kharkof, while Minhardi in three 
station years showed an infection 8 per cent higher. Nebraska No. 
28, because of its earliness, is able to escape rust better than Kharkof. 
HEIGHT OF PLANT 
The height of the wheat plant is of economic importance because 
it determines the method or ease of harvesting. The height of 
different varieties of wheat, as measured from the surface of the ground 
to the tip of the spike, has varied considerably in these experiments. 
The average height of Kharkof wheat during 106 station years in 
these semiarid areas is 30.3 inches, but its stature has varied from 
16 to 46 inches. The height of Kharkof wheat at Moccasin, Mont., 
was 46 inches in 1915, but only 17 inchesin 1919. The height of the 
wheat plant is determined by the amount of elongation of the inter- 
nodes of the culm and is influenced by numerous soil and climatic 
factors. In the Great Plains and Great Basin the height is affected 
chiefly by the climate, including the soil moisture which is the result 
of the annual precipitation. The height of the wheat plant is in- 
creased by high soil fertility, abundant moisture, humid atmosphere, 
moderately cool temperature, and other factors which favor vegeta- 
tive growth at the time of heading. In general, early varieties are 
shorter than late varieties. Late varieties which are normally 
quite tall are sometimes shorter than short early varieties in seasons 
having drought or hot winds at heading time. When the drought, 
temperatures, or hot winds are extreme, the heads of wheat may not 
be entirely exerted from the sheath. 
The average plant heights of the varieties of winter wheat grown 
during three or more station years in comparison with Kharkof are 
shown in Table 22. 
The average heights of the hard red winter varieties shown in 
Table 22 indicate that they do not differ greatly from Kharkof. 
Such varieties as Bacska, Banat, Hungarian, and Pesterboden differ 
from Kharkof in the size of the spikes and kernels as well as in height. 
The Blackhuli variety averaged 1.3 inches taller than Kharkof. 
Two strains of Crimean, C. J. Nos. 1483 and 1485, as well as Rieti 
and Ulta, appear’ to be somewhat taller than Kharkof. Other 
varieties having average heights more than 1 inch taller than Kharkof 
were grown only during limited periods. In general, those of the 
hard red winter wheats which can not be distinguished otherwise 
from Turkey and Kharkof are practically the same height as those 
varieties. Turkey (C. I. No. 1571) in 73 station years averaged 
0.1 inch shorter than Kharkof, 
