40 BULLETIN 33, U. S. DEPARTMENT OF AGRICULTURE. 
included in the regular varietal trial. All varieties are continued in 
the nursery at least three years before being discarded. 
PURE-LINE SELECTIONS. 
Pure-line selections have been made of several unpedigreed cereal 
varieties, which have proved well adapted to the conditions at 
Dickinson. Typical and sometimes unusual heads of the variety are 
selected in the field. The length of these heads and the number of 
kernels each contains are usually determined and the heads photo- 
graphed. Twenty kernels from each head are planted in rows 5 
feet long and 12 inches apart. The kernels are placed 3 inches 
apart in the row. Notes are taken throughout the growing season 
upon the comparative behavior of the different selections. Each 
row is harvested and thrashed separately, and the seed is used the 
following year for planting in the pure-line selection nursery, where 
they are more carefully studied and tested for yield. The pure-line 
selection nursery is similar to the varietal nursery, the rows being 
17 feet long and 12 inches apart. Equal weighed quantities of seed 
are sown in each row. Notes similar to those taken on the varieties 
are taken on the pure lines. Check rows sown with the unselected 
parent variety are used, and any improvement which is made is thus 
easily determined. This nursery is continued from year to year. 
All pure lines are usually grown three years before any are discarded. 
The highest yielding strains are then planted in larger plats of any 
convenient size, to increase the seed. Finally those pure strains that 
have proved superior to the parent, as well as to other pure lines, 
are introduced into the plat varietal trials. 
From such a large number of selections as there are at Dickinson a 
great mass of data has naturally been accumulated. The limits of 
this bulletin prevent its presentation here. As previously mentioned, 
a strain of Kubanka durum wheat, Kubanka No. 8 (C. I. No. 4063), 
and a strain of Early Mountain oats, Early Mountain No. 2 (C. I. 
No. 656), have been developed which have proved superior to the 
original varieties. In Table X XI some of the results obtained in 
1913 in improving the yield and the milling and baking qualities of 
Ghirka wheat are shown. This table shows the possibilities of im- 
provement and also the possible increase or decrease in quality and 
yield of grain that may be obtained from pure-line selections. 
