12 BULLETIN" 1334^ U. S. DEPAETMENT OF AGEICULTUEE 
is developing in northwestern Kansas. This area has extended 
southward into Oklahoma and Texas. The section is of especial 
interest, as there is an overlapping of conditions which allow types 
of barley adapted to quite different ecological regions to be grown in 
the same general area. In central Nebraska barleys of the Manchuria 
type grow very well. In northwestern Kansas those of the Coast 
and Stavropol types are most commonly grown. These varieties 
are cultivated farther south, and in Oklahoma their culture is found 
in the same district with winter barleys of the Tennessee Winter 
types. This is the only district in the United States where the 
extensive culture of both winter and spring varieties meets. In the 
Central States there is a margin of several hundred miles between 
the southern limit of profitable culture of spring barley and the 
northern limit of profitable culture of winter barley. It is true that 
in Ohio, Pennsylvania, and Maryland, and in the Palouse district 
of Washington, Oregon, and Idaho, both winter and spring barleys 
can be grown. Winter barleys in these States, however, are of only 
local importance, and the acreage is small. 
The general distribution of barleys over the United States has 
followed the course of the settlements. It is a natural inquiry as to 
what influence agricultural experiment stations have had, especially 
on the varieties cultivated. Prior to 1870 the barleys under cultiva- 
tion were doubtless those that had been introduced by the colonists, 
and agronomic experiments probably had little influence. Since 
then, however, the varieties grown on the farms have been greatly 
affected. As has been stated before, the experiment farm at Madison, 
Wis., began testing and distributing barley about 1873. 
It is likely that most of the 6-rowed barley of the northern Mis- 
sissippi Valley as now grown consists largely of varieties introduced 
by experiment stations. Kecently in California these stations have 
introduced varieties which have been substituted on a large scale for 
others previously grown. 
EXPERIMENTAL METHODS DEVELOPED 
There is a feeling among many agronomists that the early experi- 
ments are without value, but a study of the data shows that this 
feeling is justifiable only in part and is not entirely warranted. The 
agronomic work of the older experiment stations has passed through 
three distinct phases of development. In the earliest phase the sta- 
tions were undermanned and without suitable equipment for carry- 
ing on varietal tests. They worked with varieties obtained by chance 
and often with many of the de^^able types absent from tlie tests. 
In the middle period both equipment and personnel were on a better 
basis, and larger collections of material were available for comparison. 
The tests were conducted, however, on the single-plat basis. 
Recently the tcchnic of field testing has been improved. Plats are 
more carefully laid out. Methods of testing have been developed, 
and a sufficient number of replications have been carried to form a 
basis for a statement of the probable mathematical significance of 
the yield. Unfortunately, one is not able to fix these periods by 
dates, as each station went through these phases independently. 
Some stations are not yet replicating plats. 
