Advances in agronomy volume 05

ADVANCES IN AGRONOMY
VOLUME V


This Page Intentionally Left Blank


ADVANCES IN

AGRONOMY
Prepared under the Auspices of the

AMERICAN
SOCIETY
OF AGRONOMY

VOLUME V
Edited by A. G. NORMAN
University of Mkhigan, Ann Arbor, Michigan

ADVISORY BOARD
J. E. ADAMS
G. W. BURTON
J. E. GIESEKING
I. J. JOHNSON

RANDALL JONES
C. E. MARSHALL
R. Q. PARKS
K. S. QUISENBERRY

1953

ACADEMIC PRESS INC., PUBLISHERS
NEW YORK


Copyright 1953, by
ACADEMIC PRESS INC.
125 EAST2 3 STREET
~ ~
NEW YORX 10, N. Y.

A11 Rights Reserved

N o part ol this book may be reproduced in any
form, by photostat, microfilm, or any other means,
withozlt written permissiolt from the publishers.

Library of Congress Catalog Card Number : (50-5598)

PRINTED IN THE UNITED STAlTB OD' AMERICA


'CONTRZBUTORS
TO VOLUME
V

F. E. BROADBENT,
Associate Professor of Soil Microbiology, Department

of Agronomy, Cornell University, Ithaca, New Pork.
M. B. DAVIS,Chief, Horticulture Division, Central Experimental Farm,
Department of Agriculture, Ottawa, Canada.
C. H. GOULDEN,Chief, Cereal Division, Experimental Fwm Service,
Department of Agriculture, Ottawa, C a d .
I;. W. HURLBUT,
Chairman, Department of Agricultural Engbaeerilzg,
University of Nebraska, Lincoln, Nebraska.

M. L. JACKSON,
Professor of Soils, University of Wiscomin, Madison,
Wisconsin.
R. W. LEUKEL,Plant Pathologist, Division of Cereal Crops a w l Diseases,
BureaDepartment of Agriculture, Beltsville, Maryland.

N. A. MACRAE,Chief, Tobacco Division, Experimental Farms Nervice,
Department of Agriculture, Ottawa, Canada.
E. R. &kKIBBIN, Research Administrative Officer, Central Experimental
Farm, Departmemt of Agriculture, Ottawa, Canada.
0. R. MATHEWS,Agronomist, Division of Soil Management and Irrigation Agriculture, Bureau of Plant Industry, Soils a d Agricultural
Engineering, U.S. Department of Agriculture, Beltsville, Maryland.

0. R. NEAL,Agronomist, Chemical Corps Biological Laboratories, C a m p
Detrick, Frederick, Maryland.

P. 0. RIPLEY,Chief, Division of Field Husbandry, Xoils amd Agriczlltural
Engheering, Experimental Farms Service, D e p w t m e n t of Agriculture, Ottawa, Canada.
S. C. SALMON,
Principal Agronomist, Division of Cereal Crops and Diseases, Bureau of Plant Industry, Soils and Agricultural Engineering,

U.S. Department of Agriculture, Beltsville, Maryland.
Q. DONALDSHERMAN,
Professor of Soils, Urviversity of Hawaii, H o w -

lulu, Hawaii.

T. M. STEVENSON,
Chief, Parage Plants Division, Experimental P a m s
Service, Department of Agriculture, Ottawa, Canada.
V


This Page Intentionally Left Blank


Preface
The planning of the volumes of this series is a highly educational
experience for the editor, who solicits and receives many suggestions
from his colleagues on the Advisory Board and other agronomists. It
impresses on his mind the breadth and vigorous development of the field
of agronomy, and the diverse interests and accomplishments of those
who can be called agronomists, or who work in ancillary fields. With
this, Volume V, there will have been published more than forty articles,
no two of which cover the same ground. Along with many additional
subjects yet to be treated, it is our intention to return to some of these
forty topics in later volumes in order to present progress reports on the
most recent advances.
I n this volume the only new departure is the inclusion of a review of
somewhat unusual length, recounting authoritatively the history of the
establishment of a major crop in the United States. This crop, wheat,

occupies, and has always occupied, a vital place i n our national economy
and in world trade. At times, as now, there is a domestic surplus; at
other times there may be a shortage in world markets; a,t all times the
real need for wheat by the world’s population probably fa r exceeds the
supply. Much of it is grown in regions where substitution by other
crops is not feasible and in the face of natural hazards that may result
in crop failure. By many the adequacy of the domestic supply of wheat
is too readily taken for granted. The agronomic advances that have
been made with this crop have been less generally recognized and publicized than those with some lesser crops. It is, therefore, salutary to
look backward as well as forward in this case in order to see the distance
that has been traversed, as well as the paths that lie ahead. This has
been done by Dr. Salmon and his colleagues for the U. S., and by Dr.
McKibbin and Dr. Goulden for Canada. Taken together, these constitute a comprehensive account of wheat and wheat improvement on the
North American continent.
Equally complete, but in a wholly different field, is the review on
weathering of minerals, which is the primary and most basic natural
phenomenon in soil genesis. It might be argued that this is hardly
agronomy, a debate which will not be entertained here. Without quesvii


viii

PREFACE

tion, the inherent fertility of soils and hence their productivity stems in
great measure from the nature of the parent minerals and the type and
extent of the weathering processes.
The policy of surveying the agronomic trends in individual countries
is continued in this volume by the inclusion of a review of the pattern of
agronomy and horticulture in Canada. It is anticipated that one article

of each volume will be of this character.

A. G. NORMAN

A m Arbor, Michigan
September, 1953


CONTENTS
Contributors to Volume V
Preface

. . . . . . . . . . . . . . . . .

........................

Page
v
vii

A Half Uenturg of Wheat Improvement in the United States

. .

. .

.

. .

BY 8 C S~LLMON.
0 R . MATHEWS.AND R W LEUKEL.U S Department
of Agriculture. Beltsville. Maryland

. Introduction . . . . . . . . . . . . . . . . . . . . . .
3
. Acreage. Yield per Acre. and Production in the United States . . . . 4
. Improvement in Cultural Practices . . . . . . . . . . . . . . 25
. The Role of Improved Varieties . . . . . . . . . . . . . . . 52
. Improvements in Methods of Breeding Wheat . . . . . . . . . . 112
. Control of Diseases . . . . . . . . . . . . . . . . . . . 121
. Control of Insect Pests of Wheat . . . . . . . . . . . . . . . 133
Acknowledgments . . . . . . . . . . . . . . . . . . . . 141

I
I1
I11
IV
V
VI
VII

References.

......................

141

The Soil Organic Fraction

. .
I. Introduction . . . . . . . . . . . . . . . . . . . . . .
I1. Formation Processes . . . . . . . . . . . . . . . . . . .
I11. Distribution in Soils . . . . . . . . . . . . . . . . . . .
I V. Composition . . . . . . . . . . . . . . . . . . . . . .
V. Physicochemical Properties . . . . . . . . . . . . . . . . . .
V I. Methods of Determination . . . . . . . . . . . . . . . . .
V I I . Contribution to Plant Nutrition . . . . . . . . . . . . . . .
V I I I. Conclusion . . . . . . . . . . . . . . . . . . . . . . .
References . . . . . . . . . . . . . . . . . . . . . . .

BY F E BRO~BENT.
Department of Agrononzy. Cornelt University. Ithaca. New Pork
153
154
155
158
165
174
176
180
181

Promet!& in Agricultural Engineering

. .
I. Introduction . . . . . . . . . . . . .
I1. Concept of Agricultural Engineering . . .
111. General Characteristics of Modern Farming .
I V. Future Trends . . . . . . . . . . .

V. Concluding Statements . . . . . . . .

BY L W HURLBUT.Nebraska Agricultural Ezperiment Station. Lincoln. Nebraska

References

.
.
.
.
.

.
.
.
.
.

. . . . . . .
. . . . . . .
. . . . . . .
. . . . . . .
. . . . . . .

.......................
ix

.

.

.

.

185
186
187
190
216
216


.OONTENTS

X

Chemical Weathering of Minerals in Soils

. .

BY M L JACKBON.
U n h e r d t y of W k c o d n . Madison. W k m n d n .
AND G DONALD
SHERMAN.University of Hawaii. Honolulu. Hawaii

.

Page
221

231
240

. Introduction . . . . . . . . . . . . . . . . . . . . . .

I
I1
I11
IV

. Relative Stability of Minerals; Weathering Sequences and Indexes . . .
. Factors Affecting the Reaction Rates of Chemical Weathering . . . .
. Frequency Distribution of Minerals in Soils in Relation t o Chemical
Weathering . . . . . . . . . . . . . . . . . . . . .
V . Weathering Release of Nutrient Elements from Soil Minerals . . . . .
V I. Summary . . . . . . . . . . . . . . . . . . . . . . .
Acknowledgments . . . . . . . . . . . . . . . . . . . .
References . . . . . . . . . . . . . . . . . . . . . . .

258
291
306
309
309

The Uhanging Pattern of Agronomy and Horticulture in Canada

. .

COMPILED

BY R R MOKIBBIN.Central Experimental F m . Department of
Agriculture. Ottawa. Canada

. . . . . . . . . . . . . .

I. Introduction by R . R . McKIBBIN
320
Cereals by C. H GOULDEN . . . . . . . . . . . . . . . . 322
. Field Husbandry. Soils and Agricultural Engineering by P 0. R I P L E Y 339
352
Forage Crops by T M STEVENSON
Horticulture by M . B . DAVIS
366
Tobacco by N . A . MACRAE . . . . . . . . . . . . . . . . 375
References . . . . . . . . . . . . . . . . . . . . . . .
381

.
.
.
.

I1
I11
IV
V
VI

.

. .

.

.

. . . . . . . . . . . . .
. . . . . . . . . . . . . . .

8011 Management for Conservstfon and Produdivity

. .

BY 0 R NEAL.Camp Detrick. Frederick. Maryland

.
.
.

......................

I Introduction
I1 Factors Influencing Soil Structure . . . . . . . .
I11 Boil Management for Structure Maintenance . . . .
I V Influence of Rotations on Conservation and Productivity
V Chemical Soil Conditioners
VI.Summary
References

.

.

383

. . . . . . 384
. . . . . . 390
. . . . . . 394
. . . . . . . . . . . . . . . . . 402
. . . . . . . . . . . . . . . . . . . . . . . 404

.......................
Author Index . . . . . . . . . . . . . . . . . . . . . . . .
Subject Index . . . . . . . . . . . . . . . . . . . . . . . .

405
407
419


A Half Century of Wheat Improvement in the
United States
S. C. SALMON. 0. R. MATHEWS.

AND

R . W. LEUKEL

United States Department of Agriculture. Beltaville. Maryland
CONTENTS

.

Page
3

. . . . . . . . . . . . . . . . . . . . . .
I1. Acreage. Yield per Acre. and Production in the United States . . . .
1. Production Trends . . . . . . . . . . . . . . . . . .
a . The Southern Great Plains . . . . . . . . . . . . . .
b. The Northern Great Plains . . . . . . . . . . . . .
c. The Eastern States . . . . . . . . . . . . . . . .
d. The Pacific Northwest . . . . . . . . . . . . . . .
e. Development of the Durum Wheat Industry . . . . . . .
2 . The Preresearch Era . . . . . . . . . . . . . . . . .
a . Early Developments in Kansas . . . . . . . . . . . .
b . Early Wheat Growing in Nebraska . . . . . . . . . .
c. Early Wheat Growing in the Northern Great Plains . . . . .
d . Developments in the Pacific Northwest . . . . . . . . .
e. Wheat in California . . . . . . . . . . . . . . . .
f . Wheat Growing in the Eastern States . . . . . . . . . .
3. The Propaganda Era . . . . . . . . . . . . . . . . .
4. The Modern Research Era . . . . . . . . . . . . . . .
111. Improvement in Cultural Practices . . . . . . . . . . . . . .
1. Early Cultural Practices . . . . . . . . . . . . . . . .
2. Improved Practices in the Eastern States . . . . . . . . . .
3. Improved Practices in the F a r West . . . . . . . . . . . .
a. Methods of Preparing Fallow . . . . . . . . . . . . .
b . Disposition of Heavy Stubble . . . . . . . . . . . . .
c. Use of Fertilizers . . . . . . . . . . . . . . . . .
d. Legumes in Rotation with Wheat . . . . . . . . . . .

4. Improved Practices in the Great Plains . . . . . . . . . . .
a. Early Experiments in Dry-Land Agriculture . . . . . . .
b. Early versus Late Tillage for Winter Wheat . . . . . . .
c. Experimenta with New Tillage Implemeuts . . . . . . . .
d. Fallow in the Great Plains . . . . . . . . .
. . .
e. Fall versus Spring Plowing for Spring Wheat . . . . . . .
f . Depth and Kind of Tillage for Spring Wheat . . . . . . .
g. Time and Rate of Seeding Wheat . . . . . . .
. . .
h . Methods of Seeding Wheat . . . . . . . . . . . . .
i . Crop Rotation in the Great Plains . . . . . . . . . . .
j . Fertilizers in the Great Plains . . . . . . . . . . . .
5 . United States’ Consumption of Fertilizere on Wheat . . . . . .
6. Mechanization of Wheat Culture . . . . . . . . . . . . .
I Introduction

4
4
7
7
9
10
10
13
13
15
16
17
18

20
21
23
25
25
26
27
27
29
29
30
30
32
33
34
35
43
44
44
45
46
47
47
48


. C. SALMON. 0. R . MATHEWS.

2

S

.

AND R

. W . LEUKEL

.
.
.
.

.

.

.
.

.
.
.

.
.
.
.
.
.

.
.

.

.

.
.
.
.
.

.

.

.
.
.
.

.
.

.
.
.
.
.

.

.
.
.
.

Page
52
53
57
72
74
75
75
76
77
83
84
93

. . . . . . . . . . . . . . .
. . . . . . . .
. . . . . .
. . . . . . . . . . . .
. . . . . . . . . . . . . . . . .
. . . .
. . . . . . . . . .
. . . . . . . . . . . . .
. . . . . . . . . . . . . . .

I V The Role of Improved Varieties
1 Improved Varieties of Hard Red Spring Wheat
a Are the Improved Varieties Superior to the Old4
2 Improved Varieties of Durum Wheat
a Relative Yields
3 Improvement of Varieties for the Hard Red Winter Area
a Factors Affecting Choice of Varieties
b Early Varietal Improvement
c Principal Achievements
4 Improvement of Varieties for the Western United States
a Varieties for the Pacific Northwest
b Varieties in California
c Varieties in the Intermountain Areas
d Quality of Western Wheats
5 Improvement of Varieties for the Eastern United States
a Early Improvement in Varieties
b Recent Achievements
c Relative Yields and Increased Production
d Quality
6 Recapitulation
7 Varieties for the Future
V. Improvements in Methods of Breeding Wheat
1 Early Methods of Breeding
2 Objectives in Breeding
3 Resistance to Disease, Insect, and Weather Hazards
4 Testing for Comparative Yields
5 Techniques for Measuring Quality
a Milling Quality
b Quality for Bread

c Pastry Quality . . . . . . . . . . . . .
d Bread-Baking Tests for Soft Wheat
e Macaroni Quality
f Ancillary Quality Tests
VI Control of Diseases
1 Stem Rust
a History and Distribution
b Development of Resistant Varieties . . . . . .
c Discovery of Physiologic Races
d Barberry Eradication
2 Leaf Rust
3 Control of Rusts by Dusting
4 Stripe Rust
5 The Smuts of Wheat
a Bunt or Stinking Smut
b Loose Smut
c m a g smut
6 Wheat Mildew
7 Miscellaneous Diseases
a.Scab

. .
. .
.

.

.
.

. .

. . . . .
. . . . . . . . . .
. . . . . . . . . . . . . . .
. . . . . . . . . . 95
. . . . . . . . . . . . . 96
. . . . . 96
. . . . . . . . . . . . 98
. . . . . . . . . . . . . . . . 99
. . . . . . . . 104
. . . . . . . . . . . . . . . . . . .
109
. . . . . . . . . . . . . . . . . . . 109
. . . . . . . . . . . . . . . . 111
. . . . . . . . . . 112
. . . . . . . . . . . . . . . 113
. . . . . . . . . . . . . . . . 114
. . . . . . 115
. . . . . . . . . . . . . 117
. . . . . . . . . . . . 118
. . . . . . . . . . . . . . . . . 118
. . . . . . . . . . . . . . . . 118
. . . . 119
. . . . . . . . . 120
. . . . . . . . . . . . . . . . 120
. . . . . . . . . . . . . . 120
. . . . . . . . . . . . . . . . . . . 121
. . . . . . . . . . . . . . . . . . . 121
. . . . . . . . . . . . . . 121

. . . . 121
. . . . . . . . . . . . 122
. . . . . . . . . . . . . . . 122
. . . . . . . . . . . . . . . . . . . 123
. . . . . . . . . . . . . . . 124
. . . . . . . . . . . . . . . . . . .
124
. . . . . . . . . . . . . . . . . 124
. . . . . . . . . . . . . . 125
. . . . . . . . . . . . . . . . . . 127
. . . . . . . . . . . . . . . . . . . 128
. . . . . . . . . . . . . . . . . . . 129
. . . . . . . . . . . . . . . . 129
. . . . . . . . . . . . . . . . . . . 129


3

HALF CENTURY OF WHEAT IMPROVEMENT IN UNITED STATES

Page

. . . . . . . . . . .. . . . . . .
. . . . . . . . . . . . . . . . .

b. Anthracnose
c. Wheat Mosaics
d. Crown, Foot, and Root Rots

. . . . . . .

VII. Control of Insect Pests of Wheat . . . . . . . . .
1. Hessian Fly . . . . . . . . . . . . . . .
2. Grasshoppers . . . . . . . . . . . . . . .
3. Wheat-Stem Sawfly . . . . . . . . . . . .
4. Other Insect Pests of Wheat . . . . . . . . .

. . . . .

. . . . .
. . . . .

.
.
.
Acknowledgments . . . . . . . . . . . . . . . .
References . . . . . . . . . . . . . . . . . . .

.
.
.
.
.

.
.
.
.
.

.

.
.
.
.

.
.
.
.
.

131
131
132
133
134
136
138
139
141
141

I. INTRODUCTION
A little over fifty years ago Sir William Crookes (1899), President
of the British Association for the Advancement of Science, created a
mild sensation in the United States and startled his own countrymen by
warning them of the “deadly peril of not ha-ving enough to eat because
wheat production could not keep pace with the increase in population.”
“It is almost certain, ” he said, ( ( t h a t within a generation the ever-increasing population of the United States will consume all the wheat
grown within its borders and will be driven to import, and like ourselves,

will scramble for a lion’s share of the wheat crop of the world. The
details of the impending catastrophe no one can predict, but its general
direction is obvious enough.” The president of the British Association
was not a n alarmist and many authorities agreed with him. One in particular, John Hyde, chief statistician for the United States Department
of Agriculture, stated (1899) among other things that “for general agricultural purposes the public domain is practically exhausted and that
consequently there can be no further considerable additions to the faxm
area of this country is too well established to be the subject of controversy. ”
Allowing nearly a generation for error in timing, it is now clear that
these warnings were at least premature, for the United States instead of
importing wheat has supplied its own normal needs and produced a large
surplus for animal feed, alcohol, and food for her allies, and conquered
countries during and after the most devastating war known to mankind.
Neither Crookes nor Hyde saw, nor could they have been expected to
have anticipated, the tremendous effect tha.t research has had on the
capacity of the United States to produce wheat. This is common knowledge today but the details are not well known. Some account of them
should be of general interest and also of some value should there be, as
some believe, a continuing need for all the United States can produce.


4

S. C. SALMON, 0. R. YATIIEWS, AND R. W. LEUKEL

11. ACREAQE,
YIELDPER ACRE,AND PRODUCTION
IN THE UNITED
SFATES
1. Production Trends

In the five years ending in 1898 the United States produced 596,000,000 bushels of wheat as compared with 1,200,000,000 bushels for the five

years ending with 1948, an increase of 604,000,000bushels or slightly
more than 100 per cent. The increase is due both to more acres and to
more bushels per acre, as may be seen in Fig, 1, which shows the average
acreage, production, and yield per acre by census years or by ten-year
periods beginning with 1839. These graphs show that in spite of a
marked increase in acreage generally brought about by extension into
more hazardous and less productive areas, the average yield per acre has
not only been maintained but has increased. If the tendency to exaggerate yields per acre in the early days, as noted by Malin (1944),was
generally true, the actual increases are greater than those indicated here.
The harvested acreage and total production have increased almost
constantly since 1839. This increase is due mostly to the westward extension of wheat into new farming areas from the Atlantic Coast into
western Maryland, Pennsylvania, and New York, thence across Ohio,
Indiana, and Illinois into eastern Iowa and southern Minnesota and
reaching the eastern part of the Great Plains about 1900. Wheat production began in the Far West before the middle of the nineteenth century
and rapidly expanded after the discovery of gold in California in 1849.
Ball et al. (1921) have given an interesting account of this westward
march of wheat. Since 1900 (Baker, 1931) much of the expansion has
been into drier and more hazardous areas; this expansion was made possible by technological improvements such as development and use of
farm power and improved machinery, better methods of culture, better
varieties, more effective control of disease, insect, and weed pests, and
by a better knowledge of the relation of the wheat plant to its environment. A significant feature of this development has been a great reduction in the number of man-hours required to produce a bushel of
wheat.
Minnesota, which at one time was one of the leading wheat states,
now grows scarcely one-fourth as much wheat as fifty years ago and
Iowa one-eighth as much. Kansas, on the other hand, grows five times
as much, Nebraska twice as much, and Montana and Texas a thousand
times as much. Oklahoma, which grew practically no wheat before 1895
and less than 1,000,000 acres in any year previous to 1898, produced
an annual average crop in excess of 70,000,000 bushels during the past
ten years. Most of the increase in Kansas, Nebraska, Texas, and Montana is on land that moduced no wheat previous to 1900. Acreages have

HALF CENTURY OF WHEAT IMPROVEMENT IN UNITED STATES

5

also increased considerably in North Dakota and in the Pacific Northwest, especially in Idaho and Washington, generally into drier and less
productive areas. The California acreage and production are only about
half what they were before 1900.
The curve of Fig. 1 showing yields per acre is of special interest
because yields per acre are often used to measure or indicate technological improvements. They are reasonably good indices in countries in
which acreage remains fairly constant or where the productivity of the
new acreage does not differ materially from the old. They may be mis-

w
0

4
W
LL

u)

S
W

a

m

FIG.1. Production of wheat in the census years 1839, 1849, 1859, and 1869 and
average acreage, production, and yield per acre by ten-year periods in the United
States from 1870 to 1949.

leading, however, in a country such as the United States, where the
acreage has greatly increased into areas where the conditions for growth
are quite different. If an improvement reduces cost per acre, thereby
permitting a larger expansion on less productive land, average over-all
acre yields may actually be reduced.
The primary objective of the United States farmer has been to grow
more bushels a t a minimum of cost and inconvenience. He takes considerable pride in growing a good crop, but he is vitally concerned with
large yields per acre only to the extent that it contributes to his net income. The profit from wheat relative to that of other crops a1so has a
marked influence. If a new variety or a better cultural method results


6

5. C. SALMON, 0. R. MATHEWS, AND R. W. LEU-

in larger yields per acre, it may mean that wheat can be grown a t a profit
on less productive land. Given reasonably high prices or prospects of
such prices, the natural tendency is to increase production. A decrease in
crop acreage such as has taken place in the eastern United States may
mean a larger proportion of wheat on better land and hence larger overall yields per acre, even though there may have been no improvement
in technology.
The fact that yields per acre are based on harvested and not seeded
acres should also be considered. I n some years much wheat wm seeded
tha.t was not harvested, as shown in Fig. 2. The abandonment was espe-

1400

1910

1920
YEAR

I930

1940

FIQ.2. Acreage of winter and of spring wheat seeded in the United States but
not harvested.

cially heavy during the drought years 1933-1937, when the average exceeded 20,000,000 acres o r 28 per cent of the seeded acreage. Abandonment of winter wheat was heavy in 1912 and 1928, largely because of
winterkilling in Ohio, Indiana, and Illinois ; in 1917, because of winterkilling in Nebraska and Kansas; an d in 1925, because of winterkilling
in Washington, Oregon, Montana, and Texas.
Finally, it should be noted that the environmental conditions under
which wheat is grown today are different from those of fifty years ago,
even in the same areas. I n some cases soil fertility has declined and in
many cases there has been an increase in insect, weed, and disease pests,
in accordance with the well-known principle that concentration and con-


HALF CENTURY OF WHEAT IMPROVEMENT IN UNITED STATES

7

tinuation of a particular crop favors the pests peculiar to that crop.
Research unquestionably has aided in keeping these under control ; without research, acreages and yields per acre would probably be less than
they were in 1898.

The decline in yields per acre from 1900-1909 to 1930-1939 shown
in Fig. 1 is due largely to expansion into drier arem of the western
Plains and to the unprecedented drought during the mid-thirties. The
marked per acre increase for the 1940-1949 period, on the other hand,
was due in part to more favorable weather, to better vaxieties, to more
extensive use of fertilizers and pesticides in some sections, and to more
timely operations made possible by mechanization. Favorable prices
during this period, which permitted and encouraged the use of technological improvements, and better informed farmers as compared with earlier
periods are some of the other factors that should be recognized. It is
not possible on the basis of available information to evaluate these various factors separately, but some evidence of the importance of particular
ones will be presented later.
Figures 3,4, 5, and 6 give similar information for the principal wheat
states in the southern Great Plains, in the northern Great Plains, in the
Eastern States, and in the Pacific Northwest, respectively. Ea,ch of
these areas is relatively homogeneous as compared with the United States
as a whole.
a. The Xouthern Great Plains. Yields per acre in the southern Plains
have been relatively constant in spite of an enormous expansion in acreage into western Kansas, Nebraska, Oklahoma, and the Panhandle of
Texas. These are areas which up to about World Wa r I were generally
considered too dry to produce whea.t economically. A period of unusually high precipitation from about 1905 to 1915, aided and abetted by
real estate promoters and other enthusiasts, stimulated a n extensive influx of settlers and homesteaders into these drier areas. Many of them
failed because the information on which a sound agriculture could be
based was completely lacking, as we now know.
6. The Northern Great Plains. Excepting the ten-year period ending
in 1949, yields per acre have declined almost constantly in the northern
Great Plains, owing (1) to expansion into drier areas west of the Missouri River and (2) to increasing damage from stem and leaf rust, from
scab, and from weeds in the eastern half of the area. The severe drought
of the mid-thirties plus a severe stem rust epidemic in 1935 and extensive
damage from leaf and stem rust in 1937, 1938, and 1941 are primarily
responsible for low yields during those years. Both the northern and

southern Plains have been favored by above-average rainfall during the
past ten years. However, Heisig et al. (1945) have shown that yield


8

S. C. SALMON, 0. R. MATHEWS, AND R. W. LEUKIIL

375

20--

FIG.3. Average acreage, production, and yield per acre of wheat in Kansas,
Nebraska, Colorado, Oklahoma, and Texas for 1866 to 1869 and by ten-year periods
from 1870 to 1949.

375

300

7s

0

FIG.4. Average acreage, production, and yield per acre of wheat in Minnesota,
North Dakota, South Dakota, and Montana for 1866 to 1869 and by ten-year periods
from 1870 to 1949.


HALF CENTURY OF WHEBT IMPROVEMENT IN UNITED STATES

9

per acre trends in North Dakota and in Kansas for the period 1920-1945
are definitely upward even after they are adjusted for precipitation and
temperature effects. The indicated increase for Kansas during this period is slightly more than 2 bushels per acre and that for North Dakota,
about 4 bushels per acre. An important factor in the northern Plains
is the relative freedom from damage by stem rust since 1940.
o. The Eastern states. I n the eastern United States the acreage of
wheat has constantly declined to but little more than half that of the
peak period, 1880-1889. Yields per acre have constantly increased.

FIQ.5. Average acreage, production, and yield per acre of wheat in the Eaatern States for 1866 to 1869 and by ten-year periods from 1870 to 1949.

partly as a result of growing wheat on the more productive land while
reverting the poorer land to pasture and timber. Baker (1937) showed
a marked decline in the acreage of all harvested crops i n the eastern
United States, especially from 1919 to 1928. Johnson (1929) also mentions elimination of much of the poorer wheat land as one of the reasons
for the increase in yields of wheat in Pennsylvania. Lamb (1932, p. 15)
has shown that in Ohio wheat now occupies a smaller per cent of the
improved land than formerly. Wheat in the Eastern States is grown
almost exclusively in rotations with other crops. As Lamb (1932)
pointed out, the adoption of a rotation system of farming, and then of
longer rotations involving more spring grains, resulted in a decrease in
the wheat acreage. The constant and very material increases in yields


10

S.

C. SALMON, 0. R. MATHEWS, AND R. W. LEUKEL

per acre in the eastern United States has been due principally to more
fertilizers, better varieties, and more timely operations made possible by
power machinery.
d . The PacificNorthwest. Figure 6 shows the acreage, production,
and yields per acre in Washington, Oregon, and Idaho. Acreage increased constantly until 1920-1929 and then leveled off a t slightly less
than 5,000,000 acres. Yields per acre are relatively high, partly because
most wheat in this area is grown on summer fallow. Yields per acre
gradually increased up to 1930-1939, and much more rapidly thereafter,
owing in part to more favorable weather and also to a considerable de125

25

0

FIG.6. Average aareage, production, and yield per acre of wheat in Washington,
Oregon, and Idaho for 1866 to 1869 and by ten-year periods from 1870 to 1949.

gree to better varieties produced during this and earlier periods, and
to better cultural methods.
e. Development of the Durwm Wheat Ilzdwtry. The durum wheat
industry of the United States has been developed almost entirely since
1900. According to Carleton (1900, p. 19) a few thousand acres were
grown before that time in Texas and still are, although the amount is
insignificant in relation to the total. Also a small acreage was grown in
North Dakota from seed brought in by Russian emigrants at least as
early as 1893 (Shepperd and Ten Eyck, 1902). At the present time
more than 85 per cent of the durum wheat is grown in North Dakota,

principally in the eastern part of the state, west of the Red River Valley,


HALF CENTURY OF WHEAT IMPROVEMENT I N UNITED STATES

11

but extending into western Minnesota and northeastern South DakotaThe principal advantage of the durum wheats is resistance to the races
of leaf and stem rust that prevailed previous to 1950 and a n ability to
outyield common wheats in the durum area.
According to Ball and Clark (1918) durum wheat was first introduced into the United States in 1855 but never took hold, largely because
it lacked a market and partly perhaps because it was tried only in the
Eastern States, where it is not adapted. The early development of the
industry was due largely to the initiative and vision of M. A. Carleton,
cerealist of the United States Department of Agriculture, who made a
70

$
0

60

IS

50

l6 w

d

Q
0
W
K

14
v)
Y

In
I
30

12

20

10

10

0

1920-24

1925-29

1930-34

1935-39

1940-44

1945-49

FIO.7. Average acreage, production, and yield per acre of durum wheat in the
United States by five-year periods from 1920 to 1949.

trip to Russia in 1898-1899 and again in 1900 and made a thorough study
of the durum wheat production in that country. He was greatly impressed with the similarity of the climate and soil of this area to that of
the Great Plains of the United States and recommended the growing of
durums in the latter area. He was particularly impressed with what he
believed to be their drought resistance, and accordingly recommended
them for the drier portions of the Great Plains. He states (1901, p.
11): “They stand foremost among all wheat crops in their excellent
adaptation to heat and drought.” In a map of the United States published in 1900, he pictured the durum wheat area as comprising north
central Texas, western Oklahoma, and extreme southwestern Kansas. I n


12

S. C. SALMON, 0. R. MATHEWS, AND R. W. LEUKEL

a later ma,p (1901,p. 20) the recommended area extends in a wide belt
comprising most of the Great Plains from Mexico to the Canadian border.
As we now know, durums are not so resistant to heat and drought as
many adapted common wheats. They produced slightly higher average
yields than the common spring wheats in the drier areas, but the difference was not enough to offset the difference in market price. Carleton
recognized their leaf-rust resistance but considered this relatively unimportant. He did not realize that they were also resistant to stem rust
until after the severe and widespread epidemic of stem rust in 1904.

YEAR

FIG. 8. Average prices of hard red spring and durum wheats at Minneapolis,
Minnesota, for 1903 to 1905 and by five-year periods from 1906 to 1950. (Prices
for hard red spring wheat are for No. 1 Northern Spring, and for durum, No. 2
Amber Durum from 1903 to 1933 and No. 2 Hard Amber Durum from 1934 to 1950.)

Official estimates of the acreage and production of durum wheat as
distinct from hard red spring wheat were first made for North Dakota,
South Dakota, and Minnesota in 1909 and for the United States as a
whole in 1919. Carleton (1901) estimated that proba.bly 75,000 to
100,000 bushels were produced in 1901,and Ball and Clark (1918)state
that about 50,000,000 bushels were produced in 1906. The acreage, production, and yield per acre from 1919 to 1950 are shown in Fig. 7.
Acreage and production, it will be noted, reached a peak in the period 1925-1929 and then declined sharply to about half of the maximum,
principally because of a marked price differential in favor of the common spring wheats. Another important fact, as pointed out by Waldron


HALF CENTURY OF WHEAT IMPROVEMENT IN UNITED STATES

13

(1947), was the development of early-maturing, rust-resistant, highyielding common spring wheats beginning with CERES, eliminating most
of the advantages enjoyed by durum wheats. The prices were much less
for durum than for common spring wheat until about 1911, then nearly
equal up to and during World War I, followed with a decline soon after
the war, as shown in Fig. 8. Since 1930 the price of durum has been
about equal to, or above, that of hard red spring wheat.
The relatively low yields per acre during the 1930-1934 and 19351939 periods were due largely to unfavorable weather. The higher yields
for the 1940-1944 and 1945-1949 periods were due to more than usually

favorable weather and to the absence of severe damage from stem rust.
2. The Preresearch Era

Mr. William White has suggested that if one wants to study capitalism one of the best ways is to go where there isn’t any. Much can be
learned about research in the same way. Since wheat production before
the present century in what are now the principal producing areas was
largely without benefit of research, a study of this period should be informative. Malin (1944) has provided useful background information
for such a study in his agricultural history of four counties (Riley,
Qeary, Dickinson, and Saline) in east central Kansas, and much additional information is available in the reports of state boards of agriculture and agricultural experiment stations of the various states, in the
reports of the United States Department of Agriculture, and in the farm
press. Kansas is an especially fertile field for study because it is now
the leading state in wheat production, because it was one of the first
of the states of the Great Plains to be settled, and because the problems
of the early Kansas wheat grower were at least as numerous, aa important, and as difficult of solution as those of any other state.
a. Early Developments in Kansas. According to Malin, wheat was
grown in eastern Kansas as early as 1839, when 100 acres near Topeka
were harvested. It was seeded near Junction City, about 140 miles west
of Kansas City, in the fall of 1855, and increased rapidly thereafter in
the surrounding territory. Settlers coming to Kansas brought seed supplies, implements, and the methods and philosophies that prevailed in
the country from which they emigrated. Most of these were poorly
adapted to the new environment. Some adjustments or changes were
made quickly, but others came about very slowly.
Slow but powerful oxen broke much of the prairie for the earliest
settlers, but horses and mules were soon substituted for them. The tractor was not used for land preparation until well along in the present
century. Broadcasting the seed was a common practice; as we now


14

6. C. SALMON, 0. R. MATHEWS, AND R. W. IIETSKEL

know, this must have resulted in many heart-breaking disappointments
because of poor stands and winterkilling. It was not until about 1869
or after some fifteen or twenty years of experience that farmers were
sufflciently convinced of the advantage of drilling to ship in a substantial number of drills. Considerable wheat seems to have been broadcast
even as late as 1880. Soft winter wheat and spring wheat, the latter a t
first predominating, were the only kinds grown. Both are much more
susceptible to injury by rust, and the soft winter wheat is more easily
winterkilled than are the hard red winter varieties generally grown now
or even than were those that were common a t the close of the century.
Losses from rust and winterkilling were severe (Malin, 1944). Experimental evidence secured in recent years indicates that the soft winter
varieties then grown yielded no more than two-thirds as much, and the
spring wheat no more than one-third or one-half as much, as the TURKEY
wheat grown somewhat later. But nearly twenty-five years’ experience
was required to induce farmers to abandon spring wheat and nearly
thirty years elapsed after the introduction of TURKEY wheat before
farmers generally were convinced that it wa8 better than the soft winter wheats. Contrast this with recent Kansas experience in which three
varieties, PAWNEE, COMANCHE, and WICHITA, almost unknown to Kansas
farmers in 1944, occupied 71 per cent of the acreage in wheat in 1952;
or with the spread of THATCHER i n the northern Great Plains from a
nominal 20,000 acres in 1935 to nearly 12,000,000 acres in the United
States and 5,500,000 acres in Canada by 1941.
Little was known about the best preparation of the land or time of
seeding in the Great Plains or about the control of rust, smut, grasshoppers, chinch bugs, and Hessian fly. Time of seeding was a debatable
question as late as 1920. It still is, though to a very minor extent as
compared with fifty to seventy-five years ago. Much wheat was sown
too early and winterkilled. This caused reaction to the other extreme,
which also resulted in winterkilling or a late harvest and in more than
average injury from rust, drought, or high temperature. Much of the
wheat dried out before winter because it had been seeded on land that

had not been prepared until near seeding time, and the remainder often
produced low yields because the growth of weeds between harvest and
seeding had used up the available moisture and nitrates in the soil. Substantial improvements in tillage were made from time to time, but there
was no concerted effort to prepare the ground immediately after harvest
until about the second decade of the present century. Experiments by
the Kansas, Nebraska, and Oklahoma Experiment Stations showed very
material advantages from early soil preparation, and the advent of the
tractor made this possible.