UNITED STATES DEPARTMENT OF AGRICULTURE 
BULLETIN No. 618 
Y£^ Contribution from the Bureau of Plant Industry S__ 
sSVV VW$» WM. A. TAYLOR, Chief S^&^&fL. 
Washington, D. C. 
PROFESSIONAL PAPER 
March 13, 1918 
EXPERIMENTS WITH DURUM WHEAT. 
By Carleton It. Ball, Agronomist in Charge, and J. Allen Clark, Scientific 
Assistant, Western Wheat Investigations, Office of Cereal Investigations. 
Introduction 1 
Sources of data 1 
History 3 
Agronomic adaptation and production 5 
Adaptation 5 
Production 6 
CONTENTS. 
Page. 
Description and key. . 
Varietal experiments . 
Geographic scope. 
Results obtained . 
Summary of results. . . 
Bibliography 
Page. 
9 
13 
13 
16 
57 
61 
INTRODUCTION. 
Extensive experiments with the durum wheats have been con- 
ducted in this country for the last 10 to 15 years. During this period 
their commercial importance has increased steadily. At first they 
were regarded commercially with indifference, then with hostility, 
and finally with approval. Numerous bulletins have discussed their 
introduction and adaptation and also their value under more or less 
limited conditions. These publications are listed alphabetically by 
authors at the end of this bulletin. 
The purpose of the present bulletin is to assemble the principal 
accumulated experimental data on yields of durum wheat in the 
United States. Many of these data are here published for the first 
time. Some of them, however, have been published previously in 
the bulletins cited. The bibliography also includes citations of 
bulletins containing some results obtained with durum wheat which 
are not presented here. This bulletin discusses the history of durum 
wheat in the United States, the statistics of production, the charac- 
ters and relationships of the important varieties, and the results of 
experiments conducted at 30 field stations. 
SOURCES OF DATA. 
The experimental data have been derived from three chief sources, 
namely, experiments conducted cooperatively by the Bureau of 
Plant Industry and State agricultural experiment stations, experi- 
14644°— 18— Bull. 618 1 
