UNITED STATES DEPARTMENT OF AGRICULTURE 
In Cooperation with the 
Kansas and Missouri Agricultural Experiment Stations and the 
Brooklyn Botanic Garden 
DEPARTMENT BULLETIN No. 1284 
Washington, D. C. 
August, 1925 
SORGHUM SMUTS AND VARIETAL RESISTANCE IN SORGHUMS 1 
By George M. Reed, Curator of Plant Pathology, Brooklyn Botanic Garden, 
formerly Pathologist in Charge of Cereal-Smut Investigations, Office of Cereal 
Investigations, Bureau of Plant I ndustry, and Leo E. Melchers, Plant Patholo- 
gist, Kansas Agricultural Experiment Station, and Agent, Office of Cereal Investi- 
gations, Bureau of Plant Industry 
CONTENTS 
Page 
Introduction 1 
Smuts attacking sorghums 2 
Covered kernel smut 3 
Loose kernel smut 5 
Head smut 7 
Sorghum smuts not known to occur in 
the United States 10 
Classification of the sorghums 12 
Location of the experiments 12 
Methods employed in the varietal studies 13 
Inoculation experiments with covered kernel 
smut 14 
Results with shallu 14 
Results with sorgosand grass sorghums.. 15 
Results with broomcorn 20 
Results with kaoliang 22 
Inoculation experiments with covered kernel 
smut — Continued. 
Results with kafir 25 
Resultswith durra 29 
Resultswithmiloandfeterita 31 
Results with miscellaneous sorghums 35 
Inoculation experiments with head smut 40 
Experiments with milo and feterita with 
reference to their resistance to Sphacelotheca 
sorghi 41 
Germination studies on various sorghums . 43 
Influence of external conditions on kernel- 
smut infection 44 
General conclusions 49 
Bibliography 51 
INTRODUCTION 
The sorghums now occupy an important place among American 
farm crops. They have been found well adapted to the southern 
half of the Great Plains area, which includes the western portions 
of Kansas, Oklahoma, and Texas and the eastern portions of Colorado 
and New Mexico, where crop production is very largely governed 
by the quantity and distribution of the annual rainfall. In this sec- 
tion, under the conditions of low annual precipitation and its uneven 
i The preparation of the manuscript of this bulletin was finished by the writers on August 31, 1923, 
but publication has been unavoidably delayed. 
The senior writer is specially indebted to Director F . B . Mumford, of the Missouri Agricultural Ex- 
periment Station, for his courtesy in permitting the use of the data obtained at that station in this bulletin. 
Special acknowledgments are due to Charles R. Hursh, Fred N. Briggs, Charles H. Philpott, and Miss 
Jessie A. Cline for assistance in the investigations at the Missouri Agricultural Experiment Station, 
and to Ivan A. White and Charles O. Johnston for assistance at the Kansas Agricultural Experiment 
Station. Alden A. Potter, then assistant pathologist in the Office of Cereal Investigations, conducted 
the experiments at Amarillo, Tex., from 1916 to 1918 and also assisted the junior writer at Manhattan, 
Kans., in the same years. Miss Marion A. Griffiths gave valuable aid at Arlington Experiment Farm 
in 1919 and 1920, and Miss NaomiHowells assisted intheinvestigationsat Brooklyn in 1921. The writers 
also are greatly indebted to John F. Ross, formerly superintendent of the Cereal Field Station, Amarillo, 
Tex., for sowing and caring for the experimental plats at that station. 
This is paper No. 206 of the Department of Botany and Plant Pathology, Kansas Agricultural Experi- 
ment Station, and also Brooklyn Botanic Garden Contribution No. 33 
106639°— 25t 1 
