UNITED STATES DEPARTMENT OF AGRICULTURE 
DEPARTMENT BULLETIN No. 1386 
Washington, D. C. 
July, 1926 
SOME PANICLE CHARACTERS OF SORGO 
By Horace B. Cowgill, 1 Assistant Agronomist, Office of Sugar Plants, Bureau of 
Plant Industry 
CONTENTS 
Page 
Introduction 1 
Review of the literature 3 
Characters useful in classifying and 
identifying types and varieties 7 
Description of plant 
Vegetative portion 8 
The inflorescence 9 
Characters of the vegetative parts__ 10 
Characters of the panicle 10 
The peduncle 11 
Contrasted panicle characters-- 11 
Length, furrowing, and color oi 
the axis 13 
Page 
Characters of the panicle — Contd. 
Pubescence of the axis 14 
Branches of the panicles 14 
Pubescence of the branches 15 
The fertile spikelet 15 
The sterile spikelet 25 
Varietal groups 28 
Descriptions of varieties 30 
Effuse group 30 
Contracted group 32 
Compact group 34 
Literature cited 36 
INTRODUCTION 
A more complete knowledge than has hitherto been published of 
varietal differences in sorgo, the group of sorghums known as the 
saccharine group, is needed for the following purposes: (1) For dis- 
tinguishing between sorts recognized by growers and between tax- 
onomic forms and for classifying and making a key to them; (2) for 
determining the purity of sorts, since frequently, as cultivated, they 
are intermixtures of a number of more or less diverse races, and as 
such intermixtures often become intercrossed heterozygous forms 
also are frequently included: and (3) for use in the study of inheri- 
tance in breeding. 
The need of making careful distinctions between types is doubt- 
less greater where the crop is utilized for making sirup than where 
used as forage for livestock. In the former case the relative value 
of varieties is dependent upon definite requirements in the composi- 
tion of the stalk, to a degree equal to or greater than that of tonnage 
yield of stalks obtainable per acre or than that of agronomic suit- 
ability. Although composition may have some significance also when 
1 Acknowledgment is due to James F. Brewer for much assistance in the photographic 
work. 
67898— 2( 
