UNITED STATES DEPARTMENT OF AGRICULTURE 
BULLETIN No. 644 % 
f^* Contribution f»-om the Bureau of Piant Industry ^yw¥^ 
-$Zft*^5u WM - A - TAYJ-O % Chief 
Washington, D. C. 
PROFESSION 4L PAPER 
January 18, 1918 
LINT PERCENTAGE AND LINT INDEX OF COT- 
TON AND METHODS OF DETERMINATION. 
By G. S. Meloy, Assistant, Crop Acclimatization and Cotton Breeding. 
CONTENTS. 
Page. 
Relation oflintpercentagestolintindexes 1 
Lint percentages 2 
Lint indexes 2 
Illustrations of the relation between lint per- 
centage and lint index 3 
Lint index determines the number of bolls to 
the pound of fiber 5 
Relation of the lint index to the cost of pick- 
ing 5 
Increasing the lint percentage does net alter 
the cost of production if the lint index re- 
mains constant 8 
Page. 
Improved methods for obtaining lint per- 
centages 8 
Advantages of using samples cf standard 
weight 10 
Methods of calculating lint indexes and seed 
weights 10 
Number of seeds in a standard sample an in- 
dication of their size 10 
Planters can estimate the lint index 11 
Summary 11 
RELATION OF LINT PERCENTAGES TO LINT INDEXES. 
The danger of reducing the vitality and earliness of cotton vari- 
eties and of breeding varieties with undesirable characters by over- 
emphasizing the percentage of lint as a measure of their compara- 
tive values was pointed out in 1908 by Mr. O. F. Cook. 1 It was sug- 
gested that the weight of the lint or fiber ginned from 100 seeds, in- 
stead of the lint percentage alone, be used as an additional standard 
for judging varieties. This standard of comparison was called the- 
lint index. Subsequent experience has not only demonstrated the 
desirability of using this standard, but has led to the development 
of improved methods and devices for determining both the lint index: 
and the lint percentage in experimental samples of seed cotton with 
which breeders have to work. 
1 Cook, O. F. Danger in judging cotton varieties by lint percentages. U. S. Dept. Agr., 
Bur. Plant Indus. Cir. 11, 16 p. 1908. 
21683°— 18— Bull. 644 
