28 
BULLETIN 918, U. S. DEPARTMENT OF AGRICULTURE. 
Loss in the Quality of Lint. 
The 2-pound gin samples were sent to the United States Bureau 
of Markets for examination. Mr. George Livingston, Chief of 
Bureau, reported in letter dated April 13, 1920, as follows: 
In a general •way it may be stated that all of the samples were of very poor quality, 
especially as regards length and strength of staple. The results obtained through 
the ordinary commercial classification of cotton were confirmed by individual fiber 
strength tests which produced subnormal results. It is commonly considered that 
upland cotton should show an average strength for individual fibers of about 8 
grams, but none of the Mexican samples possessed that degree of strength. Several 
of the samples were so weak that a considerable portion of the fibers broke upon being 
inserted in the jaws of the testing machine. Such cotton is so weak in staple as to be 
practically unspinnable. 
The exact degree of the deterioration in the quality of lint men- 
tioned above which is due to the pink boliworm can not be definitely 
stated, but undoubtedly a certain percentage of it is caused by mal- 
nutrition of the seed, which arrests the development of the lint. 
Ballou (11, p. 265) states: 
In addition to the actual damage done to the lint and seed of the attacked seed, 
there is the injury which results to sound seed in attacked bolls. This appears to be 
a matter of malnutrition, the attacked seed making demands on the supply of the 
plant food to such an extent that nearly all the seeds in the boll are deprived of a 
portion of their nutriment. 
Loss in Weight of Seed. 
As the amount of seed destroyed or practically destroyed by 
P. gossypiella was found to assume proportions worthy of consider- 
able notice, an attempt was made to ascertain the exact loss by 
weight caused in this manner. From material picked during the 
year, samples of seed cotton were accurately weighed, hand-ginned, 
and the seed examined individually and weighed, with the following 
results : 
Table XIII. — Loss by weight to seed when hand ginned. 
Weight 
of 
sample. 
Total 
num- 
ber 
seed. 
Sound seed. 
Damaged seed. 
Lint. 
Sample. 
Num- 
ber of 
seed. 
Weight 
in 
grams. 
Aver- 
age 
weight 
per 
seed in 
gram. 
Num- 
ber of 
seed. 
Weight 
in 
grams. 
Aver- 
age 
weight 
per 
seed in 
gram. 
Loss in 
weight 
per 
seed in 
gram. 
Weight 
in 
grams. 
Per 
cent. 
First pick, Zara- 
gosa. 
Second pick, 
Zaragosa. 
Third pick, San 
Isidera. 
458 gms. 
(lib.) 
...do 
...do.... 
2,438 
2,855 
3,678 
2,282 
2,388 
1,753 
252.65 
244.38 
180.20 
0.1107 
.1023 
.1027 
156 
467 
1.925 
8.80 
34.40 
125.30 
0-0561 
.0736 
.0651 
0.0546 
.0287 
.0376 
158.12 
159.5 
141.5 
34.5 
34.8 
31 
Table XIII shows there was a smaller number of seeds in the 
sample from the first pick but that the individual seeds were heavier 
and the percentage of lint in the two samples was practically the same. 
