20 BULLETIN 1374, U. S. DEPARTMENT OF AGRICULTURE 
As will be noted, none of the check samples were entirely free 
from pink bollworm damage, the average percentage reduction in 
weight of seed of these samples being 0.83 of 1 per cent. This was 
due to the difficulty of determining from outside appearances that 
locks of cotton actually contained seed that had been damaged by 
the pink bollworm. The average percentage reduction in weight 
of the seed (4.7 per cent) would appear rather low. This was to be 
expected, however, as all the samples were of the first and only 
picking in the fields from which they were taken, no second crop of 
any consequence having been produced in these fields. This fact 
should also be taken into consideration in connection with the data 
on damage to the lint. 
DAMAGE TO LINT 
In Table 16 are given the results of tests of the lint samples sub- 
mitted to the Bureau of Markets. 
The first four headings under "'Lint'' come under "quality," 
whereas the "percentage of lint" shows the effect of the pink boll- 
worm on the quantity of lint. There is more difference in the case 
of the unirrigated than in the irrigated cotton. The 1.7 per cent dif- 
ference, however, is not the entire reduction in quantity of lint. It 
is based on the actual weight of the seed, and this had been reduced 
by the pink bollworm. Comparing with the calculated production 
of lint in the check samples, there is a reduction of the quantity of 
lint in the samples of average pick of 5.9 per cent. As in the case of 
the seed samples, however, the lint samples were possibly too small 
to be considered as accurately giving the lint turnout. This is indi- 
cated by the rather wide variations found in some of the. samples. 
The averages given must therefore be considered only as approxi- 
mations. 
NONPICKABLE COTTON 
In the foregoing discussion "nonpickable cotton'' was referred to as 
representing part of the total damage done by the pink bollworm to 
the crop of bolls that actually reach maturity. Nonpickable cotton 
(fig. 8) is the open cotton left in the fields after the crop has been 
harvested on account of being too severely damaged by the pink 
bollworm to be picked. It is expressed as a percentage of the total 
crop matured and can be determined fairly accurately. In deter- 
mining the percentage of nonpickable cotton, several representative 
points were selected in each field, and in 1921 counts were made of 
all bolls, both picked and unpicked, on a certain number of plants 
and- the number of impicked locks in these bolls, and in 1922 counts 
were made of a certain number of bolls both picked and unpicked on 
consecutive plants and the number of unpicked locks in these. The 
total bolls and the unpicked locks were then reduced to the same 
basis, using for the number of locks per boll a figure either arbitrarily 
set or determined by actual boll examinations in the fields in which 
counts were made. (In 1921 the first method was followed, the 
figure used being 4.5 locks per boll; in 1922, using the second method, 
an average of 4.43 locks per boll was obtained.) From these figures 
the percentage represented by the unpicked locks is calculated. 
In Table 17 are given the percentages of nonpickable cotton sep- 
arately for the irrigated '■ and unirrigated fields for both 1921 and 
1922 and for "zoca" (volunteer cotton) for 1922, based on counts 
