50 
BULLETIN 1374, U. S. DEPARTMENT OF AGRICULTURE 
double seed and locks of cotton were picked out of this sample and 
examined for pink boliworms. The larvae found were removed from 
the seed and kept in pill boxes for a time to make certain that none 
revived. 
Results of one set of tests are given in Table 42. 
Table 42. — Tests conducted with a dry heat disinfecting machine for destruction 
of the pink bollworm in cottonseed 
[Time of exposure ranging from 2)4 minutes to 6M minutes] 
Test 
No. 
Steam 
pres- 
sure 
212 
237 
216 
207 
214 
233 
234 
217 
238 
243 
218 
244 
220 
242 
221 
231 
229 
215 
211 
219 
213 
240 
236 
239 
222 
245 
230 
226 
210 
232 
241 
228 
209 
223 
235 
208 
227 
224 
225 
Pounds 
8- 4 
16-15 
15-11 
20-30 
21-23 
11- 9 
15-21 
20-20 
22-21 
20-21 
20-21 
22-22 
20-18 
18-18 
27-25 
15-17 
14-17 
20-19 
24-22 
20-35 
18-16 
25-27 
15-21 
25-25 
26-26 
22-22 
20-20 
35-33 
25 
18-18 
24-25 
20-21 
35-30 
40-41 
33-48 
40 
32-33 
63-59 
44-40 
Time of 
exposure 
Minutes 
2^-6 
3 -6 
23^-5^ 
2^-6 
3 -6 
3 -6 
2M-6 
3 -6 
3 -6M 
3 -6H 
3 -6 
3 -6H 
3 -6 
2M-63^ 
2H-6 
2V2-6H 
2M-6 
2^-6 
I 2^-6 
! 3 -&A 
2H-6 
i 3 -6H 
j 2H-5K 
3M-6M 
3 -6 
1 2M-6 
2H-6M 
2M-6 
2M-6M . 
3 -6M 
, 2H-6M 
3 -6 
2^-6 
3M-6M 
2H-6 
2H-m 
3 -6U 
Number Temperature 
of larvae of seed on 
in test discharge 
Mor- 
tality 
Germina- 
tion 
25 
34 
29 
21 
25 
2o 
16 
22 
29 
25 
21 
24 
27 
23 
25 
23 
27 
28 
25 
25 
22 
27 
33 
37 
28 
3u 
27 
19 
26 
30 
IS 
21 
24 
12 
20 
31 
19 
28 
27 
° F. 
141 -136 
138 -137 
142. 5-138 
141 -138.5 
141 -139 
139. 5-139. 5 
139. 5-153 
140 -140 
143. 5-140 
140. 5-141 
141 -144.5 
143 -142.5 
143 -143 
144 -143 
146. 5-143 
143 -148 
143 -153 
147. 5-143. 5 
148. 5-144 
144 -149 
-145 
-146. 5 
-156 
-145. 5 
-145. 5 
-147 
148. 5-153 
151 -149.5 
150 -150 
150 -151 
155. 5-150. 5 
150. 5-158 
153 -151 
154 -151.5 
152. 5-169 
153 -154 
156. 5-158 
161. 5-163 
163 -166 
146 
145 
145 
146 
148 
146 
Per cent 
100 
91.2 
93.1 
90.5 
100 
100 
100 
86.4 
100 
96 
100 
100 
100 
100 
. 100 
100 
100 
100 
100 
100 
100 
100 
100 
100 
100 
100 
100 
100 
100 
100 
100 
100 
100 
100 
100 
100 
100 
100 
100 
Pet cent 
75.5 
75.0 
70.5 
81.0 
71.0 
80.5 
70.0 
73.5 
64.0 
82.0 
61.5 
71.5 
73.5 
72.5 
68.0 
Average 
Average 6 untreated checks. 
72.6 
74.8 
Steam pressure readings were taken at the beginning and at the 
end of each test. The difference between the two readings which 
usually r, occurred can be ascribed to difference in boiler pressure. 
The greater pressure required in some tests than in others, though 
the same discharge temperatures were obtained, was due either to 
difference in feeding or to absorption of heat by the machine, which 
usually took place for some time after steam was first applied each 
day. The time of exposure was ascertained by dropping a handful 
of colored seed into the hopper while the machine was in operation. 
The time required" for the first and the last of these seed to pass 
through gave the two readings. Both extremes represent only single 
scattered seeds, the majority coming out within a period of about 
one minute. In the column " Number of larvae in test" are included 
only larvae that were alive before the seed was treated. Tempera- 
ture records were obtained by catching one bucket of see,d immedi- 
