﻿50 



BULLETIN 1374, U. S. DEPAETMENT OF AGEICULTUEE 



double seed and locks of cotton were picked out of this sample and 

 examined for pink boUworms. 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}^ minutes to 6M minutes] 



Test 

 No. 



Steam 

 pres- 

 sure 



Time of 

 exposure 



Number 

 of larvse 

 in test 



Temperature 

 of seed on 

 discharge 



Mor- 

 tality 



Germina- 

 tion 



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 



Aver. 



Aver 



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 

 24r-25 

 20-21 

 35-30 

 40-41 

 33-48 

 40 



32-33 

 63-59 

 44-40 

 ige 



Minutes 

 2H-6 

 3 -6 

 2>^5K 

 2M-6 

 3 -6 

 3 -6 

 2M-6 

 3 -6 

 3 -6M 

 3 -6J/2 

 3 -6 

 3 -6H 

 3 -6 

 2M-6J^ 

 2J4-6 

 2>^6M 

 2>^6 

 2M-6 

 2M-6 

 3 -5^ 

 2}i-6 



3 -evz 



2H~m 



3M-6M 

 3 -6 



2M-6 



2Ji-6M 



2M-6 



2M-6M 



3 -6H 



2J^6M 



3 -6 



2J^-6 



3M-6J€ 



2M-6 



2M-6M 



3 -6H 

 3 -6 



25 

 34 

 29 

 21 

 25 

 26 

 16 

 22 

 29 

 25 

 21 

 24 

 27 

 23 

 26 

 23 

 27 

 28 

 25 

 25 

 22 

 27 

 33 

 37 

 28 

 30 

 27 

 19 

 26 

 30 

 18 

 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 

 146 -145 



145 -146.5 



145 -156 



146 -145.5 

 148 -145.5 

 146 -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 



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 



Per cent 









































75.5 

 75.0 

 70 5 

 81.0 

 71.0 

 80 5 

 70 

 73.5 



64.0 

 82.0 

 61.5 



71.5 

 73.5 



72.5 

 68.0 



72.6 

 74.8 



ige 6 untr 



eated check 



s .. 













Steam pressure readings were taken at the beginning and at the 

 end of each test. The difference between the two readings which 

 usually 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 larvse that were alive before the seed was treated. Tempera- 

 ture records were obtained by catching one bucket of seed immedi- 



