6 



BULLETIN 1029, U. S. DEPAETMENT OF AGRICULTURE. 



jury to the seed was caused at 96 hours ; therefore this method gave 

 some promise as a practical means of controL When it was extended 

 to other seed lots, however, the deleterious effects of the treatment 

 became evident at a much shorter exposure. This was most notice- 

 able in the case of No. 2-18 seed when treated in the second year. 



Table I. 



-Effect of desiccation and heat upon commercial cabbage seeds and 

 upon the black-leg fungus within infected seeds. 





Effect upon in- 

 fected seeds. 



Effect upon commercial seeds. 





o 



s 



■3 



o 



"3 



3 



> "^ 



a 



3 



M 



.2S 

 > >- 



■3-S: 



M 



22.3 

 







One-year 



-old seed. 





Two-year- 

 old seed. 



Treatment and length of 



Lot 3-18.0 



Lot 4-19.6 



Lot 10- 



18.': 



Lot2- 



18.0 



Lot 2-18.a 



exposure. 



It 



If 



"3 fe 

 ^^ 



ft 



a 

 o 



« o 



O 



>> 



d 



a 

 S 



(-1 ^ 



0) 



ft 



3 



«^ 



II 



(a o 



O 



■a 



>. 



t-i 

 3 



'5" 



S 



CO 



ft 



^^ 

 at 



oj a 

 O 



•a 



.2. 

 'a 



a 



o 



'■3 



as 



o 



s 



•3 

 S 



m 



■2 c 



11 



'S s 



hi 



q 



ft 

 a 



o 



03 



ll 



3 o 

 O 



>% 



3 



Untreated: 



4-18 

 1-19 



130 

 24 



75.3 

 66.6 





Exposed at constant tem- 

 perature: 

 At 85° C— 



6.38 



97 



o 



6.9 



3.17 

 2.97 

 1.69 

 1.51 

 1.42 

 1.22 



92 



77 

 64 

 79 

 62 

 67 

 54 



o 

 e 



4- 



93 



o 



92 



o 



7.11 

 ? 69 



77 



37 

 38 

 37 

 33 

 29 

 20 



o 



+ 



2 hours 

























2.31 



+ 



























+ 



6 hours 



4-18 

 4-18 

 4-18 

 4-18 

 4-18 

 4-18 

 4-18 

 4-18 



22 



4(1 9 







6.1 

 8.8 

 

 



16.0 

 2.2 

 



1.27 

 1.27 

 1.02 

 .85 

 .85 

 .72 

 .93 

 .78 



95 

 97 

 95 

 95 

 96 

 95 

 96 

 87 



o 



o 

 o 



e 







94 

 88 

 85 

 90 

 84 

 74 

 55 

 53 



8 



O 

 n 



2.12 

 1.85 



1.85 



-t- 



12 hours 



49 32.6 



87 

 88 



8 



-f 



24 hours 



45 

 49 

 46 

 25 

 44 

 49 



17.7 

 20.4 



4.3 

 36.0 



9.0 







-t- 







36 hours 



1.29 

 1.15 

 .73 

 1.22 

 1.10 



63 

 42 

 31 

 25 

 17 



-f- 

 + 

 + 

 + 

 + 







o 



1 Q? 



32 

 22 

 13 

 14 

 12 



+ 



48 hours 



71 

 58 

 17 



-i- 



-i- 1.63 

 -:- 1.32 



-~ 'i.a3 



+ 





-t- 



96 hours 



-f 



120 hours 





1 60 



4- 



At 90° C— 



4-18 

 4-18 

 4-18 

 4-18 

 4-18 

 4-18 



24 

 25 

 24 

 48 

 24 

 47 



25.0 

 4.0 

 4.1 

 4.1 

 

 





 

 

 

 

 



::;: 



93 

 63 

 57 

 10 



o 

 e 



-i- 



70 

 77 

 70 

 16 



O 



8 



78 

 29 

 30 

 



+ 

















* 





36 hours 















































2.06 

 1.40 

 1.02 

 .68 



.72 



3 



86 

 80 



85 

 88 

 87 



4- 

 O 



o 

 o 

 o 

 o 









38 



"=" 



3 



-(- 









At 95° C— 

 1 hour 





46 

 58 

 55 

 56 

 53 



+ 

 + 



-f 

 + 

 -1- 





2.53 

 2.09 

 1.85 

 1.74 

 1.85 



10 



1 

 5 

 2 



1 



+4- 





















+-f- 





















-\--\- 



6 hours 



















Jr + 





4-18 

 4-lS 

 4-18 

 4-18 



35 

 23 

 24 

 20 



2.8 

 

 

 





 

 

 



34 



^ 



66 

 33 



I 



4- 



-f- 



+ -I- 



18 hours 







.48 

 .36 

 .25 

 .31 

 .27 



1.31 



77 



21 















90 



22 











e 





21 



35 



15 







-1- 

 + 

 + 

 + 



8 

 2 



+ 

 + 



1 76 



2 

 1 

 

 



+ + 



36 hours 



.„.1.75 



4— t- 







1.63 

 1.74 



-f-4- 



72 hours ... 























-I-+ 



96 hours 

























Dried at 37° to 50° C. 5 days, 

 at 73° 3 days, then at 

 100° C: 











o 



-1- 













































































1 







36 hours 



























1 

































1 







a Wisconsin Hollander variety grown at Racine, Wis., in 1918. 



b All Seasons variety grown at La Conner, Wasn., in 1919, 



c Wisconsin All Seasons variety grown at Kacine, Wis., in 191S. 



d Symbols used: 0=Noinjury; ©=slight; -f-=medium; -f=severe; ++= very severe. 



