THE CONTROL OF CABBAGE BLACK-LEG. 



15 



plats (Nos. 3 and 4) were watered artificially, care being taken to 

 avoid splashing and the distribution of pycnospores. 



A few infection centers appeared in all plats on or shortly after 

 June 9. Following this date the appearance of new centers and suId- 

 sequent spread was greatest in plat 2 and nearly as rapid in plat 1, 





MAY 

 5 10 15 20 25 5 



JUNE 

 /O 15 20 25 



JULY 

 5 (0 15 20 11 



AUGU5T 



5 10 15 ZO 25 



SEPTEMBER 



5 10 15 20 25 









1 1 



1 J . L_ 1 



1 





























nAU/VL^ W/O. /7/0 







































g 





























1. 



L_J . 





p , , 





1 





1 







1 







A 







j 









1 





















RACING, W/S.I9J9 





















































































II . 



\ 



L_iL_ 



1 











1 



L _i 















































MAD/30/V,W/3.l9/9 

















































L 



































1 



. 1 





! 









1 



i 



_Lj 

















































Af^A^/lS///l,lV/J. 19/9 























































La 





























\ . 



\ . 



. A. 







1 . 



J 



, 



1 I.I 













L 



i. 





N£^ LO/VD 



o/v,w/3.im 

































1 1.0 



1 

































'\\\ 



— -■- - - 



































_ J. 





l_ _! 



1 1 



_, 











1 



^ ' 



5 to 15 20 Zb 5 10 15 20 Zb 



MAY JUNE 



5 10 15 20 Z 



JULY 



5 5 iO 15 20 25 



AUGUST 



5 10 15 -< 



5EPTEM 



25 



Fig. 1. — Precipitation records made by the United States Weather Bureau at Racine, Wi: ., 

 in 1918 and 1919 and at Menasha, Wis. (nearest station to Appleton), and New Lon- 

 don, Wis. (nearest station to Shiocton), in 1919. 



while in the protected plats very little spread took place. The rain- 

 fall which occurred at Madison during the experiment is recorded in 

 figure 1. The beds were kept under observation until August 4, 

 which is about four weeks beyond the normal date for transplanting. 

 The final estimate of the extent of the disease made at this time is 

 presented in Table V. It is clear that where the splashing action of 



