22 
5ULLETIX 1029, TJ. S. DEPARTMENT OF AGRIC"CXTURE. 
general. however, the disease was not very prevalent in Racine fields 
at the end of the season. Where the mercuric-chlorid and dry-heat 
treatments were combined, very little disease developed, but since 
mercuric chlorid alone controlled the disease as well in this locality, 
the superiority of the double treatment was not demonstrated. 
Table IX. — Development of cabbage black-leg in commercial fields grown from 
treated seeds in Wisconsin in 1919. 
Treatment. 
Field 
No. 
Diseased plants. 
Date 
Locality and seed lot. 
Affected. 
Prevent- 
ed from 
heading. 
of 
observa- 
tion. 
Racine: 
15-lSa 
15-lSa 
1 to 1,000 HgCl" 30 minutes, rinsed 
do 
1 
2 
3 
3 
4 
5 
6 
7 
8 
9 
10 
11 
12 
13 
Per cent. 
31.0 
97.0 
Per cent. 
4 
60 
11 
3 
25 
2 
11 
4 
1 
2 
1 
1.2 
( 6 ) 
.25 
Sept. 19 
Do 
13-18 a 
1 to 500 HgCl: 30 minutes, rinsed 
do 
Oct. 12 
2-18 a 
Do 
2-18 a 
do 
25 
2 
11 
4 
Oct 13 
2-18 a 
do 
Do 
2-lSa 
do 
Do 
2-18 a 
do 
Oct 11 
3-18a 
do 
Sept. 19 
Oct. 13 
3-lSa 
do 
2 
1 
1.2 
« 
.25 
3-lSa 
do 
Do. 
3-18. 
1 to 1,000 HgCl 2 20 minutes, rinsed, 
plus drv heat 85° C. for 72 hours. 
1 to 1.000 HgClo 20 minutes, rinsed, 
plus' drv heat 90° C. for 36 hours. 
1 to 1,000 HgCl 2 20 minutes, rinsed, 
plus dry heat 95° C. for 12 hours. 
1 tn 50Q HpTl g SO minntps, rinsed 
Do 
3-1S 
Do 
3-1S 
Do. 
Average, 5 fields, 
lot No. 2-18. 
Average, 3 fields, 
10.5 
1.0 
9.0 
1.3 
do 
lot No. 3-1S. 
1 to 1,000 HgCl; 30 minutes, rinsed 
do 
14 
15 
15 
Appleton: 
2-1S 
100 
100 
92 
90 
68 
63 
Oct. 10 
2-18 
Do. 
2-1S 
1 to 500 HgCl:: 30 minutes, rinsed 
1 tn 1,000 HgCl- SO Trtirmtps, rinsed 
Do. 
Average, 3 fields, 
lot No. 2-18. 
1 tn 500. TfgCA *30 Tninrttps, rinsed . . 
97.3 
73.6 
do 
16 
17 
18 
19 
Shiocton: 
3-lSo 
50 to 90 
50 to 90 
50 to 90 
50 to 90 
50to90 
50 to 90 
90 
Oct. 11 
3-lSa 
do 
Do. 
3-lSa 
. do .. 
Do. 
14-lSa 
1 to 256 HCHO 30 minutes, rinsed 
1 to 500 HgCl 2 30 minutes, rinsed 
Do. 
Average, 3 fields, 
lot No. 3-18. 
50 to 90 
50 to 90 
a Disinfected by seed grower. 
b One diseased plant found in a 3-acre field. 
Conditions were decidedly different in the Appleton and Shiocton 
districts. A survey showed that the disease had developed into a 
uniformly severe epiphytotic in fields of both localities grown from 
Xos. 2-18 and 3-18 seed (Table IX). Unfortunately the seed beds 
were not examined, but the even distribution and advanced stage of 
the disease left no doubt that the fungus had become widespread be- 
fore transplanting. In one field at Shiocton where the formalde- 
hyde treatment was used the disease was not controlled. A com- 
parison of precipitation records (fig. 1) taken at Menasha (near 
