Bui. 1029, U. S. Dept. of Agriculture. 
PLATE II. 
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Cabbage Black-Leg. Relation of Spread in the Seed Bed to 
Subsequent Development in the Field. 
These illustrations show the wide difference in destructiveness of the disease in plantings 
from the same seed bed made on different dates and in two neighboring fields. The seed was 
treated by the grower with 1:1,000 mercuric chlorid for 30 minutes before sowing. When the 
first planting was made, on .Tune 11, practically no blackdeg was noted in the seed bed, while 
on July 1, when the second planting was made, the disease had become widespread in the bed. 
Photographed at Racine, Wis., September 27, 1919, shortly before harvest. 
A.— Planting of June 11. Of these plants 31 per cent were affected with black-leg, but only i 
per cent were prevented from heading by the disease. (See Table IX, field No. 1.) 
B— Planting of July 1 in the foreground. Of these plants 97 per cent were diseased and 60 per 
cent were prevented from heading by black-leg. The portion of the field in the background 
is an earlier planting from a different seed bed. (See Table IX, field No. 2.) 
