I] Potato Disease and Allicd Diseases 35 
Spraying with Bordeaux mixture or with a 3 per 
cent. solution of iron sulphate will help to check the 
disease as by this means the spores are prevented from 
sending their germ tubes into the plant. 
CHAPTER III 
FINGER AND TOE, AND WART DISEASE 
Finger and Toe (Plasmodiophora brassicae). 
This disease also goes by the name of ‘“‘anbury,” 
“club root,” or “club.” It attacks all cultivated 
plants of the cabbage order such as turnip, cabbage, 
rape, kohl rabi, mustard, stocks and wallflowers, and 
also the weeds, e.g. charlock, shepherd’s purse, and 
hedge mustard. As far as we know it is confined 
entirely to the Cruciferous order} to which these plants 
belong. This disease is very widespread and has done 
a considerable amount of damage, especially since the 
practice of using acid manures became common and 
the use of chalk and lime declined. 
On taking up young cabbage plants from seed 
beds for the purpose of transplanting, the roots are 
sometimes found to be swollen and knotted. These 
knots, which vary considerably in size and shape, may 
occur on any part of the root system. If these plants 
are put out into the field they do not grow normally ; 
a few small leaves may be formed, but they soon 
1 Order Cruciferae. It is exceedingly useful in this and several other 
diseases to know the characteristics of this order, which are very simple 
and can be found in any book on Systematic Botany. 
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