Chapter 9. 



DISEASES OF ROOTS AND TUBERS. 



Fingers-and'Toes of Turnips, Cabbages, etc. Habits and life 

 history of the fungus. Remedial treatment. "'Liming of the 

 soil, etc. Similar diseases, ^-g-y Black Scab or Wart Disease of 

 Potatoes, ''Spongy Scab,'' etc. 



The disease commonly known as Fingers-and-Toes, 

 •or Club-Root disease, attacks all cruciferous crops, includ- 

 ing Cabbages, Cauliflowers, Brussels Sprouts, Kohl Rabi, 

 Broccoli, Turnips and Sw^edes. It is produced by a fungus 

 known as Plasmocliofhora Brassicae^ and causes consider- 

 able damage both in the gardens and fields in many dis- 

 tricts of England ; its ravages are even greater on the 

 Continent, and it is also abundant in America. 



The general appearance of the disease is well known. 

 Plants, w^hich are attacked, show irregular warty swellings 

 on the root, and in bad cases the whole root may simply 

 consist of a mass of these excrescences. The disease can 

 often be recognised m its earliest stages on pulling up 

 young cabbages for transplanting. If such seedlings are 

 planted they prove practically useless, for the disease 

 simply increases at the expense of the roots, any leaves 

 •developed being feeble and unable to provide for healthy 

 growth. 



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