168 THE POTATO 



Potato worm, 

 Potato stalk weevil, 

 Potato eelworm. 



One of the diseases of the potato that is attract- 

 ing much attention abroad is the wart disease 

 and steps have been taken to prevent its intro- 

 duction into America. Following a discussion of 

 this, the various blight, scab and rot diseases are 

 described. 



WART DISEASE 



In "Leaflet 105" of the Board of Agriculture and 

 Fisheries of the British Government, (information 

 and illustrations from this source are used by per- 

 mission of the Controller of His Britannic Majesty's 

 Stationery Office), this disease is described as *f ol- 

 io ws: 



"The disease known as Wart Disease (Syncny- 

 trium endobioticum Percival), formerly known as 

 Chrysophlyctis endobiotica, Cauliflower Disease, 

 Canker, 'Fungus' or Black Scab, attacks the tubers 

 and haulms of potatoes, giving rise to large and 

 irregular outgrowths which suggest a resemblance 

 to pieces of cauliflower. In bad cases these ' warts ' 

 may appear at the surface of the soil and can be 

 detected at the base of the haulm as yellowish 

 green masses. 



"Warts or wrinkles appear at first in the eyes of 

 the young tuber, and later several warts by grow- 

 ing together form a brown spongy scab, which 

 finally rots and becomes black. This scab has no 

 connection with ordinary potato scab and does not 

 resemble it in appearance, but as both are fre- 



