204 GARDEN FOES. 



B — DISEASES. 



American Potato Disease — A fungoid disease 

 said to ha\e come from America attacked potato crops in 

 tliis counti'y a year or so ago. The fungus is said to be 

 a species of Rhizoctonia, which covers the tubers with a 

 purpHish mycelium, and develops root-like sclerotia which 

 penetrate the surrounding soil. The effect of an attack is 

 to restrict development of the young tubers and produce 

 a useless crop. 



IIemedies. — Burn all infected tubers and haulm. Dress 

 the soil in winter with ground lime at the rate of lc\At. 

 per twelve square yards. 



Amencan Potato Scab (Oospora scabies).— A dis- 

 ease prevalent in America, but not common in England. 

 It has a similar effect upon the tubers to the Potato Scab. 



Remedies. — Authorities say that the presence of lime in 

 the soil eneoiu'ages the development of this disease ; so that 

 lime should not be used in the event of the disease attack- 

 ing the crops. Steeping the tubers in the formalin solu- 

 tion advised for the Potato Scab will destroy the fungus. 



Black. leg:, or Stem Rot — This disease is said to 

 be cansed by a bacteria (Bacillus phytopthorus). It causes 

 the leaves to wilt and turn yellow, the stems to be covered 

 with brownish stains, and eventually to become rotten. 

 The disease is more active in hot, damp weather, and 

 seriously affects the value of late crops especially. Car- 

 rots, turnips, marrows, and mangolds are said to be simi- 

 larly affected. The disease also affects the tubers. 



Remedies. — Pull up and burn infected haulm. ])o not 

 plant cut sets. Secure seed from a source whence the 

 disease has not appeared. Lime, nitrate of soda, and 

 sulphate of ammonia are favourable to spi"eading the 

 disease. 



Leaf Curl.- A fungoid disease wliich has long been 

 prevalent in this country. It causes the foliage to curl at 



