328 PLANT DISEASES 



branches and extending downwards. Removing diseased 

 branches checks the spread of the disease. 



Massee. Kew Bulletin, 1898, p. 119. 



SLEEPING DISEASE OF TOMATO 



(Fusarium lycopersici, Sacc.) 



This disease was first recorded from Guernsey, where 

 the culture of tomatoes constitutes at present the principal 

 source of revenue. It has also been recorded quite 

 lately from widely separated localities in Britain. In some 

 instances where only a small area is under cultivation, the 

 annual loss has amounted to ^300, and in some instances 

 an average-sized house containing tomatoes will, if attacked 

 by the disease, mean the loss of ^"100 to .200 in a 

 season. 



The disease is indicated by the dull colour of the leaves, 

 which commence to droop ; this is quickly followed by a 

 collapse of the stem, hence the name 'sleeping disease.' 

 If the plants are not attacked until the fruit is present, 

 this frequently ripens, and to the naked eye, or even when 

 examined microscopically, appears to be free from disease ; 

 nevertheless it is well known that seed obtained from dis- 

 eased plants produces diseased seedlings. 



The root is invariably attacked first, the fungus gaining 

 an entrance through the rootlets, gradually extending to 

 the taproot and lower portion of the stem. Its presence 

 is indicated to the naked eye by a brown discoloration 

 of the vascular bundles, and when this stage is reached 

 the plant droops, or ' sleeps.' Shortly after the sleeping 

 stage has been reached, the portion of stem just above 

 ground is more or less covered with a very delicate white 



