49 DISEASES OF CULTIVATED PLANTS 



Cercospora viticola (Sacc.) forms irregular, dry, brown spots 

 on vine leaves ; most abundant during a damp season, and 

 most abundant on the lower, shaded leaves. 



Cercospora ceracella (Sacc.) attacks cultivated cherries. 

 Forms roundish, brown spots with a grey centre on the leaves. 

 Spores 50-90 X 3*5-4 fi, very pale, slightly thickened at one 

 end, 3-5-septate. 



Cercospora beticola (Sacc). This fungus is a very frequent 

 parasite on the leaves of beetroot, but as a rule does not 

 prove very injurious. It forms irregularly rounded, greyish 

 dry blotches, bordered with reddish brown. The conidia 

 are produced on the under surface of the leaf on the grey 

 spots. 



The short conidiophores burst through the epidermis in 

 clusters, colour brownish ; conidia narrowly club-shaped, 

 attached by the broad end, multiseptate, hyaline, 60-140 X 

 3-4 5 l>- 



Prillieux, Mia/ad. des Plantes Agric, 2, p. 357 (1897). 



FUSARIUM (Link.) 



Spore-mass pulvinate or effused, more or less gelatinous 

 when moist ; conidia fusoid or falcate, typically many-septate 

 at maturity, hyaline. 



Sleeping disease of tomato. This peculiar disease derives 

 its name from the fact that apparently vigorous, full-grown 

 plants suddenly wilt and droop, suggesting the idea of having 

 gone to sleep, but which in reality proves to be the sleep of 

 death. The malady was first observed in Guernsey, where 

 large quantities of tomatoes are grown for the London 

 markets. It has since been recorded from widely separated 

 localities in England, although now, fortunately, it appears 

 to be rarer than heretofore. When the epidemic was at its 

 height, a loss of ^100 to ^200 was not unusual on a single 

 tomato house. 



Fusarium lycopersici (Sacc.) is the fungus in question. 



The first suggestion of the presence of the disease is the 

 wilting of the leaves, followed by a drooping of the upper 

 and weaker portion of the stem, and within a few days the 

 plant is dead. There is no sign of blotching or yellowing of 

 the leaves, which are perfectly free from disease, the wilting 

 being due to lack of water, the supply taken up by the roots 



