POTATO SCAB 225 



POTATO SCAB 



(Sorosporium scabies, Fisch. de W.) 



This disease forms large olive scabs or rough patches on 

 the surface of nearly full-grown potatoes. It is not very 

 injurious, and in fact is often considered as a sign that the 

 potato attacked is good and floury. When present in large 

 quantity the market value is depreciated. Adding lime to 

 the soil is said to prevent the disease. 



BEETROOT TUMOUR 



(Oedomyces leproides, Trabut. 



= Urophlyctis lepr aides, P. Magnus.) 





 Beetroot Beta vulgaris, var. rapacea growing in the 



grounds of the School of Agriculture, Rouiba, near Algiers, 

 was attacked by a disease not previously recorded. Large 

 nodulose or brainlike outgrowths develop near the apex 

 of the root, and may consist of modified leaves or rootlets ; 

 the tumours are fleshy, attached to the root by a short, 

 narrow neck, and in the substance are numerous cavities 

 filled with dark-coloured spores. The spores are subglobose, 

 produced at the apex of a hypha, which bears a large 

 vesicular swelling just below the spore. 



PREVENTIVE MEANS. As resting-spores are formed, all 

 diseased material should be removed from the soil and 

 burned. 



Trabut, Rev. Generate de Bot., vol. vi. p. 409, i pi. (1894). 

 Saccardo and Mattirolo, Malpighia, vol. x. (1895). 

 Magnus, Ann. Bot., 1897, p. 87, 2 pi. 



P 



