504 



DISEASES OF CULTIVATED PLANTS 



sclerotia are formed in the tissues of dead and dying parts, 

 which produce spores the following season. 



Conidiophores fasciculate, simple, short, erect, septate, 

 brown ; conidia large, subpiriform or rather irregular in form, 

 tapering towards the tip, 4-io-septate, becoming muriform, 

 constricted at the septa, brown, 60-80 x 40 



FIG. 152. Macrosporium nobile, i, portion of dis- 

 eased carnation ; 2, two conidia ; 3, portion of conidium 

 germinating ; 4, Fusarium spores, mixed with, but 

 no proof of any relationship with, the Macrosporium. 

 Figs. 2, 3, and 4 highly mag. 



Spray with ammoniacal copper sulphide, or with potassium 

 sulphide, but as carnations will not bear too much moisture, 

 much will depend on promptly removing leaves on the first 

 appearance of the disease, which shows on the lowest leaves 

 first. If the stems are attacked, and in all bad cases, the 

 plants should be burned, not thrown on one side, otherwise 

 the sclerotia will produce spores the following season, and 

 endanger healthy plants. 



Clover leaf spot. Malkoff has noticed a clover disease in 

 Germany caused by Macrosporium sarcinaeforme (Cav.). The 

 fungus forms numerous minute dark brown spots on the 

 leaves, which soon wither and die, 



