FIG. 20. BEET DISEASES. 



a. Crown gall, b. scab, c. downy mildew, d. Conidiophore of Peronospora schachlii 

 arising from a stomate of an infected beet leaf, e. germinating zoospore of P. schach- 

 tii,f. oospore of P. schachtii, g. Cercospora leaf spot (after Halsted), h. conidiophore 

 and conidia of Cercospora beticola (after Duggar), i. Phoma leaf spot (after Pool and 

 McKay), k. pycnidium of Phoma beta (after T. Johnson) (d.-f. after Prillieux). 



