FUNGI IMPERFECTI 343 



Control. This disease is readily controlled by spraying with 

 Bordeaux, and weaker fungicides are often very effective. Spray- 

 ings made as late as July have been found to entirely prevent the 

 disease. 



Cylindrosporium Chrysanthemi Ell. & Dearn 1 produces blotches, 

 commonly termed blight, upon the leaves of some varieties of the 

 cultivated chrysanthemum. It may become epidemic at the time 

 that the flowers are opening, apparently due to lessened vitality of 

 the lower leaves. 



XLI. H'EART ROT AND BLIGHT OF BEETS 

 Phoma Betce Frank 



Frank, B. Ueber die biologischen Verhaltnisse des die Herz und Trockenfaule 

 der Ruben erzeugenden Pilzes. Ber. d. deut. bot. Ges. 13: 192-199. 

 1895. 



Frank, B. Die Pilzparasitaren Krankheiten der Pflanzen. I.e. pp. 399-403. 



Kruger, F. Die bis jetzt gemacht Beobachtungen iiber Frank's neuen Rtiben- 

 pilz Phoma Betae. Zeitsch. f. Pflanzenkr. 4: 13-20. fig. 1. 1894. 



Habitat relations. This is one of the most serious diseases of 

 the sugar beet in portions of Germany, Austria, and France. It 

 begins to manifest itself as a rule in August by blackening and 

 drying of the younger heart leaves, and later older leaves also suc- 

 cumb, so that before the period of harvesting all the leaves may 

 be dead and merely the beet stub remain. In cases where the beets 

 are grown for seed, the fungus may also be found upon the seed 

 stalks and cases. It is thought that this is one means by which 

 the fungus may pass over from one year to the next. From the 

 affected leaves, particularly along the course of the fibrovascular 

 bundles, the browning and general discoloration of the tissues ex- 

 tend into the tissues of the root, and there rot sets in. If the 

 disease begins early in the season great injury may be done. It is 

 considered probable that this organism was a chief agent in the 

 great losses sustained by beet growers in Europe during the mid- 

 dle of the nineteenth century, and the organism was certainly 

 again unusually prevalent and destructive in 1892- 189 3. Frank 

 considers the Phyllosticta tabifica Pril. & Del. to be the same 



1 Halsted, B. D. Recent Chrysanthemum Blight. N.J. Agl. Exp. Sta. Rept. 15 : 

 365-368. 1894. 



