484 SPECIAL PLANT PATHOLOGY 



rubbing against the plant may be colored owing to the abundance pro- 

 duced. Later in the season the black rust stage appears with the forma- 

 tion of elliptic two-celled teliospores, 30 to 60/1 by 21 to 2Sfi, and with 

 a thickened apex and long pedicels. Infection of asparagus plants in 

 cultivated fields is, according to Duggar/ through the asciospores pro- 

 duced on wild or escaped plants and not directly from the germination 

 of the teliospores, which remain in or about the soil. Bordeaux mix- 

 ture, used as a spray alone, has not been very successful. A more 

 successful treatment has been obtained by adding a resin mixture to 

 the Bordeaux solution. Sirrine recommends the following: Bordeaux 

 mixture, 5-5-40 formula, 40 gaUons; resin mixture, 2 gallons, dUuted 

 10 gaUons. The resin mixture consists of resin 5 pounds; potash lye i 

 pound; fish oil i pint; and water 5 gaUons. Under certain climatic con- 

 ditions in California it has been found efficient to dust the young tops 

 with dry powdered sulphur on a dewy morning at the rate of one 

 and a half sacks of sulphur per acre, followed in a month by a 

 second application, using two sacks of sulphur per acre. 



Banana {Musa sp.) 



Bud-rot {Bacillus musee, Rorer). — Bud rots of the banana have 

 been reported from the greater Antilles (Cuba, Jamaica) from Central 

 America and Trinidad. The disease in Trinidad has been investigated 

 by a mycologist from the United States, J. B. Rorer, the mycologist 

 of the island government, and he has proved that an organism which 

 he has isolated and named BaciUiis musa is the responsible parasite. 

 However, the bud-rots of the banana are probably due to the same 

 cause, but the matter has not been investigated satisfactorily outside 

 of Trinidad. The disease usually appears on the young plants, attack- 

 ing the young leaves and the core, which become brown. The tissues 

 disorganize and a putrid rot sets in with the death of the parts 

 attacked. 



March is the month in which the disease usually begins and in 

 three or four months its destructive effects are seen. 



Beet {Beta vulgaris, L.) 



Leaf -spot {Cercospora beticola, Sacc.).— This disease is distributed 

 widely in America and Europe and the refl garden beet is seldom free 

 ' Ddggar, B. M.: Fungous Diseases of Plants, 406. 



