DISEASES OF PLANTS. 65 



bundles in the tubers and where such potatoes were used for need a diseased crop 

 usually followed. The cause of this disease is thought to be possibly the same as 

 that described in the United States and elsewhere under the name of Bacillus solana- 

 cearum. A number of other diseases of less frequent occurrence are briefly described. 

 The relation of date of digging- potatoes to the development of the rot, 

 L. R. Jones and \V. J. Morse (Proc. Soc. Prom. Agr. Sri., 1904, pp. 90-95). — An 

 account is given of the authors' investigations on. the relation between the late blight 

 (Phytophthora infestans) and the rotting of potatoes after harvest. This account is 

 based on the investigations which have been hitherto reported (E. S. R., 14, p. 1084; 

 15, p. 1088). 



The brown rot of the Swedish turnip, M. C. Potter (Jour.Bd. Ayr. [London], 

 10 (1903). No. 3, pp. 314-318, pi. 1). — A short account is given of the brown rot of 

 Swedish turnips which has been under observation since 1898. 



The disease was noticed as beginning in October on roots still growing in the fields 

 and was frequently met with in storage. The disease is unquestionably due to the 

 action of bacteria and is attributed to the same organism as that causing the black 

 rot of turnips and cabbage, Pseudomonas campestris. The author has succeeded in 

 producing all stages of the disease on perfectly sound roots by inoculation with pure 

 cultures of the bacteria isolated from naturally decaying roots. This organism of 

 decay appears confined to the Cruciferaa. The author suggests prolonged rotation of 

 crops as a means of preventing serious injury by disease. 



The occurrence of this disease in the United States is commented upon and the 

 author believes that the greater immunity observed in England may be due to the 

 system of rotation of crops adopted there, as well as the fact that the summer tem- 

 perature in England is not so high as it is in this country. It has been shown that 

 a temperature of 80 to 90° F. accompanied by a damp atmosphere particularly favors 

 the development of the bacteria. 



Two plant diseases in Hawaii, J. <i. Smith (Hawaii Sla. Press Bui. 9, pp. 6). — 

 A description is given of the pineapple disease of sugar cane and a disease of coffee 

 called the brown-eyed disease. 



The pineapple disease of sugar cane, which is due to Thielaviopsis ethacetieus, made 

 its appearance in Hawaii in 1903. The disease exists in a number of forms accord- 

 ing to the different parts of the cane plant affected, and when occurring on the young 

 seed cane it frequently injures it to such an extent that there is no germination. It 

 is said that serious outbreaks almost invariably follow the work of some insect pest, 

 either the cane borer or leaf hopper. Although the fungus is truly parasitic, its 

 entrance is much facilitated by the injury caused by the insects. 



The disease derives its name, pineapple disease, from the odor of the freshly cut 

 stalks, somewhat resemblingthat of pineapples. This is said to be due to the formation 

 of acetic ether by the fungus from the saccharin substances within the cane. For the 

 protection of the cane seedlings against this fungus it is recommended that the ends 

 be coated with tar before planting, that care be exercised in selecting seed cane, 

 that they be perfectly sound and healthy, and that all infected stalks left after the 

 cane has been harvested should be gathered and burned. 



The coffee disease is due to the fungus Cercospora coffeicola. This fungus seems 

 to be rather widely distributed and attacks both the leaves and the fruit. On the 

 leaves it produces round or oval spots of a clear brown on the lower surface and 

 dark brown on the upper, the center of the spots being lighter in color. On the 

 fruit small dark spots appear. These by spreading involve about half of the fruit 

 which soon becomes brown and dried. Considering the nature of this fungus, the 

 author believes that the use of Bordeaux mixture or similar fungicide will hold it in 

 check, and he gives directions for the preparation and application of this and other 

 fungicides. 



A bacterial disease of sesame, K. Malkoff (Centbl. Bakt. u. Par.. ;. Ah/., 11 



