752 EXPERIMENT STATION RECORD. 



cabbage rust is indicated, and the destruction of the grass is recommended as 

 a precautionary measure. 



A disease of Japanese ginseng caused by Phytophthora cactorum, S. Hoei 

 {Bui. Imi). Cent. Agr. Ea-pt. Sta. Japan, 1 {1901), No. 2, pp. 153-162, pi. 1).— 

 The author reports a serious loss through the attacks of P. cactorum on ginseng, 

 •which is cultivated quite extensively in a number of the provinces of northern 

 Japan. The fungus was first definitely determined in 1904, and following its 

 appearance the author recommended the spraying of the plantations with 

 Bordeaux mixture. Where this was thoroughly done and two applications of 

 the fungicide given, the spread of the disease was checked. 



While investigating the cause of this disease, the author corresponded with a 

 number of pathologists in this country who have been studying ginseng dis- 

 eases, and he reports the almost simultaneous observation of the fungus in 

 Ohio and Japan. A report has already been noted concerning the disease in 

 Ohio (E. S. R., IS, p. 342). 



Black scab or warty disease of potatoes, E. S. Salmon {Gard. Chron., 3. 

 scr., -',2 {1007), No. 1093, pp. 397-399. pfjs. '/)•— A description is given of the 

 black scab of potatoes caused by the fungus ChrysopMyctis cndoMotica, and 

 the author traces its spread throughout England. The disease is said to be a 

 very serious one, and it is recommended that stringent measures be adopted 

 for combating it. The author rejects the opinion hitherto published (E. S. It., 

 16, p. 169; 18, p. 149) that .this fungus is identical with or related to (Edomyccs 

 Icproidea. 



Winter rot of potatoes {Bd. Agr. and FisJicrics [London], Leaflet 193, pp. 

 2,- fig. 1). — A description is given of a disease of stored potatoes that is due to 

 the fungus Ncctria .solani. This fungus is said to be almost constantly present 

 on potatoes and only requires a hot, dry season to favor its rapid development. 

 The tubers only are attacked, and if kept dry and exposed to the air no further 

 development takes place. If, on the other hand, they are stored before being 

 perfectly dry and placed in heaps so that the air is excluded and the tempera- 

 ture raised, within a short time the mycelium present in the tubers begins to 

 develop, and later appears in the form of white tufts over their surface. From 

 these tufts are produced crops of spores, which are rapidly distributed through- 

 out the bins or heaps, producing a soft, ill-smelling rot. 



The best preventive against attacks of this kind is to see that the potatoes 

 are well dried before storing and to rotate crops, using kainit or lime on the 

 land to destroy the fungus. 



Fungus diseases of pineapples, F. A. Stockdale {West Indian Bui., S {1907), 

 No. 2, pp. 15S-166). — The principal diseases of pineapples described are tangle 

 root, blight, black heart or core rot, and diseases of the fruit that appear dur- 

 ing shipment. 



The tangle root is a well-known disease characterized by the yellowing which 

 begins at the tips of the leaves and gradually extends over the entire plant. 

 The roots of such plants are wound al)out the body of the plants, hence the name 

 tangle root. The cause of this disease is believed to be improper preparation of 

 the land, and certain varieties seem to be more subject to this trouble than 

 others. 



The blight described is due to an unidentified fungus, and is characterized 

 by the yellowing and drying up of the leaves, which during the progress of the 

 disease lose their turgidity and become withered. The plant eventually dies 

 and becomes rotten, and suckers from such plants are infested in a similar 

 manner. The author recommends the digging up and destruction of all diseased 

 IJlants and liming of the soil where they have grown. 



