1919] DISEASES OF PLANTS. 345 



The careful removal of infected beet tops after harvest Is claimed to delay 

 the appearance of the disease in nonrotated fields the following season and 

 to materially reduce the injury therefrom. Treatment of Infected beel seed 

 with formaldehyde (15:1,000) for 7 minutes kills the fungus without Injuring 

 the germination of the seed, and plants grown from seed thus treated arc Bald 

 to attain greater development and productivity than those from untreated in- 

 fected seed. 



The organism is destroyed in its passage through the alimentary tract of 

 animals, and also when infected beet tops are subjected to a temperature of 

 100° C. for 30 minutes or 110° for 15 minutes. The best method for prevent- 

 ing the spread of the disease through feeding practices is said to be the 

 removal and storage of the beet tops in silos, as the organism does not survive 

 the siloing process for even two weeks. 



Sugar-beet fields should not only be rotated but should also be separated 

 from nonrotated fields by at least 100 yds. to avoid the spread of the disc, 

 from one field to another. The organism is said to be spread to some extent by 

 the air, insects, and irrigation water. 



Perennial mycelium of Gymnosporangium blasdaleanum, J. S. Boyce 

 (Phytopathology, 8 (1918), No. 4, pp. 161, 162).— Attention is called to the fact 

 that originally the telial stage of G. blasdaleanum was considered as not 

 deforming its host, but subsequent investigations have shown that it is 

 capable of producing pronounced witches' brooms in the incense cedar (IAbo- 

 cedrus decurrcns). In addition to the witches' brooms, the author describes 

 spindle-shaped swellings found on the branches and on the trunks of trees of 

 all sizes. These swellings are considered a result of a very decided increase in 

 the development of the wood with ^negligible increase in the bast. Mycelium 

 was found in abundance in the browned areas of the wood in both the witches' 

 brooms and the spindle-shaped swellings. No internal sori have been found 

 within the swellings, and it is believed that the life of the fungus within 

 these swellings is strictly vegetative. 



The occurrence of Puccinia graminis tritici compacti in the southern 

 United States, E. C. Stakman and G. R. Hoekneb {Phytopathology, 8 (1918), 

 No. 4, pp. U t l-lJ f 9, figs. 2; abs. in 8 (1918), No. 2, p. 77).— In a previous publi- 

 cation (E. S. R., 37. p. 749), a strain of P. graminis occurring on club wheat 

 and grasses in the Pacific Northwest was described, and in the present paper 

 the authors report that this strain has been found on wheat in southwestern 

 Texas, in Louisiana, and in Alabama. This strain is considered identical with 

 that occurring in the Pacific Northwest, and the fact that it is so constant on 

 different hosts in widely separated localities is considered to Indicate strongly 

 that it is not merely a local variant form of V. graminis tritici. The geographic 

 limits of the form described are imperfectly known, but it has been reported 

 from the South and the Pacific Northwest and it may be much more widely 

 spread, though it probably does not occur in the upper Mississippi Valley or 

 the northern Great Plains. 



Differences between the species of Tilletia on wheat, A. A. PoTTEB and 

 G. W. COONS (Phytopathology, 8 (1918), No. S. pp. 106-11S. Jigs. I,; abs. in S 

 (1918), No. 2, p. 72). — The authors call attention to differences manifested by 

 T. Iwvis and T. tritici on wheat, continuing the observations previously reported 

 on the occurrence in southwestern Michigan of high and low types of the 

 Stinking smut (E. S. R., 4, p. 352). 



The high smut is characterized by the production of culms from 2 to 4 in. 

 shorter than normal, while the low form averages fully 1 ft. shorter than the 

 height of healthy plants. The high form is said to be due to T. la vis and the 

 shorter to T. tritici. Other differences between the manifestations of disease 



