250 EXPERIMENT STATION RECOED. [Vol.38 



very late planting, and growth on very rich soil are conducive to attack, and 

 vigorously growing plants between 2 and 3 ft. high are most susceptible. 



The spores of U. zeae can cause infection when either young or old. They 

 germinate readily as soon as mature and retain their viability for .several years. 

 The spores, almost without exception, lost their viability after having been 

 kept in a silo for a few weeks, a result brought about, it is thought, by the 

 acids formed by the silage. 



Drying and freezing temperatures were found to injure the sporidia very 

 little. Alternate freezing and thawing, however, were injurious to moist 

 sporidia, less so to desiccated sporidia. The optimum temperature for the bud- 

 ding of the sporidia was found to be between 20 and 26° C, the maximum at 

 about 40°, and the thermal death point near 46°. The ability of sporidia, as 

 well as of spores, to withstand unfavorable conditions is considered very sig- 

 nificant in explaining some of the facts in the parasitism of U. zccc. 



The occurrence of Colletotrichum solanicolum on eggplant, P. J. O'Gaba 

 (Phytopathology, 7 {1911), No. 3, pp. 226, 227, fig. i).— The author reports an 

 attack by C. solanicolum on eggplants growing in a field which had produced 

 potatoes the previous year. 



Sclerotium bataticola. the cause of a fruit rot of peppers, W. H. Maktin 

 (Phytopathology, 7 (1917), No. J,, pp. 808-312, figs. 10; abs. in ditto, 7 (1917), 

 No. 1, p. GJf). — A disease of peppers is described which is characterized by the 

 presence of numerous minute black sclerotia throughout the fruit as well as 

 on the seed. A fungus which is identical with »S. bataticola has been isolated 

 from diseased material and grown in pure cultures. Successful cross inocula- 

 tions have been made on peppers and sweet potatoes, as well as on cucumber, 

 tomato, apple, and eggplant. 



The pathogenic action of Rhizoctonia on potato, H. T. GiJssow (Phyto- 

 pathology, 7 (1917), No. 3, pp. 209-213. fig. i).— According to the author, there 

 is no satisfactory evidence demonstrating the pathogenic action of Rhizoctonia 

 on its various host plants, particularly the potato. He has made a study of the 

 subject from which he concludes that the destruction caused is largely duo 

 to injury to the feeding roots, and that the loss of the feeding roots in potato 

 plants accounts for all the .symptoms associated with this disease. This 

 hypothesis is also believed to offer an explanation of the soil contamination 

 and the persistence of the organism in land once infected. 



Potato diseases in Indiana, H. S. Jackson and G. A. Osner (Indiana Sta. 

 Circ. 71 (1917), pp. 16, figs. 5). — The authors describe the more common potato 

 diseases known to occur in Indiana and offer suggestions for their control. 



Bacillus niorulans n. sp., a bacterial organism found associated with curly- 

 top of the sugar beet, P. A. P.oncquet (Phytopathology, 7 (1917), No. If, pp. 

 269-2S9, figs. 7).— In a previous publication (E. S. R., 34, p. 645), the occur- 

 rence of a bacterial organism in connection with the curly top disease of sugar 

 beets was reported. In the present paper the author describes B. morvlans 

 n. sp. as the cause of the disease, and gives an account of his bacteriological 

 investigations and the results of isolation experiments with the organism. 



Lightning injury to sugar cane, .T. A. Stevenson (Phytopathology, 7 (1917), 

 No. //, pp. 317, 318, fig. 1). — A description is given of the destruction by lightning 

 of a small area of sugar cane in one of the fields of the Insular Experiment 

 Station at Rio Pledras, P. R. 



Studies on Bacterium solanaceanim, E. E. Stanfokd and F. A. Wolf (Phyto- 

 pathology, 7 (1917), No. S, pp. 155-165, fig. i).— Data are presented regarding 

 the distribution within North Carolina of the disease of tobacco and tomato 

 due to B. solanacearum, on cultural studies to determine the identity of the 

 strains from the several hosts, and on the results of cross inoculations. The 



