550 EXPEEIMENT STATION EECORD. 



toes due to Phytophthora infestans, with suggestions for control. The control 

 measures recommended consist of thorough spraying with Bordeaux mixture. 



Investigations of the potato fungus Phytophthora infestans, L. R. Jones. 

 N. J. GiDDiNGS, and B. F. Lltman {Vermont Sta. Bui. 168, pp. 100, pis. 10, 

 figs. 10). — This is a reprint of Bureau of Plant Industry Bulletin 245 (E. S. R., 

 2n, p. 544), the work having been carried on in cooperation between this De- 

 partment and the Vermont Station. 



The rotting of potato tubers by a new species of Phytophthora having a 

 method of sexual reproduction hitherto undescribed, G. H. Pethybridge {Set. 

 Proc. Roy. Dublin Soc, n. ser., 13 {1913), No. 35, pp. 529-565, pis. 3).— This 

 paper deals with a new and characteristic type of tuber rot which occurs in 

 Ireland and is caused by a new species of fungus to which the name P. ery- 

 Ihroseptica is given. 



The rot begins when the tubers are still in the ground, but at what particular 

 stage of growth the infection occurs has not yet been ascertained. It causes 

 a rapid decay and produces wet rather than dry rot. The cut surfaces of 

 affected tubers quickly turn pink when exposed to the air and later become 

 almost black. The fungus has been isolated and grown in pure cultures, and 

 inoculation experiments have been carried on which demonstrated that the 

 disease was due to the organism in question. Studies were made of the char- 

 acters of the fungus concerned with other species of the genus Phytophthora, 

 and these led to the author's concluding that there should be a rearrangement 

 of the species of this genus based on the sexual characters as described. 



Leaf roll of potatoes, W. Drx {Fuhling's Landw. Ztg., 62 {1913), No. 6, pp. 

 21.lf-222). — As the result of several series of experiments, it is stated that it is 

 not possible to distinguish with any certainty normal plants from seed potatoes 

 or young plants destined to produce crops showing the characteristic effects of 

 leaf roll, nor is it possible at present to guard against this trouble. 



The powdery scab of the potato in Maine, I. E. Melhus {Science, n. ser., 

 S8 {1913), No. 969, p. 133).— The author calls attention to the discovery of the 

 powdery scab of potatoes due to Spongospora solani in a lot of potatoes examined 

 at Houlton, Me., in June, 1913. A considerable number of diseased specimens 

 exhibited a mild form of the scab, which resembled the common scab due to 

 Oospora scaMes. Attention is called to this disease with the hope that pathol- 

 ogists will recognize it and assist in stamping it out as quickly as possible. 



The history of beet rot (Rhizoctonia violacea), A. Stift {Osterr. Ungar. 

 Ztschr. Zuckerindus. u. Landw., 42 {1913), No. 3, pp. 4'i5-!i61). — This is a brief 

 chronological summary of the studies published up to 1913 on the rot of sugar 

 beets, concluding with some practical suggestions regarding its control. 



The role of oxidases in curly top of sugar beets, H. H. Bunzel {Biochem. 

 Ztschr., 50 {1913), No. 3-.',, pp. 1S5-20S).— The main results of this investiga- 

 tion have already been noted (E. S. R., 29, p. 48). 



It is stated that the suppression of any normal function of a plant shows its 

 effect in a heightened content of oxidases. The sap of all parts in such cases 

 becomes more active, the seed leading in this respect and the leaves and roots 

 following in turn. In the green parts of the plant a general correspondence 

 seems to exist between the activity of the oxidases and the intensity of colora- 

 tion. 



Diseases and enemies of tobacco, L. Peters and M. Schwartz {Mitt. K. 

 Biol. Anst. Land u. Forstic, 1912, No. 13, pp. 128, figs. 92; abs. in Ztschr. 

 Landw. Versuchsw. Osterr., 15 {1912), No. 12, p. 1309; Bot. CentU., 123 {1913), 

 No. 3, pp. 65, 66). — The two parts of this article are dealt with separately by 

 the authors. The first section discusses in considerable detail seed bed, wilt, 

 and leaf diseases, phanerogamic parasites, and troubles of tobacco in the process 



