676 EXPERIMENT STATION RECORD. 



DISEASES OF PLANTS. 



Chlorosis of plants and methods of combating- it, A. Dementjew [Ann. Sci. 

 Agron., 2. ser., 1904, II, No. 1, pp. 63-81). — The author reviews the various theories 

 regarding the cause of chlorosis in plants ami methods for preventing the disease, 

 after \\ hich he gives the results of his own observations regarding it. Jn general he 

 believes that chlorosis is due to injuries of the toots of plants, and that perhaps in 

 most cases root lice are the most important agents in causing the disease. 



For combating chlorosis anything that will destroy the root lice may be recom- 

 mended, although in the absence of more definite information the author does not 

 give suggestions regarding its control. 



Plant pests, T. W. Kirk (New Zealand Dept. Agr. Rpt. 1904, pp. 296-309, pis. 2).— 

 Accounts are given of rose rust, grain smuts, and oat rusts, with suggestions for their 

 prevention, and a brief account is given of fruit flies by T. Broun. 



Plant diseases in Bohemia, F. Bubak (Ztschr, Landiv. Versuchsw. Oesterr.,7 (1904), 

 No. 10, pp. 731-741)- — Notes are given of the fungus diseases and insect enemies 

 observed on plants of economic importance during 1902. A tabulation is given 

 showing that these pests were most abundant in May, June, and October, nearly 

 three-fourths being observed during these months. 



Diseases of economic plants in the Tropics, G. Delacroix (Agr. Prat. Pays 

 Chauds, 4 (1904), No. ,.'0, pp. 201-225, figs. 3). — A general account is given of the 

 character of plant diseases, the author classifying them into those which are due to 

 wounds, atmospheric or other conditions, and those caused by parasites. A descrip- 

 tion is given of a number of the more common diseases of the first class. 



A prodromus of cryptogamic diseases in Belgium, H. Vanderyst (Bui. Agr. 

 [Brussels], 20 (1904), No. 5, pp. 858-944, fig*- 17). — This is a preliminary account of 

 some of the plant diseases observed in Belgium, the present paper dealing with the 

 Peronosporineae. About 52 species are technically described, together with their 

 distribution in Belgium and their host plants, and so far as known methods of pre- 

 vention are given. 



An internal infection germ of cereal smuts, L. Hecke (Ztschr. Landw. Ver- 

 suchsw. Oesterr., 7 (1904), No. 2, pp. 59-64). — A preliminary report is given of investi- 

 gations by the author which have led him to doubt the claim frequently made that 

 smut infection of cereals takes place only at the time of the germination of the 

 seed or immediately subsequent thereto. 



Pot experiments are described in which spores of Ustilago hordei were placed on 

 the pistils of barley flowers. All the care practiced in artificial pollination was fol- 

 lowed, and the plants grown to maturity. When harvested there was no trace of 

 smut on the seeds, all of which were sow r n. The plants from these seeds when 

 harvested gave from 16 to 30.7 per cent infested heads. 



From this the author argues that there are some internal means of infection by 

 smuts, and that soaking seed in copper sulphate or other fungicides will not protect 

 against this method of infection. 



Potato diseases and their treatment, F. C. Stewart and II. J. Eustace ( U. S. 

 Dept. Agr., Office of Experiment Stations, Farmers' Inst. lecture 2, pp. 30). — This is a 

 syllabus of a lecture on potato diseases and their treatment. The lecture is designed 

 to be accompanied by 47 views illustrating the method of controlling potato diseases. 

 The information is drawn largely from experiment station investigations, and a con- 

 siderable bibliography of the subject is appended to the bulletin. In an appendix 

 detailed directions are given for the preparation and application of the different 

 fungicides recommended. 



"Blackleg" of potatoes, M. C. Cooke (Gard. Chron., 3. ser., 36 (1904), No. 915, 

 p. 28). — An account is given of a disease of potatoes in which the lower part of the 

 stem was blackened and the production of tubers was reduced to a few very small 



