1917] DISEASES OF PLANTS. 251 



of the trees by employing a spray made up of 2 per cent copper sulphate, 1 per 

 cent lime, and 0.2 per cent ammonium chlorid. 



A substitute for self-boiled lime-sulphur and other summer sprays for 

 peaches, L. G. Gillam {New Jersey Stas. Circ. 63 (1911), pp. 2-4). — Direc- 

 tions are given for the preparation of a summer spray for peaches to be used 

 as a substitute for self-boiled lime-sulphur. This fungicide is composed of 8 

 lbs. fine sulphur, 4 lbs. hydrated lime, and 1^ oz. gi-ound glue dissolved in 3 

 gal. water, the whole diluted with water to make 50 gal. In the preparation 

 of the spray the dry sulphur and lime should be mixed, then thoroughly incor- 

 porated with the glue solution before the addition of the water. 



A test of this fungicide proved its value for preventing scab and brown rot 

 without injury to the trees. 



On a new canker disease of Prunus yedoensis, P. mume, and other species 

 caused by Valsa japonica n. sp., T. Hemmi {Jour. Col. Agr. Tohoku Imp. 

 Univ., 7 {1916), Xo. 4, pp. 257-319, pis. 4). — An account is given of a study on 

 a disease fli"st noticed in Sapporo in 1913 and at present limited to Hokkaido. 

 It is common on P. yedoensis, P. sachalinensis, and P. mume, and is found 

 also on P. persica and other species of Prunus. The trouble is said to be due 

 to a new species of fungus of the subgenus Euvalsa, which has been named 

 V. japonica. It may simply cause a canker or else a girdling disease of a 

 different type on the branches. 



In the saprophytic condition V. japonica seems almost omnivorous. As a 

 parasite it attacks its host most readily through old wounds having a layer 

 of dead cells. Gummosis always develops as a result of the invasion. 



Treatment with copper sulphate and sodium carbonate appears to be in- 

 effeotive. Corrosive sublimate at from 0.05 to 0.1 per cent is the most effective 

 fungicide employed in this connection. 



Dieback in currant, O. Appel and E. Wekth {Mitt. K. Biol. Anst. Land u. 

 Forstw., No. 16 {1916), pp. 13, 14)- — A dieback of currant bushes, extending 

 from a center and increasing the second year (resistance differing with va- 

 rieties), is ascribed to Plowrightia ribesia. Somewhat different from this 

 fungus as to mode of development, but resembling each other in some ways, 

 are dieback di-seases ascribed respectively to Botrytis cinerea and to Pleonectria 

 berolinensis, to both of which all varieties appear to be about equally sus- 

 ceptible. 



Peronospora in 1915, and its control, A. Mabescaxchi {Ann. R. Accad. 

 Agr. Torino, 58 {1915), pp. 349-357, figs. 7 ; abs. in Riv. Patol. Veg., 8 {1916), 

 No. 3, pp. 81, 82). — The very violent outbreaks of downy mildew "occurring 

 May 24 and 25, June 4 and 5, and June 27 and 28, with one of lesser violence 

 May 10 to 12, are said to be closely connected with the high temperature, 

 humidity, and cloudiness which were common in 1915, but not so closely with 

 the actual amount of precipitation. The author points out the necessity for 

 the early and effective dissemination of information regarding the imminence 

 of mildew attack and the necessity for timely sprayng. * 



Treatment of Peronospora during 1915, E. C. DAlbaretto {Ann. R. Accad. 

 Agr. Torino, 58 {1915), pp. 304-312). — Giving an account, with discussion, of 

 experiences in connection with the unusually violent grape downy mildew out- 

 breaks of 1915, the author states that while in some cases from 10 to 20 spray- 

 ings were ineffective as regards control, five sprayings with the ordinary copper 

 solutions controlled the mildew with a great saving of materials and labor. 

 The precise observance of the prescribed manner and times of spraying is 

 thought to be essential to success in dealing with grape downy mildew and 

 to be sufficient even in years of unusually unfavorable conditions. 



