1917] DISEASES OF PLANTS. 751 



prunispinosm) , and peach freckle, black spot, or scab {Cladosporium, carpo- 

 pMlum), as regards their relations, behavior, and control. 



Plum diseases, E. Rabat^ {Ann. Serv. Epiphyties, Mem. et Rap., 2 (1913), 

 pp. SJfiS^S). — This is a brief account of observations regarding brown rot 

 {MonUia cinerea) of plum, which was followed by plum pockets {Exoascus 

 prvni), resulting in serious loss in the neighborhood of Agen. 



Comparative tests with fung-icides ag'ainst grape downy mildew, G. Caruso 

 (Atti R. Acoad. Econ.. Agr. Georg. Firenze, 5. ser., 12 (1915), No. 2, pp. 150- 

 155). — Tests carried out during the months of May to July, 1914. as described 

 in connection with rainfall, are said to show that about the same protection 

 against grape downy mildew is given by nine sprayings with a 1 to 1.5 per cent 

 preparation of a copper product, recommended by the electrical and electro- 

 chemical society of Caffaro, as by the same number of sprayings with a 0.5 to 

 1 per cent Bordeaux mixture. 



Second series of comparative tests with fungicides against grape downy- 

 mildew, G. Caruso (Atti R. Accad. Econ. Agr. Georg. Firenze, 5. ser., IS 

 (1916), No. 2, pp. ^1-55). — The work above noted was continued in 1915, the 

 frequency and abundance of precipitation necessitating 10 treatments extending 

 from May 12 to Aiigust 11. A degree of superiority of Bordeaux mixture at 

 0.5 to 1 per cent over the competing compound at concentrations lower than 

 1 to 1.5 per cent was again demonstrated. 



A bacterial disease of the gooseberry, B. T. P. Barker and O. Grove (Univ. 

 Bristol, Ann. Rpt. Agr. and Hort. Research Sta., 1915, pp. 91-99). — Specimens 

 of gooseberry bushes diseased in a peculiar manner were found to contain an 

 organism apparently identical with that described in connection with a disease 

 of pear (E. S. R., 33. p. 148). The outbreaks may be conditioned by such 

 factors as the influence of weather on susceptibility. 



A new remedy for American gooseberry mildew, I. E. Barbarin (Reprint 

 from Zap. Simferopol. Otd. Imp. Ross. Obshch. Sadov., No. 151 (1915), pp. 10). — 

 The author has continued his studies (E. S. R., 34, p. 842) of arsenical com- 

 pounds as fungicides. The results of field spraying experiments with sodium 

 arsenate in 1915 fully corroborated the positive evidence previously secured in 

 laboratory stucjies. Four applications of this compound, one before, three after 

 the blossoming period, with intervals of from 10 to 20 days, held in check the 

 gooseberry mildew (Sphcerotheca mors-uvce). 



The author recommends making the spraying solution not stronger than 1 gm. 

 of sodium arsenate to 3 liters of water, and solutions of 0.5 to 0.75 gm. in the 

 same amount of water are considered preferable. There seems to be very 

 little danger of burning the leaves of the gooseberry plant. As this danger is 

 quite serious in case of some other plants, the use of sodium arsenate for these 

 is not recommended until dehnite methods are discovered to prevent burning 

 of the leaves. 



Studies on diseases of mulberry in 1913, G. Arnaud and C. Secr£tain 

 (Ann. Serv. Epiphyties, Mem. et Rap., 2 (1913), pp. 233-265, figs. 19).— This 

 is a report of studies regarding mulberry gummosis (Bacterium mori), leaf rust 

 (Cylindrosporium mori), dieback (Nectria cinnaharina) . sclerotium disease 

 (Sclerotinia libertiana) , a root disease shov.-ing symptoms analogous with those 

 of the root rot due to Armillaria mellea (which is also described as destructive), 

 and a dropsy or gummosis of the trunk sometimes showing concretions of oxalate 

 of lime crystals, along with other factors influencing diseases of mulberry. 



" Canker " and " dieback " disease of mulberry, E. S. Salmon and H. 

 Wormald (Gard. Chron., 3. ser., 60 (1916), No. 1548, pp. 95, 96, figs. 5).— A de- 

 scription is given of a dieback of mulberry twigs due to their being partly or 



