044 EXPERIMENT STATION RECORD. 



downy mildew of the grape due to Plasmopara viticoU(. with notes for its 

 control by means of spraying. 



Treatment of downy mildew, Belle and Fondard (Rev. Vit., 32 (1909), 

 No. 812, pp. .'/7, //.S). — Suggestions are given for the prevention of attacks of 

 the downy mildew of grapes. 



The authors claim that in ordinary seasons 3 sprayings are sufficient, the 

 first application to be made when the new shoots are 12 to 15 cm. in length, 

 the second immediately after flowering, and the third when the grapes begin 

 to ripen. The second treatment is considered the most important, and in 

 unfavorable years two or more sprayings should be given the vines after the 

 second application. The authors recommend various fungicides to which 

 sugar, soap, and other adhesives are added, but they prefer one in w'hich 

 resin is a component. This fungicide is prepared by dissolving 0.5 kg. of car- 

 bonate of soda in 4 or 5 liters of water to which is added an equal weight of 

 resin. This is then thoroughly mixed with 10 to 15 liters of water containing 

 a solution of 1 per cent coi)i)er sulphate, and the whole is brought, by the 

 addition of water, to 100 kg. The carbonate of soda may be replaced by lime, 

 but the authors prefer the purest form obtainable of carbonate of soda. This 

 fungicide is very adhesive, and as prepared it has neutralizetl the sulphate 

 of coi)per. 



When exceedingly severe attacks of the disease are suspected it is recom- 

 mended that for some of the earlier treatments a copper acetate solution be 

 substituted for the other fungicide. 



The blister rust of pines and the European currant rust, G. G. Atwood 

 {X. Y. Dept. Agr., Horf. Bui. 2, pp. 15, pis. 2). — A reiiort is given on the blister 

 rust of pines {Peridermium strobi), which was found on a number of .3-year-old 

 seedlings imported in 1909. This is one of the stages in the life cycle of the 

 fungus, the other occurring on currants and gooseberries. On the currant this 

 disease has been previously reported by Stewart (E. S. R., 18, p. 747) and the 

 account given of this stage of the fungus is practically a reprint from that 

 source. 



Following the recognition of this new fungus on imported stock, a meeting 

 was held of plant pathologists, foresters, and others, in which the situation was 

 discussed and conclusions reached regarding the control of the disease. It is 

 recommended that all premises be inspected, and that wild and cultivated goose- 

 berries and currants be destroyed within 100 yds. of where any of the intro- 

 duced white pines have been planted. A close watch should be kept on culti- 

 vated strawberries and gooseberries, as well as on all the suspicious pine trees, 

 and all affected plants should be destroyed by burning. It is especially im- 

 portant that the currants and gooseberries be examined in the summer or fall, 

 as they would not be expected to show signs of the disease until after July 15. 



Peridermium strobi in America, P. Spaulding {Science, n. ser., 30 (1909), 

 No. 763, pp. 200, 201). — The author reports having found in June specimens of 

 w^hite pine affected with the leaf blister due to P. strobi. Later investigations 

 have shown that this fungus is present on imported stock in New York, Ver- 

 mont, Massachusetts, and Connecticut, and there appears to be no doubt that it 

 was present in the German nurseries from which the trees were obtained. 



Cedar rust, W. H. Hein (Insect' Pest and Plant Disease Bur. Xebr., Div. Bot. 

 Circ. 1, pp. Jf, figs. 4). — A popular account is given of the cedar rust (Gynino- 

 sporangium macropus), and its relation to the apple leaf rust pointed out. Sug- 

 gestions are given for the treatment of these diseases, which consists of re- 

 moval of the cedar trees and the planting of the more resistant varieties of 

 apples. Thorough spraying has been recommended as a treatment, but investi- 



