DISEASES OF PLANTS. 51 



cessive invasions, the grapes are sure to suffer from a general epidemic. As 

 a result of these observations, it is recommended that the grapevines be 

 sprayed as many times as the sycamores have the mildew, this to be followed by 

 dusting with sulphur and copper sulphate. 



Experiments on the control of the grape Peronospora, A. Weinbau (Landtv. 

 Jahrb. Schiveiz, 24 {1910), No. J,, pp. 326-328) .—The results are given of ex- 

 periments with 2, li. and 1 per cent Bordeaux mixtures, Tenax 1 and 2 per cent 

 solutions, Reflorit, salt water, carbolineum, and Cucasa in combating the downy 

 mildew of the gi-ape. 



Four sprayings with the Bordeaux mixtures at intervals of from 10 to 17 

 days gave satisfactory results. The 2 per cent Tenax solution was only mod- 

 erately satisfactory, while Reflorit, salt water, and carbolineum gave unsatis- 

 factory results in controlling the mildew. The value of Cucasa in combating 

 this disease can not be definitely determined without further experiments. 



On the treatment of grape mildew, A. Geevi^s (Prog. Agr. et Vit. (Ed. 

 VEst-Centre), 31 (1910), No. 35, pp. 256-258).— It is claimed that by alternately 

 spraying with copper sulphate solutions and dusting with a mixture composed 

 of powdered copper sulphate and sulphur, the mildew can be successfully con- 

 trolled. Directions are given as to dates of application, sequence of treatment, 

 etc. 



On the efficiency of copper salts in combating the mildew, S. Andr^ (Prog. 

 Agr. et Tit. (Ed. VEst-Centre), 31 (1910), No. 33, pp. 198-200) .—The author 

 gives in tabulated form the number and variety of vines treated, the dates of 

 treatments with both liquid (neutral acetate of copper), and powdered copper 

 salts, the solutions used, and the results obtained in controlling the mildew on 

 the foliage and the fruit. 



It was found that the mildew was practically controlled when the salts of 

 copper were applied at the right time and a sufficient number of treatments 

 were given. 



The acetates of copper, A. Dejeanne (Rev. Vit., 33 (1910), No. 863, pp. 

 701-707). — This is a discussion of the relative efficiency of neutral and basic 

 acetates of copper as fungicides in combating diseases of the grape, especially 

 with reference to their adhesion to the leaves. 



The formulas for the preparation of acetate sprays as recommended by 

 various writers are given. 



New formula of silver nitrate for combating the grape mildew, V. Ver- 

 MOREL and E. Dantony (Prof. Agr. et Vit. (Ed. VEst-Centre), 31 (1910), No. 32, 

 pp. 168, 169; abs. in Bui. Soc. Agr. France, 1910, Aug. 15, pp. 162-16^; Weinbau 

 u. Weinhandel, 28 (1910), No. 33, p. 327).— In a previous note (E. S. R., 23, p. 

 746) a general formula was given for preparing this spray. In this paper more 

 specific directions are given as to the amount of soap to be used. 



For distilled or pure rain water, 150 gm. soap, 20 gm. nitrate of silver, and 

 100 liters water are sufficient. For water having a hydrometer test of 15°, 300 

 gm. soap should be used, for 20°, 350 gm., etc., or 10 gm. soap for every 

 hydrometer degree. 



This spray can be applied with the ordinary sprayers used for Bordeaux mix- 

 ture, lime sulphur, etc., and the time and number of applications are the same 

 as for the copper sprays. 



Concerning the new formula for silver salts, L. Degrully (Prog. Agr. et 

 Vit. (Ed. VEst-Centre), 31 (1910), No. 33, pp. 191, 192).-lt is suggested that 

 the formula proposed above be modified as follows : Dissolve from 15 to 20 gm. of 

 nitrate of silver and from 250 to 300 gm. of sulphate of copper in a few liters 

 of water to which a little ammonia has been added; then dissolve from 40 

 to 50 gm. of pyrogallic acid in 95 liters of water and pour the solution of sil- 



