104 REPORT OF THE COMMISSIONER OF AGRICULTURE. 



ronospora have not given any useful results: (2) that among the 

 remedies in the form of powder thus far tried the most efficacious are 

 those in which sulphate of copper is used; (3) that the mixture of lime 

 and ashes and of lime and sulphur have not as yet given results suffi- 

 ciently satisfactory to enable us to recommend their use; (l) among 

 the liquid remedies, the milk of lime, prepared so as to make it con- 

 venient for application, has proven quite satisfactory. However, its 

 use from a practical and economic standpoint encounters in many 

 places serious difficulties; (5) that the remedies most successful in 

 the results obtained are the mixed liquids or solutions containing sul- 

 jjhate of copper. 



It was further conchided that the action of the remedies is, prevent- 

 ive; therefore only the preventive application can check the invasion 

 of the Mildew, and repeated applications act only in so far as they pre- 

 vent future invasions of the disease. In localities much subject to 

 the Mildew it is necessary to apply the remedies to the vine before the 

 season of bloom, and in all places it is needful to apply them with the 

 greatest thoroughness as soon as the Mildew appears, and to rejjeat 

 the application according to the necessities and the nature of the 

 remedy. 



No evidence was adduced showing that the applications of tlie salts 

 of copper to the vine had resulted in injury to the public health. 



A simj)le solution of sulphate of copper, 300 to 500 grams to the 

 hectoliter* of water, has proved in some instances to be equally effect- 

 ive in warding off the Mildew as the copper mixture of Gironde. As 

 its application is attended with much less inconvenience and expense, 

 further trials should be made to determine its relative value. This 

 solution, like all others, should be applied preventively, say about 

 June 15, unless the Mildew appears earlier ; a second application being 

 made about the 1st of August, f 



SKAWINSKI'S POWDER FOR COMBATING THE MILDEW ALONE, OR THE 

 MILDEW AND THE OIDIUM TOGETHER. | 



Having determined the value of sulphate of copper as a remedy for 

 the Mildew, Mr. Skawinski, a viticulturist of Chateau-Giscours, 

 France, experimented, with the view of discovering means for fixing 

 the particles of this salt upon the leaves of the vine. He discovered 

 that coal dust or calcined alluvial earth, added in proper proportions 

 to the finely triturated sulphate of copper, gave to it the quality of 

 adherence desired. 



Tlie compound for the treatment of the Mildew alone consists of 

 sulphate of copper, finely powdered, 10 kilograms; soot or alluvial 

 earth, 15 kilograms; coal dust, 75 kilograms. 



For combating the Mildew and the Oidium : Sulphate of copper, 10 

 kilograms ; sulphur, 50 kilograms ; coal dust, 32 kilograms ; soot or 

 calcined alluvial earth, 3 kilograms. 



The first treatment should be made when the shoots are about 6 

 inches long ; a second may be given at the time of flowering ; a third, 

 when the berry is formed ; and a fourth, at the time of ripening of 

 the fruit. 



*One hectoliter = 23 gals. 



fTlie application of the sulphate of copper compounds for preventing ]\Iildev7 

 should be made in cloudy or rainy weather, for at such times the danger of corrosion 

 from a too rapid evaporation of the solutions is avoided, and they will also be more 

 evenly and thorouglily distributed over the surface of the leaves. 



X La Vigne Americaine, November, 1886. 



