replaced, from reasons of economy, by a mixture of the milk of lime and some salt of copper, the sulphate being commonly used, on account of its cheapness. This mixture was of the consistency of cream, and was of a light blue color. It was applied to the vines by means of brooms, or whisks of heath. The design was to apply enough of the mixture to each vine to give it the appearance of having been well poisoned, the operation, of course, being delayed until the period of ripening approached. The vines thus treated were the ones which had retained their foliage through the fall of 1882, while others growing further from the road lost their leaves. The cause of the beneficial action of the mixture was soon ascribed to the copper, for lime used alone had proved unsatisfactory as a remedy for mildew. Prillieux and Millardet were among the first to note the effect of the mixture and to ascribe its action to the proper cause; but Millardet is the one who did the most towards perfecting the mixture and testing its action upon foliage, and upon the mildew. (See frontispiece.) He was materially assisted by U. Gayon, professor of chemistry in the Faculty of Sciences, of Bordeaux. These two may justly be considered the leaders in the study and use of the preparation which was destined to prove superior to all fungicides that have been used to the present day, and which is now so well known, in a modified form, under the name of the Bordeaux mixture. Although these men were the most energetic in conducting the work, and the first to publish results, they apparently were not the only ones working in this field. Prillieux asserted 1 that the treatments of Jouet and of E. Ferrand were made simultaneously with those of Millardet, and independently of the latter, and that they did not even know of Millardet's investigations. Their work, however, does not appear to have been carried on systematically, nor were results published which go to show that the experiments began so early as did those of Millardet and Gayon. It is consequently to these two men that the honor of having first experimented with the "bouillie bordelaise," as it then began to be called, may be granted, and to Millardet in particular may be given the credit of being the 1 Société Nationale d'Agriculture de France, session of Nov. 4, 1885, 590. first to plan and publish results which showed plainly the value of the copper compounds in commercial work.1 The first systematic applications of copper compounds for the prevention of the downy mildew were made 2 on the 18th of August, 1883, or the year following the observation of the apparent value of lime and copper sulphate when applied together. The work was done on the grounds of the castle of Dauzac in the Médoc, by E. David, steward of the place, but under the direction of Millardet. In these experiments the sulphates of iron and of copper were used. They were applied in pure solutions, and also mixed with lime in varying proportions. In 1883 Millardet, believing that copper was the most efficient agent in the destruction of the mildew, applied this metal in other forms than the sulphate. He used, in addition, the carbonate, phosphate, and sulphide of copper, and also the corresponding salts of iron. Lime was also applied alone. In 1884 the same work was repeated, and although the mildew was not very abundant, still he and Mr. David came to the conclusion that the mixture of the sulphate of copper and the milk of lime was the most promising of all the materials applied. They decided to give up the use of the iron salts, as well as the simple solution of copper sulphate. It was found that the latter burned the leaves when used stronger than one-half part of the salt in 100 parts of water. This result, however, does not agree with those obtained by Messrs. Ad. Perrey, P. de Lafitte, and Maginen. On the estate of Salle de Pez, at St. Estèphe, an 8 per cent solution of copper sulphate proved to be nearly as efficient as when lime was added. During these two years the mildew was not very prevalent in the treated vineyards, so that only partially satisfactory results were obtained. These were, however, of sufficient value to warrant the publication 5 of an article by Millardet, in which were given the following directions for preparing and applying the mixture: In 100 liters of water dissolve 8 kilos of commercial 1 Jour. d'Ag. et d'Hort. de la Gironde, Oct. 1. Cited in Jour. d'Ag. Prat. 1885, Dec. 3, 804. 2 Jour. d'Ag. Prat. 1885, Dec. 3, 804. 3 Ibid. 708. 4 Ibid. Nov. 5, 661, 662. 5 Annales de la Société d'Ag. de la Gironde, 1885, April 1, 73 et seq. sulphate of copper. In another vessel make a milk of lime by slaking 15 kilos of quicklime in 30 liters of water. This is then added to the copper sulphate solution, causing a bluish precipitate. The workman should stir the mixture well, and then pour a part of it into a pail or watering pot. This is carried in the left hand while with the right he sprinkles the foliage by means of a small broom. Care should be taken that none of the mixture shall strike the grapes." Such was the first formula for making the Bordeaux mixture; and the first apparatus used for its application was a broom! On Dec. 3, 1884, some time previous to this publication, Baron Chatry de la Fosse had called the attention of the Agricultural Society of Gironde to the good effects following the use of the mixture of lime and copper sulphate, but he gave no direction for its preparation nor for its use. During 1885 the downy mildew developed with much intensity. Many experiments were tried, and the year brought out a number of facts regarding the various treatments. The value of the "bouillie bordelaise was proved beyond all doubt. Wherever it had been properly used, the results were all that could be wished. Untreated vines lost their leaves, and those to which the mixture had been applied, retained them in an almost perfect condition. These results are all the more remarkable on account of the very crude method of applying the mixture, a small broom being generally used for the purpose. The most marked and promising results of the year were probably obtained by de Ferrand, Johnston, and David.1 The original formula of the mixture was modified by various vineyardists in 1885. De Ferrand used 2 successfully about the same quantity of lime as of copper sulphate. David added glue to the mixture at the rate of 6 kilos strong glue dissolved in 800 liters of the mixture. This first trial of the addition of glue was apparently followed by beneficial results. The first application of the Bordeaux mixture for the prevention of other diseases than those of the vine seems also to have been made this year. Prillieux, in his report to the minister of agriculture, dated Oct. 22, 1885, says that Jouet, at Château-Langoa (Médoc), made an application to tomatoes 1 Jour. d'Ag. Prat. 1885, 699 et seq. 2 Ibid. 701. 4 3 Ibid. 661. 4 lbid. 662. which were apparently attacked by the same peronospora that is found upon potatoes. He believed he had cured or stopped the disease. Since this fungus is closely related to the peronospora of the vine, it seemed very probable that the remedy would prove equally valuable for all similar diseases. Prillieux even went so far as to advise, for the first time, the use of the mixture upon potatoes and tomatoes, and events have shown that his advice was well worthy of being followed. At the beginning of the year 1885 the general opinion appears to have been to wait until the appearance of the mildew upon the vines before making an application; and it was also believed that one treatment was sufficient. But after the work of the year Millardet thought 1 that in case of severe rains it might be advisable to make a second. At the close of the year Prosper de Lafitte summed 2 up the methods then in use for checking the downy mildew of the grape, as follows: 1. "The treatment of Beaune, which consists in covering the posts and the tying material, rye straw being commonly used for this purpose, with a five-tenths per cent solution of copper sulphate. (Page 24.) 2. "The treatment of which Millardet is the promotor" consists in protecting the vines by means of a mixture of the milk of lime and a solution of copper sulphate. (Page 27.) 3. "Spraying the foliage with a simple solution of copper sulphate. (Page 27.) 4. "Spraying the foliage with the milk of lime, using approximately a 2 per cent mixture." (Page 20.) To the above might have been added also: 5. The treatment which consists in the application of powders. (Page 32.) The use of the "bouillie bordelaise" became more general in 1886 and many cases are reported in which its beneficial and almost specific action was proved. The general opinion seemed to be that it was superior to any of the other substances recommended. In accordance with the advice given by Prillieux in the fall of 1885 Jouet, in the Médoc, made what appears to have been the first application of the mixture to potatoes for the preven 1 Jour. d'Ag. Prat. 1885, 734. 2 Ibid. 880 et seq. tion of the rot, a disease which was then very destructive. The experiment is reported1 by Prillieux, who says that the area treated covered about three hectares.2 The application was made as soon as the rot appeared, and no further injury resulted from the disease. Jouet was equally successful with the blight of tomatoes, both diseases being attributed to Phytophthora infestans, DeBary. Another tomato grower, at Écully, is likewise reported to have been successful. Origin of the Ammoniated Copper Fungicides, and Various Combinations. A new fungicide, one destined to become very well known, was tried in 1885 for the first time. It was proposed by Professor Audoynaud of the agricultural school at Montpellier. He gave the following directions for its preparation : Copper sulphate. Water, sufficient to spray .1 kilo. 1 liter. The copper salt was dissolved in the ammonia and then this solution was added to the water. Such a solution had already been known to pharmacists under the name of "eau céleste,” meaning "heavenly water," so called on account of its deep blue color. It was used during the year by several experi menters. In 1886 a great many men conducted experiments to test the value of the compounds of copper, very few other substances being used. Among the many who did valuable work during the year may be named Millardet and David, Gaillot, and Dr. G. Patrigeon.5 These experimenters planned the work so thoroughly that their results embodied the most important of those obtained by other workers. In almost every instance the "bouillie bordelaise," or Bordeaux mixture, gave the most satisfactory results. Millardet 1 Société Nat. d'Ag. de France, session of Aug. 18, 1886, 465. 2 A hectare is 2.47 acres. 3 Progrès Agricole et Viticole, 1886, March 28. Cited by Viala et Ferrouillat, "Traitment des Maladies de la Vigne," 1888, 30. Jour. d'Ag. Prat. 1886, Nov. 25, 764; Dec. 9, 831. 5 Ibid. Nov. 11, 696. |
