108 The Spraying of Plants. 



mended. The precipitated carbonate of copper was thought 

 to be valuable as a fungicide, but it has since fallen from 

 favor. 



Professor L. R. Jones, of Vermont, began work upon potato 

 diseases in 1890, and since that time valuable reports have been 

 published by him regarding the various diseases of this crop. 

 In the annual report of the station for that year may be found 

 a condensed account of the work upon potatoes as well as upon 

 the diseases of other plants. 1 



In Gajloway's report for the year 2 1890 is the statement : 

 " In treating the disease [leaf blight of pear, cherry, and straw- 

 berry] the present season, the best results were obtained from 

 the use of the ammoniacal copper carbonate and the Bordeaux 

 mixture. As far as the efficacy of the two fungicides is con- 

 cerned, there is little choice. The ease with which the ammo- 

 niacal solution is prepared and applied, however, makes it more 

 desirable in the end." These two fungicides were at the time 

 generally considered to be the best. 



In 1891, Galloway published an account of the use of Bordeaux 

 mixture made of different strengths, and the results obtained 

 showed that for grape diseases it was not necessary to use as 

 much copper sulphate and lime as the formula given in Circular 

 4 of the Section of Vegetable Pathology called for. " There 

 was little difference between the plats treated early with full- 

 strength and those treated in the same way with the half- 

 strength mixture." 3 The " half-strength " was made by using 

 one-half the amount of materials called for by what has later 

 been termed the " standard " formula mentioned in Circu- 

 lar 4, the amount of water used remaining the same. The 

 half-strength or " normal " formula was soon very generally 

 adopted. 



Goif in 1891 established the fact that Paris green possesses 

 marked fungicidal value, especially during dry seasons. 4 Later 

 experiments made by Lodeman have shown that the poison is 



1 Ann. Kept. Vt. Agric. Exp. Sta. 1890, 129-144. See also Bull. 24 of the same 

 station for more detailed descriptions. 



2 Ann. Kept. U. S. Com. Agric. 1890, 393-408. 

 s Ann. Kept. U. 8. Com. Agric. 1891, 367. 



Ibid. 364; and Ann. Kept. Wis. Agric. Exp. Sta. 1891-92, 264. 



