11 



Guaranties. — In compliance with the insecticide act of 1910, and the 

 various rules and regulations which have been promulgated in interpre- 

 tation of it, every package of commercial copper fungicide (not materials 

 such as copper sulfate (bluestone), etc.) has on the label a statement of 

 (1) the percentage of metallic copper, and (2) the percentage of inert 

 ingredients which it contains. Thus one well-known commercial brand 

 of drj' Bordeaux mixture, typical of most of them, is guaranteed as 

 follows : — 



Per Cent. 

 Active ingredients, copper (as metallic), not less than . . . . .11 



Inert ingredients, not more than ........ 89 



The percentage of copper varies in different brands from 1.5 per cent 

 to as much as 25 per cent, being, of course, higher in the powdered copper 

 fungicides than in those which contain various percentages of water. 



In case an insecticide which contains copper, e.g., Paris green, is in- 

 cluded, the guaranty states the amount of copper present as copper of 

 Bordeaux, and in addition may also state the total amount of copper 

 (as metallic) in both the fungicide and the insecticide. In this case the 

 copper of Bordeaux should be used as the basis for calculating the value 

 of the substance as a fungicide. To the purchaser who has been accus- 

 tomed to thinking in terms of 4-4-50 Bordeaux mixture, this statement 

 of ingredients may mean but little. For this reason, Table II, on page 

 15, is presented, interpreting the guaranties in terms of the standard 

 4-4-50 Bordeaux. 



2. Sulfur Fungicides. 

 As previously stated, sulfur compounds have both fungicidal and in- 

 secticidal values. The form of guaranty under which they are sold is the 

 same, regardless of the purpose for which the spray is sold. In interpret- 

 ing the guaranty, however, there is one important difference. The free, 

 undissolved sulfur, of practically no value as an insecticide, is of value as 

 a fungicide. For the same reason sulfur dust is recognized as a fungicide, 

 although not as an insecticide. 



(1) Lime-sulfur Solutions. — Formulas for Application. 

 Most of the commercial brands of lime-sulfur test about 33° by the 

 Baum6 hydrometer. As a summer spray for the orchard this should be 

 diluted at the rate of Ij gallons to the barrel. If the home-made solution 

 is used, it should be tested with the hj^drometer, and the rate of dilution 

 ascertained by consulting the dilution table on page 14 of this bulletin. 

 The dilution for dormant spray (e.g., for peach leaf curl) is the same as 

 recommended for San Jos6 scale under insecticides, page 9. 



