Spray Calendar. 55 



J 



more, not necessary to go into details as to the relation of spraj^- 

 ing to hygiene; suffice it to say, that if the work is properly done, 

 no danger whatever to health need be apprehended. 



Superionty of the hordeaux mixture — During the past four years 

 numerous solutions, powders, etc., have been tested, with a view of 

 determining their value as economicalj effective, and practical pre- 

 ventives of fungous parasites. While a number of these prepara- 

 tions have given promise of value, none have been found which fill 

 so many requirements as bordeaux mixture and the ammoniacal so- 

 lution of copper carbonate. Of the two preparations, bordeaux 

 mixture has long been recognized as possessing the most valuable 

 qualities, and it is probably more generally used today than all 

 other fungicides combined. The chief points in its favor are: (1) 

 Its thorough effectiveness as a fungicide; (2) its cheapness; (3) 

 its safety from a hygienic standpoint; (4) its harmlessness to the 

 sprayed plant; and (5) its beneficial effects on plants other than 

 those resulting from the mere prevention of the attack of parasites. 



Bordeaux mixture formula — All things considered, it is believed 

 that the best results will be obtained from the use of what is known 

 as the 50-gallon formula of this preparation, as follows : 



Ingredients — Water, 50 gallons. 



Copper sulphate, six pounds. 

 Unslacked lime, four pounds. 



Must he well made — It has been found that the method of com- 

 bining the ingredients has an important bearing on both the chem- 

 ical composition and physical structure of the mixture. For exam- 

 ple, if the copper sulphate is dissolved in a small quantity of water 

 and the lime milk diluted to a limited extent only, there results, 

 when these materials are brought together, a thick mixture, hav- 

 ing strikingly different characters from one made by pouring to- 

 gether weak solutions of lime and copper sulphate. It is true, fur- 

 thermore, that if the copper sulphate solution and lime milk 

 are poured together while the latter, or both, are warm, different 

 effects are obtained than if both solutions are cool at the moment 

 of mixing. Where the mixture has been properly made there is 

 scarcely any settling after an hour, while the improperly made mix- 

 ture has settled more than half. 



