New York Agricultural Experiment Station. 329 



soda bordeaux and soda lime bordeaux. 



Experiments with the soda bordeaux mixture have been in progress 

 for several years at the New Jersey Experiment Station. Tests have 

 also been made of this mixture at the Ohio Station, together with 

 field tests in some of the grape districts of that State. Soda bordeaux 

 is made by adding caustic soda to a solution of copper sulphate until 

 the mixture becomes exactly neutralized. Much care must be taken 

 not to have an excess of either ingredient. In the hands of fruit 

 growers this mixture has sometimes resulted disastrously to the 

 foliage because of the presence of an excess of one or the other ingre- 

 dient in the mixture. It is not surprising that some fruit growers 

 find difficulty in bringing soda bordeaux to exact neutrality. On ac- 

 count of the difficulty, Dr. Halsted of the New Jersey Experiment 

 Station, has recommended that the soda be added to the copper 

 sulphate solution until it approaches a neutral condition, and that the 

 preparation of the mixture be then completed by adding small 

 amounts of milk of lime. No experiments with either soda bordeaux 

 or soda-lime bordeaux have been made at this Station, and no litera- 

 ture has been published. Publications on this subject can be obtained 

 from the New Jersey and Ohio Stations, and for detailed informa- 

 tion with regard to this mixture the reader is referred to the Botanists 

 at the above mentioned Stations. 



BORDEAUX DUST OR DRY BORDEAUX MIXTURE, 



The utility of the so-called " dust sprays " will not be discussed here 

 but will be touched upon in presenting the subject of " dust sprayers." 

 Bordeaux mixture is prepared for use in dust sprayers in two princi- 

 pal ways: 



1. The lime is slaked by pouring over it the copper sulphate in 

 strong solution. 



2. The freshly slaked lime in the form of thin paste is mixed with 

 the strong copper sulphate solution. 



