Minnesota Plant Diseases. 219 



Copper sulphate solutions. Copper sulphate is sometimes 

 used without lime. The following formulae have been recom- 

 mended : 



"(A) Copper sulphate I pound. 



Water 25 gallons. 



For use before the buds open, the above solution is easy to 

 prepare and to apply. It should not be applied to any plant after 

 the leaves burst, as it will burn the foliage. Its action is equal 

 to bordeaux mixture, but it does not seem as lasting. 



Weak copper sulphate solutions. 



(B) Copper sulphate i pound. 



W^ater 250 gallons. 



(C) Copper sulphate I pound. 



Water 500 gallons." 



"We have been much pleased with the results obtained from 

 the above weak solutions. Formula (B) can be used without 

 danger of injuring the foliage upon all except the most tender 

 plants, but for use upon peach and other tender plants we pre- 

 fer to rely upon still weaker solutions as given in formula (C)." 

 [Mich. Bull. No. 121 : 71895.] 



The strong solution has also been used as a seed steep (10 

 to 12 hours) to prevent smut in oats and wheat. It is then 

 followed by steeping the seed in a solution of lime (one pound 

 in four to ten gallons of water) for about five minutes, which 

 protects the grains from any injurious effects by the sulphate. 

 [Oregon Bull. No. 75 1903]. 

 Eau celeste (blue water.) 



Copper sulphate 2 pounds. 



Ammonia I quart. 



Water 50 gallons. 



Dissolve the copper sulphate in six or eight gallons of wa- 

 ter, then add the ammonia and dilute to fifty or sixty gallons. 

 Ammoniacal copper carbonate. 



"Copper carbonate 5 oz. 



Ammonia (26 Beaume) 3 pints. 



Water 45 gallons. 



Dissolve the copper carbonate in ammonia. This may be 

 kept any length of time in a glass-stoppered bottle and can be 

 diluted to the required strength. The solution loses strength 



