Massachusetts 

 Agricultural Experiment Station 



BULLETIN No. 254 June, 1929 



The Preparation and Effective- 

 ness of Basic Copper Sulfate 

 as a Fungicide 



By E, B. Holland, C. O. Dunbar, G. M. Gilligan and W. L. Doran 



Copper fungicides have been a subject for investigation during the past 

 few years. The work comprises a study of chemical composition, physi- 

 cal characteristics and general effectiveness in field work, together with 

 the use of various supplementary products. The main objective was the 

 preparation of a Bordeaux substitute that could be readily suspended in 

 water and used as a spray, or mixed with a free-flowing carrier and applied 

 as a dust. The product must give practical control of disease but not 

 necessarily equal to a highly dispersed Bordeaux of the same copper con- 

 tent. The advantages of such a product in the saving of time, labor and 

 equipment in preparation, and the gain in uniformity and stability of the 

 spray mixture are evident. Since basic sulfates are generally considered 

 preferable to basic carbonates, attention has been directed largely to 

 them. 



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AGRICULTURAL EXPERIMENT STATION, 

 AMHERST, MASS. 



