v"^ 



Massachusetts 

 Agricultural Experiment Station 



BULLETIN No. 252 JUNE, 1929 



Supplements for Copper Fungicides 



E. B. Holland, C. O. Dunbar, and G. M. Gilligan 



Ever since copper fungicides were introduced, numerous supplementary 

 products have been recommended for incorporation in the spray with a 

 view to remedying some real or fancied defect. The contradictory evi- 

 dence presented by different investigators relative to various supplements 

 may be due in part to differences in amount of substance employed, in 

 method of preparation and of application, but more often to an insufficient 

 number of replications with different crops under varying weather and 

 soil conditions. The use of supplements is not warranted unless they re- 

 duce infection and consequent economic losses. This study was under- 

 taken to determine the intrinsic and relative values of the materials recom- 

 mended for use as supplements. 



Requests for Bulletins should be addressed to the 



AGRICULTURAL EXPERIMENT STATION 

 AMHERST, MASS. 



