384 MAINE AGRICULTURAL EXPERIMENT STATION. 191O. 

 BORDEAUX mixture: WITH IRON STICKKR- FORMULA 2. 



Copper sulphate (blue vitriol) 2 pounds 



Iron sulphate (copperas) 2-4 " 



Fresh stone or lump lime 4-6 " 



Water to make 50 gallons 



This formula is proposed and recommended by Dr. A. D. 

 Selby of the Ohio Experiment Station. It has not been used 

 by the writers in Maine, but Doctor Selby makes the following- 

 statement with regard to it : * 



"In this spray the iron sulphate is added in order that it may 

 be precipitated by the lime and serve as a more complete sticker 

 than is provided by standard bordeaux mixture. It would ap- 

 pear possible by the weak solution as given for the copper com- 

 pound and by this possible efficient sticker to make the reduced 

 amount of the copper sulphate do the work as fungicide just 

 as effectively and with less risk of foliage injury than with 

 standard bordeaux mixture. Trials made up to this time upon 

 apples in full foliage, upon grapes, and upon potatoes indicate 

 that the spray is efficient. The iron sulphate is not considered 

 a fungicide/' 



Where spray injury upon apple trees is experienced and the 

 orchardist does not wish to go to the trouble of preparing his 

 own lime-sulphur sprays or go to the expense of purchasing 

 the prepared brands of lime-sulphur, a trial of this modified 

 form of bordeaux mixture is suggested. 



Lime-sulphur sprays. The orchardist who desires to use 

 lime-sulphur compounds for summer spraying may choose one 

 of the following: a self-boiled lime-sulphur, a home-cooked, or 

 a factory-cooked concentrated material which must be diluted 

 before it is applied. The first is comparatively easy to prepare 

 but less effective than the other two. The home-cooked con- 

 centrated may be prepared some time before needed and later 

 diluted as fast as required for use. It has the disadvantage of 

 being somewhat more difficult to prepare, requiring some form 

 of cooker and other pieces of apparatus. Of the factory-cooked 

 concentrated material there are several brands on the market 

 which seem to equal the home-cooked in efficiency and in free- 

 dom from the production of spray injury if used in sufficient 



* Selby. A. D. Ohio Exp. Sta. Bui. 214, p. 358, 1910. 



