270 STATE BOARD OP AGRICULTURE. 



DUST SPRAYS. 



Attempts have been made to use copper sulphate and Paris green 

 as dust sprays. Very unsatisfactory 'results have been secured when 

 the dust sprays are used as fungicides but they ansv\-er fairly well 

 against the codling moth and curculio, especially as the cost of the 

 applications is much less than for liquid sprays. However, as the injury 

 -done by fungi is often greater than that by insects and it is always 

 •desirable to use Bordeaux mixture in liquid form, there will be little 

 or no occasion for applying dust sprays of arsenites as they can be readily 

 ^dded to the liquid Bordeaux mixture. * 



SODA BORDEAUX. 



Concentrated lye 1 pound 



Lime 5 ounces 



Copper Sulphate 3 pounds 



Water 50 gallons 



Dissolve the copper sulphate and lye, and slake the lime in two gal- 

 lons of hot water for each; mix the lime and copper sulphate solution 

 and after adding the lye solution dilute to 50 gallons. 



This is used upon the grape for the black rot and upon other fruits 

 just before they are ripe. 



COPPER SULPHATE SOLUTION. 



Copper Sulphate 2 pounds 



Water .jO gallons 



For use before the buds open the above solution is fully as effectual 

 as Bordeaux mixture and is easier to prepare and apply, but it should 

 not be applied to any plant after the buds have opened. For use against 

 the leaf curl of the peach this solution is especially desirable. If used 

 before the middle of April a thorough application will entirely prevent 

 the attack. 



WEAK COPPER SULPHATE SOLUTION. 



Copi^er Sulphate 1 pound 



Water 150 to 200 gallons 



A solution of copper sulphate of this strength can be used with safety 

 upon nearly all plants. The stronger solution can be used upon all 

 fruit trees except the peach, for which a weak solution Avould be pre- 

 ferable. Although less effective than Bordeaux mixture, the weak solu- 

 tions of copper sulphate may be used to advantage where it is not desir- 

 able to a})ply mixtures containing lime. They seem fully as effectual 

 as the ammonia solutions and are much cheaper. 



