380 MAINE AGRICULTURAL EXPERIMENT STATION. I9IO. 



of the process before attempting to prepare a quantity of spray- 

 ing material. All material should be carefully weighed and 

 measured. 



B0RDE;aUX MIXTURE, FORMUI<A I. 



Copper sulphate (blue vitriol) 3 pounds 



Fresh stone or lump lime 3 " 



Water 50 gallons 



It will be noted that the bordeaux mixture here recommended 

 is only three-fifths as strong as that commonly used on potatoes 

 in this State and formerly recommended by this and other Sta- 

 tions for use upon the apple. This is because later work has 

 shown that the weaker bordeaux controls the apple scab nearly 

 as well and is much less likely to injure the fruit and foliage 

 than the stronger. The 5-5-50 formula should still be used upon 

 potatoes, and upon apple trees before the buds open. 



Metal vessels should not be used in the preparation of bor- 

 deaux mixture. Empty kerosene barrels with one head re- 

 moved (50 gal. capacity) are more commonly used, but larger 

 wooden tanks are frequently employed. For convenience these 

 should hold multiples of 50 gallons, or have the capacity in 25 

 or 50 gallon units indicated by tacking a short, thin strip of wood 

 at the required height on the inside of the tank. 



Slake the lime and dissolve the copper sulphate in separate 

 barrels and then dilute each with half of the water. It is neces- 

 sary to strain the milk of lime solution after slaking.* This 



* The most satisfactory strainer that the writers have ever used is 

 constructed as follows : Make a box about 12-15 inches long, without 

 ends and just small enough to slide easily inside the top of the dilution 

 barrel. Then one end of the box is sawed off at a considerable angle, 

 making one side much shorter than the other. No. 50 brass wire strainer 

 cloth is then tacked securely over this end. (Pieces of discarded wire 

 screen cloth used on the machines in paper mills are excellent for this 

 purpose but are of somewhat finer mesh). Two pieces of board about 

 2 inches wide, and long enough to reach across the top of the barrel are 

 then nailed to the sides close to the other end. The completed strainer 

 is then placed in the top of the dilution barrel with the wire bottom 

 down and the two cross pieces extending across the top of the barrel 

 and serving as supports. With a little care such a screen never troubles 

 with clogging as the wire bottom is placed at such an angle that the 

 solid particles are continually washed to the lower side of the screen 

 leaving the remainder unclogged. 



