INSECTICIDES AND EQUIPMENT FOR CONTROLLING INSECTS 7 
bordeaux mixture should be freshly prepared when used. Ready- 
prepared mixtures are available on the market. 
This spray has a blue color and leaves a bluish-white deposit on 
sprayed surfaces. Its sticking properties are excellent. It is used 
as a control for the potato leafhopper on potato and as a repellent 
for flea beetles on various vegetable and flowering plants. Bordeaux 
mixture is essentially a fungicide and as such is often combined with 
various insecticides such as nicotine, lead arsenate, calcium arsenate, 
and others. 
It is also used as a safener for lead arsenate on apple foliage and 
as an emulsifier for tank mixtures of lubricating-oil sprays on dor- 
mant apple, pear, quince, prune, plum, and peach trees. 
Various formulas for making bordeaux mixture are used. The 
following is one that 1s often recommended : 
For 100 gallons For small quantities 
Copper sulfate (bluestone) —~—~-___-_____- 8 pounds. 4 ounces. 
BEES li hay Chisente Cie ii ran ees see ee ae 12 pounds. 6 ounces. 
Vater soe ro aes Sala Agile Ss ~~ 100 gallons. 3 gallons. 
On tender plants that would be injured by the above spray it is 
advisable to use half the quantities of copper sulfate and lime indi- 
eated in the formula. 
When used as a safener for lead arsenate on apples, it may be 
reduced in Ciototh to 14 or 34 pound of copper sulfate with 1 or 114 
pounds of lime, respectively, per 100 gallons. The use of bordeaux 
mixture on apple foliage should be avoided in cool, wet weather, 
since under such conditions it may cause severe russeting of fruit. 
Powdered copper sulfate is preferable to the crystal or lumpy forms 
for use in making bordeaux mixture, since it is readily soluble in cold 
water. When power sprayers are used the required quantity of the 
powdered copper sulfate is poured, or washed through a screen, into 
the partly filled sprayer in which the agitator is kept running. After 
the copper sulfate is completely dissolved, the lime is added either as 
a dry powder or in the form of a water mixture. The remainder of 
the required quantity of water is then added to the tank and the 
agitation maintained while this is done. When small quantities are 
needed for use with compressed-air or knapsack sprayers, the total 
quantity of water to be used is divided and placed in two pails. The 
powdered copper sulfate is dissolved in one pail, and the lime mixed 
with the water in the other. Then the copper sulfate solution and the 
lime-water mixture are poured together and thoroughly mixed. 
The mixture is then poured thr ough | a strainer into the sprayer. If 
copper sulfate crystals or lumps are used, they should preferably be 
dissolved in a quantity of hot water representing one-half the total 
volume desired. If hot water is not available, place the copper 
sulfate crystals in a cloth sack and suspend this in the vessel con- 
taining cold water in such a way that the bottom of the sack is 
just below the surface of the water. Complete solution should occur 
in 1 to 2 hours. The suspension of lime in the other half of the 
water is then added, as the mixture is being agitated, and the whole 
poured through a strainer into the sprayer. 
For convenience or where large quantities of bordeaux mixture 
are needed, stocks of copper sulfate solution and lime suspension may 
