Bulletin 229, Diseases of Citrus in Florida


proof and the writers are convinced that many of the abuses
heaped upon bordeaux mixture as a fungicide are due to im-
proper preparation and careless application.
 In making up small lots of bordeaux mixture, observe the fol-
lowing directions: Dilute the required amount of stock bluestone
solution in a vessel which contains water to half the amount of
spray solution to be made. Dilute the required amount of stock
milk of lime in another vessel which contains water to half the
amount of spray solution to be made. Then pour the contents of
the two containers simultaneously into a third container or the
spray tank, stirring the combined mixture as the two solutions
are poured together. For example, for 50 gallons of 3-3-50 bor-
deaux mixture, use 3 gallons of stock solution A, diluted to 25
gallons, and 3 gallons of stock solution B, diluted to 25 gallons.
For 200 gallons of 3-3-50 bordeaux mixture, use 12 gallons of
stock solution A and 12 gallons of stock solution B. Be sure to
strain all solutions poured into the spray tank through a fine
mesh screen to remove the coarse particles of sediment that may
cause the nozzles to clog. If bordeaux-oil emulsion is desired,
the required amount of oil emulsion may be washed through the
screen before the tank becomes full, using 31/3 quarts to each 50
gallons of bordeaux mixture, or 31/3 gallons in a 200 gallon tank.
 The wetting or "spreading" power of bordeaux mixture can be
 increased considerably by the addition of a casein spreader at
 the rate of 1 pound to 100 gallons of the spray mixture, although
 the use of a spreader is not so essential when oil emulsion is com-
 bined with the bordeaux mixture. Casein spreader, which is
 marketed under a number of trade names, is made from casein,
 a milk product, and hydrated lime. The required amount of
 spreader should be put into a bucket half full of water and
 beaten vigorously with a wire whip and then poured through the
 screen into the spray tank containing the bordeaux mixture
 while the agitator is running.
 TESTING THE MIXTURE
 When bordeaux mixture is properly prepared it is of a bril-
 liant sky-blue color. If insufficient lime has been used to neutral-
 ize the copper sulphate or the lime is air-slaked (carbonated) or
 otherwise inferior in quality, resulting in a bad mixture, the
 preparation will have a greenish cast and, if this is very pro-
 nounced, the mixture is liable to burn tender tissues.