BORDEAUX-OIL EMULSION. 9 
very rapidly. Even this method of preparation was used in certain 
tests. 
In most cases the Bordeaux mixture was prepared according to the 
3-3-50 formula, but this was varied somewhat to meet certain con- 
ditions. At tunes the mixture was used as strong as 4-4-50 or as 
weak as a -J— J— 50. The commercial bluestone used contained from 
98 to 99 per cent of copper sulphate, while the lime was in the 
form of commercial hydrated lime or commercial quicklime. In 
most cases the hydrated form was used because of the ease of hand- 
ling it (4 pounds replacing 3 pounds of quicklime). In general 
effectiveness Bordeaux mixture made with hydrated lime has proved 
throughout these experiments to be equal to that made with quick- 
lime. After the Bordeaux mixture was made the agitator was run 
for two or three minutes before putting in the emulsion, and this 
agitation was continued while the oil emulsion was added and was 
kept up until the spray tank had been emptied. On several plats 
proprietary Bordeaux pastes or powders were used in such quantity 
as to give a Bordeaux mixture equaling in copper content the ordi- 
nary 3-3-50 formula. In some cases it was necessary to add a 
little lime to the commercial paste or powder in order to render the 
Bordeaux mixture miscible with oil emulsion. The oil emulsion 
was added to the diluted commercial Bordeaux-mixture preparation 
in the same manner as with the homemade product. 
PREPARATION OF BORDEAUX-OIL EMULSION SPRAY. 
As a guide in the preparation of this material in quantity, a con- 
densed statement of the successive steps follows: 
Prepare 3-3-50 Bordeaux mixture in the usual way. The following plan is suggested 
for 200-gallon outfits: (.4) Prepare a stock solution of bluestone by suspending 50 
pounds in a sack at the top of a 50-gallon barrel of water; (B) slake 50 pounds of quick- 
lime into a thick paste and make up to 50 gallons; (C) measure out 12 gallons (carry- 
ing 12 pounds of lime) 4 of the stock solution of lime (after thorough stirring) and pour 
it through a strainer into the spray tank about three-fourths full of water; (D) after 
stirring the stock solution, pour 12 gallons of the stock solution of bluestone (carrying 
12 pounds of bluestone) into the tank while the agitator is running; (E) add Jhe oil 
emulsion while the Bordeaux mixture is being agitated. Completely fill the tank with 
water. Of the oil emulsion (Government formula or equivalent) 3 gallons in 200 
gallons of Bordeaux mixture gives 1 per cent of oil. Run the agitator while spraying. 
Preparation of boiled-oil emulsion (Government formula) — 
Paraffin oil 2 gallons. 
Water 1 gallon. 
Caustic potash-fishoil soap 2 pounds. 
Put oil, water, and soap into a kettle or other vessel that will stand fire and heat to 
the boiling point. While still very hot but after removal from fire, pump the ma- 
terial into another vessel with a bucket pump and then pump back again. 
In a former publication (13) it was pointed out that the copper in 
Bordeaux-oil emulsion adhered to the sprayed parts somewhat better 
than in simple Bordeaux mixture. Further tests, using the same 
method (11), were made during the growing seasons of 1921 and 1922 
in order to determine the persistence of copper salts on orange and 
grapefruit leaves sprayed with various Bordeaux mixtures containing 
4 If quicklime is not available 16 pounds of hydrated lime may be substituted for 12 pounds of quicklime, 
using the following procedure instead of steps B and C: Run the agitator while filling the spray tank. 
When the water has risen to about the level of the agitator, sift the hydrated-lime powder in gradually. 
By the time the tank is three-fourths full the 16 pounds should be all in and the agitator will have churned 
it into a suitable milk of lime. Then proceed with step D, as above. 
52770°— 23— Bull. 1178 2 
