Department of Plant Patholocv. 425 



Never pour together two strong solutions and then dilute afterwards. Never pour 

 together the two solutions until ready to use. It is well to strain the mixture as it 

 goes into the sprayer to take out anything that might clog the nozzle. Do not use 

 tin or iron vessels in making the bordeaux. They will be eaten by the copper 

 sulfate. 



When large quantities of Bordeaux are to be made, prepare concentrated stock 

 solutions by dissolving the copper sulfate at the rate of one pound to the gallon 

 and slake the lime, one pound to the gallon of water. Dilute 5 gallons of the vitriol 

 solution in 30 or 40 gallons water and add 5 gallons of the lime solution. Add 

 water to make 50 gallons. 



When only a small amount of the mixture is wanted at a time prepare dilute 

 stock solutions, by dissolving 5 lbs. copper sulfate in 25 gallons of water, and slake 

 5 lbs. of lime and dilute to 2 5 gallons in water. Now to prepare any desired amount 

 of the mixture, stir the solutions thoroughly and pour together equal parts of each 

 into a third vessel or in the sprayer tank. Stock solutions should be kept in 

 barrels with tight lids to prevent concentration by evaporation. 



Ferrocyanide test. It is not necessary to weigh the lime, if some test is used to 

 determine when sufficient of the lime milk has been added. The most convenient 

 test is the "ferro-cyanide" test. Put an ounce of yellow prussiate of potash in a 

 pint bottle and fill it with water. This is poison and should be so labelled. Stop 

 the bottle with a cork from one side of which has been taken a V shaped piece so 

 as to give a small opening into the bottle. Add lime milk to the copper sulfate 

 solution until the ferro-cyanide solution will not turn brown when dropped from 

 the bottle into the mixture. Then add an extra gallon or so of lime milk. An 

 excess of lime will do no special harm and may aid in some cases in holding the 

 mixture to the plants or possibly prevent spray injury. 



The following common diseases are controlled by Bordeaux mixture: Apple 

 Scab, New York Apple-Tree Canker, Asparagus Rust, Bean Anthracnose (in some 

 cases). Leaf-spot of Beets, Leaf-Blight of Celery, Leaf-spot of Cherry, Cucumber 

 Mildew, Leaf-spot of Currant, Ginseng Blight, Black Rot of Grapes, Anthracnose 

 and downy Mildew of the Grape, Hollyhock rust. Onion Mildew, Leaf curl of the 

 Peach, Leaf-spot and Scab of the Pear, Leaf-spot of the Plum, Late Blight of 

 Potatoes, Leaf and Fruit-spot of the Quince, Raspberry Anthracnose, Black-spot 

 of the Rose, Strawberry Leaf-spot, Leaf-spot of Tomato. 



In applying Bordeaux to some plants, it is desirable to add something to the 

 mixture to make it adhere satisfactorily. The following has been useful in spray- 

 ing such plants as onions, cabbage, asparagus, etc. By the use of this "sticker" 

 the effectiveness of the mixture on other plants would perhaps be greatly increased 

 and the number of applications in some cases reduced. 



Resin Sal Sod.\ Sticker. 



Resin 2 lbs. 



Sal Soda (crystals) i lb. 



Water i gal. 



Boil in an iron vessel until of a clear brown color i to ij hours. Cook in the 

 open and watch carefully as it is apt to boil over. For spraying plants like cabbage, 

 onions and the like, add this amount to 50 gallons of Bordeaux, for spraying other 

 plants add half the amount to 50 gallons of the Bordeaux. Bordeaux containing 

 this "sticker," once dry, will not be washed off by the heaviest rains. 



