90 SIXTEENTH BIENNIAL REPORT 



Dissolve the iron siilfate in a few gallons of water. Fill the spray tank with 

 water, add the lime-sulfur and Start the agitator. Add slowly the dissolved iron 

 Sulfate. A black precipitate will be formed. Enough lime-sulfur should be used 

 to combine with all the iron sulfate. 



DUST SPRAYING 



This method of Controlling orchard diseases has not been tested out in Oregon 

 up to the season of 1916. White there appear to be some possible advantages in 

 this method, yet there are certain possible drawbacks to be reckoned with. Since 

 this method of dealing with orchard pests has not been given sufficient practical 

 demonstration in the United States, growers are urged to be cautious about sub- 

 stituting the dust method for the tested and tried methods of spraying, until 

 the fungicidal efficiency of the new method shall have been demonstrated beyoud 

 question by thorough tests under Oregon conditions, which, by the way, are 

 distinctly unlike the conditions in any of the eastern states. 



COMBINED BORDEAUX OIL EMULSION SPRAY 

 By Dr. C. A. Macrum 



This emulsion spray was evolved by Dr. C. A. Macrum, commisioner for the 

 Fourth District, State Board of Horticulture. 



If applied as the buds are opening, before the blossoms appear, will control 

 scab, San Jose scale, aphis, leaf roller, red spider, curl leaf of the peach, and the 

 copper will be present to prevent the ravage of the anthracnose spore when the 

 rains come in the fall of the year, and control the disease in prunes due to the 

 cylindros porum. 



The method of preparatiou is as foUows : Prepare the copper sulfate Solution 

 in the usual proportions of one pound to the gallon of water, dissolve one and 

 one-half pounds of common glue in one and one-half gallons of water, slack 

 twelve pounds of lime, or stir twelve pounds of hydrated lime in water at time of 

 using. Fill a 200-gallon spray tank three-fourths füll of water. Pour 

 twenty-four gallons of bluestone Solution into the tank, start the agitator 

 and add the lime milk slowly imtil a neutral Solution is had. Test with 

 litmus paper to teil when the Solution is neutral. Add the one and one-half gallons 

 of glue Solution. Measure out twelve gallons of the General Chemical Company's 

 No. 1 oil emulsion. or a corresponding oil emulsion, add a little water and stir 

 until emulsion is started as shown by the mixture turning milky. Pour into the 

 spray tank and add water to make 200 gallons. The agitator must be kept running 

 during the whole procedure. The spray should be applied as soon as prepared. 



The above are the proportions for a 200-gallon tank. In making stock Solutions 

 for a day's spraying the quantities given can be multiplied by the number of 

 tanks required. 



The strength of the Bordeaux can be varied as deemed necessary. The amount 

 of copper sulfate in the above formula is the same as the ordinary 6-6-50. It is 

 necessary that the Bordeaux Solution be neutral and not alkaline as Bordeaux is 

 ordinarily made. This is determined by adding the lime milk slowly, allowing 

 the lime milk and copper Solution to be well mixed, and testing with blue or red 

 litmus paper to determine when the neutral point is reached. 



If no rain follows the application of Bordeaux oil emulsion spray for 24 hours, 

 the spray dries thoroughly and stays on the bark of the trees throughout the 

 season, and is effective against anthracnose development after the fall rains begin. 



