SPRAYING MATERIALS. I69 



phate in twenty-five gallons of water, and four to five pounds of 

 lime in twenty-five gallons of water. The two solutions are then 

 mixed and well stirred. Before using, the mixture is strained 

 through coarse burlap or a fine sieve. To this stock solution Paris 

 green is added at the rate of about one-fourth pound to fifty gallons 

 of the mixture. Such a combination has the advantage of being 

 an insecticide and a fungicide and is especially applicable for the 

 spraying of potatoes to prevent the spread of blight, as well as to 

 cause the destruction of the bugs. 



Some prefer the dust sprays because of their great efficiency 

 of application. A good dust spray is made by dissolving four 

 pounds of sulphate of copper in four gallons of water, and four 

 pounds of lime in four gallons of water. Mix the two solutions and 

 allow them to settle. It is the sediment obtained by settling of the 

 Bordeaux mixture that is the active ingredient. The water iS 

 poured oflf, the sediment is allowed to dry in the air and then mixed 

 with sixty pounds of pulverized slaked lime. To this Paris green 

 can be added if desired. Other mixtures and combinations have 

 been proposed and found efifectual, but these are the standard 

 Bordeaux preparations. 



The copper sulphate used in the preparation of the Bordeaux 

 mixture is not generally adulterated. Many of the special prepara- 

 tions put out under trade names, as paragrene, slug shot and black 

 death, contain adulterants from sixty to ninety-two percent, and 

 they are not efficient for spraying purposes. 



On the whole it is best for the horticulturist to use only stand- 

 ard brands of Paris green that have been shown by inspection in 

 other states to be of high purity, to use with the Paris green a lit- 

 tle slaked lime to prevent the arsenic from going into solution, and 

 in special cases to make a joint use of Bordeaux mixture and Paris 

 green. 



Mr. Merritt : How will dust spray affect the timothy and clover 

 cut in the orchard if fed to cattle? Will it not be very injurious? 



Prof. Snyder: It depends largely upon the amount of spray 

 you have used. The usual method of spraying is to take one pound 

 of Paris green to 200 gallons of water, and immediately under the 

 tree there is a little danger, but if there has been some rain or a 

 little dew after spraying that is largely washed off. If the spraying 

 has been done in such a way that accumulations have been formed 

 in some places it might be somewhat injurious, but where it is prop- 

 erly done and evenly put on the trees there is very little danger. 

 However, on the whole it is better to use that part of the cutting 

 for mulch or some other purpose than feeding. 



