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the stock mixture and should keep for a month. In time it 

 will break up again and the oil, separating out, will appear on 

 the surface. It is then no longer fit to use. 



For use against plant lice, crawling scale insects, etc., take 

 1 gallon of this stock mixture, mix thoroughly with about 9 gal- 

 lons of water, and spray. For more resistant insects; mix 1 gal- 

 lon of the stock with 4 or 5 gallons of water. 



If the materials fail to thicken while being "churned," it is 

 probably because hard water has been used. In that case add 

 a little borax or soda to soften it. 



Lime-sulfur Wash. — This wash was first developed as a 

 scale killer and this is still its chief use as an insecticide. It 

 has been found, however, that it is also a valuable fungicide, 

 and is therefore of greater value than was at first thought. It 

 was originally made by boiling together varying amounts of 

 lime and sulfur (usually 15 pounds of each) in 50 gallons of 

 water for about an hour, but the time and labor involved has 

 led to its being produced and put on sale in concentrated 

 form, requiring only dilution with the proper amount of water 

 to make it ready to spray. The usual directions for dilution 

 to use during the winter months, while the trees are dormant, 

 are to mix 1 gallon of the concentrate with 8 or 9 gallons of 

 water, but different brands vary somewhat in this. Further 

 suggestions for using it are given in Chapter VI under the head- 

 ing " San Jose Scale." 



However diluted, the results obtained will depend to a 

 great extent on the thoroughness with which it is applied. 

 Careless spraying will fail to reach many of the scales, and 

 those left will reproduce rapidly enough to injure the tree 

 seriously in such cases. 



For summer use on badly infested trees the concentrate 

 must be diluted much more than for winter spraying. Treat- 

 ment for scales during the summer is always made under such 

 disadvantages that only trees so heavily infested as to make 

 it doubtful whether they will live through the season are 

 given this spray. If it seems necessary, however, 1 gallon of 

 the concentrate is usually diluted with about 30 to 40 gallons 

 of water. The exact amount to dilute for summer as well as 

 for winter work is best learned by getting the reading of the 



