322 Landscape Gardening 



to 100 and even 50 gallons of water without injury to the 

 foliage. When the Bordeaux mixture (see ''Fungicides") 

 is used, the lime in that mixture has the same effect, and 

 I pound of Paris green to 50 or 100 gallons of the mixture 

 may be used without injury to the foUage (except upon 

 the peach and cherry trees), and the work of destroying 

 insects and fungi thus reduced one-half. 



Arsenate of Lead is similar in effect to Paris green, 

 but is a combination of arsenic with lead instead of copper. 

 It is less soluble than the former, adheres longer to the 

 foliage and will not burn the leaves when used in large 

 quantities. It can be used with the Bordeaux mixture or 

 the lime sulphur solution, and being in the form of a white 

 powder or paste may be more readily detected upon the 

 leaves. In cost it is about the same per pound as Paris 

 green, but about twice as much is needed to do effectual 

 work. Arsenate of lead may be used as a dry powder with 

 lime or flour or in water. 



Lime-sulphur Solution. — This is a solution that kills 

 scale, aphides (plant lice), etc., by contact, many brands of 

 which are to be found in the market. 



It is unpleasant to use on account of its caustic properties, 

 and in spraying it is best to apply with the wind. It is 

 effectual as a fungicide used at the rate of from 3 to 5 gallons 

 to 50 gallons of water while the trees are dormant, or i to 

 1 1 gallons to 50 of water when in foliage. Self-boiled lime- 

 sulphur is made by slaking fresh caustic lime in a small 

 amount of water and when at its highest adding an equal 

 quantity of fine sulphur. Cover and let boil until a molasses- 

 like liquid is formed, which is to be diluted as for the com- 

 mercial lime-sulphur solution. 



^ Soluble Oil is made by treating crude petroleum so as 

 to make it soluble in water. This kills scale insects, aphides, 

 etc., and all sucking insects by contact. 



