MAINTENANCE 79 



tank. When many trees are to be sprayed a power sprayer should be 

 used in order to secure a pressure which will enable the forcing of a fine 

 spray to all parts of the tallest trees. For spraying tall trees an 

 apparatus which works up a pressure of two hundred pounds is required 

 so that the spray mixture may leave the nozzle in a solid stream and 

 break into a mist as it nears the top of the tree. This is not required 

 for spraying smaller trees or bushes or flowers where the requirement 

 becomes that of producing a fine spray a few feet from the nozzle. 



Spray chemicals which are to be used in dust form are applied 

 by means of so-called "powder guns" when large amounts are used on 

 large trees. These are seldom useful on ornamental plants because 

 of the usual proximity of houses or public streets and the consequent 

 annoyance caused by clouds of obnoxious dust flying in the air. Many 

 times, however, sulphur dust or hellebore can be applied by means of 

 small hand force pumps adapted to using the dry dust, or this dust can 

 be applied by sifting over the plants through holes punched in the con- 

 tainer in which it is purchased. 



Formulas for Sprays. The formulas for some of the simpler 

 insecticides and fungicides will be given here; but it is generally more 

 advisable for the amateur to purchase his chemicals already mixed and 

 in packages of a size adapted for his immediate requirements. 



Poisons: 



Paris green — aceto arsenite of copper. 



Arsenite of lime. 



Arsenate of lead; use 2 lbs. to 50 gal. water. 



Hellebore; use 1 ounce to 1 gallon of water. 

 Poison Baits: 



For cutworms 1 lb. Paris green mixed with 10 lb. bran. 



For cutworms 1 lb. white arsenic and 1 lb. of sugar or molasses in 6 lbs. of bran. 



For grasshoppers use the arsenic, sugar, and bran mixture, placing 1 tablespoonful 

 every 6 or 8 feet. 



For sow bugs or pill bugs use slices of potato dipped in a dry arsenical or a strong 

 solution. 



Contact Insecticides: 



For plant lice use one lb. soap to 5 to 8 gallons water. 



For aphids and larvae use nicotine sulphate at strength given on package or 1 lb. 

 tobacco stems boiled in 2 gal. water (Dilution of nicotine sulphate is generally 

 1 pint to 50 gallons of water. The addition of 2 lbs. of soap is desirable). 



For scales use 2 gal. kerosene and 1 gal. sour milk. 



For plant lice use 2 gal. kerosene and 1 gal. soft water and J lb. soap. 



