92 Maine; agricultural, experiment station. 1913. 



Directions for use come with the products. There is nothing to do 

 in the preparation of these extracts except to stir the contents of the 

 can before pouring out any quantity for dilution. In most cases one 

 gallon of the Black Leaf will be found sufficient for each seventy gallons 

 of water. But if in the treatment of any louse this does not seem suf- 

 ficient it may be used in proportion of one gallon to sixty or sixty-five 

 gallons of water. Careful sprayers have usually succeeded in killing 

 plant lice with this preparation in the proportion of one gallon to each 

 one hundred gallons of water. Thoroughness of application is of as 

 much importance as the strength of the material used. 



Nikofeen is a more concentrated abstract, i part being used with 

 from 400 to 600 parts of water. 



Black Leaf 40 is a concentrated solution of nicotine-sulphate and is 

 widely and successfully used in large western orchards, at the rate of i 

 part to 700 or 800 parts of water. 



It is the common practice to add soap, — whale oil soap or good laun- 

 dry soap at the rate of 2 bars to 50 gallons. This is to lessen the' 

 formation of drops, causing the spray to cover surfaces more in the 

 form of a thin film. 



Better success is obtained by some by using a little lime instead of 

 soap, the inert solid in suspension aiding the extract to "wet" and 

 "stick" to the bodies of the aphids. For this purpose i pound of 

 stone lime, slaked and strained into 50 gallons of tobacco extract as 

 prepared for application, is sufficient. 



When other plant enemies besides aphids are present "Combination 

 sprays" are frequently successfully applied. Self-boiled lime-sulphur 

 (8-8-50 cold) may be used adding 1-70 of its volume of Black Leaf. 

 On the same basis Black Leaf may be combined with Bordeaux (5-5-50) 

 or with lead arsenate or with both together when foes combine against 

 one kind of plant. 



