2l8 MAINE AGRICULTURAL EXPERIMENT STATION. I915. 



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 70 gallons of water. But 

 if in the treatment of any louse this does not seem sufficient it 

 may be used in proportion of one gallon to 60 or 65 gallons of 

 water. Careful sprayers have usually succeeded in killing plant- 

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

 100 gallons of water. Thoroughness of application is of as 

 much importance as the strength of the material. 



Nikoteen 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. Some have 

 been successful with i part to 1000 parts of water. 



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

 good laundry 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 in- 

 stead of soap, the inert solid in suspension aiding the extract to 

 "wet" and "stick" to the bodies of the aphids. For the pur- 

 pose 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 "Com- 

 bination 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. 



Even when the spraying is thoroughly done some of the 

 aphids are likely to escape. Watch should therefore be kept and 

 if the first application seems unsatisfactory, a second treatment 

 in the course of a week is desirable. 



When a small quantity of spray is required one teaspoonful 

 of Black Leaf 4o in one gallon of water is a convenient amount 

 to mix. 



