Sprays and Spraying. 61 



however, to employ for this purpose special soaps made with 

 fish-oils, and sold as whale-oil soaps. These vary consider- 

 ably in composition, some being made with soda, others with 

 potash lye. The latter are much superior and buyers should 

 insist on having potash soaps. 



For scale insects, whale-oil soap is sometimes used in as 

 concentrated a Solution as two pounds of soap to one gallon 

 of water, but only upon dormant plants. As a remedy for 

 the various plant-lice one pound of soap to eight or ten gallons 

 of water is usually sufficient. Hop growers are inclined to 

 believe that better results are obtained, when spraying for 

 hop-lice, by adding some quassia decoction to the soap Solu- 

 tion, as follows : 



Whale-oil soap 10 pounds 



Quassia 5 pounds 



Water 100 gallons 



Place the quassia chips in a sack, cover with eight or ten 

 gallons of water and soak 12 to 24 hours. Then bring to a 

 boil, remove the chips, add the soap and boil until it is dis- 

 solved. Add water to make 100 gallons. The whale-oil soap 

 and quassia spray is used principally by hop growers. 



BLACK LEAF-40. 



Black leaf-40, a proprietary tobacco preparation, may be 

 used for the same purpose as kerosene emulsion or whale-oil 

 soap and quassia and has the advantage that it does not injure 

 foliage and is ready for use. One gallon diluted with 800 

 to 1,000 gallons of water makes a very efficient aphidicide. 



WHEN TO SPRAY. 



General directions as to how many times to spray and when 

 the applications should be made are at best unsatisfactory. 

 The answer to both questions clepends not only upon the variety 

 of fruit to be sprayed, but also upon the conditions prevailing 

 in the orchard to be sprayed, and the relative importance of 

 the orchard crop to other crops. The orchardist can afford 

 to do more spraying than can the farmer. 



An almost universal practice in this State — and a good one 

 — is to spray the orchard, whatever the kind of fruit, with 

 lime-sulphur at some time while the trees are dormant. While 

 this application is made primarily for San Jose scale, I believe 

 there is no other which has such a generally beneficial result. 

 It is the annual "house-cleaning" of the orchards. 



