222 SECOND THOUSAND QUESTIONS IN AGRICULTURE 



Soap Powder. 



Among the recent commercial insecticides is a soap powder which 

 readily dissolves in hot or cold water and has very good insecticidal 

 powers. The amount of dilution varies with the product, but is usually 

 one pound to five or six gallons of water or as stated on the container. 



Tobacco Decoctions. 



For soft-bodied insects in greenhouses, conservatories, or on house 

 plants, as well as for plant lice, leaf-hoppers and other similar insects in 

 the open, the tobacco decoctions are invaluable because they do not injure 

 the foliage and give excellent killing results. For home-made extract, take 



Tobacco leaves or stems 1 pound 



Water 4 gallons 



Steep the tobacco in the hot water and apply directly. 



The commercial extracts containing two and three-quarters per cent 

 nicotine should be diluted to sixty parts of water. The extract containing 

 forty per cent nicotine should be diluted from one to one thousand parts 

 or one to fifteen hundred parts of water. 



DUSTS. 



A number of valuable insecticides are applied dry as dusts. We have 

 already referred to Paris green and lime as being used in this way. Dusts 

 are easy to mix and handle and are often of great service to the farmer 

 and orchardist. 



Flowers of Sulphur. 



For a number of years flowers of sulphur was used alone as a remedy 

 for mites on citrus and almond trees. It was distributed over the trees by 

 hand or with a blower in the early morning when the foliage was damp, 

 thus enabling it to adhere. The warm sunshine volatilizes some of the 

 sulphur and oxidizes a part so as to liberate two gases, which are killing 

 factors. Accordingly sulphur is of little avail in the cool summer weather 

 of the coast counties or during the winter months anywhere. However, 

 in the warm interior districts this is still a very effective remedy for mites. 



Sulphur and Lime. 



Even better than sulphur alone is hydrated lime and flowers of sulphur 

 mixed in equal parts and blown upon the trees with a power machine. 

 In the citrus orchards this is a very important method of controlling the 

 citrus red spider and the two-spotted mite. 



Lime, Sulphur and Sal Bordeaux. 



This mixture is prepared as follows : 



Hydrated lime (dry, finely powdered, water-slaked lime). 40 pounds 



Flowers of sulphur 5 pounds 



Sal Bordeaux (a mixture of bluestone, charcoal and 

 naphthol) 5 pounds 



