APPLE GROWING 



lice. It is a mixture of one-half pound of soap 

 and two gallons of kerosene In one gallon of 

 water — preferably In hot water. For dormant 

 trees one gallon of this mixture should be di- 

 luted with six gallons of water. While this 

 spray Is effective It Is no more so than lime- 

 sulphur and Is quite difficult and disagreeable 

 to handle. As a summer spray, however, It 

 is often necessary. Several preparations of 

 petroleum known as the misclble oils are some- 

 times used. Their use Is the same as that of 

 lime-sulphur and they are not as good. 



Within the last few years a tobacco concoc- 

 tion known as black leaf tobacco extract (nico- 

 tine sulphate) has come Into quite common use. 

 It can be purchased commercially under various 

 brand names, and should be diluted accord- 

 ing to Its strength, but usually about one part 

 to fifty of water. It may be made by boiling 

 one pound of good tobacco stems in two gallons 

 of water for one-half hour. Objections to It 

 are that It evaporates very quickly, although 

 It Is supposed to be non-volatile, and that it is ex- 

 pensive, but it Is very convenient to use, can be 

 readily mixed with other summer sprays, and 

 is very effective against plant lice and mites. 



Bordeaux Mixture. Fungicides are mix- 

 114 



