38 DISEASES OF ECONOMIC PLANTS 



is SO susceptible to spray injury that ordinary Bordeaux 

 mixture cannot be used as a summer spray on peach trees ; 

 neither can the sulphur washes which contain any consider- 

 able quantity of sulphides in solution. The self-boiled 

 lime-sulphur wash, however, when prepared as a mechani- 

 cal mixture of lime and sulphur with only a small per- 

 centage of the sulphur in solution, is not injurious to 

 peach foliage and has proved to be a good fungicide. It 

 may also serve a good purpose in spraying varieties of 

 apples, like the Ben Davis and Jonathan, which are often 

 injured by applications of Bordeaux mixture. 



The mixture that appears to be the most satisfactory 

 is composed of 



Lime . . . 10 pounds 



Sulphur 10 pounds 



Water 50 gallons 



This can best be prepared in rather large quantities — 20 

 pounds, or even 40 pounds at a time — so as to get 

 enough heat to produce a violent boiling for a few min- 

 utes. Place the lime in a barrel and pour on enough 

 water (about 3 gallons to 20 pounds) to start it slaking 

 and to keep the sulphur off the bottom of the barrel. 

 Then add the sulphur, which should first be worked 

 through a sieve to break up the lumps, and- finally enough 

 water to slake the lime into a paste. Considerable stirring 

 is necessary to prevent caking on the bottom. After the 

 violent boiling which accompanies the slaking of the lime 

 is over, the mixture should be diluted ready for use, or at 

 least enough cold water added to stop the cooking; 5 to 

 15 minutes, according to whether the lime is quick-acting 



