i9io.] 



Shot-hole Fungus. 



213 



minutes. 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 spraying, and at least enough 

 cold water added to stop the cooking. Five to fifteen minutes 

 are required for the process, according to whether the lime 

 is quick-acting or sluggish. The intense heat seems to break 

 up the particles of sulphur into about the physical condition 

 of precipitated sulphur, and the violent boiling makes a good 

 mechanical mixture of the lime and sulphur. Only a small 

 percentage of the sulphur — enough to improve the adhesive- 

 ness of the mixture — goes into solution, but if the hot mass 

 is allowed to stand as a thick paste the sulphur continues to 

 unite with the lime, and at the end of thirty or forty minutes 

 enough of the reddish liquid is produced to burn peach 

 foliage, and even apple foliage in some cases. Hence the 

 necessity for cooling the mixture as soon as the lime is well 

 slaked. The finely divided sulphur in mechanical mixture 

 with the lime is depended upon for the fungicidal action 

 rather than the sulphides in solution, the latter being harmful 

 to foliage except in very dilute form. 



"The mixture should be strained through a sieve of 20 

 meshes to the inch in order to remove the coarse particles of 

 lime, but all the sulphur should be worked through the 

 strainer. 



"The amount of water required to make the best mixture 

 depends largely upon the lime. Some grades of lime respond 

 quickly and take a large quantity of water, while others heat 

 slowly and are easily "drowned" if too much water is added 

 at once. Hot water may be used to good advantage in 

 preparing the mixture with sluggish lime, but with quick- 

 acting lime hot water is not necessary, and is likely to bring- 

 too much of the sulphur into solution. If desired, the 

 mixture may be kept for a week or more without deterioration, 

 but should be thoroughly stirred before using. 



