FUNGICIDES, ETC. 279 



value. Many plants are more susceptible to this 

 mixture than to Bordeaux, and it should be used with 

 caution. It should never be used without first making 

 a test on a few plants. 

 Potassium Sulphide. 



Water 10 gallons. 



Potassium sulphide . . 3 oz. 



Heat a few quarts of water and dissolve the potassium 

 sulphide in it, then add enough cold water to make a 

 total of ten gallons. It is used to control powdery 

 mildews and rusts. 



Iron Sulphate and Sulphuric Acid. 



Hot water . . . 100 pints. 



Iron sulphate . . as much as will dissolve. 



Sulphuric acid . . 1 pint. 



Put the iron sulphate in a wooden vessel, pour on the 

 acid and then the water. Use fresh and apply with a 

 swab. It is used for anthracnose and cankers on 

 stems, for disinfecting wounds, etc. It must not be 

 used on the foliage. 



Carbolic Acid. Equal parts of crude carbolic acid 

 and water is sometimes used as a wash in the treatment 

 of the gummosis of citrus and other fruits. 



White Lead. It is used to paint wounds in order to 

 prevent the entrance of fungi. 



Coal Tar. Its use is to paint wounds to prevent the 

 entrance of fungi. 



STICKER 



It is very difficult to make spray mixtures stick to 

 some plants, but this difficulty can usually be overcome 

 by using a sticker made as follows : 



Resin 2 Ibs. 



Sal soda (crystals) . 1 lb. 



Water .... 1 gallon. 



Mix and boil until the preparation is a clear brown ; 

 about 1^- hours. Avoid danger from fire by boilni</ 

 in the open, in an iron kettle. 'Dilute with from 50 

 to 100 o-allons of Bordeaux mixture. 



