Plants as Affected by Fungous Parasites. 177 



In all these diseases, however, the treatment is preventive 

 rather than curative. The first application should be made 

 before the disease appears and should be followed occa- 

 sionally by others as new foliage is formed or as the 

 material, is washed off by rains. 



331. Ammoniacal Solution of Copper Carbonate possesses 

 nearly the same fungicidal properties as Bordeaux mix- 

 ture, but adheres less strongly to foliage. Being a 

 solution, it requires no straining or stirring, and it leaves 

 less stain on drying than Bordeaux mixture, which makes 

 it preferable to the latter for use upon plants of which 

 the fruit is nearly mature. To make this solution, 

 dissolve one and a half ounces of precipitated copper 

 carbonate in one quart of strong commercial ammonia, 

 and add 25 gallons of water. The ammonia should be 

 procured in a glass or earthen vessel, which should be 

 kept tightly corked. To prevent waste of the ammonia 

 toy evaporation, prepare immediately before spraying. 



332. Potcissium-Sulfid Solution is used to some extent 

 to prevent gooseberry mildew (330), and a few other 

 diseases, but it is less enduring in its effects than the 

 copper compounds. To prepare it, dissolve one-half 

 ounce of potassium sulfid (sulfuret of potassium, liver of 

 sulfur) in one gallon of water and apply immediately. 

 The sulfid is best dissolved in a little warm water and 

 then diluted. 



333. Moisture Favors Spore Germination, hence a free 

 circulation of air through the orchard and vineyard tends 

 to prevent fungous diseases by absorbing excessive moist- 

 ure (227). Branches of fruit trees should not be per- 



* Sphcerotheca Mors-uvce. f Entomosporium maculatum. 



