186 Principles of Plant Culture. 



precipitated copper carbonate in one quart of strong 

 comraercial 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 pre- 

 vent waste of the ammonia by evaporation, prepare im- 

 mediately before spraying. 



332. Lime Sulphur (295) is also employed extensively 

 for the control of fungous diseases. Greater dilution 

 is practiced for fungous diseases than when this mate- 

 rial is used as an insecticide. At one part lime sulphur 

 to thirty or thirty-five of water applications can be 

 made when the trees are in full leaf. A modified lime 

 sulphur known as self-boiled lime sulphur is used on 

 tender plants which are injured by the boiled product. 

 For the preparation of this material students are ad- 

 vised to consult the bulletins of the U. S. Department 

 of Agriculture. 



333. Moisture Favors Spore Germination, hence a 

 free circulation of air through the orchard and vine- 

 yard tends to prevent fungous diseases by absorbing 

 excessive moisture (226). Branches of fruit trees should 

 not be permitted to hang near the ground, and weeds 

 should be kept down. 



Grapes are sometimes inclosed in paper bags on the 

 vine, to keep them dry, and thus preserve them from 

 fungous attack. Grape vines sheltered from rains by a 

 cornice are seldom much troubled with fungous diseases. 



334. Fungi that Develop chiefly on the Outside of 

 the Plant {epiphytic (ep-i-phyt'-ic) fungi), are as a 

 rule readily controlled by sulfur, either in the form of 

 flowers of sulfur, or the solution of potassium sulfid 



