196 BOARD OF AGRICULTURE. [Pub. Doc. 



crops will sometimes escape injury if we make no attempt 

 to destroy the pests that attack them, it is not a wise policy 

 to leave them to chance. It has been proved in many cases, 

 yes, in most cases, by careful experiments, that the greater 

 number of injurious insects and fungi may be destroyed or 

 prevented from injuring our crops l^y the timely application 

 of insecticides or fungicides. Many progressive farmers, 

 gardeners and fruit growers have provided themselves with 

 the most approved apparatus for the use of insecticides and 

 fungicides, and spraying is as much a part of their routine 

 as that of cultivation or fertilization. 



Fungicides. 



Of the many substances suggested for the destruction of 

 fungous pests, the Bordeaux mixture, from its clieapness, 

 eifectiveness and lasting qualities, has superseded all others. 



Formula. — Copper sulphate, four pounds ; caustic or 

 quick-lime, four pounds. The copper sulphate or blue 

 vitriol is quickly sohible in hot water, one or two gallons ; 

 or, if suspended in a basket or coarse sack in a tub or cask 

 of cold water, it will dissolve in two or three hours. The 

 caustic or unslaTced lime is slaked slowly by adding small 

 quantities of water until every particle of lime is reduced, 

 and you have a thin paint or lime wash. When both liquids 

 arc cool they are mixed together, straining out the hard par- 

 ticles of lime by pouring through a fine-mesh sieve or 

 burlap strainer. To this mixture is added water sufficient to 

 make («) twenty-five or (b) fifty gallons, as may be desired. 

 The agent of destruction in this mixture is probably the 

 very minute quantity of copper precipitated by the union 

 of the two substances, and which is held upon the sur- 

 face of the plant by the lime, ready to destroy or prevent 

 germination of the fungus spores. It is known that fungus 

 spores cannot germinate on the surface of copper vessels, 

 and that one part of free copper in ten million parts of water 

 will also prevent the germination of the spores of many kinds 

 of fungi. But, whether it be the small quantity of fi'ee cop- 

 per sulphate in the solution, the hydroxide of copper, or 

 something not quite understood as yet, we do know that the 

 use of this substance when properly prepared is the most 



