APPENDIX I 



Perhaps what follows may be looked upon by some teachers as hardly forming 

 appropriate laboratory exercises, and, therefore, should be treated as in the nature 

 of appendices. In agricultural and horticultural schools, the manufacture and 

 use of fungicides and sprays may very well form a part of the curriculum designed 

 for laboratory, and especially for field purposes, where in the experimental farm, or 

 garden, the spraying apparatus and its construction can well be experimented with 

 as a regular part of the instruction. Hence the making of sprays is given prominence. 



Fungicides. — Definition of Terms. — Fungicides are substances which are capa- 

 ble of destroying, or preventing, the growth of spores, or the mycelia of fungi. Germi- 

 cides are those substances used for a similar purpose with germs, or bacteria. Such 

 materials may- be used as a spray, in the form of a powder dusted on the plant, or in 

 the form of a steep into which the plant, or plant part, is dipped. A substance to 

 be useful as a fungicide must not only not injure the plant, but must at the same 

 time destroy or hold in check the parasite. Usually the material is most effective 

 when the fungous parasites can be reached directly by the spray. If the fungus 

 works internally, as the chestnut blight fungus, such fungicides usually do harm to the 

 host without touching the parasite and are, therefore, ineffectual. 



The chemic substances used are naturally of a poisonous character and should 

 be used with precautions taken to prevent their injurious effects upon human beings. 

 An up-to-date agriculturist, horticulturist, or orchardist considers the use of 

 fungicides, germicides, or insecticides, as essential, as any of the other major opera- 

 tions on the farm. 



For convenience of treatment and ease of reference the following fungicides and 

 insecticides are arranged alphabetically. The formula have been taken from a num- 

 ber of reliable sources and they may be considered as dependable in ordinary work. 



Ammoniacal Copper Carbonate.— This, is not as good for general purposes as 

 Bordeaux mixture. It is used instead of Bordeaux when it is desirable to avoid the 

 spotting of leaves or fruit. It is prepared as follows : 



Copper carbonate, 5 ounces. 



Strong ammonia (26° Baume), 2 to 3 pints. 



Water to make 50 gallons. 



Dilute the ammonia with about 2 gallons of water, as it has been found that 

 ammonia diluted seven or eight times is a greater solvent for copper carbonate than 

 the concentrated liquid. Add water to the carbonate to make a thin paste, pour on 

 about half of the diluted ammonia and stir vigorously for several minutes: allow it 

 to settle and pour off the solution leaving the undisturbed salt behind. Repeat 

 this operation, using small portions of the remaining ammonia water until all the 



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