Fungicides 



plants open to attack by fungi which live inside the 

 plant, and enter through the pores in the leaves. 

 They are used for the purposes (1) of killing the 

 fruiting threads of the fungi as they emerge into the 

 air to form spores, and (2) of preventing the germina- 

 tion of spores which faU upon the leaf. 



Care must be used in spraying with them when 

 parts of plants which are eaten are to be dealt with ; 

 e.g. spraying broad beans attacked by rust with a 

 copper fungicide would be perfectly safe, as only the 

 shelled immature seeds are to be eaten, but spraying 

 dwarf beans when the pods are formed wiU be 

 inadvisable. 



Three mixtures containing copper are used for 

 the summer spraying of foliage, and one for winter 

 spraying of dormant trees only. They are respect- 

 ively Bordeaux mixture, soda - Bordeaux or Bur- 

 gundy mixture, ammoniacal copper carbonate, and 

 copper sulphate solution. 



Great care must be exercised in preparing these 

 fungicides (which are better made at home), but if 

 the following directions are followed there need be 

 no difficulty. 



Bordeaux Mixture. — Put 6 lbs. copper sulphate 

 (of 98 per cent purity) (called also blue stone or blue 

 vitriol), broken small or powdered, into a loosely 

 woven canvas bag and hang it the night before the 

 fungicide is to be used in a wooden tub containing 

 about 20 gallons of water. [An iron or galvanized 



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