Fungicides and Insecticides 213 



3. Bordeaux Mixture. Formula: 



Copper sulphate (98 per cent) ... ... ... 2 Ib. 



Lime (freshly burnt) ... ... ... ... 1 M 



Water ... 10 gal. 



O 



Dissolve copper sulphate in 5 gal. water in wooden vessel. When lime 

 has slaked to a tine powder, mix it with remaining 5 gal. water, and then 

 pour into copper solution. Stir the mixture thoroughly to secure even 

 distribution. Bordeaux mixture is regarded as one of the most useful 

 and effective fungicides. To test the liquid add a few drops of potassium 

 ferrocyanide (1 oz. to 10 oz. of water), and if the liquid becomes brown 

 add more lime. To make a strong solution add an extra Ib. of copper 

 sulphate to 10 gal., and to make a weak solution reduce the copper sulphate 

 | Ib. from formula. 



4. Carbon Bisulphide. This is a volatile and inflammable clear liquid, 

 which gives off an insect-killing vapour at a low temperature. The vapour 

 being heavier than air, it is advisable to apply the liquid at top of holes 

 when it is desired to eradicate ground pests. For vaporizing houses about 

 pt. of liquid is sufficient for 500 cub. ft. of space, and for ground pests 

 about 2 oz. poured into holes about 2 ft. apart is considered sufficient. It 

 appears to be a much more costly and less efficacious method of ridding the 

 soil of pests than turning up the soil with the spade or fork and exposing 

 the pests to the birds. 



5. Caustic Wash or Winter Wash. There are several formulae for 

 making caustic winter washes to be applied to trees in a dormant condition. 

 These caustic washes cleanse the bark of fruit trees and bushes from such 

 parasitic plant growths as mosses, lichens, and algae, thus allowing them 

 to breathe more freely. If applied quite hot with a strong-haired brush, 

 the eggs of many insect pests are also destroyed, such as Scale, American 

 Blight, &c. These washes must be used in winter up to February and 

 March, but not after the flower and leaf buds begin to open. 



The following formulae for winter washes are given: 



I. Caustic soda (98 per cent) ... ... ... 2 to 2| Ib. 



Water 10 gal. 



This is made simply by dissolving the caustic soda in the water and 

 applying hot if possible. Care, however, must be taken of the hands 

 and face. 



II. Iron sulphate ... ... ... ... ... \ Ib. 



Quicklime ... ... ... ... ... \ 



Caustic soda ... ... ... ... ... 2 



Water 10 gal. 



Paraffin (solar distillate) 5 pt. 



In this formula dissolve the iron sulphate in 9 gal. of water; slake the 

 lime in a little water and make into milk of lime by adding more water. 



