212 Commercial Gardening 



outbreaks by means of fungicides that have been found more or less 

 effectual. 



Fungicides are applied either in the form of sprays or washes, as dry 

 powders, or as vapour. So far as the sprays and washes are concerned 

 the grower will find fungicides applied in a hot or warm state much better 

 than in a cold one. The writer has carried out many experiments with 

 fungicides and insecticides dissolved in boiling water, and has applied them 

 in the form of a fine misty spray to outdoor crops without causing the least 

 injury to the plants, but often destroying the pests and diseases with one 

 good application. The reader must distinguish between applying an in- 

 secticide or fungicide boiling hot through a fine-spray nozzle, and dipping 

 the leaves and shoots of a plant in the same solution. When the hot liquid 

 is sent with force through a fine-spray nozzle, it impinges on the leaf or 

 stem surface in the form of tiny globules in a mist-like spray. A good deal 

 of heat is lost in transit, and the tiny globules are still further cooled to 

 air temperature almost as soon as they touch the leaf surface. They have, 

 however, retained a higher temperature than is healthy for the fungus or 

 insect pest; hence these are usually killed outright. In spraying large 

 areas, the only difficulty is to maintain the liquid up to a temperature of 

 212 F. or boiling-point, but this may be overcome by having a small 

 portable boiler and fire attached. 



The following is a list of the most effective insecticides and fungicides 

 on the market at present: 



1. Ammoniacal Copper Fungicide or Cupram. Recipe: 



Copper sulphate (98 per cent) 1| oz. 



Carbonate of soda (98 per cent) ... ... ... If 



Ammonia solution (strongest) ... ... ... 12 fluid oz. 



Water 12 gal. 



Dissolve the copper sulphate and carbonate of soda separately, each in 

 | gal. water; pour soda into copper solution and stir well. When precipi- 

 tate has settled, pour off' clear liquid. Wash precipitate a second time, 

 and pour off" liquid when clear. Then add liquid ammonia to precipitated 

 copper carbonate, sufficient to dissolve it. Add water up to 10 gal., 

 and the liquid will be read}' for use. It has properties similar to those 

 of Bordeaux Mixture. See also " Eau Celeste ". 



2. Arsenate of Lead (Sugar of Lead). Formula (Strawson): 



Acetate of lead (98 per cent) ... ... ... 2| oz. 



Arsenate of soda (98 per cent) ... ... ... 1 



Water to make ... ... ... ... ... 10 gal. 



Place materials in water and stir till dissolved, when the liquid will be 

 ready for use. One pound of treacle or soft soap may be added, if desired, 

 to make the liquid adhere better. This mixture is now considered superior 

 to Paris Green, as it is much lighter and does not scorch the foliage. From 

 1 to 2 Ib. of arsenate of lead to 150 gal. water has proved effectual. 



