702 Journal oi Agriculture. [lo Nov., 1909. 



is constantly used for the treatment of Black Spot of the apjile and pear, 

 and other diseases of fungus origin, and the same preparation is suitable 

 for the Potato disease. Spraying is recommended not only for Irish 

 or Late Blight, but also for other diseases, such as Early Blight, which 

 is common in some districts in certain seasons, and, since Paris green may 

 be added to the mixture, it may be used as a combined insecticide and 

 fungicide. It is generally found that spraying increases the yield, even 

 in the absence of Irish Blight, and that it will pay to spray as a regular 

 operation. 



{a) Bordeaux mixture consists of bluestone or copper sulphate and 

 lime. Fresh quicklime is necessary, and the copper sulphate 

 should be procured in the form of tlie blue crystals. A con- 

 venient formula to use is — 



Bluestone ... ... ... ... ... 6 lbs. 



Quicklime ... ... ... ... ... 4 ,, 



Water ... ... ... ... ... 50 gallons. 



The bluestone is dissolved in a barrel or wooden tub, and 

 made up to 25 gallons. The quicklime is slaked, and, when 

 in the form of a fine powder, 25 gallons of water are added 

 to form milk of lime. The bluestone solution and milk of 

 lime are poured evenly together into a third barrel or direct 

 into the spray-pump, and after being thoroughly agitated the 

 mixture is ready for use. 



{b) A form of Bordeaux may Ije used in which lime-water takes the 

 place of the milk of lime. Less bluestone is necessary, and 

 the solution is equally efficacious. The formula is — 



Bluestone .. •■• ... ... ... 3 lbs. 2 ozs. 



Lime-water ... ... ... ... 42^ gallons. 



Water to make up to ... ... ... 50 ,, 



The lime-water may be prepared by placing the quicklime 

 (2 J lbs.) in a gunny bag (or any bag of loose texture will do) 

 and suspending it in the proper quantity of water in the morn- 

 ing, and next morning it will be ready for use. It may be run 

 off into the bluestone solution, and after thorough mixing it is 

 ready for spraying. 



(c) There is also the 'Copper-.soda solution which may be used, and 



consists of — 



Bluestone ... ... ... ... ... 6 lbs. 



Washing soda ... ... ... ... 7 ,, 



Water ... ... ... ... ... 50 gallons. 



The bluest(jne is dissolvt'd as before, and also the washing 

 .soda, and then poured into a third vessel and intimately 

 mixed. The potato plant .should be sprayed when 6 to 8 

 inches high, and again when in bloom ; but if the season is 

 moist, intermediate sprayings may be given at intervals of a 

 fortnight. A quarter of a pound of Paris green added to the 

 50 gallons serves to destroy the grubs as well. 



(d) To prevent the spores, even when formed, reaching the tubers in 



the soil, a process of earthing-up or protective moulding has 

 been recommended by Jensen. He found that the soil acted 

 IS a sort of filter, and prevented the passage of the spores. 



