Rotation 



are cold mix thoroughly just before using. To test 

 this mixture use litmus - paper. If red Utmus is 

 turned blue by it, add more copper sulphate; if 

 blue litmus is turned red, add more soda solution. 

 It should have no effect upon Utmus-paper. 



This is rather easier to make, and seems to be 

 almost as efEective as Bordeaux mixture when used 

 for the same purposes, although it has not yet been 

 used to any great extent in this country. 



Ammoniacal Copper Carbonate. — ^Make 5 oz. of 

 copper carbonate into a paste with a little water, 

 add strong ammonia ('880) until the copper car- 

 bonate is just dissolved so as to form a deep blue 

 solution (about 3 pints will be required) ; dilute this 

 to 45 gallons with water. The stock solution may 

 be kept in a tightly stoppered bottle. This may be 

 used where Bordeaux mixture is likely to cause 

 defoliation, as with peaches against shot-hole. 



Copper Sulphate Solution. — One pound of copper 

 sulphate (98 per cent) is dissolved in 25 gallons of 

 water in a wooden vessel. 



This solution must be used only in winter, while 

 the trees are dormant. 



(e) Potassium permqnganate diluted to a rose- 

 red colour is useful against some rust fungi such 

 as rose rust, hollyhock rust, carnation and Saxifrage 

 rust. 



8. Rotation of crops and breaking up areas 

 occupied by one kind of crop. Modern methods of 



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