THE JOURNAL 



OF THE 



BOARD OF AGRICULTURE. 



Vol. XVI. No. 10. 

 JANUARY, 1910, 



THE MAKING AND APPLICATION OF BORDEAUX 



MIXTURE. 



E. S. Salmon, F.L.S., 



Mycologist to the South- Eastern Agricultural College, Wye, Kent. 



I. The Making of Bordeaux Mixture. — Directions as to the 

 best method of making Bordeaux mixture have already been 

 given in this Journal.* In order, however, to make the 

 present article more complete, these are here repeated. 



Bordeaux mixture for spraying fruit-trees generally (ex- 

 cluding peaches) should be made according to the following 

 formula and in the following manner : — 



Copper sulphate ("Milestone ") f 4 lb. 



Quicklime (in lumps) 4 lb. 



Water 50 gallons. J 



Dissolve the 4 lb. of copper sulphate in a wooden tub or 

 bucket — iron or tin vessels must not be used. The easiest way 

 to do this is to suspend the material, wrapped in a piece of 



* Vol. xv, p. 191 (1908;. 



+ In purchasing copper sulphate an article of 98 per cent, purity should be 

 demanded; substances described as "agricultural bluestone " or "agricultural 

 sulphate of copper " must be avoided, as these are usually adulterated with iron 

 sulphate. In this Journal for September last a number of cases were recorded of the 

 sale in this country of adulterated copper sulphate ; it is clear, therefore, that it is 

 important for the fruit-grower to insist on an article of 98 per cent, purity. 



X The strength of Bordeaux mixture at present most widely recommended in the 

 United States is \\ lb. of copper sulphate, 4! lb. quicklime, 50 gallons (Imperial) 

 of water. This strength is expressed in America by the formula 4 :4: 50, since, as 

 Mr. S. U. Pickering has lately pointed out, the relative value of the American and 

 Imperial gallon is different, the former weighing 8-345 lb. and the latter 10 lb. As, 

 however, excellent results have followed the use in this country of Bordeaux mixture 

 made of the strength 4 : 4 : 50 (Imperial), and as, further, some " scorching " is liable 

 to occur on some varieties of apples, it would seem advisable, for the present at 

 any rate, for the English grower lo continue to use this as his "standard" mixture. 



3 K 



