ni6 Journal of Agriculture, Victoria. [lo Feb., 1912. 



VINE DISEASES IN FRANCE. 



{Continued from page jO.) 



F. de Castella, Government Viticulturist. 



FUNGICIDE SPRAYS— coji//««ec?. 



French Bordeaux Mixture or Copper-Lime. 



The usual formula is: — Sulphate of copper, 6 lbs. ; quicklime. 3 lbs. ; 

 water, 30 to 40 gallons; according as one wants a 2 per cent, or a ij per 

 cent, mixture. The copper sulphate is dissolved in the greater part of 

 the water and a milk of lime made with the balance; the latiter is poured 

 into the former in a thin stream, with constant stirring. Authorities are 

 emphatic as to the necessity of pouring the lime into the copper sulphate ; 

 if the reverse were done, a coarser grained and less adherent form of copper 

 hydroxide would be obtained. 



The chief difificulty in properly preparing the mixture is due to the 

 variable composition of the lime ; it is, on this account, impossible to 

 exactly gauge the proper quantity by weight. The correctness of the lime 

 dose is of vital importance. If too little is used the mixture will be acid 

 and burn the foliage ; if too much, it will be alkaline, less adherent, and 

 \vill not run through the spray nozzles so easily. Exact neutrality is. 

 most desirable ; in order to obtain it, a slight excess of milk of lime should 

 be prepared, which is added carefully until neutralization is shown by an 

 indicator. Litmus paper may be used for the purpose, but phenolphthalein 

 papert is more convenient, the pink colour to which it changes being more 

 readily noticed than the blue of the litmius. The following instructions 

 are conci.se and easily followed. They are taken from a sheet, distributed 

 by the Viticultural Station at Lausanne (Switzerland) : — • 



Weigh 2 lbs. of bluestone, and dissolve in 5 gallons of water in an open cask, in 

 which the 10 gallon level is marked by a peg. Solution is facilitated by suspend- 

 ng the bluestone in a basket just below the surface of the water, a day beforehand. 

 Thoroughly mix the blue liquid so as to have an even solution. 



Take about 2 lbs. of quicklime and place it in another tub ; slake it gradually 

 with small quantities of water at a time; when thoroughly slaked, make up to about 

 5 gallons with water and stir carefully so as to make a thin milk of lime. 



Prepare the mi.xture, dipping out the milk of lime with a dipper and pouring" 

 it through a fine sieve into the bluestone solution, carefully stirring with a stick,. 

 meanwhile ; do not dip too deeply into the lime, so as to avoid lumps. As soon. 

 as a couple of gallons have been thus added, an assistant (a child will do) with 

 clean hands and who has particularly avoided touching either bluestone or lime, 

 takes a strip of the white indicator paper, cuts off a small piece, and drops it into 

 the mixture. Usually, if the milk is thin enough, the first piece remains white. 

 The operator then adds more milk, stirring well. The assistant drops in a second 

 fragment of the paper, and so on until the piece of paper becomes pink ; the other 

 pieces previously dropped, change colour also. There is now enough lime ; make 

 up to 10 gallons with pure water and stir well. The rest of the milk of lime may 

 be thrown away. 



Thanks to the indicator paper, weighing the lime may be dispensed with ; alt 

 that is necessary is good, fresh lime, from a builder, slaked to a very thin milk. 



If one is prevented from using the mixture at once, add, to every 10 gallons, 

 2 ozs. of sugar dissolved in a little water. This will cause it to keep its power for 

 several weeks. It is, nevertheless, better to use freshly prepared mixture. 



Many sub.stances in addition to sugar are often added to increase adher- 

 ence. Gelatine seems to be one of those which has most to recommend it. 



t strips of white blotting pipL'rdippel in a '2 jer cent, .solution of Phfnolpluh.ilein and allowed to. 

 dry, make a very g-ood indicator. 



