lo March. 191 -.] V/)/r Diseases in France. 



is now generally recognised that they cannot, when used alone, be 

 relied upon as efficient protection, and for a good manv years little has 

 been heard of their use. Since the disastrous mildew visitations of the 

 19 10 summer, they have once more come to the fore, not, however, as 

 •substitutes for. but as a com])lement to the usual copper sprays. An 

 application of suitable powder, applied with the bellows or, preferablv, 

 with the knapsack machine, in the same way as sulphur, immediatelv" 

 after spraying, very considerably increases the efficiency of the prntectinn 

 afforded by the latter. It will be readily understood that a powder can 

 easilv be blown into the interior of the vine, thus making it possible to 

 reach parts which it would be difficult to get at with the liquid spray. 



Numerous forms of copper-containing powders are now for sale in 

 France. Some are mixtures of sulphur and sulphate of copper, .so that 

 the same application mav serve to combat oidium as well as mildew. 

 In other cases the copper sulphate is simply mixed with an inert sub- 

 stance, serving to dilute it and to enable it to be ground into a finer 

 powder than would otherwise be possible. Such is Sulp ho steatite a very 

 popular preparation which is a finely powdered mixture of talc and copper 

 sulphate. In some powders, again, the copper is in the form of oxide, 

 or of acetate (verdet). whilst the oxychloride of copper, previously referred 

 to as a spray, constitutes an excellent powder for use in the dry state. 

 These latter substances have the advantage of not burning the foliage. 

 If the copper is present in the form of sulphate it is recommended to add 

 a certain quantitv of lime before use to prevent damage to the foliage. 



Conclusion. 



The abo\'e is a brief re\iew of modern French and Sw^ss opinions 

 on the whole question of fungicide sprays, so far as their composition is 

 concerned. It will be remarked that they do not agree on all points 

 with modern English views ai stated in the Eighth Report of the Wobuni 

 Experimental Fruit Farm (1908) which was reviewed by Mr. McAlpine, 

 late Vegetable Pathologist for ^'ictoria, in the Journal for November, 

 1910. The chief difference consists in the proportion of copper con- 

 sidered necessary in order to secure adequate protection. Even with 

 verdet and oxychloride, which permit a reduction in the quantity of copper 

 used, very much stronger mixtures are recommended than the 10 ozs. to 

 50 gals, provided for by the Woburn formula. 



A point of the most vital importance, of greater importance, perhaps, 

 than the composition of the spraying mixture, is the absolute necessity 

 for early treatment if protection is to be achieved. The first spraying 

 must be carried out before there are any visible signs of the disease. 

 This was emphatically impressed upon the Socrete des Agriculteurs de 

 France by M. Capus in February last, as follows : 



. . . For the defence of leaf, bunch and grape, one moment alone is of 

 importance : that of invisible invasion or contamination, after which the enemy 

 being in occupation, any intervention by the vine-grower is rendered futile. ^^ hat 

 we must guard against by treatment is thus, not the visible invasion, but the hidden 

 invasion. 



