10 July, 1918.] Xules un Vine Black Spot. 423 



European authorities are unanimous in considering the winter treat- 

 ment to be very much more efficacious than any that can be applied 

 during the growing period of the vine, so far as this particular fungus 

 is concerned. Until quite recently, in fact, many authorities freely 

 expressed the view that copper sprays, so valuable against Downy Mildew, 

 are of little use in combating Black Spot. Mixtures of lime and sulphur 

 have long been held to be the standard treatment of Black Spot during 

 the growing period of the vine. At Mildura last season, such dustings 

 were extensively applied, with most disappointing results, the experience 

 in this district being quite in accord with more recent views in France, 

 in which countiy a marked change of opinion is evident within recent 

 years. Amongst othei- authorities, Professor Ravaz urges the efficacy 

 of preventive copper sprays to combat Anthracnose during the growing- 

 period of the vine. The following two quotations will suffice. Refer- 

 ring to treatment of Anthracnose in Progres Agricolc, of 8th June,. 

 1913, he says : — 



" During summer scientific mixtures of lime and sulphur have 

 been prescribed, the efficacy of which has always been equal to that 



of a blister on a wooden leg The disease is amenable 



to copper. Copper sprays are efficacious against it, provided they 

 are applied frequently during rainy weather, or even if moist condi- 

 tions should prevail." 



Again, replying, in Progres Agricole, of 10th May, 1915, to a vine- 

 grower, whose military duties had prevented him from swabbing, and 

 whose wood was shockingly damaged, he writes: — 



" Failure to swab does not leave us altogether disarmed against 

 Anthracnose. It, also, is amenable to copper sprays. But, as it 

 attacks canes and bunches as well as leaves, treatment must be so 

 applied that the base of the canes and the young stalks are well 

 coated with copper. One must not be content with blessing (i.e., 

 sprinkling with holy water) the young shoots; they must be hathed, 

 as the Italians say. Subsequent treatments against Mildew Avill 

 also control Anthracnose," 



The efficacy of copper sprays against Anthracnose receives striking 

 confirmation from the fact, very noticeable to any visitor to Europe, 

 that this disease is much less in evidence nowadays than it was forty 

 years ago. This is not because climatic conditions do not now suit it, 

 but because the copper sprays so extensively applied to combat Downy 

 Mildew have a strong restraining effect on Anthracnose. It is, indeed, 

 chiefly in connexion with direct producers* that Anthracnose is heard 

 of nowadays in France. 



The greater prevalence of the disease on these vines is not due to 

 any special liability to it, but to the fact that they are not protected 

 by the copper sprays which must be applied against Downy Mildew to 

 pure vinifera varieties. 



That copper sprays should protect vines against Black Spot is not 

 astonishing; their mode of action is absolutely similar to that by Avhich 

 they, protect the vine against Downy Mildew, viz., on properly sprayed 



* By direct producers are understood thfi hybiid vines raised of recent years to atthesume time resist 

 phylloxera and yield wine of fair quality. Mmy of these po?sess such a high resist in?o to Downy Mildew 

 tliat spraying can be dispensed with. 



