406 Jdiiiiial of Agrictilturr, Victoria. [10 July, 1917. 



previously devoted to other cultures, so that the disease is much better 

 known in Europe than it was formerly. 



Outward Appearance. 



The outward manifestations of the disease are by no means un- 

 familiar in most districts after last season's visitation; nevertheless, 

 there has been some confusion in places where it was less prevalent, the 



markings often left by 

 Oidium on canes being 

 sometimes mistaken for 

 Anthracnose. The dif- 

 ference between the two 

 is so great that to persons 

 familiar with both dis- 

 eases confusion is impos- 

 sible. The scars caused 

 by Anthracnose, especi- 

 ally thosfe on the canes, 

 are always <<unken in, 

 the depressed centre be- 

 ing usualljf surrounded 

 by a more or less swollen 

 rim or cusliion of hyper- 

 trophied tissue. The 

 mai'kiugs — - they can 

 scarcely be termed scars 

 — left by Oidium are 

 discoloured, sometimes 

 even rough, but they are 

 never sunken in — the 

 surface is always flush. 

 That the two are alto- 

 gether distinct is well 

 seen in Figs. 4 and 5. 



The appearance of a 

 vine badly attacked by 

 Black Spot in spring is 

 characteristic ; (see Figs. 

 1, 2, and 3); once seen 

 it is not easily forgotten. 

 The young shoots are 

 stunted, the leaves dis- 

 torted, and more or less 

 blackened, and the em- 

 bryo bunches withered 

 and corroded. All the 

 growing parts of the 

 vine are seared with black-edged scars, the leaves being often perforated 

 by holes of varying size, rimmed with black. The vine looks as though 

 it had been sprinkled with some corrosive substance, hence the popular 

 French name of " Charbon " (charcoal). 



French writers distinguish three different forms of Anthracnose, 

 termed respectively Maculate, Punctuate, and Deforming. The first 



Fig. 3. 



Anthracnose scars. Photograph taken ;n • 

 Jannary, 1916. Verdeilho vines grown in Yarra 

 Valley Di-striet. 



