466 



Journal of Agriculture, Victoria. [lo July, 1911. 



though bruised j the whole berry becomes invaded, turns brown and dries 

 up. The presence of a number of minute black spots is characteristic — 

 these constitute the Pycnidia, or summer spore-bearing bags of the fungus. 



On the leaves, the disease is confined to small brown patches, also 

 •showing minute black spots. Though damage to the foliage is slight, it 

 must be carefully observed, since invasion of the young leaves precedes 

 the invasion of the fruit. It gi\es urgent warning of the need for preven- 

 tive treatment. 



Black Rot is a slow-spreading disease as compared with Mildew. The 

 Pycnidia appear tO' be a less efficient mechanism for spore dissemination 

 than the external branching filaments of Plasmofara. Its mycelium, being 

 internal, can only be combated by preventive 

 spraying, such as the copper compounds ap- 

 plied against Mildew. In fact, the same 

 treatment is effectual against both fungi, though 

 the best time for application cliffers. j^.^ 



BLACK ROT (Guigtiardia Bidivellii). 



I. On young leaf. 2. On cane. 3. Spot on leaf (actual size). 4. On mature 

 leaf. 5. On grapes [after Chaiicrin). 



Careful study of the development of the disease has enabled the most 

 opportune moment to be fixed upon for different localities. In the success- 

 ful way in which the disease has been systematically fought in the Cadillac 

 district, near Bordeaux, by carefully following the instructions sent out 

 from time to time by the Comice, or Viticultural Association, we have an 

 example of the value these co-operative associations can prove to their 

 members. Our immunity from attack by it prevents further space being 

 here devoted to this interesting, though most injurious fungus.* 



Black Spot or Anthracnosis {Manginia ampelina). 



The fungi so far dealt with have been one and all imported into Europe 

 from the United States of America. This fact is now conclusively proved. 

 In Black Spot, on the other hand, we have a fungus which has been known 

 in Europe since the very earliest times, as witness its mention by agricul- 

 tural writers of ancient Greece and Rome. It has also been known in Aus- 

 tralia ever since the vine was first introduced. 



Though long known under the name of Sphaccloma ampelinum, and 

 later as Glcsosporium ampelophagum, these names, based on relationships 

 which were not thoroughly traced, must, since the exhaustive researches of 

 Viala and Pacottetf, be abandoned in favour of that of Manginia ampelina, 



* Those interested are referred to the scries 

 A-qI. L\'., &a 



t Revue de Viticulture, Vols, XXII, XIV. XW, 



)f articles hv M. A. I'ninet in Remie de VitiruHure, 



