424 Journal of Agriculture, Victoria. [10 July, 1918. 



vines, every rain or dew drop dissolves a trace of copper, sufficient to 

 prevent tlie germination of any fungus spore which may fall into it. 

 It is scarcely necessary tx) repeat that Black Spot is a fungus which 

 must be prevented ; it cannot be cured. It is not astonishing that the 

 same means of prevention, so effective in the case of Downy Mildew, 

 should also enable us to control Black Spot. 



The number of spring or summer sprayings required must be largely 

 governed by weather conditions. In a very wet spring, several applica- 

 tions will be necessary, the essential point is that the first spraying 

 should be early enough. It should be applied as soon as the young 

 shoots are a couple of inches long, on all vines where the fungus was in 

 evidence last season. This spray should be repeated a fortnight or so 

 later, in order to protect all growth which has been made subsequent 

 to the first application. Further spraying may be necessary in a wet 

 «pring. 



There is a tendency in some quarters to rely entirely on spring and 

 summer treatment. We must lodge an emphatic protest against such. 

 It should be needless to point out that the fewer the spores in spring, 

 the more effective will be the protection of preventive copper sprays; 

 the prevalence of . such spores is obviously enormously reduced if the 

 bulk of the wintering forms are destroyed by efficient swabbing at the 

 close of winter. 



The composition of Bordeaux Mixture and Copper Soda, in fact, of 

 copper fungicides in general, will be dealt with in a subsequent issue; 

 it will be sufficient to here state that standard Bordeaux Mixture, 

 containing 2 per cent, of copper sulphate, with enough lime to neutralize, 

 constitutes the best protection against Anthracnose during the growing 

 period of the vine. 



Cultural Considerations. 



Where vines have been severely affected, advantage should be taken 

 of any modification in cultural methods which may tend to lessen 

 liability to fugus contamination, during the growing season. 



The air in the vicinity of freshly-worked land is always moister than 

 that overlying land which has not been recently disturbed. The dew 

 point, and, consequently, the amount of dew deposited, is greater in the 

 former case, thus increasing the chances of infection. Winter cultiva- 

 tion should be completed as early as possible, so that the land Avill not 

 be in recently-M^orked condition in early spring. Such cultural work 

 as must be carried out among sprouting or actively growing vines in 

 spring, should be executed as soon after spraying as possille, so as to 

 profit by the protection thereby afforded whilst at its maximum. The 

 spray might also follow the plough or cultivator on the same day, though 

 it must be remembered that the traction of the spray outfit would be 

 heavier on the newly-Avorked soil. 



The presence of weeds, and particularly of cover crops (green 

 manuring), acts in similar manner to freshly-worked soil. The vine- 

 yard must be so worked as to insure the absence of either of these at 

 periods when contamination is to be feared. 



Irrigation must be carefully regulated, both as regards quantity of 

 water applied and time of application. Wherever vines suffered severe 

 damage last season they should be sparingly watered; a heavy crop 

 cannot be expected from such vines; the best one can hope is to provide 



