404 Journal of Agriculture, Victoria. [10 July, 1917. 



ANTHRACNOSE OR BLACK SPOT OF THE VINE 



{Manginia ampelina, V. and P.). 



Bi/ F. de. Castella^ Government Viticvltnrist, and C. C. Brittlehanh, 

 Government Pathologist. 



After an almost complete absence from Victorian vineyards extend- 

 ing over some twenty years, Black Spot has re-appeared and, in Syome 

 localities, at least, in an unusually virulent form. Our long immunity 

 has led growers, ©specially those whose experience of the vine dates 

 back less than twenty years, to view the recent outbreak with consider- 

 able alarm ; yet there ia really no cause for such. 



In the first place the disease is quit© amenable to treatment, especi- 

 ally preventive; and, in the second, the pest is not by any means a new 

 one. In Europe it has been known since ancient times, whilst in Vic- 

 toria, both in Rutherglen and Mildura, our two chief vine districts, 

 older vinegrowers remember it only too well. In the latter district 

 many of the first planted Sultana blocks suffered severely — the cuttings 

 of this variety, which is very liable to the disease, having come from 

 cooler districts where it was prevalent. The winter " swab " on which 

 we must once again fall back, was well known to Mildura growers in the 

 nineties. 



Has our climate changed? Meteorologists say not; but we seem to 

 have entered on a cycle of moist, rainy springs, favorable to the disease, 

 which, together with the absence of steps to combat it, have permitted 

 it to obtain a firm hold. 



As regards the future : Given a return to normal spring weather, 

 unfavorable to its Sipread, the disease will no doubt revert to the unim- 

 portant position it has so long occupied. But if we fail to get a dry 

 spring, and if no preventive steps are taken, grave damage is not only 

 probable, but certain. A repetition of last year's weather might easily 

 lead, in the absence of treatment, to a real disaster to growers of 

 Sultanas and other susceptible varieties, owing to the abundance of the 

 fungus in its hibernating or resting stages, in which it awaits the return 

 of spring to renew its activity. 



It is hoped that the gravity of the situation will be generally 

 recognised, and that the standard preventive treatment about to be 

 described and concerning the efficacy of which there is no room for 

 doubt, will become general in all vineyards where any signs of 

 Anthracnose were noticed last spring and summer. 



Conditions Favorable to the Disease. 



Like most fungi, moisture and heat are essential, but Black Spot 

 seems to be able to develop at a lower temperature than many other 

 fungus pests. Localitv thus plays an important part; vines on low- 

 lying ground are particularly susceptible. The varying intensity of the 

 disease in different parts of a vineyard is often marked ; serious damage 

 may be don© in a moist corner liable to fogs and heavy dews, whilst 

 higher, better drained and better aerated poi'tiona may escape alto- 

 gether. The susceptibility of moist spots can often b© lessened by 

 drainage. 



Sandy soils, notwithstanding their good drainage, seem conducive 

 to the spread of Anthracnose; this was particularly noticeable at Mildura 



