PARASITIC FUNGI AND MOULDS. 35 



the branches and the stock itself. The third applica- 

 tion should be made early enough for the sulphur to 

 have disappeared from the grapes before the vintage 

 takes place. It is evident that its introduction into 

 the ■wine would have the worst effect : in process of 

 fermentation sulphuretted hydrogen would be given 

 off, which is injurious to the alcohol, and this gas 

 would give an unpleasant taste to the wiae. 



The morning is the best time for applying the 

 sulphur, since the dew enables the powder to stick 

 to the leaves and branches; and it should be made 

 on a fine day, since heavy rain would carry off the 

 sulphur before it has time to act upon the oidium. 



The sulphur which ultimately reaches the soil 

 below the vine is transformed into sulphate of lime, 

 which is an excellent dressing for the vine. 



Mildew. — This new parasite, of which the scientific 

 name is Peronospora viticola, belongs to the group 

 of Oomycetes. It also comes to us from America. 

 It was imported into Europe in 1878, with the 

 American plants destined to replace those destroyed 

 by the phylloxera, and was rapidly diffused through 

 France, and thence to Algeria. It appears in the 

 form of irregular patches of a whitish colour, not 

 very thick, and with an almost crystalline appear- 

 ance like that of a saline efflorescence (Planchon). 

 It has not the mouldy smeU of oidium, and appears 

 later in the season, generally on the autumn shoots. 

 Its mycelium penetrates more deeply than that of 



