586 [ DISEASES 6F THE VINE. 



afterwards is spread all over Europe and Northern 

 Africa. This fungus attacks all the green parts of the 

 vine, viz : the leaves, the green shoots, and the bunches, 

 from the time of flowering until the prapes are approach- 

 ing maturity, causing superficial greyish and greasy spots 

 on the upper surface of the leaves and on the green 

 epidermis of the shoots. The greyish spots on the 

 snoots become brown when the epidermis takes its nor- 

 mal reddish colour of ripened wood. On the green 

 berries the disease takes its well known form of greyish 

 or rusty spots, and if the spot is large enough to cover 

 practically the whole berry, the growth of the rind is 

 interfered with, and the internal pressure causes the 

 berry to burst. The perithecia are developed on the 

 stems, where they hybernate during the winter, and 

 early in spring they produce the disease in its conidial 

 form on the newly formed green tissues of the plant. 



The only remedy against this fungus is dusting with 

 finely powdered sulphur, which has a spec fie action both 

 against the conidial form in spring and summer, and 

 against the ascophorous form in winter. The first dust- 

 ing with sulphur should be dune very early, that is when 

 the bunches are yet quite small and compact, and partly 

 covered with their original hairy production. The second 

 dusting should be done when the flowers are in bloom, at 

 which time the ovaries are more liable to infection and 

 the virulence of the fungus is almost at its height. This 

 second dusting is also useful to assist fertilization and to 

 cause the berries to set more easily and is therefore a 

 preventive against shanking. The third dusting is done 

 after an interval of about fifteen days, when the berries 

 are as large as a pin's head ; and is advisable to apply a 

 fourth, and in certain cases also a fifth, dusting at other 

 intervals of fifteen days. There are in commerce various 

 types of sulphur in powder, viz : triturated, ventilated, 

 sublimated and precipitated, but the efficacy of any par- 



