528 



Sulphur is the readiest cure for oidium. The finer the sulphur 

 the better, and for that reason " precipitated " sulphur is supposed 

 to have greater virtues than either "ground" or "sublimed" 

 sulphur. 



Moist, warm, and damp weather favours the growth of the 

 fungus, and at the same time checks the formation of sulphur 

 fumes. Great heat, such as occurs in the summer, kills the blight. 

 It is best to sulphur in the morning, when the leaves are still damp 

 with dew, and before the high winds begin to blow. The months of 

 November and December are, with us, the most suitable for sulphur- 

 ing, and in later districts it is even practised in January. 



Sulphuring, to be efficacious, must be used as a preventive 

 remedy. If it is delayed until the formation of the fruits of the 

 fungus (perithicia) it does not act so readily, as the seeds of the 

 blight plant (ascospores) are then more resistant than are the grow- 

 ing mycelial threads of the fungus. 



The sulphuring is best done with the aid of specially made 

 sulphur bellows. Some simply put the crushed sulphur into a sugar 

 bag and shake it over each vine, but this method is wasteful of the 

 sulphur, and does not distribute it so effectively as do the bellows. 



In persistent cases, and in districts favourable for the growth 

 of the fungus, as many as four sulphurings are given, but generally 

 two or three will be found sufficient. 



The quantity of sulphur per acre varies, according to the state 

 of fineness of the powder ; the sulphur distributor used ; the season, 

 and the prevalence of the disease, from 151bs. to 601bs. of sulphur 

 per acre. 



When oidium is severe, and in case of emergency, the following 

 formula will be found to answer well : 



Water ... ... ... 22 gallons. 



Soft Soap lib. 



Liver of Sulphur ... . . , lib. 



This treatment is not meant to replace sulphur, but to check 

 oidium. on grapes. The liver of sulphur acts promptly by contact, 

 whereas sulphur acts by emitting sulphur fumes, which may be 

 checked by unfavourable weather. There are times when sulphur 

 does not act as it should, because it is washed away by showers of 

 rain, or because the temperature is too low for a sufficient emission 

 of sulphurous acid gas. In such cases try liver of sulphur. Do 

 not increase the dose, as liver of sulphur is corrosive, and soft soap 

 may impart a nasty taste to the grapes. 



CROWN GALL of the grape (called " Broussin " in France) shows 

 like large cancerous growths at the crown of the vine. A knock with 

 the hoe or the plough, the bite of insects, sunscald, or a variety of 

 causes will produce these unsightly growths. The treatment should 

 be somewhat similar to that of cancer of the apple. 



