152 FRUIT CULTURE. 



certain preparation of the surface for the seed, 

 so to speak, or is, on the other hand, the inde- 

 pendent cause of all the evil. Certain it is that 

 the more delicate varieties are much the most 

 subject to the disease, and these especially so in 

 some soils, and when in weak condition. It is 

 noticeable with what rapidity many kinds of 

 mildew spread upon decaying vegetation. It is 

 also certain that a warm, humid state of the at- 

 mosphere greatly facilitates the rapid growth of 

 fungi. Sections subject to heavy dews at night 

 are much troubled with mildew. A projecting 

 coping which covers the vine from night dews is 

 said to protect from fungus. We may avoid the 

 evil by selecting varieties which have tough 

 foliage and are least subject to attack. But we 

 shall thus exclude our best kinds. We can give 

 special care to furnish specific food, like phos- 

 phates and potash, and thus give vigor to resist. 

 Thorough drainage and protection from rains 

 and dews are preventives. Last of all we can 

 kill the fungus. It is a low form of vegetable 

 growth, and consequently sensitive to any in- 

 fluence that is destructive to vegetable life. Any 

 drying powder, simple wheat flour for example, 

 will, in some conditions, seem to absorb the 

 moisture, or smother the delicate mildew growth 

 and hold it in check. This, however, is not 



