GRAPES AND GRAPE CULTURE 105 



holds true with the methods employed east of the Rocky Mountains with 

 American Euvitis, it being in the training methods and not the pruning 

 that they differ. All the systems have the same underlying principle, 

 namely, the grape usually bears its fruit on shoots of the previous year's 

 growth. Therefore, the pruning should be so as to renew the wood at 

 a given point from year to year, through this regulating its production 

 and keeping the plants thoroughly shaped and under constant control. 



With a thorough knowledge of the nature of the vine, it is easy to 

 prune correctly. However, the nature of no fruit-bearing plant is so little 

 understood by horticulturists. Many horticulturists easily learn to prune 

 other fruit-bearing plants, but fail to master the vine and the same state- 

 ment is equally true of grafting it. 



Diseases and Insects. Of serious insect enemies of the grape east 



VINIFERA VINES PRUNED TO SPURS IN CALIFORNIA 



of the Rocky Mountains should be mentioned the Grape root-worm, 

 Grape vine flea-beetle, Grape berry-moth, Grape curculio, all of which 

 can be combated with arsenical sprays. 



Against the rose chafer, arsenical sprays, clean culture of land and 

 hand extermination at times become necessary. 



Against the Grape leaf-hoppers, clean culture of land, turning sheep 

 into the vineyard immediately after the vintage to pasture on grape 

 leaves and other rubbish and when the hoppers are nymphs, spraying 

 with whale oil soap and nicotine, are among the most effective remedies. 



Of grape diseases especially destructive east of the Rocky Mountains 

 are black rot, downy mildew, powdery mildew and anthracnose. All of 

 these are controlled by systematic spraying with Bordeaux mixture. 



In California, some seasons, considerable damage is done by the 

 Grape leaf-hopper and powdery mildew. The so-called California vine 

 disease, which has in the past wiped out thousands of acres of California 

 vineyards, is now seldom heard of. 



