GRAPE-PRUNING ON THE PACIFIC SLOPE 155 



The difficulty of obtaining new wood from the renewal spurs 

 is even greater than in the system shown in Fig. 23 C. The 

 length and vertical position of the fruit canes cause the main 

 growth and vigor of the vine to be expended on the highest 

 shoots. The renewal spurs are thus so shaded that, even though 

 their buds start, the 

 shoots make but a weak 

 growth. The result is 

 that at the following 

 pruning all the good 

 new wood is at the top 

 of the fruit canes of the 

 previous year, where it 

 cannot be utilized. The 

 pruner has to choose 

 then between reverting 

 to spur pruning and 

 getting no crop or using 

 the weak growth from 

 the renewal spurs for 

 fruit canes, in which 

 case he may get blos- 

 soms but little or no 

 fruit of any value. 



Other defects of this 

 method are that the 

 fruiting shoots are ex- 

 cessively vigorous and 

 therefore often tend to drop their blossoms without setting and 

 the fruit when produced is massed together so that it ripens 

 unevenly and is difficult to gather. It also requires a tall 

 and expensive stake. 



Figure 24 B represents an improvement on the last system. 

 It differs only in the method of treating the fruit canes. These 



A B 



FIG. 24. Forms of head pruning : A, ver- 

 tical fruit canes and renewal spurs ; B, bowed 

 fruit canes and renewal spurs. 



