GRAPE-PRUNING ON THE PACIFIC SLOPE 171 



must be carefully made. At each winter pruning a number of 

 spurs of fruit wood must be left to produce the crop to be ex- 

 pected from the size and vigor of the vine. Besides these 

 fruit spurs, it may be necessary to leave spurs of sterile wood 

 to permit of increasing the number of fruit spurs the following 

 year. 



This will be made clear by comparing Figs. 30 A and 31. 

 Figure 30 A shows a vine at the third winter pruning with two 

 fruit spurs of two buds each and one fruit spur of one bud — 

 five fruit buds in all. 



If these five fruit buds all produce vigorous shoots during the 

 following summer, they will supply five canes of fruit wood 

 which can be used to form five fruit spurs at the following win- 

 ter pruning, which will be about the 

 normal increase necessary. Some of 

 these fruit buds, however, may produce 

 weak shoots or shoots so badly placed 

 that they would spoil the shape of the 

 head if used for spurs. Other shoots, 

 however, will be produced from base, 

 secondary and adventitious buds which, 

 while less fruitful, can be used to form 

 spurs for the starting of new arms. 



Figure 31 shows a vine after the 

 fourth winter pruning which had devel- 

 oped from a vine similar to that shown 

 in P^ig. 30 A. From the three fruit 

 spurs left the previous year foiu* canes 

 have been chosen for the fruit spurs of 

 this year. The old spur on the left has furnished two new 

 spurs and the two old spurs at the right each one new s})ur. 

 The pruner, judging that the vine is sufficiently vigorous to 

 stand more wood, has formed two spurs from water sprouts 

 which, while not likely to produce much fruit the first season. 



Fig. 31. Four-year-old 

 vine pruned for vase-formed 

 head. 



