154 



UNIVERSITY OF CALIFORNIA EXPERIMENT STATION. 



THIRD YEAR. 



Winter Pruning. After the leaves have fallen at the end of the third 

 summer every vine should have a well-formed, straight stem with two, 

 three, or more canes growing from the upper part, and the formation of 

 the "head" or crown should commence. Any vines which have not 

 been brought to this condition must be pruned like two- or one-year- 

 old vines, as the case may be. 



If the work up to this point has been well done, the formation of the 

 head is a simple matter. It consists in leaving two, three, or four spurs, 



FIG. 6. Three-year-old vines after pruning. 



a. Average vine with two spurs. 



b. Vigorous vines with three spurs, the lowest of which is to be 



removed the following year. 



c. Vigorous vine with three spurs. 



arranged as symmetrically as possible near the top of the vine. The 

 stronger the vine, as evidenced by the number, length, and thick- 

 ness of the canes, the larger the number of spurs and buds that should 

 be left. 



A spur consists of the basal portion of a cane, and normally of two 

 full internodes. This leaves two buds besides the base bud. The 

 number of buds to leave on a spur depends on the strength or thickness 

 of the cane from which the spur is made. A thin, or weak, cane should 

 be cut back to one bud or even to the base bud. A strong cane, on the 

 other hand, should be left with three buds besides the base bud. 



The pruning of each vine requires judgment, and it is impossible to 



