GRAPE-PRUNING ON THE PACIFIC SLOPE 151 



Vine Pruning in California ^ 



The systems of pruning in use in California may be divided 

 into two classes according to the arrangement of the arms on 

 the trunk of the vine. In the commonest systems, there is a 

 definite head to the trunk, from which all the arms arise sym- 

 metrically at nearly the same level. The vines of these systems 

 may be called "headed vi-ies." In the other systems, the 

 trunk is elongated four to eight feet and the arms are distributed 

 regularly along the whole or the greater portion of its length. 

 The vines of these systems, owing to the rope-like form of the 

 trunks, are called "cordons.'' 



The headed vines are divided according to the length of the 

 vertical trunk into high, 2-3 feet, medium, 1-1^ feet, and 

 low, 0-6 inches. The cordons may be vertical or horizontal, 

 according to the direction of the trunk, which is from four to 

 eight feet long. The horizontal cordons may be single (uni- 

 lateral) or composed of two branches extending in opposite 

 directions (bilateral). Double and even multiple vertical 

 cordons occur, but they are very inadvisable and have no 

 advantages. 



The arrangement of the arms of a headed vine may be sym- 

 metrical in all directions at an angle of about 45 degrees. Such 

 a vine is said to be "vase-formed," though the hollow center 

 which this term implies is not essential. This is the form used 

 in the great majority of our vineyards whether of wine, raisin, 

 or shipping grapes. It is suitable for the "square" system of 

 planting and cross cultivation. Where vines are planted in the 

 avenue system, particularly when trellised and where cross 

 cultivation is impossible, the arms are given a "fan-shaped" 



• The remainder of this chapter is republished by permission from 

 Bal. 24-6, Calif. Exp. Sta., Vine Pruning in California, published in 

 1916 by F. T. Bioletti. Not all of the bulletin is reproduced, but the 

 parts republished are transcribed verbatim. All of the illustrations in 

 this chapter have been redrawn from Professor Bioletti's bulletin. 



