This principle of increase of fruitfulness by mechanical injury 

 is very useful if properly understood and applied. It is a well-known 

 fact that vines attacked by phylloxera or root rot will for one year 

 bear an exceptionally large crop on account of the diminution of 

 vigor caused by the injury to their roots. A vine also which has been 

 mutilated by the removal of several large arms will often produce 

 heavily the following year. In all these cases, however, the transient 

 gain is more than counter-balanced by the permanent injury and 

 loss. The proper application of the principle is to injure tissues only 

 of those parts of the plant which it is intended to remove the next 

 year (fruit canes), and thus increase fruitfulness without {icing any 

 permanent injury to the plant. 



PRUNING OF YOUNG VINES. When a rooted vine 

 is first planted, it should be cut back to two eyes. If the 

 growth is not very good the first season, all the canes but 

 one should be removed at the first pruning, and that one 

 left with two or three eyes, according to its strength. The 

 next year, or the same year in the case of strong grow- 

 ing vines in rich soil, the strongest cane should be left about 12 

 inches long and tied up to the stake The next year two spurs may be 

 left, of two or three eyes each. These spurs will determine the posi- 

 tion of the head or place from which the arms of the vine spring. It 

 is important, therefore, that they should be chosen at the right height 

 r'rom the ground. From ten to twenty inches is about the right 

 height; the lowest for dry hillsides where there is no danger of frost; 

 the highest for rich bottom lands where the vine will naturally grow 

 large. Vines grown without stakes will have to be headed lower than 

 this in order to make them support themselves. In the following few 

 years the number of spurs should be increased gradually, care being 

 taken to shape the vine properly and to maintain an equal balance of 

 the arms. 



In general, young vines are more vigorous than old, and tend 

 more to send out shoots from basal and dormant buds. They should, 

 therefore, be given more and longer spurs in proportion than older 

 vines. They also tend to bud out very early in the spring, and are 

 thus liable to be frost-bitten. For this reason they are generally 

 pruned late (March) in frosty locations. This protects them in two 

 ways. In the first place, in unpruned vines the buds near the ends of 

 the canes start first and relieve the sap pressure, and though these 

 are caught by the frost the buds near the base, not having started, 

 are saved. In the second place, the pruning being done when the sap 

 is flowing there is a loss of sap from the cut ends of the spurs which 

 further relieves the sap pressure and retards the starting of the lower 

 eyes. This method of preventing the injury of spring frosts by very 

 late pruning has been tried with bearing vines, but is very injurious. 

 Older vines being less vigorous are unable to withstand the heavy 

 drain caused by the profuse bleeding which ensues; and though no 

 apparent damage may be done the first year, if the treatment is 

 continued they may be completely ruined in three or four years. 



. SYSTEMS OF PRUNING. 



The systems of pruning adapted to vineyards in California may 

 be divided into six types according to the form c,-'\en to the main 

 body of the vine t \nd the length of the spurs and fruiting canes. 



