158 MANUAL OF AMERICAN GRAPE-GROWING 



arms and spurs at the top of the trunk tend to absorb the 

 energies of the vine and the lower arms and spurs become 

 weaker each year until finally no growth at all is obtained be- 

 low. After several years, most of the vines therefore lose their 

 character of cordons and become simply headed-vines with 

 abnormally long trunks. 



The cordon can be reestablished in this case by allowing a 

 vigorous sucker to develop one year from which to form a new 

 trunk the next. The following year the old trunk is removed 

 entirely. An objection to this method is that it makes very 

 large wounds in the most vital part of the vine the base of 

 the trunk. 



Figure 27 is a photograph of a four-year-old Colombar vine, 

 illustrating the unilateral, horizontal cordon system. It con- 



FIG. 27. Unilateral horizontal cordon with fruit spurs. 



sists of a trunk about seven feet long, supported horizontally 

 by a wire two feet from the ground. Arms and spurs are ar- 

 ranged along the whole horizontal part of the trunk. 



This system accomplishes the same objects as the vertical 

 cordon. It allows a large development of the vine and nu- 

 merous fruit spurs without crowding. It is superior to the ver- 

 tical cordon in the distribution of the fruit, which is all exposed 

 to approximately the same conditions owing to the uniform 

 distance from the ground of the fruit spurs. All parts of the 

 trunk producing an annual growth of wood and fruit are equally 

 exposed to light and the tendency of the growth to occur prin- 



