RESISTANT VINEYARDS GRAFTING, PLANTING, CULTIVATION. 91 



4. Grafting the resistant vines when too old. A grafted vine to be 

 a permanent success must have a perfect union. The younger the 

 tissues, the more complete and lasting the union. Budding and graft- 

 ing herbaceous canes produce unions which are practically perfect. If 

 the scion and stock are each only one year old, as in cutting grafting, 

 the union is nearly always as perfect and permanent. No wood older 

 than one year is ever used as a scion, but the stock is often grafted 

 when much older. If the stock is more than one year old many varie- 

 ties fail to give good unions, and if three or four years old a large 

 number of the grafted vines will fail after they have produced a few 

 crops. Some of the best resistant stocks fail almost completely if 

 grafted when several years old, and though they bear well and appear 

 strong for a few years they soon begin to fail, and every year after 

 the first two or three crops a certain proportion of the unions fail and 

 the tops die. A vineyard may linger in this way for eight or ten years, 

 until finally from 50 to 75 per cent of the vines are dead. This is one 

 of the strongest objections to field grafting, and is more thoroughly 

 discussed later. 



5. Planting or grafting too deep. The result of this is that the scions 

 form their own roots and finally become independent of the resistant 

 stock, which dies. Such vines are, of course, non-resistants and just as 

 quickly killed by phylloxera as if grown in the first place from vinifera 

 cuttings. Some vine-growers, of long experience with vinifera vine- 

 yards but unfamiliar with resistants, do not believe that this death of 

 the resistant stock will take place under the conditions described. They 

 state that it is an advantage for the scion to have its own roots as 

 well as those of the resistant. They argue that, if there is little or no 

 phylloxera present, the vines will do better with two sets of roots than 

 with one, and that, when the phylloxera increases to dangerous propor- 

 tions and destroys the vinifera roots, the resistant roots are there to 

 save the vine. 



This theory is based on the false assumption that the roots are the 

 main, or only, feeding organs of a plant, and overlooks the fact that 

 the roots require the materials furnished by the leaves quite as much as 

 the leaves require those furnished by the roots. For both to be vigorous, 

 therefore, there must be a mutual exchange of food matters. 



This exchange takes place through the medium of the tubes and 

 cells of the wood and bast of the stem of the vine. The soil nutrients 

 pass with the sap, principally through the younger wood, from the roots 

 to the leaves. In the leaves these materials are combined with -gases 

 absorbed from the air and are elaborated into the real food of the vine 

 which passes back, principally through the bast or region exterior to the 

 wood, into all parts of the plant, to supply the material necessary for 

 growth and other various vital functions. 



