242 



AMERICAN VINES. 



Fig. 124. Mattock used for severing 

 the roots. 



The roots growing on the scion are not, after all, a -very 

 great hindrance to the knitting; and if their development, 

 as everybody knows, is in reverse ratio to the production of 

 callus, they are generally the result of knitting which has 

 been slowly effected. Their removal in July or August is too 

 late to appreciably improve the knitting, but it is import- 

 ant, howe-ver, to stop their further development; they should 



therefore be removed. As a 

 matter of fact, when the scion 

 is nourished partly by the 

 roots of the stock and partly 

 by its own, the stock, only 

 bearing a limited part in the 

 growth of the plant, dwindles, 

 remains slender, and can only 

 partially contribute to the 

 solidity of the knitting; its 

 roots remain small and 

 slender; in a word, they 

 waste away, so much the 

 more as the roots of the 

 scion, growing under much 

 better conditions of soil and situation, assume more rapid 

 development. The stock ceases to be useful to the scion, 

 which henceforth becomes liberated and grows indepen- 

 dently. This is shown in Fig. 125 ; a scion growing on 

 its own roots. The roots of the scion are not, therefore, an 

 obstacle to the herbaceous growth ; on the contrary, they 

 favour it, especially in calcareous soils (calcareous soils of the 

 Charentes). Vines grafted on Riparia nourished both by the 

 roots of the scion and stock are the only ones resisting chlo- 

 rosis; but this only lasts as long as the phylloxera is not on 

 their roots. 



If the removal of, the roots of the scion is effected too late 

 in the season, the vine is placed in a bad condition for nutri- 

 tion; the dwindled root system of the stock is not sufficient 

 to nourish it any longer, and if the soil is unsuitable it withers 

 and dies. 



The severing of the roots must be done as early as pos- 

 sible, in order to furnish the plant with the substance neces- 

 sary to its existence. 



According to regions this operation is done in July or 

 August in France. The soil is earthed up again, but not 



