60 



MANUAL OF MODERN VITICULTURE. 



seems to have a greater influence than any, and the limits of 

 limestone given hereafter, which were established from 

 experiments made in the dry parts of the Mediterranean 

 region, must he reduced in damper countries. 



V. Riparia. Two 

 wild forms have heen 

 retained, the Riparia 

 Gloire de Montpellier 

 and R. Grand (rlabre, 

 which may he regarded 

 as equivalent. Like all 

 Riparias they have the 

 inconvenience of form- 

 ing a trunk of smaller 

 diameter than that of 

 the scion (Fig. 23), but 

 they certainly consti- 

 tute the best graft- 

 bearers in the majority 

 of soils on account of 

 the abundance of their 

 production. Therefore, 

 whenever the drought 

 and the percentage of 

 limestone is not too 

 great, they should be 

 preferred. They may be 

 used with almost every 

 chance of success in 

 soils containing up to 

 20 per cent, of carbon- 

 ate of lime. In the 

 Mediterranean region 

 we may even use them 

 in soils containing 25 

 per cent., under the 

 condition that the sub- 

 soil is at a, depth of at 

 least 20 inches, and 

 that the soil is fertile. 



V. Rupestris. Again two forms have been selected as 

 superior : the R. Martin and R. du Lot. The former is very 

 resistant to phylloxera, and succeeds under conditions similar 



Fig 1 . 23. V. Vinifera grafted on V. Riparia, 



showing almost normal difference between size of 



stock and scion 



