The choice of the rootstock is a possibility to respond to the given conditions, such as soil, water supply, trellising system and vineyard site. Actually, you can say the rootstock adapts the scion variety to these conditions.

From the amount of rootstocks which exist all over the world we've chosen the ones which grow best in our conditions. Most of them are a crossbreed between Vitis berlandieri and Vitis riparia.

The following table should give you an overview of the characteristics of these rootstocks:

variety	cross	(1) drought resistance	(1) Chlorose- resistance	(1) Active lime- tolerance	(1) Vigorousity	(2) influence of maturation	(1) rooting ability	(1) grafting ability	remarks
5 BB	V. Berlandieri x V. riparia	6	7	20 %	7	4	7	8	very good adaptibility not suitable for varieties which are endangered to shattering on vigorous soils
125 AA	V. Berlandieri x V. riparia	5	5	17 %	6	5	6	6	useable nearly everywhere except very weak and compacted soils. Good for varieties which endagered to shattering.
SO 4	V. Berlandieri x V. riparia	4	7	20 %	5	6	5	6	good fertility and not to vigorous doesn't like to high yields   mostly used rootstock in Europe
Binova	Mutation of SO 4	4	7	20 %	6	6	5	6	very close to SO4, a bit more vigorous

(1)
1 = low
9 = high

(2)
1 = late
9 = early