Rootstock derived from the cross of Vitis berlandieri and Vitis riparia originating from Euryale Resseguier. Today there are 24 different clones of this rootstock: 5, 15, 18, 20, 72, 73, 74, 102, 103, 104, 106, 156, 157, 158, 159, 161, 165, 166, 174, 203, 204, 205, 761 και 762.

SO 4 degree of resistance to the root form of phylloxera is high. It also has high tolerance to Meloidogyne incognita and Meloidogyne arenaria nematodes and is susceptible as rootstock to the Meloidogyne hapla nematodes.

SO 4 is up to 40- 45% tolerant to total calcium and 22% to active calcium and CCI* (see R 110) up to 30. Tolerance to iron chlorosis can be considered moderate. It performs well in acidic soils and performance in millerandage of some varieties can be positive. SO 4 adapts quite well to drought but is extremely susceptible to excess moisture and drying wood. It poorly absorbs magnesium from the soil and promotes back drying. It is particularly suitable for sandy, deep and clay soils, of medium fertility, while it does not adapt well to dry, saline and compact soils.

In general, SO 4 is well compatible with grafts of various varieties while the robustness of the plant is moderate. We can say that the rootstock has "thin legs" because of the difference in the diameter of the rootstock from the vaccine. The rate of growth of grafted plants is high and the robustness it carries is high especially during the first years of the vineyard's life (first 15 years). SO 4 allows high yields, in the first years after planting, to the point that the practice of grape cluster thinning may be required. It causes good sugar production, but the wines produced often have medium body and botanical characters due to high performance. SO 4 usually promotes the production of wines with high pH.

Wood production is high (60.000 to 100.000 m / ha ), sometimes, however, with a certain percentage of the wood dry. It responds well to fertilization and irrigation, but wood formation is slow. It also has a very good ability for shredding, removing buds, and grafting. The internodes are medium-sized in length and diameter, while the growth of the node buds is limited.

SO 4 is  susceptible to the foliar form of phylloxera, but manifests a high degree of mildew disease tolerance.