All vinifera need to be grafted in the north east (and most of the rest of the world) because of phylloxera. Rootstock for grafting can help the vine adapt to various soil types, and can also change vigor and ripening time slightly. Sometimes they are even used for hybrids. Here’s a list of some common rootstocks for the area and some information on what they do. Most of this is from D.P. Pongracz “Rootstocks for Grapevines” which can be a difficult book to acquire. Pongracz also lists salinity limits for each type of rootstock. The soil tests for the vineyard site show minimal salinity (ECe measurement was 0.5 dS/m)
- 3309C – Good for deep, well-drained soils. Sensitive to drought (not usually in issue in PA). Sensitive to nematode injury.
- 101-14 – Wood hardens earlier than 3309C. Sensitive to drought, some nematode resistance, can tolerate clay and poorly drained soils
- SO4 – Good for wet soils, sensitive to drought, very high nematode resistance (includes the fanleaf virus vector). Pongracz lists it as accepting vinifera scions better than 3309C and 101-14. Vegetative cycle similar to 3309C and 5BB, but longer than 101-14
- Riparia – Moderate nematode resistance (better than 3309C, but not as good as 5BB or SO4), can tolerate wet feet, sensitive to drought.
- 5BB – Nematode resistant, sensitive to drought, shortens vegetative cycle. Pongracz reports some issues with grafting joints. Suited for humid, compact soils.
- 5C – Similar to 5BB, but shorter vegetative cycle
