GRAD®Kober 125AA, Clone 1

GRAD®1 Kober 125AA is an excellent choice for vineyards where irrigation and rainfall are limited but where deep soil moisture is retained into the last three months of the growing season. In addition, because of its deep plunging root system it is also of considerable utility in organic vineyards where under-vine cultivation is limited or is not practised.

GRAD®1 Kober 125AA rootstock in brief:

  • Unique new GRAD® clonal re-selection from Gm4 source, selected for more moderate vigour, easier attainment of vine balance, and greater all-round durability
  • 4 x P.C.R. free of detectable virus; all Stanmore Farm mothervines have further tested negative by E.L.I.S.A. for GLRaV1,2,3, and GVA prior to supply and planting
  • Robust deep-plunging (often vertical) root system that utilises much deeper sub-soil strata than V. riparia or V. riparia x V. rupestris stocks
  • Provided deep soil moisture remains available, will resist very dry upper and mid-level soil conditions once established
  • Because of its genetically-programmed deep rooting habit, once it is established this is an excellent stock for use in organic vineyards where minimal or no under-vine tillage or weed control is practised
  • Highly compatible with the natural adaptation of the major Bordeaux scion varieties to seeking out, and relying upon, progressively deeper soil moisture as summer and early-to-mid autumn progress. 125AA is thus a particularly well-adapted stock for medium-spaced (2000 – 2500 vines / ha.) plantings of Sauvignon blanc or gris, Carmenere (especially), Cabernet Sauvignon, Merlot, and Semillon  etc., provided soil fertility is low to low-moderate and deeper soil strata retain moisture into autumn
  • Tolerant of moderate free lime in soil, tolerant of deep clay soils, performs very well in deep stony soils with moisture-retaining deeper clay / silt / loess strata
  • Advances scion ripening and enhances fertility, giving robust vines capable of supporting and ripening large crops in well managed conditions
  • One of Europe’s main ‘go to’ stocks for high-cropping ‘industrial’ vineyards, but its deeper root system means it often out-performs Kober 5BB and Teleki 5C in prolonged hot / dry weather provided deep-level soil moisture remains available
  • Vines grafted with GRAD®1 Kober 125AA rootstock are available in New Zealand through Stanmore Farm nursery under license from GRAD®.
  • Website:
    E-mail for orders or inquires:
    Phone: 0800 Stanmore (0800 782 666)
    Mobile: 027 544 0140
    For more information, or advice about its use and suitability for your vineyard, contact Dr. Gerald Atkinson at
  • A comprehensive non-propagation contract must be signed off as part of your purchase order.
  • Download Complete GRAD 125AA In Brief Fact Sheet PDF


Source and History

There have been only two importations of Kober 125AA into New Zealand. The first was by Lincoln University’s David Jackson, who imported the Gm4 clone from Geisenheim ca. 1975. Later, the stronger-growing Gm3 clone was brought to New Zealand in the 1980s by Professor Helmut Becker of the Geisenheim Grape Breeding Institute.  For reasons that are quite unclear, the Jackson import, although nominally available to the industry, seems never to have been widely distributed or utilised. By comparison, the Gm3 clone was available from various New Zealand Grape Vine Improvement Group sources from the late 1980s until the mid-2000s. Today, aside from the GRAD®1 clone at Stanmore Farm nursery, Gm3 seems to be the only 125AA clone planted and grafted in New Zealand. Meanwhile, plantings of the original David Jackson imported Kober 125AA Gm4 may well have disappeared completely in New Zealand.

Up to the mid-2000s there was however a stand of Geisenheim clone 4 Kober 125AA in a Waipara rootstock block. I began systematic season-by-season observation of this planting over 4 years, and it became clear that one Gm4 125AA vine in particular was both somewhat less vigorous but nevertheless more hardy in the deep, hard, fast-draining, very stony raised river terrace on which its block was planted. I made a considerable number of selections from this vine and then whittled their numbers down through exposure to dry conditions in poor soil. In due course only the single most hardy selection was retained as the GRAD®1 clone of Kober 125AA.

As with all the Teleki – Kober stocks, Kober 125AA originated by way of serial re-selection (first by Teleki, later by Kober) from one of thousands seeds from open pollinated Vitis berlandieri (actually Vitis cinerea, var. Helleri) crossings. Hoping to develop rootstocks resistant to both phylloxera and calcareous soil for the renown vineyards in Villány in Hungary, Teleki was prevented by Hungarian quarantine regulations from obtaining V. berlandieri cuttings. He therefore instead purchased  ten kilos of open-pollinated ‘V. berlandieri’ seeds from southern French vine breeder Euryale Resseguier. Of these, some apparently were crosses with V. vinifera; some apparently with V. rupestris; some with V. riparia. Teleki germinated his mass of seeds and embarked upon a multi-year process of selection, during which he identified and distinguished 10 groups of seedlings based on morphological criteria. For example, the group he coded as ‘7B’ was composed of vigorous vines with an appearance intermediate between V. riparia and V. berlandieri. Of the male flowered vines in this group, the seedling line eventually nominated as ‘125AA’ became a key selection through the subsequent work of Franz Kober, the superintendent of the Oppenheim research station, to whom Zsigmond Teleki had sent a range of his stocks.

DNA analytical work by a number of researchers has confirmed that Kober 125AA is, as Teleki and Kober seem to have confidently expected, a cross of V. berlandieri (actually V. cinerea, var. helleri) with V. riparia. However, after that, the finer genetic details are less clear. Some researchers say the V. riparia was ‘Michaux’, while others now suggest that deeper genetic analysis points to ‘Gloria de Montpellier’, but there has also been disagreement about which parent was the pollen source, as well as whether only one of Resseguier’s ‘berlandieri’ selections was involved. If it was more than one, then the possibility of ampelographically indiscriminable separate hybrid varieties arises. This a situation not yet proven, but it is nevertheless suspected by some researchers investigating 125AA’s DNA structure.  Certainly, the problem of poly-genetic lines (implying separate hybrid varieties, not mere different clones) appears to be a real one for key central European type-specimens of Kober 5BB and Teleki 5C from which, arguably, all other collections around the world originally received these stocks. Despite its complexity, this issue is quite significant because it is indicative of the underlying cryptic nature of virtually all of the Teleki – Kober rootstocks’ parentage due to their open-pollinated origins. But in any case, in New Zealand the GRAD®1 clone of Kober 125AA is definitely genetically distinguishable at clonal and performance level from the Gm3 clone, and appears rather likely also to be genetically distinct from its original Gm4 source by way of its differing performance characteristics.

Kober 125AA leaves, upper side (left), and underside. Photo source: Vitis International Variety Catalogue at


Health status

The GRAD®1 clone of Kober 125AA has been proven to be free of detectable virus by four consecutive PCR tests. Subsequent E.L.I.S.A. tests on the GRAD®1 nursery foundation vine for GLRaV1,2,3, and GVA were all negative / clear. All the mothervines at Stanmore Farm are first generation propagules of this 4 x PCR clean foundation source.



In its appearance, Kober 125AA has an almost archetypal V. riparia inherited leaf shape, but its downy internodes, with their fine velvety hairs (which can lightly persist even on the lignified wood), very much bespeak Vitis cinerea (of which, of course, V. berlandieri is now classified merely as the Helleri variety). Certainly, the vine is easily distinguished from any of the other major Teleki-Kober stocks (i.e.: SO4; 5BB; 5C; and 8B), and thus the visual basis by which Teleki grouped it separately from them is readily evident.

The vigour of 125AA very much depends on the amount of water and, more to the point, nutrient it obtains in the subsoil as it is not a shallow-rooting stock like Riparia Gloire or the V. riparia x V. rupestris hybrids so widely in use in New Zealand. In addition, my observations, made over the last 18 years, suggest that of the two Geisenheim clones introduced to New Zealand, Gm 3 is rather more vigorous than Gm 4. By comparison, GRAD®1 clone 125AA is moderately less vigorous than either of these Gms, and particularly Gm3. That said, the GRAD® 1 clone it is still capable of strong growth in deep fertile humid soils.

This stock’s roots are genetically programmed to plunge downward and deep (a V. cinerea characteristic), and as a consequence it will not thrive in shallow soil.  It is therefore vital when utilising 125AA rootstock to ensure that prior to planting, shallow pans, and ideally the overall vineyard subsoil structure up to as much as two metres depth, are broken up by deep ripping if and as necessary. As a corollary of this,  I have observed that the GRAD®1 clone of 125AA can prove very durable in quite dry upper and middle soil strata conditions where V. riparia and V. riparia x V. rupestris (and even some other V. berlandieri x V. riparia) stocks suffer badly from significant water deficit in the top 50 – 70 centimetres of the soil profile. This is because the 125AA rootstock is obtaining its water and nutrient at a deeper level than these other stocks. As vine age increases, and providing it has free enough access to deeper soil strata, GRAD®1  125AA can therefore prove an excellent choice for vineyards where irrigation and rainfall are limited but where deep soil moisture is retained into the last three months of the growing season. That said, as experiments at GRAD’s r&d nursery in Christchurch have shown, GRAD®1  125AA is not a true drought-resistant stock. Its deep root system is very well adapted to surviving on deep sub-soil moisture reserves, but in genuinely dry deep soils (with deficits of -80mm or more of soil moisture) it, and its scion, will suffer water stress.

Interestingly however, GRAD®1  125AA’s characteristics in many ways match the adaptations of most major Bordeaux wine grape varietals. For prior to the phylloxera crisis, when all Bordeaux vines were of course grown on their own roots, Cabernet Sauvignon, Carmenere (in particular), Sauvignon, Semillon, Cabernet Franc, Merlot, etc. depended on subsoil moisture reserves often held in deeper Bordeaux gravel layers and fed in a sponge-like fashion by porous limestone base-rock water sources. None of these classic Bordeaux scions is genuinely drought resistant, and especially Carmenere, but provided deeper sub-soil moisture is available — but with limited, only modest, nutrition — they are very much ‘at home’ in these conditions as summer progresses into autumn. As a consequence GRAD® 1 clone 125AA is a very suitable, highly compatible, rootstock choice in these specific circumstances.  (Planting at 2000 – 2500 vines / ha. would likely be optimal under these conditions; only in the very poorest soils should 125AA ever be used for close-planted (5000 / vines / ha.) vineyards.)




















Leaf of GRAD® 125AA clone 1 foundation vine photographed at the GRAD® r&d nursery in Christchurch. (Image © copyright  GRAD® / Grapevine Research and Development)


Qualitative potential

In Germany, 125AA is much valued for its cool-climate adaptation and deep plunging root system. It is widely used in high-cropping valley floor vineyards with deep (often clay) soils that retain subsoil moisture. It is also widely used in eastern European countries, and across central and eastern Europe it is a popular and well-proven ‘go to’ stock for high-cropping / high-production vineyards. It typically performs hugely better than V. riparia or V. riparia x V. rupestris stocks for this sort of ‘industrial’ utilisation, and in Europe it matches Kober 5BB and 5C in such circumstances, while showing better tolerance of drought conditions where it roots deeper into moisture-retaining subsoils. In France, 125AA is used in 200 ha. of plantings in Alsace, perhaps reflecting the region’s German connections. In New Zealand, in older Marlborough stands of Sauvignon blanc in particular, 125AA has proven a very tough and reliable rootstock that gives robust vines capable of sustaining high crop yields with ease on deep stony soils with underlying moisture-retaining silt-clay / loess strata. Further and much wider use of 125AA in these conditions would be extremely sensible instead of continuing with weak-growing and shallow-rooting V. riparia and V. riparia x V. rupestris stocks.

As for its utility on other soil types, 125AA is moderately tolerant of active lime, but I have observed that in acidic soil conditions and deep young sandy soils GRAD®1 clone 125AA can suffer from Magnesium deficiency, although dressing with dolomite very quickly overcomes this. I would not recommend close-planting (5,000+ vines / ha) with 125AA except in very poor fertility deep soils. While water restriction at deep soil levels (70cm+) will control this stock’s vigour, it will ultimately do this at the cost of inducing stress in both the stock and its scion. That said, GRAD®1  125AA was specifically selected for its lower vigour than the Gm3 and Gm4 clones, and as a result it is correspondingly easier to bring into balance in a wider range of conditions .


Ripening period

125AA is renowned as showing a strong V. riparia-derived disposition to advance scion ripening. It gives strong vines with enhanced fertility that can sustain sizeable crops in suitable conditions and bring them, thanks to its Vitis riparia genes, into relatively early maturity.



GRAD’s licensed New Zealand nursery, Stanmore Farm, has GRAD®1  125AA mothervines in full production. For current season and forward orders, contact Stanmore Farm for  details regarding grafting quantities available.

Vines grafted with GRAD®1 Kober 125AA rootstock are available through Stanmore Farm nursery under license from GRAD®
E-mail for orders or inquires:
Phone: 0800 Stanmore (0800 782 666)  
Mobile: 027 544 0140

For more information on this rootstock, or advice about its use and suitability for your vineyard, contact Dr. Gerald Atkinson at

Please note that a strict and comprehensive non-propagation contract must be signed off as part of your purchase order.

GRAD® is a New Zealand registered trademark uniquely and exclusively used to identify the vines in the GRAD® vine collection. Use by unauthorised parties to identify any vine material, or other use for commercial gain, is an infringement of this trademark.

Genetic ‘fingerprinting’ and clonal traceability

Vine pirates BEWARE! It is now possible to genetically fingerprint, uniquely identify, and detect grapevine clones using the latest-developed molecular genetic sequencing techniques. See the breakthrough research paper by Michael J. Roach et al, “Population Sequencing Reveals Clonal Diversity and Ancestral Inbreeding in the Grapevine Cultivar Chardonnay”, published November 20, 2018 at



Questions about this rootstock? Contact us.

Author: Dr. Gerald Atkinson

Company director, viticulturist, grapevine researcher and historian, and sometime wine-writer.