he necessity of using For instance, Couderc 3309 and Rootstocks rootstocks is a question other V. riparia x V. rupestris root- Impact Vine T frequently being asked by stocks have limited tolerance to water grape growers in the Pacific north- stress (Pongracz, 1983). The use of Performance and western U.S. and British Columbia. moderately drought-sensitive root- Vinifera grapevines are customarily stocks to control growth and improve Fruit Composition grafted to prevent injury from biotic wine quality in irrigated areas is not a problems such as grape phylloxera well-researched subject. Excessive ni- of Grapes in (Dactylosphaera vitifolii) or nematodes trogen uptake may lead to large vine (Pongracz, 1983). Numerous studies size, hence canopy shade, reduced win- British Columbia (Howell, 1987; Reynolds and Pool, ter hardiness, excessive potassium (K+) 1980; Shaulis and Steele, 1969; uptake, and low wine quality (Smart, Striegler and Howell, 1991) have dem- 1991). Rootstocks 5C and SO4 re- Andrew G. Reynolds and onstrated the advantage of using stocks duced cluster rachis ammonium (NH4) such as Couderc 3309 (3309), and nitrate (NO concentration in Douglas A. Wardle 3) Selektion Oppenheim 4 (SO4), Kober ‘Riesling’ but not ‘Chardonnay’ or 5BB (5BB), and Teleki 5C (5C) to ‘Gewurztraminer’ (Reynolds, unpub- improve yields and fruit composition. lished). Ruhl et al. (1988) demon- ADDITIONAL INDEX WORDS. Vitis, yield, Most of these responses, however, have strated the effect of rootstock on po- Vitis vinifera, French–American been attributed to secondary effects of tassium accumulation in ‘Muscat hybrids rootstocks mediated through increases Gordo Blanco’ petioles and lamina SUMMARY. Nine wine grape cultivars in vine vigor, usually as a consequence and on ‘Chardonnay’ musts. The con- [’Chardonnay’, ‘Gewurztraminer’, of phylloxera resistance. Few studies clusions drawn from these studies were ‘Ortega’, ‘Riesling’, ‘De Chaunac’, have concentrated on the benefits of that petioles of some scion cultivars, ‘Marechal Foch’, ‘Okanagan Riesling’, rootstocks in overcoming abiotic prob- under the influence of specific root- ‘Seyval blanc’, and Verdelet’], own lems such as salinity (Downton, 1977; stocks, may act as reservoirs for some rooted or grafted to four rootstocks 1988), nutrient uptake (Downton, ions, to prevent toxicities and undesir- [‘Couderc 3309’ (Vitis riparia x V. 1977; Ruhl et al., 1988), chlorosis able whole-plant responses. rupestris); ‘Kober 5BB’ (5BB), ‘Teleki (Valat et al., 1988), and drought Rootstocks have also been shown 5C’, and ‘Selektion Oppenheim 4’ (Pongracz, 1983), and fewer still to have indirect effects on scion hardi- (SO4) (V. riparia x V. berlandieri)] were planted into a randomized (Reynolds and Wardle, 1995) have ness that are mediated by and through complete block experiment in 1985. been conducted in the absence of con- vine vigor. Hence a vigorous vine (e.g., Data were collected on yield compo- founding biotic factors. one grafted to 5BB) may have a higher nents, weight of cane prunings (vine In order of importance, rootstocks percentage of shootless nodes follow- size), and fruit composition between are selected based upon seven major ing a cold winter than a smaller, 1989 and 1996. Yield per vine, criteria: 1) phylloxera resistance; 2) ungrafted vine. Striegler and Howell clusters per vine, cluster weight, and nematode resistance; 3) adaptability (1991), however, found that hardi- berry weight were not affected by to high pH soils (lime); 4) adaptability ness of ‘Seyval blanc’ vines was sub- rootstock, but SO4 tended to produce to saline soils; 5) adaptability to low stantially improved through grafting lowest berries per cluster. Lowest vine pH soils; 6) adaptability to wet or onto its own roots, and increased fur- size was associated with 5BB and own-rooted vines were usually largest; poorly drained soils; and 7) adaptabil- ther when 3309 rootstock was used. 5BB was also associated with highest ity to drought. In areas such as the Also, rootstocks such as ‘Millardet et crop load (yield to vine size ratio). Pacific northwest, there are little or no de Grasset 101-14’ (101-14) allegedly Own-rooted vines tended to produce biotic problems with which to con- have shorter vegetative cycles than berries with lowest percentage soluble tend. Moreover, most of the soils be- some other rootstocks (Pongracz, solids (%SS) while 5BB led to highest ing used for viticulture are well-drained, 1983). This could theoretically allow %SS. Titratable acidity was not coarse-textured, and free of major more degree-days between veraison strongly affected and pH differences physical and chemical problems such and harvest and allow late-season cul- between rootstocks were very small. as salinity, waterlogging, and extremes tivars to mature more thoroughly. As These data suggest that rootstocks in pH. Therefore, the question of with winter hardiness, this apparently may not provide significant advantage over own-rooted vines under condi- whether rootstocks should be used is anecdotal response needs to be tested tions found in the arid regions of the frequently posed. with vines of similar sizes; small vines Pacific northwestern U.S. and British Use of rootstocks in nonphyl- on 101-14 will obviously mature their Columbia. loxerated areas may be justified if a fruit faster than large vines on 5BB or specific rootstock can improve vine SO4. performance and winegrape quality by At the time that this trial was 1) lowering vine size due to minor initiated, there was no rootstock re- water stress; 2) controlling uptake of search in the Pacific northwest. More- Agriculture and Agri-Food Canada Research Centre, specific nutrients; 3) improving winter over, only three or four grape root- Summerland, British Columbia, Canada V0H 1Z0. hardiness independent of vine size ef- stocks were readily available to Cana- The cost of publishing this paper was defrayed in part fect; and 4) shorten the vegetative dian nurseries and growers. It was by the payment of page charges. Under postal regula- tions, this paper therefore must be hereby marked cycle to allow more veraison-to-har- hypothesized that despite the intended advertisement solely to indicate this fact. vest heat units. growing conditions (no phylloxera; ● July–September 2001 11(3) 419 ResRpts.2 419 5/30/01, 1:03 PM RESEARCH REPORTS Table 1. Effect of use versus nonuse of rootstock on vine performance and fruit composition of nine grape scion cultivars, Summerland, B.C., 1989–96. Variable Own-rooted Graftedz Significance Interactiony Yield (t·ha–1)x 16.7 16.0 NS ** Clusters/vine 71 69 NS * Cluster weight (g)x 138 139 NS *** Berries/cluster 85 85 NS *** Berry weight (g)x 1.63 1.62 NS NS Soluble solids (%) 21.7 22.4 *** *** Titratable acidity (g·L –1)x 11.8 12.1 *** *** pH 3.36 3.33 *** *** Weight of cane prunings (kg/vine)x 1.31 1.26 ns *** Crop load (kg yield/kg cane prunings)x 10.7 10.7 ns ** zBased on means of Couderc 3309, Kober 5BB, Teleki 5C, and Selektion Oppenheim 4 rootstocks across all scion cultivars. yRepresents interactions between scion cultivar and use/nonuse of rootstock. xMetric conversions: 1 t·ha–1= 0.45 tons/acre; 28.4 g= 1.0 oz; 1.0 g·L–1= 0.13 oz/gal; 1.00 kg= 2.2 lb. NS,*,**,***Nonsignificant or significant at P ≤ 0.5, 0.01, or 0.001, respectively. low nematode populations; virus-free cultivars that are well-known to be (1983) and was subsequently used to vines; soil pH 6.5, no visible nutrient phylloxera-resistant. determine titratable acidity (TA) with deficiencies or toxicities; deep, coarse- Soil was a Osoyoos gravelly sandy the aid of a Brinkmann automatic ti- textured soil; irrigation), rootstocks loam with a field capacity of 15% soil trating ensemble (Metrohm, Herisau, might nonetheless have significant water (Kelley and Spilsbury, 1949). Switzerland). The remainder of each impact upon yield components or fruit Irrigation was provided by drip emit- sample was juiced, and soluble solids composition through any of the afore- ters that delivered 16 L (4.2 gal) of and pH were measured thereon by a mentioned mechanisms. water per vine per day until veraison, temperature-compensated Abbé re- and 8 L (2.1 gal) per day thereafter. fractometer (AO Scientific, Buffalo, Materials and methods Pest control practices were consistent N.Y.) and Fisher Accumet 825MP pH EXPERIMENTAL DESIGN AND PLANT with those recommended (British meter (Fisher Scientific, Vancouver, MATERIAL. Nine scion cultivars Columbia Ministry of Agriculture and B.C.), respectively. (’Chardonnay’, ‘Gewurztraminer’, Fisheries, 1996). The vineyard was STATISTICAL ANALYSIS. All data were ‘Ortega’, ‘Riesling’, ‘De Chaunac’, fertilized annually at budburst with 85 analyzed using the SAS statistical pack- ‘Marechal Foch’, ‘Okanagan Riesling’, kg·ha–1 (75.8 lb/acre) ammonium ni- age (SAS Institute, Cary, N.C.). The ‘Seyval blanc’, and ‘Verdelet’), own trate (34N–0P–0K). Vineyard floor General Linear Models Procedure was rooted or grafted to four rootstocks management consisted of clean culti- utilized for analysis of variance. Single (‘Couderc 3309’, ‘Kober 5BB’, ‘Teleki vation until veraison, followed by a degree-of-freedom contrasts were used 5C’, ‘Selektion Oppenheim 4’) were natural weed cover that was retained to ascertain species-based differences planted at the Agriculture and Agri- until budbreak the following spring. between the rootstocks. Food Research Center, Summerland, Vines were trained to bilateral cordons B.C. in 1985. Scion and rootstock at a height of 1.7 m (66 inches), spaced Results and discussion wood for all cultivars was collected the 3.0 m between rows and 1.8 m in row GENERAL TRENDS. Data were first previous season (1984) from the Re- (10 × 6 ft), and pruned to 20 nodes/ analyzed by combining 8 years of data search Center cultivar collection and m (6 shoots/ft) of row in the form of from the nine cultivars and five root local vineyards. All own-rooted vines two-node spurs.