New for table

Matthew Fidelibus UC Davis and Jennifer Hashim-Maquire Formerly UCCE Viticulture Advisor Outline

• Potential benefits • General characteristics of common rootstock parent species and hybrid groups • Site factors that influence selection • Value of testing programs; university or on- farm trials • Review of selection programs and some sample data

Potential rootstock benefits

• Resistance to and nematodes • Influence vine mineral nutrition and salt tolerance • Influence scion capacity and vigor • Influence vine yield, fruit quality, and maturation rate • Tolerance to water deficit

Plant parasitic nematodes in CA

• Root knot (Meloidogyne spp.) – Adults females are sedentary, feeding & developing within roots – Penetration and development causes large galls – May reduce yield by 25% parasitic nematodes in CA

• Dagger (Xiphinema index & X. americanum) – Live outside the root & uses its long stylet to penetrate & feed on roots – Feeding by X. index may cause direct damage to root tips, including galls and hooks – X. americanum vectors tomato ringspot (yellow vein) virus and X. index vectors grapevine fanleaf

Plant parasitic nematodes in CA

• Citrus (Tylenchulus semipenetrans) • Ring (Mesocriconema xenoplax) • Lesion (Pratylenchus vulnus)

Characteristics of some rootstock species and hybrids • Original purpose of rootstocks was to overcome phylloxera • riparia & Vitis rupestris resistant to phylloxera, root well from dormant cuttings, & graft well with V. vinifera scions • does better on calcareous soils, but roots poorly, so it was crossed with V. riparia and V. rupestris

• High phylloxera resistance • Easy to propagate and grafts well • Riparian origin and low drought resistance, moderate salt tolerance • Shallow roots, low vigor, early fruit maturity • Low root knot nematode resistance; moderate resistance to dagger nematode • Riparia Gloire a selection of V. riparia

Vitis rupestris

• Deep roots can help protect against drought, but not on shallow soils • High phylloxera resistance but low nematode resistance • Easy to propagate and grafts well • St. George is a selection of V. rupestris Vitis berlandieri

• Variable phylloxera resistance • Good lime tolerance • Deep rooting provides some drought tolerance • Very difficult to root from hardwood cuttings, so no V. berlandieri selections are used as rootstocks, but V. berlandieri is important as a rootstock parent V. riparia x V. rupestris hybrids

• Easy to root and graft • High phylloxera resistance • Low to moderate vigor • Early fruit maturity • Low drought tolerance (better than V. riparia) • Not adapted to calcareous or high pH soils • Includes 101-14, Schwarzmann, 3309 C, 3306C V. berlandieri x V. riparia hybrids

• High phylloxera resistance • Moderate vigor • Moderately sensitive to drought • Includes Teleki 5C, Kober 5BB, SO4, 420A V. berlandieri x V. rupestris

• High phylloxera resistance • Moderate to high scion vigor • Adapted to deep, well-drained soils • Good drought and salt tolerance • Moderate to high nematode tolerance • Includes 1103 P, 140 Ruggeri, 110 Richter, 99 Richter

Vitis candicans / mustangensis

• Resistant to phylloxera and nematodes • Difficult to propagate Vitis x. champinii

• Natural hybrid of V. candicans x V. rupestris • Moderate phylloxera & dagger nematode resistance, high root knot nematode resist. • Deep roots, high vigor, high drought & salt tolerance • Dog Ridge & Ramsey are V. champinii selections; Freedom, Harmony, RS3, RS9, & RSD-34 are complex hybrids with V. champinii parentage

Vitis rufotomentosa

• Part of V. aestivalis species complex • Broadly distributed in eastern US • Used to introduce another source of nematode resistance • Parent in GRN 2, 3, and 4 Site factors that influence selection

• Presence of absence of particular pests • Soil depth, texture, and chemistry • Availability of water and water quality • Potential scion vigor • Difficult to make perfect choice; avoid making the worst choice • Try to use local observations or data to guide decisions

California rootstock evaluation efforts • Raisin trial in Fresno • grape trials throughout the state • Table grape trials in Ducor, Goshen, and Traver • Hundreds of yet untested rootstock selections from USDA and UC Davis breeding programs

Which rootstocks are being tested? ‘Autumn King’, Ducor, California

Rootstock Origin Parentage ‘Autumn King’ USDA, Fresno V. vinifera Freedom USDA, Fresno V champinii x 1613C Harmony USDA, Fresno V. champinii x 1613C Teleki 5C Hungary V. berlandieri x V. riparia Salt Creek (Ramsey) V. candicans x. V. rupestris 1103-P Sicily, Italy V. berlandieri x V. rupestris ‘Crimson Seedless’ USDA, Fresno V. vinifera USDA 10-17 A USDA, Fresno V. simpsoni x Edna ((V. lincecumii x V. rupestris) x V. vinifera) RS-3 UC KAC, Parlier (V. candicans x V. rupestris) x (V. riparia x V. rupestris) RSD-34 UC KAC, Parlier ((V. candicans x V. rupestris) x (V. riparia x V. rupestris)) x V. doaniana GRN1 UC Davis V. rupestris x M. rotundifolia hybrid GRN2 UC Davis (V. rufotomentosa x (V. champinii Dog Ridge x Riparia Gloire)) x Riparia Gloire GRN3 UC Davis (V. rufotomentosa x (V. champinii Dog Ridge x Riparia Gloire)) x V. champinii c9038 (probably V. candicans x V. monticola) GRN4 UC Davis (V. rufotomentosa x (V. champinii Dog Ridge x Riparia Gloire)) x V. champinii c9038 (probably V. candicans x V. monticola) GRN-5 UC Davis (V. champinii Ramsey x Riparia Gloire) x V. champinii c9021 (probably V. candicans x V. berlandieri) ‘Autumn King’, Traver, California

Rootstock Origin Parentage ‘Autumn King’ USDA, Fresno V. vinifera Freedom USDA, Fresno V champinii x 1613C Harmony USDA, Fresno V champinii x 1613C Salt Creek Texas V. candicans x. V. rupestris (Ramsey) Teleki 5C Hungary V. berlandieri x V. riparia RS-3 KAC, Parlier (V. candicans x V. rupestris) x (V. riparia x V. rupestris) RS-9 KAC, Parlier (V. candicans x V. rupestris) x (V. riparia x V. rupestris) USDA 10-17A USDA, Fresno V. simpsonii x Edna ((V. lincecumii x V. rupestris) x V. vinifera)) RSD-34 KAC, Parlier ((V. candicans x V. rupestris) x (V. riparia x V. rupestris)) x V. doaniana ‘Scarlet Royal’, Goshen, California

Rootstock Origin Parentage ‘Scarlet Royal’ USDA, V. vinifera Fresno Freedom USDA, V champinii x 1613C Fresno 1103-P Sicily, Italy V. berlandieri x V. rupestris Kober 5BB Austria V. berlandieri x V. riparia Teleki 5C Hungary V. berlandieri x V. riparia RS-3 KAC, Parlier (V. candicans x V. rupestris)x(V. riparia x V. rupestris) RS-9 KAC, Parlier (V. candicans x V. rupestris) x (V. riparia x V. rupestris) USDA 10-23B USDA, V. doaniana Fresno 10-17A USDA, V. simpsoni x Edna ((V. lincecumii x V. rupestris) x Fresno V. vinifera)) RSD-34 KAC, Parlier ((V. candicans x V. rupestris) x (V. riparia x V. rupestris)) x V. doaniana

‘Autumn King’, Ducor, 2013

P K Ca Mg NO3-N (total) (total) (total) (total) Rootstock (%) (%) (%) (%) (ppm) 10-17A 0.106 cd 2.25 bc 2.13 ab 0.456 cde 987 cbd 1103 P 0.114 bcd 1.83 cd 1.73 ef 0.569 b 921 bcd ‘Crimson’ 0.122 bcd 2.12 bcd 1.81 de 0.51 bcd 738 cd Freedom 0.124 bcd 2.83 a 1.89 cde 0.694 a 1724 a GRN1 0.176 a 2.09 bcd 1.95 bcd 0.55 b 1644 a GRN2 0.128 bcd 2.48 ab 2.19 a 0.41 e 1196 b GRN3 0.152 ab 2.69 a 2.06 abc 0.52 bc 913 bcd GRN4 0.110 bcd 2.71 a 2.07 abc 0.44 cde 1051 bc Harmony 0.104 c 2.12 bcd 1.59 f 0.42 de 603 d Own-rooted 0.138 abc 1.89 cd 1.82 de 0.53 bc 767 cd RS3 0.138 abc 2.69 a 2.06 abc 0.564 b 850 bcd RSD34 0.0875 d 2.10 bcd 2.07 abc 0.512 bc 617 d Salt Creek 0.124 bcd 2.02 cd 1.78 de 0.41 e 1055 bc Teleki 5C 0.116 bcd 1.83 cd 1.92 cde 0.45 cde 596 d ‘Autumn King’, Ducor, 2013

B Zn Mn Fe Cu Na Cl (total) (total) (total) (total) (total) (total) (IC) Cultivar (ppm) (ppm) (ppm) (ppm) (ppm) (ppm) (%) 10-17A 86.4 ab 25.6 cde 96 bc 89 8.2 a 0.02 f 0.30 a 1103 P 80.0 b 24.2 cdef 136 ab 86 5.6 defg 0.02 f 0.10 d ‘Crimson’ 79.8 b 35.2 a 157 a 84 6.8 bc 0.11 a 0.35 a Freedom 87.2 ab 23.8 cdef 123 abc 75 4.4 hi 0.08 b 0.20 b GRN1 78.6 b 30.6 abcd 159 a 57 5.8 def 0.04 d 0.10 d GRN2 92.0 ab 19.2 ef 125 abc 85 5.4 defg 0.03 de 0.20 b GRN3 83.4 ab 26.0 bcde 104 bc 80 5.6 defg 0.02 ef 0.12 cd GRN4 90.8 ab 16.6 f 130 abc 63 4.2 i 0.02 ef 0.12 cd Harmony 86.8 ab 31.0 abc 100 bc 92 4.8 ghi 0.05 c 0.12 cd Own-rooted 98.2 a 33.4 ab 166 a 80 7.0 b 0.08 b 0.30 a RS3 89.4 ab 24.4 cdef 123 abc 61 6.0 cde 0.06 c 0.10 d RSD34 80.0 b 22.7 def 104 bc 76 5.2 defgh 0.08 b 0.18 bc Salt Creek 89.6 ab 31.2 abc 84 c 81 6.2 bcd 0.02 ef 0.10 d Teleki 5C 99.2 a 23.2 cdef 128 abc 89 5.0 fgh 0.03 def 0.10 d ‘Autumn King’, Ducor, 2013

Berry weight Brix pH TA Cultivar (g) (%) (%) (g/100 ml) 10-17A 6.0 abcd 15.3 e 3.90 cd 0.293 bcd 1103 P 6.6 ab 16.9 bcd 3.94 c 0.307 abc ‘Crimson’ 5.6 cde 16.4 d 3.91 cd 0.290 bcd Freedom 5.6 cde 16.7 bcd 4.01 ab 0.296 bcd GRN1 5.4 de 16.4 d 3.93 c 0.308 abc GRN2 5.9 abcde 16.5 cd 3.96 abc 0.330 a GRN3 6.3 abc 16.7 bcd 3.96 abc 0.290 bcd GRN4 6.1 abcd 16.9 bcd 3.95 bc 0.299 bcd Harmony 5.8 bcde 17.5 abc 4.02 a 0.274 d Own-rooted 5.1 e 16.6 cd 3.84 d 0.289 bcd RS3 5.9 abcde 16.9 bcd 3.96 abc 0.308 abc RSD34 5.4 de 18.1 a 3.93 c 0.283 cd Salt Creek 6.8 a 16.4 d 3.95 bc 0.283 cd Teleki 5C 5.5 cde 17.6 ab 3.95 bc 0.311 ab ‘Autumn King’, Ducor, 2013

First Cull Second Cull Total harvest Cull harvest wt/vine harvest wt/vine wt/vine Packed Packed wt/vine wt/vine Cultivar (kg) (kg) (kg) (kg) (kg) 10-17A 23.06 abc 7.85 ab 9.5 3.8 32.6 abcde 11.7 1103 P 31.24 a 4.2 b 16.1 6.6 47.3 a 10.8 ‘Crimson’ 27.47 ab 5.5 b 8.0 2.6 35.4 abcd 8.1 Freedom 24.18 abc 7.1 b 7.0 2.4 31.2 bcde 9.5 GRN1 12.19 bc 5.9 b 8.8 3.9 21.0 de 9.8 GRN2 14.99 bc 4.6 b 7.5 3.4 22.5 cde 7.9 GRN3 31.58 a 7.8 ab 12.9 4.5 44.1 ab 11.5 GRN4 23.88 abc 6.2 b 7.4 3.6 31.3 bcde 9.8 Harmony 23.72 abc 7.5 ab 6.3 3.2 30.0 bcde 10.8 Own-rooted 9.71 c 2.6 b 8.0 2.9 17.7 e 5.5 RS3 18.95 abc 5.3 b 16.4 6.6 37.5 abc 12.5 RSD34 14.17 bc 7.5 ab 2.6 0.9 16.8 e 12.5 Salt Creek 34.27 a 12.5 a 8.9 2.9 43.1 ab 8.3 Teleki 5C 19.72 abc 4.6 b 12.3 3.4 30.9 bcde 8.2

‘Scarlet Royal’, Goshen

N K S Ca Mg NO3-N (total) P (total) (total) (total) (total) (total) (total) Cultivar (%) (%) (%) (ppm) (%) (%) (ppm) RS-3 0.86 bc 0.293 bcd 3.24 bc 1393 c 1.62 e 0.605 a 228 cd RS-9 0.85 bc 0.291 bcd 2.81 d 2144 a 1.77 d 0.584 a 186 cd Freedom 0.90 b 0.282 bcd 3.70 a 1249 c 2.09 c 0.584 a 503 a Own Root 0.85 bc 0.289 bcd 3.51 ab 1356 c 1.87 d 0.418 b 226 cd Teleki 5C 0.77 c 0.347 b 3.16 bcd 1339 c 2.30 b 0.387 b 96 d Kober 5BB 0.89 b 0.407 a 3.43 ab 1356 c 2.36 b 0.436 b 312 bc 10-17A 0.80 bc 0.244 d 3.01 cd 2077 a 2.65 a 0.431 b 125 d 1103-P 0.81 bc 0.435 a 3.27 bc 1311 c 2.28 b 0.611 a 229 cd 10-23B 0.88 b 0.251 cd 3.31 bc 1668 b 2.24 b 0.319 c 295 c RSD-34 1.11 a 0.313 bc 3.18 bcd 1727 b 1.49 e 0.409 b 447 ab

Significance <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 ‘Scarlet Royal’, Goshen

B Zn Mn Fe Cu Na Cl Pruning (total) (total) (total) (total) (total) (total) (IC) weight/vine Cultivar (ppm) (ppm) (ppm) (ppm) (ppm) (ppm) (%) (kg) RS-3 36.7 d 33.7 b 39.0 c 31.9 7.9 c 288 b 0.26 c 2.93 c RS-9 45.2 a 33.5 b 25.9 d 32.6 7.6 c 133 c 0.12 d 3.53 bc Freedom 46.3 a 24.8 de 49.2 bc 30.2 6.0 g 137 c 0.30 c 4.84 a Own Root 38.0 cd 38.3 a 45.2 bc 31.2 8.7 b 1245 a 0.80 a 4.00 abc Teleki 5C 41.8 b 26.4 d 38.3 c 31.1 6.2 fg 109 c 0.07 d 3.65 bc Kober 5BB 39.5 bc 33.5 b 62.8 a 32.4 6.8 def 113 c 0.08 d 4.16 ab 10-17A 40.8 b 27.6 cd 23.3 d 29.3 9.4 a 120 c 0.48 b 3.42 bc 1103-P 47.0 a 30.7 bc 65.0 a 33.1 7.5 cd 135 c 0.07 d 3.68 bc 10-23B 39.8 bc 14.4 f 46.4 bc 32.0 6.7ef 166 c 0.03 d 3.21 bc RSD-34 37.6 cd 22.5 e 52.5 b 31.2 7.4 cde 128 c 0.09 d 3.45 bc

Significance <0.01 <0.01 <0.01 0.12 <0.01 <0.01 <0.01 0.03 ‘Scarlet Royal’, Goshen, 2012

First harvest First harvest Second harvest Second harvest Total packed cull wt/vine packed wt/vine cull wt/vine packed wt/vine Total cull wt wt Cultivar (kg) (kg) (kg) (kg) (kg) (kg) RS-3 1.41 13.04 ab 10.87 ab 15.73 12.28 54.86 RS-9 1.59 12.99 ab 6.12 b 13.25 7.71 52.21 Freedom 1.77 21.01 a 5.16 b 12.19 6.93 75.23 Own Root 2.57 17.65 ab 5.14 b 14.78 7.71 67.74 Teleki 5C 2.15 23.70 a 5.91 b 10.30 8.06 81.40 Kober 5BB 2.26 16.25 ab 8.94 ab 9.66 11.20 58.41 10-17A 1.61 14.87 ab 5.92 b 12.81 7.53 57.43 1103-P 2.48 23.82 a 4.75 b 10.29 7.23 81.76 10-23B 2.40 22.29 a 7.21 b 16.44 9.61 83.30 RSD-34 1.37 9.82 b 13.19 a 20.33 14.56 49.79

Significance 0.10 0.05 0.04 0.50 0.08 0.07 ‘Scarlet Royal’, Goshen

Berry weight Brix Berry length Berry width pH TA Cultivar (g) (%) (%) (g/100 ml) (cm) (cm) Teleki 5C 9.2 abc 16.3 abc 3.34 bc 0.974 abc 3.1 2.2 Kober 5BB 9.6 a 15.6 c 3.34 bc 1.01 ab 3.2 2.3 1103-P 9.7 a 16.2 abc 3.35 abc 0.970 abc 3.1 2.3 Freedom 9.4 ab 16.6 a 3.36 ab 0.960 abcd 3.1 2.3 RS-3 9.6 a 15.7 bc 3.33 bc 0.943 abcd 3.1 2.3 RS-9 9.5 a 15.9 abc 3.34 bc 0.911 bcd 3.1 2.3 RSD-34 8.3 d 15.5 c 3.31 c 1.03 a 3.1 2.3 10-23B 8.7 cd 16.4 ab 3.39 a 0.866 d 3 2.2 10-17A 8.9 bcd 16.0 abc 3.39 a 0.870 cd 3.1 2.2 Own Root 9.5 a 15.8 abc 3.36 ab 0.981 ab 3.1 2.3

Significance <0.01 0.05 <0.01 <0.01 0.4 0.5 General Preliminary Test Results

• Rootstocks strongly influence petiole mineral nutrient content • Freedom usually increases N • RS-3, Freedom, GRN-4 increase K • Own-rooted vines increase Zn • Most stocks except 10-17A (which has V. vinifera parentage) decrease Cl & Na compared to own-root General Preliminary Test Results

• Low pest pressure so far • Inconsistent effects on yield and fruit quality; effects might increase as pest pressure increases Still looking for better stocks

Acknowledgements

• California Table Grape Commission • Grower Cooperators • Don Luvisi, Peter Cousins, M. Andrew Walker, Allison Ferry-Abee, Ashraf El Kereamy