Rootstocks: The Viticulture Perspective · Michelle M. Moyer Associate Professor Viticulture Extension Specialist WSU-IAREC Prosser, WA wine.wsu.edu Rootstocks: The Viticulture Perspective.

Michelle M. MoyerAssociate Professor

Viticulture Extension SpecialistWSU-IARECProsser, WA

wine.wsu.edu

Rootstocks: The Viticulture Perspective

Washington Winegrowers ConventionNew Pests: Phylloxera and Spotted Lanternfly

4 March 2020

THE GOOD, THE BAD, AND THE UGLY

News travels fast. Bad news travels faster.

Bad news and shocking headlines sell stories.

The 2019 media blitz on phylloxera in Washington spread unnecessary panic to anyone willing to consume it.

Let’s consume information, not click-bait.

ROOTSTOCKS – SOME HISTORY

• If you have read it, you should• A fascinating narrative on the history of

phylloxera and rootstock use in wine grapes

• Thorough coverage of the “panic” that ensured, the “research” that was conducted, and the final adoption of rootstocks across a continent

• Places the situation in WA into perspective One of my favorite non-journal reads on the subject!

ROOTSTOCKS

A quick review.

THE PARENT VINES (NORTH AMERICAN)

V. rupestris: Vigorous, long vegetative cycle. Deep roots. Native to southern and central US.

V. x champinii: Vigorous, drought tolerance, lime tolerance, salt tolerance, deep roots. Native to Texas

V. riparia: Low vegetative vigor. Does not do well in drought. Lateral roots. Native to central and eastern Canada, and central and northeastern US.

V. berlandieri: Vigorous, deep roots. Drought tolerant. Native to southern North America (New Mexico, Texas, Arkansas)

ROOTSTOCKS AND THEIR PARENTAGECross Common Rootstocks Generalized Attributes

V. riparia Riparia Gloire Vigor: Low to moderate.

V. rupestris St. George Vigor: moderate to high.

V. x champinii (Natural cross of V. mustangensis and V. rupestris)

Ramsey, Dog Ridge (parent species for Freedom, Harmony, RS-3, RS-4, Kingfisher, GRN-2, GRN-3, GRN-4)

Nematode resistance. Vigor: High

V. berlandieri x V. riparia 161-49C, Kober 125AA, Kober 5BB, 420A MTG, SO4, Teleki 5C

Vigor: moderate to high.

V. berlandieri x V. rupestris 1103P, 99R, 110R, 140Ru, Soil: drought tolerant, low to moderate depth. Vigor: moderate-high.

V. riparia x V. solonis (V. acerfolia) 1616C Vigor: Low to moderate.

V. riparia X. V. rupestris 3309C, 101-14 MTG, Schwarzman Soil: deep, fertile, moist. Vigor: moderate.

Rootstocks in bold are ones that have been, or are currently, being evaluated in-field by WSU.

ROOTSTOCKS IN WASHINGTON

Results of limited trials. Good news: they agree!

SITE – SPECIFIC ROOTSTOCK EVALUATIONS = DIFFICULT

• Rootstock evaluations en masse will have to be industry-driven

• A university-driven rootstock study takes time:– Pest evaluations – typically 3-4 years (after establishment)– Viticulture evaluations – typically 4-5 years (after establishment)– Resulting wine impacts – typically 6-10 years (after establishment)

• Any university-driven rootstock study will not be able to answer the question “ what is best for my site and scion choice” – too many possible combinations

A FEW UNIVERSITY ROOTSTOCK TRIALS DO EXIST, HOWEVER

• Keller & Harbertson & team• Location: Prosser, WA• Planted: 1999; grafted 2002• Scions: Merlot, Syrah, Chardonnay• Rootstocks: 5C, 99R, 140Ru,

1103P, 3309C, Own-rooted

• Intent:

• Moyer & Zasada & team• Location: Paterson, WA• Planted: 2015• Scions: Chardonnay• Rootstocks: 5C, 1103P, Harmony,

101-14 MTG, Own-rooted

• Intent: Evaluate efficacy against nematode-induced decline.

Viticulture Evaluation Pest Evaluation

WASHINGTON ROOTSTOCK – VITICULTURE EVALUATIONS (1999)

• Field grafted; 99R struggled with long vegetative cycle

• In a non-pest background, own-rooted vines on average had:– Higher pruning weights than

vines on rootstocks– Moderate to higher yield than

vines on rootstocks– Moderate to no difference in

berry weights

WASHINGTON ROOTSTOCK – NEMATODE EVALUATIONS (2015)

• Pest-infested (root-knot nematode) background– All rootstocks support some level of

nematodes– Rate of nematode population increase is

variable across non-vinifera rootstocks

• After 5 years, starting to see significantly higher vigor and yield in rootstocks – because own-rooted is beginning to decline

UNDERSTANDING ROOTSTOCKS AND INTERPRETING ROOTSTOCK CHARTS

Knowing where data is generated is critical.

ROOTSTOCK ROOTING PATTERNSFort et. al., 2017. HortSci. 142:36–46. doi: 10.21273/JASHS03919-16

Figure from: https://mpva.com.au/exfiles/Rootstock_selection.pdf; modified from Guillon, J. M. (1905) Étude générale de la vigne: Historique les vignobles et les crus anatomie et physiologie, sol et climat. Masson, Paris

Soil Depth

(10-20 in)

Matadorvinifera

1103P3309C

Moyer, East, Zasada small-plot trials (2017-2018, WSU) – first year plants

V. berlandieri x V. rupestris V. riparia x. V. berlandieri V. riparia x V. rupestris

1103 P, 140 RU, 110 Ritcher, 99 Ritcher

Teleki 5C, Kober 5BB, SO4, 420A,

101-14 MTG; Schwarzmann, 3309C

V. champinii (Ramsey)

ROOTING PATTERN MATTERS

• Many of the “rootstock” attributes we see in dryland farmed grapes are related to the rootstock rooting pattern

• Irrigation (incl. chemigation, fumigation) will have to consider BOTH soil type and rooting habit

• Shallow-rooted vines– Prone to drought stress (but about with irrigation??)– Does the duration of your set push nutrients past the root-zone?

• Deep-rooted vines – May be prone to vigor on deep soils– May not do well in some of our shallow soils

VIGOR

Cross Common Rootstocks Vigor

V. riparia Riparia Gloire Low to Medium

V. rupestris St. George HighV. x champinii (Natural cross of V. mustangensis and V. rupestris)


High


Low to Medium

V. berlandieri x V. rupestris 1103P, 99R, 110R, 140Ru, Medium to High

V. riparia x V. solonis (V. acerfolia)

1616C Low

V. riparia X. V. rupestris 3309C, 101-14 MTG, Schwarzman Low to Medium

Information modified from: Wine Grapes Varieties in California: Rootstocks. Bettiga et al (ed). http://iv.ucdavis.edu/files/24347.pdf

Consider the stronger influence: Genetics, or available water….

DROUGHT TOLERANCE

Cross Common Rootstocks Drought Tolerance

V. riparia Riparia Gloire Low

V. rupestris St. George Low to ModerateV. x champinii (Natural cross of V. mustangensis and V. rupestris)


Low to Moderate


Low to Moderate

V. berlandieri x V. rupestris 1103P, 99R, 110R, 140Ru, Moderate to High


1616C Low

V. riparia X. V. rupestris 3309C, 101-14 MTG, Schwarzman Low to Moderate


Consider the influence of irrigation strategy, and response to RDI

TOLERANCE TO ACTIVE LIME

• Calcareous soils can often result in Fe-induced chlorosis – and cause issues with update of other nutrients– High CaCO3 – active lime – is often

associated with these higher pH soils– Many grapevine rootstocks are better

adapted to lower soil pH and are often very intolerant of high active lime

• Vitis vinifera is more tolerant of high soil pH and active lime, than most rootstock species

Sulfur (tons/acre) needed to lower soil pH. May take multiple years with multiple additions. Soil Type pH 7.5

to 6.5pH 8.0 to 6.5

pH 8.5 to 6.5

Sandy Soil 0.2 - 0.3 0.5 - 0.7 0.7 - 1.0Clay Soil 0.4 - 0.5 0.7 - 1.0 1.0 - 1.3

High soil pH and high active lime content of soil in eastern WA will be a major factor in the success of different rootstocks.

IMPORTANT FOR EASTERN WA

TOLERANCE TO ACTIVE LIME

Cross Common Rootstocks Active Lime Tolerance

V. riparia Riparia Gloire Low

V. rupestris St. George Medium



Medium


Medium to High

V. berlandieri x V. rupestris 1103P, 99R, 110R, 140Ru, Medium to High


1616C Low to Medium

V. riparia X. V. rupestris 3309C, 101-14 MTG, Schwarzman Low to Medium


IMPORTANT FOR EASTERN WA

“RESISTANCE” RATINGS

• Root pest resistance ratings are challenging to interpret– Many are done over very short

periods of time what are the long-term effects of pest feeding?

– Many are done in pot studies pest feeding in pot studies is usually higher than in nature

– Many are done for pests that may not be in your region More studies come out of California, Texas, or the east coast

Table from: Ferris, H., L. Zheng, and M.A. Walker. 2012. J Nematol 44(4) 377-386.

“RESISTANCE” RATINGSCross Common Rootstocks M. incognita

S. Root-knot NematodeX. indexDagger Nematode

V. Riparia Riparia Gloire Low Medium

V. Rupestris St. George Low


Ramsey, Dog Ridge (parent species for Freedom, Harmony, RS-3, RS-4, Kingfisher, GRN-2, GRN-3, GRN-4)NOTE: These have a range of phylloxera resistance.

Medium to High Low to Medium


Medium to high Low to Medium

V. berlandieri x V. rupestris

1103P, 99R, 110R, 140Ru, Low to high Low


1616C High Medium

V. riparia X. V. rupestris 3309C, 101-14 MTG, Schwarzman Low Low


We do not have M. incognita or X. index in Washington.

Special topic – no resistance, but no phenotype?

ESTABLISHING AND MANAGING GRAFTED VINES

A brave “new” world.

VINEYARD ESTABLISHMENT

• Ordering timeline– Depending on particular rootstock : scion combo and type of planting

material, may take up to 18 months to prepare order– Rushing an order has long-term consequences (graft union success)

• Planting considerations– With own-rooted we got away with later-season plantings – planting in

July or later is NOT a good practice– The graft union is a wound – that effects water movement

• When you use rootstocks, you are playing the long game. Patience will pay off.

COLD DAMAGE MANAGEMENT

• Most rootstocks varieties are very cold hardy• A grafted vine is as cold hardy as its least-hardy part

– The least hardy part is the V. vinifera scion– A graft union isn’t any less cold hardy than the scion – unless it is

compromised (crown gall, poor union healing)• Risk of cold damage stays the same – but what you do to

prepare for cold damage, and how you respond, is different• Retraining is not really an option – but you can regraft• Two scion trunks. Two scion trunks. Two scion trunks.

Myth: Grafted vines are less cold-hardy than own-rooted vines.

SPECIAL TOPIC – VIRUS CHALLENGES

• Rootstock-specific viruses– Grapevine virus A,B,D, and E, and Rupestris stem-pitting associated virus can result in

a variety of rootstock-specific disorders (rupestris stem pitting, LN 33 stem grooving, Kober stem grooving, corky bark)

– V. vinifera can be an asymptomatic host – so WA has typically not really focused on these viruses

– BUT, if infected scions are grafted to susceptible rootstocks, it can become an issue (e.g., non-certified stock)

• “Scion” viruses and graft incompatibility– GLRaV-2 graft incompatibility with 5BB, 5C, 3309C and 1103P– Red Blotch and decline / incompatibility with Freedom

Myth: Using rootstocks increases risk of virus infection.Fact: Rootstocks do not increase risk of virus infection, but severity of response to infection may be high.

ROOTSTOCKS ARE A VALUABLE TOOL

• Fear of the known is a dangerous master

• A future not dependent on own-roots should not be feared

• Rootstocks offer many viticulture advantages we currently do not take advantage of

• Rome wasn’t built in a day, and the transition to rootstocks doesn’t have to be either

[email protected]/extension

www.facebook.com/wsu.vit.enol.ext@WSU_Vit_Ext

VITICULTURE EXTENSION WASHINGTON STATE UNIVERSITY

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QUESTIONS?

Grape Pest Information: http://wine.wsu.edu/extension/grapes-vineyards/grape-pests/

Rootstocks: The Viticulture PerspectiveThe Good, the Bad, and the UglyRootstocks – Some HistoryRootstocksThe Parent Vines (North American)Rootstocks and their parentageRootstocks in WashingtonSite – Specific Rootstock Evaluations = DifficultA few University Rootstock Trials Do exist, HoweverWashington Rootstock – Viticulture Evaluations (1999)Washington Rootstock – Nematode Evaluations (2015)Understanding Rootstocks and �Interpreting Rootstock ChartsRootstock Rooting PatternsRooting Pattern MattersVigor Drought Tolerance Tolerance to Active LimeTolerance to Active Lime“Resistance” Ratings“Resistance” RatingsEstablishing and Managing Grafted VinesVineyard EstablishmentCold Damage ManagementSpecial Topic – Virus ChallengesRootstocks are a valuable toolQuestions?

Rootstocks: The Viticulture Perspective · Michelle M. Moyer Associate Professor Viticulture Extension Specialist WSU-IAREC Prosser, WA wine.wsu.edu Rootstocks: The Viticulture Perspective.

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