Evaluation of grapevine propagation protocols against trunk diseases through a European nursery survey

Evaluation of grapevine propagation protocols against trunk diseases through a European nursery survey David Gramaje and Stefano Di Marco COST Action FA1303 Sustainable control of grapevine trunk diseases

1. Management of grapevine mother fields 2. Nursery operations 3. Field nursery management

Country Ques,onnaries sent to nurseries Replies received Response rate (%) Total number of nurseries Algeria 6 3 50.0 7 Bulgaria 15 10 66.7 22 Croa5a 13 12 15.4 15 Czech Rep. 3 3 100 15 France 200 13 6.5 400 Germany 7 5 71.4 100 Greece 5 2 40 12 Hungary 73 36 49.3 250 Israel 6 2 33.3 10 Italy 90 16 17.7 120 Portugal 19 6 31.6 116 Romania 4 4 100 15 Slovenia 15 5 33.3 29 Spain 170 32 18.8 380 Switzerland 40 7 17.5 - TOTAL 666 146 21.9 1491

Part 1: Management of grapevine mother fields 1.1 How often do you replace rootstock mother plants? 22.1% Less than 15 years 15-25 years More than 25 years 47.8% Not sure 1.2 How often do you replace scion mother plants? 26.4% Less than 15 years 15-25 years More than 25 years 47.8% Not sure

Part 1: Management of grapevine mother fields 1.3 How long are cuttings in transit before they arrive at the nursery from the mother fields? Not sure More than 24 hours 10.7% (15 nurseries) 12-24 hours 8-12 hours 4-8 hours Less than 4 hours 53.6% 0 10 20 30 40 50 60

Part 1: Management of grapevine mother fields 1.4 Which irrigation system do you currently use? 56.4% Drip irriga5on Overhead sprinklers 20.0% No irriga5on 1.5 Which trellising method do you currently use? 20.0% Sprawled on the ground Trellis 63.5% Both

Part 1: Management of grapevine mother fields 1.6, 1.7 Do you usually protect pruning wounds with chemicals or biocontrol agents? 100 90 80 70 60 50 40 30 20 10 0 92.8% 62.9% Yes No Yes No Chemicals Biocontrol agents

Part 1: Management of grapevine mother fields 1.8 Do you use any product to disinfest pruning tools regularly? 52.1% Yes No 1.9 Do you eliminate the pruning debris from the mother field? 72.1% Yes No 80.6% burn the pruning material 19.4% compost pruning waste

Part 2: Nursery operations 2.1 Hydration of rootstock cuttings: Before cold storage Before grafting 50.7% 52.1% 15.0% 15.7% Not at all Less than 1 hour 1-2 hours 2-8 hours 8-12 hours 12-24 hours More than 24 h Not at all Less than 1 hour 1-2 hours 2-8 hours 8-12 hours 12-24 hours More than 24 h

Part 2: Nursery operations 2.2 Hydration of scion cuttings: Before cold storage Before grafting 50.7% Not at all Less than 1 hour 1-2 hours 2-8 hours 8-12 hours 12-24 hours More than 24 h 28.5% 25.7% 10.0% Not at all Less than 1 hour 1-2 hours 2-8 hours 8-12 hours 12-24 hours More than 24 h

Part 2: Nursery operations 2.3, 2.4, 2.5 Cleaning Hydration tanks 24.2% 14.2% 42.8% Frequently during the season Occasionally End of the season Start of the season Never Cool storage room/s 35.0% 20.7% Frequently during the season Occasionally End of the season Start of the season 27.8% 78.5% Bins, boxes or crates before use in cold storage Yes No

Part 2: Nursery operations 2.6 How long is material stored in cool room? Rootstock cuttings More than 6 months 4-6 months 1-3 months Less than 1 month Not stored in cold rooms 65.7% 0 10 20 30 40 50 60 70 Scion cuttings More than 6 months 4-6 months 1-3 months Less than 1 month Not stored in cold rooms 0 10 20 30 40 50 60 70 65.7% 1-year old vines More than 6 months 4-6 months 1-3 months Less than 1 month Not stored in cold rooms 32.8% 39.2% 0 5 10 15 20 25 30 35 40 45

Part 2: Nursery operations 2.7, 2.8 - Do you use fungicides/bca in any of these circumstances? Dip 1- y- old before despatch Dip 1- y- old vines before storage Dipping cuzngs a[ gra[ing Dipping cuzngs before storage Callusing boxes Hydra5on tanks Yes No Dip 1- y- old before despatch Dip 1- y- old vines before storage Dipping cuzngs a[ gra[ing Dipping cuzngs before storage Callusing boxes Hydra5on tanks 0 10 20 30 40 50 60 70 80 90 100 Fungicides Chinosol (8-hydroxyquinoline sulphate) Thiophanate methyl Captan Mancozeb Thiram BCA Trichoderma sp. Bacillus sp. Glomus intraradices Organic algae 0 10 20 30 40 50 60 70 80 90 100

Part 2: Nursery operations 2.12 Have you heard about hot-water treatment (HWT) to control pests and diseases in the grapevine propagation process? 85.7% Yes No 2.13 Do you currently use, or have you used, HWT? 71.4% Both (17.5%) 40 n At the end of the propagation (17.5%) Before grafting (47.5%) Yes No

Part 2: Nursery operations Reasons for not using HWTs:! The reliability and efficacy: significant losses are still being attributed to HWT! It is an ineffective treatment for eliminating trunk disease pathogens! The logistic involved in these treatments are too difficult! The lack of studies in commercial batches are barriers to adoption of HWT

Part 2: Nursery operations 2.14 Do you use any product to disinfest pruning tools or grafting machines regularly? 57.1% Yes No 2.15 Which bench grafting method do you use? 95.0% Omega Whip Other

Part 2: Nursery operations 2.16 How long do you leave grafted plants in the callusing room? 40.7% Less than 15 days 15-20 days More than 20 days 2.17 Mean temperature for callusing and rooting? 45.0% Less than 25ºC 25-28ºC More than 28ºC

Part 2: Nursery operations 2.18 Which substrate do you use for the callusing stage? 60 53.6% 50 % of nurseries 40 30 20 10 12.1% 12.1% 11.4% 5.7% 5.0% 0 Sawdust Peat Perlite Other Vermiculite Water Substrate

Part 2: Nursery operations 2.19 Do you plant grafted vines in pots for growing in the greenhouse as an alternative of nursery field rooting? 71.4% Quality of planting material 40 n 11 n 12 n Not sure Has no effect Decreases Increases Yes No

Part 3: Field nursery management 3.1 Have you ever grafted vines in the field? 25.0% Yes No If so, do you think that the method of grafting plants in the field improves the phytosanitary quality of the vine? 57.1% Yes No

Part 3: Field nursery management 3.2 Do you use any herbicide to control weeds in the nursery field? 57.1% Yes No 3.3 Do you apply any treatment against pests and diseases other than GTDs? Yes No 82.1%

Part 3: Field nursery management 3.4 Do you have any comments you would like to make? 20.7% of respondents (29 nurseries)! 13 commented about the lack of knowledge and training about the principles and methods to improve the phytosanitary quality of grapevine planting material, especially in West- European countries.! 10 respondents requested more research into control methods such as hot-water treatment, ozonation, chemicals or rootstock in vitro production.! Others missed some information such as the amount of plants produced per year or the number of different scion/ rootstock combinations they usually offer to the grower.

European Nursery Survey Conclusions " Practices likely to have an impact on grapevine trunk disease infections: i) Pruning wound protection in mother blocks is uncommon and can increase shoot infection by trunk pathogens before cuttings enter the propagation process in nurseries ii) Nurserymen do not regularly disinfest pruning tools in both mother blocks and during the propagation process, leading to possible vine to vine contamination by GTD pathogens iii)planting material is soaked for very extended periods of time after cold storage which can severely compromise sanitation by providing multiple opportunities for microorganisms from the tissue and bark of infected cuttings to contaminate the hydration water and from there, infect propagation wounds on uninfected cuttings

European Nursery Survey Conclusions " Practices likely to have an impact on grapevine trunk disease infections: iv) One-year-old vines are usually stored for very extended periods of time which can result in fatal tissue damage v) Grafted plants are left in callusing boxes for long periods of time at high temperatures which can have fatal consequences for the cuttings

European Nursery Survey " GRAFTING: Conclusions Could the advent of mechanisation in grafting have resulted in poor quality vines that are almost always infected with GTD pathogens? Mourvèdre cultivar directly onto rootstocks in the field = 0.51% Neighbouring plot planted with omega bench grafted vines = 12% dead plants and 24% with esca The average level of expression of esca among several susceptible varieties was ten times greater on the omega grafts (8.80%) than on manual grafts (0.64%) Birebent (2015), Conférence La Vigne au 2ème siècle

European Nursery Survey " MANAGEMENT: Conclusions The consistent use of fungicides questions their efficacy Are fungal trunk pathogens developing resistance to fungicides? Inadequate timing of application? The adoption and use of Biocontrol Agents is still limited Reliability and efficacy of HWT continues to be questioned There is clear need for further research into the effects of treatments on grapevine viability, such as HWT, and the potential of BCA and other newly developed strategies such as ozonation to control GTDs in nurseries.

European Nursery Survey Aknowledgements Z. Bihari, A. Kun and N. Rakonczas (Hungary) P. Larignon, L. Audeguin and O. Zekri (France) M. Fischer and J. Eder (Germany) J. Armengol, J. Reyes, T. Sánz and N. Gómez (Spain) I. Tsvelkov (Bulgaria) M. Baranek (Czech Republic) D. Rusjan (Slovenia) O. Viret (Switzerland) L. Tomoiaga (Romania) G. Mordenti (Italy) J. Kaliterna (Croatia) A. Berraf (Algeria) S. Tjamos (Greece) D. Ezra (Israel) J. Sofia and C. Rego (Portugal)

Evaluation of grapevine propagation protocols against trunk diseases through a European nursery survey David Gramaje and Stefano Di Marco Thanks for you attention! COST Action FA1303 Sustainable control of grapevine trunk diseases