Update on Ontario Grape Virus Research Wendy McFadden-Smith OMAFRA CCOVI Research Affiliate CCOVI Lecture Feb 10, 2021 Acknowledgements § With financial support from: 2 Acknowledgments Acknowledgements § Grower cooperators § McFadden-Smith crew § Rachel Hamm, Lexi Kozel, Raquel Schoenberg, Bingyao Guo, Michael MacGillivray, Ashleigh Ahrens, Gord Robert, Irina Perez, Laura Finlay, Ky Tynan, Katrina Kastelic, Cindy Stancovici, Aleyna Bingham-Burns, Jordyn Domio, Daniel Walmsley, Anthony Miller, Justin Freeman, Andreanne Hebert-Hache, Julie Lupia, Zach Anderson, Mallory Walters, Stephanie Van Dyk, Jesse Plante, Ryan Wenham, Caitlin Smith, Amde Mekoya § Poojari crew § Tony Wang, Matteo Lacucci, Minh Vu Abdallah Meknas § Renkema crew § Lori Bittner, Hannah McRae, Lauren Nesbitt § Willwerth crew § Steph Bilek, Alex Gunn Grape Leafroll Symptoms § Starting in late Aug-early Sept at base of shoot and progressing up § Downward curling of the leaf edges § Interveinal reddening or yellowing § Poor fruit maturation 8 Red Blotch Symptoms • Symptoms first appear in late Aug-early Sept • No leaf rolling • Red vinifera • Irregular pink to crimson blotches on blades starting on basal leaves • Secondary and tertiary veins turn red (BUT inconsistent!) • Occasional interveinal red between secondary veins • White vinifera • Yellow margins, progressing to brown crispy margins Red Blotch – Cabernet franc Red blotch symptoms – Cabernet franc Fuchs Red blotch symptoms Cabernet sauvignon Fuchs Pinot noir Red blotch - Pinot noir Symptomatic Asymptomatic Red blotch – early symptoms Chardonnay Cooper Red blotch – advanced symptoms Chardonnay Variable symptoms of Red Blotch C sauv C franc Merlot P noir Syrah 16 Chardonay Chambourcin Variable symptoms of Red Blotch C franc C franc No P noir pNY358 pNY358 virus P gris Chard 110R pNY175ab pNY175ab pNY175ab rupestris pNY175ab 3309C pNY175ab SO4 pNY358 Red Blotch Symptoms 18 https://media.oregonstate.edu/media/t/1_f77n9lay Symptom Expression Varies with Year 19 Effects on Vine Physiology § Reduced photosynthesis and transpiration in leaves § Reduced sugar movement out of leaves § Increased leaf starch (@veraison and post-veraison) § Triggers maturation of leaves § production of anthocyanins in reds, chlorosis in whites § Larger berries – lower concentration of sugar § Secondary metabolism inhibited (e.g. anthocyanins) 20 For an indepth explanation on how GRBV affects vines: 21 https://media.oregonstate.edu/media/t/1_e3e1lu2g/2528412 For an indepth explanation on how GRBV affects vines: § Less CO2 § Photosynthesis decreased § Transpiration reduced 22 https://www.youtube.com/watch?v=DDljPqaGG4Y For an indepth explanation on how GRBV affects vines: § Photosynthesis impacted in green areas of leaves with red symptoms with GRBV § Also in asymptomatic leaves in vines with GRBV 23 https://www.youtube.com/watch?v=DDljPqaGG4Y Vine Vigour, 2018-2019 900 800 700 600 500 400 300 Pruning weight (g) 200 100 0 Chardonnay C franc GRBV + GLRV+ GLRV- GRBV- 24 Vine Vigour, 2019-2020 600 500 400 300 200 Pruning wt. (g) 100 0 Vidal C franc GLRV+GRBV+ GRBV+ GLRV+ GLRV-GRBV- 25 Harvest Parameters, Vidal, 2020 60 50 40 30 20 10 * 0 # clusters Total yield (kg) Brix TA pH GLRV + GRBV GRBV GLRV + GRBV GLRV-GRBV- 26 Harvest Parameters, Cabernet franc, 2020 35 30 25 * 20 15 10 5 0 # clusters total yield (kg) Brix TA pH GRBV + GLRaV+ GLRaV- GRBV- 27 GLRaV-3 and GRBV – Effect on Cold Hardiness Chardonnay (2018-2019) -10 Solo GLRV or GRBV â cold hardiness compared to virus free Jan-Feb GLRV + GRBV â cold hardiness compared to solo infections -15 C) ◦ -20 LTE 50 ( -25 -30 Dec 2018 Jan 2019 Feb 2019 Mar 2019 Apr 2019 GLRV + GRBV+ GLRV+ GRBV+ GLRV- GRBV- 28 GLRaV-3 and GRBV – Effect on Cold Hardiness Chardonnay (2019-2020) -10 Solo GLRV or GRBV â cold hardiness slightly compared to virus free Jan-Feb -12 GLRV + GRBV â cold hardiness compared to solo infections -14 ) C ◦ -16 -18 LTE 50 ( -20 -22 -24 Nov 2019 Dec 2019 Jan 2020 GLRaV- GRBV- GRBV+ GLRaV+ GLRaV+ GRBV+ 29 GLRaV-3 and GRBV – Effect on Cold Hardiness Cabernet franc (2018-2019) -10 GRBV â cold hardiness more than GLRV -12 -14 C) ◦ -16 -18 LTE 50 ( -20 -22 -24 Feb 2019 Mar 2019 8 Apr-19 GLRV + GRBV + GLRV- GRBV- 30 GLRaV-3 and GRBV – Effect on Cold Hardiness Cabernet franc (2019-2020) -10 GRBV â cold hardiness more than GLRV -12 -14 ) C ◦ -16 -18 LTE 50 ( -20 -22 -24 Nov 2019 Dec 2019 Jan 2020 GLRaV- GRBV- GRBV+ GLRaV+ 31 GLRaV-3 and GRBV in Ontario § Questions: § How common GLRD and GRBD? § Effects of infection on cold hardiness? § Effects of co-infections? § Changes in distribution of infection over time? Vectors? Control? 32 GLRV and GRBV % vineyard blocks sampled per year with > 25% incidence 100 90 80 70 60 50 40 30 20 10 0 GRBV GLRV GRBV GLRV GRBV 2016 2018 2019 red vinifera white vinifera Baco Vidal 33 Incidence of GLRaV and GRBV, 2018 & 2019 2018 2019 20% 10% 36% 11% 16% 53% 26% 28% 34 GLRVA+ GRBV+ GRBV+ GLRaV+ GLRaV- GRBV- GLRaV (solo or co-infection with GRBV), 2018 & 2019 2018 2019 35% 40% 60% 65% <25% > 25% +ve 35 +ve GRBV (solo or co-infection) 2018 & 2019 2018 2019 35% 46% 54% 65% <25% > 25% +ve 36 +ve Can we do anything to change the effects of viruses? Crop thinning? Little to no effect Longer hang time? No effect K fertilizer? Little to no effect Irrigation? Variable effect Only with water deficit 37 https://www.researchGate.net/profile/Alexander_Levin4/publication/335843063_Supplemental_Vineyard_Inputs_May_Partially_MitiGate_Ne Gative_Effects_of_Grapevine_Red_Blotch_Disease_in_OreGon_Pinot_noir/links/5d7ffcd9299bf10c1ab2429b/Supplemental-Vineyard- 38 Inputs-May-Partially-Mitigate-NeGative-Effects-of-Grapevine-Red-Blotch-Disease-in-OreGon-Pinot-noir.pdf More info on impact of cultural practices vs GRBV 39 https://media.oregonstate.edu/media/t/1_u29vsfg9 More info on impact of cultural practices vs GRBV 40 https://media.oregonstate.edu/media/t/1_f77n9lay More info on impact of cultural practices vs GRBV 41 https://media.oregonstate.edu/media/t/1_f77n9lay A possible Hormonal Link to GRBD? § Abscisic acid (ABA) § Linked to anthocyanin biosynthesis § Lower concentration in berries from GRBV +ve vines § GRBV may limit capacity of sources and sinks for exchanging reduced carbon and plant hormones simultaneously without shutting down the plant completely 42 ABA to mitigate GRBV effects on Fruit Maturity § 4 vineyards: 2 Cab franc, 1 Riesling, 1 Chard § Vines identified with GRBV only (no GLRV) § ABA (Protone) @ 400 ppm ABA § applied once or twice to full canopy § 50% veraison and 2 weeks later § Fruit harvested at commercial ripeness 43 ABA to mitigate GRBV effects on Yield? 7 GRBV â yield GRBV â yield ABA no effect ABA á yield of GRBV+ve 6 1 app vs 2 apps? 5 4 3 2 1 Mean weight of fruit/vine (kg) 0 Chard Ries C franc 1 C franc 2 GRBV +ve GRBV + ABA1 GRBV + ABA2 GRBV -ve 44 ABA to mitigate GRBV effects on Brix? 25 GRBV â Brix GRBV no effect GRBV â Brix GRBV no effect ABA no effect on Brix ABA no effect on Brix Brix) ◦ 20 15 10 5 Mean soluble solids ( 0 Chard Ries C franc 1 C franc 2 GRBV +ve GRBV + ABA1 GRBV + ABA2 GRBV -ve 45 ABA on Riesling 2020 25 20 15 10 5 0 Total weight (kg) Brix TA pH GRBV+ ABA 1x ABA 2x GRBV- 46 ABA on Chardonnay 2020 50 B 45 40 35 AB 30 AB A 25 20 15 10 B AB A AB 5 0 # clusters Total yield Brix TA pH (kg) GRBV+ ABA 1x ABA 2x GRBV- 47 Mycorrhizae? § 200g BioCult Mycorrhizae in 350L over 0.83 Acres 48 Mycorrhizal Treatment, Chardonnay, 2020 30 25 20 15 10 5 0 Total # clusters Yield (kg) Brix TA pH Untreated GLRV+ BioCult GLRV+ Untreated GLRV- BioCult GLRV- 49 GRLaV and GRBV Transmission • No mechanical transmission of GLRaV in vineyards § pruning, hedging, trimming, harvesting, suckering, etc • No vine-to-vine transmission via root grafting Insect Vectors of GLRaV § Mealybugs and Soft Scales § grape mealybug, (P. maritimus), obscure mealybug (P. viburni) longtailed mealybug (P. longispinus) vine mealybug (Planococcus ficus) § Soft scales § lecanium scale (Parthenolecanium corni) 51 Insect Vectors of GLRaV § Mealybugs § More efficient at transmitting GLRaV-3 than soft scales § Early instars more efficient than more mature stages § Virus is semi-persistent § Feeding by one viruliferous insect sufficient to cause infection § Acquire GLRaV within 24 hours of feeding on infected vines § Symptoms not until the following year Which mealybug is in Ontario? Representative samples collected into 95% EtOH Analyzed by PCR Confirmed grape mealybug (Pseudococcus maritimus) Grape mealybug in Ontario. So what? § 2 generations/year (overwintering and summer) § Other species 3-7 generations/year § Does not infest roots § Other mealybugs do § Pheromones are species specific § Monitoring, mating disruption Grape Mealybug § 1st instar nymph § Most efficient vector stage § Most mobile stage § Walk vine to vine (1 m) § Wind (low proportion, up to 8 m) (Grasswitz & James, 2008) § Hitchhiker on workers, machinery? Grape Mealybug Life Cycle Overwinter as eggs and 1st instars 56 Grape Mealybug Life Cycle 57 Grape Mealybug Life Cycle Adult females 1st instars in egg cluster 2nd instar 3rd instars 58 Grape Mealybug Life Cycle Emerge in spring and move onto canes to feed, hiding beneath bark 59 Grape Mealybug Life Cycle 12 10 8 Adult females move back under trunk bark to lay 6 Adult females move back under trunk overwintering eggs 4 bark 2 Mean number/10 vines 0 1 7 12 20 25 1 8 15 23 30 9 13 20 27 6 10 17 24 3 9 14 28 May June July Aug Sept Egg Cluster 1st instar 2nd instar 3rd instar Adults 60 Monitoring for Grape Mealybug § Pheromone traps https://cataloG.extension.oreGonstate.edu/sites/cataloG/files/project/pdf/em9092.pdf