Projects

Ongoing Project
Lead Researcher: Wendy McFadden-Smith

Cultural practices and chemical treatments will be integrated to manage sour rot.  These will address this challenge in several ways: reducing cluster tightness, increasing skin resistance to splitting, reducing vinegar fly infestations and reducing sour rot pathogen populations.  Several chemical treatments, including biocontrol agents and potassium metabisulphite will be tested to determine optimum use timing and rate.  Cluster architecture will be manipulated by plant growth regulators (natural and synthetic), reduction of photosynthate available during bloom (mechanical and hand leaf removal and antitranspirant spray) and mechanical blossom thinning post bloom.  The relationship among the vector (vinegar flies), sour rot organisms, and host susceptibility will be elucidated.  Using field observations and inoculations under controlled environment, a model will be developed to determine when berries are susceptible to infection.  A threshold for degree of vineyard infection relative to volatile acidity will be developed and the impact of different levels of sour rot on wine quality will be evaluated. The effects of crop load and leaf removal timing and severity on sour rot, yield and fruit quality will be determined. 

Project Ongoing
Lead Researcher: Dr. Debbie Inglis, CCOVI, Brock University

3-alkyl-2-methoxypyrazines (MPs) are a potent class of grape- and insect-derived odor-active compounds associated with wine quality and climatic conditions. 3-Isobutyl-2-methoxypyrazine (IBMP), 3-isopropyl-2-methoxypyrazine (IPMP) and 3-sec-butyl-2-methoxypyrazine (SBMP) are found in many vinifera grapes and elicit green and vegetative aroma and flavour in wine. Although these MPs can positively influence wine quality in Sauvignon blanc at low concentrations, in other varieties, and at higher concentrations, they are dominant and unpleasant, mask fruity/floral aromas, and are associated with under-ripe, low quality fruit. A more detrimental source of MPs is that of insect origin. Specifically, MPs from the Multicoloured Asian ladybeetle (Harmonia axyridis;MALB) and the seven-spotted ladybeetle (Coccinella septempunctata;C7) have been found in wine. When these Coccinellidae are inadvertently incorporated with grapes at harvest, elevated MP concentrations are found, concurrent with development of an off-flavor coined ‘ladybug taint’ (LBT). IPMP is the primary compound believed responsible for LBTalthough IBMP and SBMP have also been identified at low concentrations in some affected wine. Both MALB and C7 are non-native ladybeetles repeatedly introduced to North America as biological control agents, and enter vineyards just prior to grape harvest. Climate change has contributed to a northerly progression in the distribution of these insects, and warmer winters in Ontario over the last few years are associated with much higher survival rates of MALB, with subsequent potential for proliferation the following year. These pests continue to plague the industry, and long-term solutions for managing the insects and their taint are required.

 Due to the negative impact of LBT in wine, the industry has instigated an almost zero tolerance policy for ladybeetles in grapes intended for juice and wine production, with subsequent substantial economic losses to grape growers. Currently, the use of insecticidal sprays in the vineyard is the only tool available to the majority of growers; to date, this approach has had variable success, and does not address the quality issues associated with high natural MP levels in grapes. MPs, regardless of source, are very resistant to removal by traditional grape and wine processing measures, which has led us to search for alternative approaches for reducing MP levels in juice/wine.  The technology to be optimized in this proposal is the use of proteins with naturally high affinity for MPs to bind to and remove MPs in juice and wine, whether the MPs are grape- or insect- derived.

Completed - continuing as project 2900 below
Lead Researcher: Dr. John Cline and Dr. Helen Fisher

Wine grape growing is new to Norfolk County, being a novel land use, a substitute for previous high value tobacco crops or as an adjunct to eco-tourism. Although Norfolk County has ample acreage of successful fruit and vegetable horticulture, commercial wineries are recent enterprises, with vineyard production difficulties due to excess vine vigour and cold winters. This area of Ontario has a mild climate but colder, more unpredictable winters than the Niagara Peninsula. Lake Erie tends to freeze over during the winter, affording less thermal dampening/protection to the lands immediately adjacent (AES-ice, 2019). Also, the deep Norfolk sands encourage high vigour, exacerbating wine grape susceptibility to winter injury.

During summer/fall of 2012, 905 genotypes of Vitis riparia MICHX were GPS marked, collected and propagated by green shoot or hardwood cuttings and planted at SRS, Simcoe, Ontario in spring 2013 as 3 single vine replications. Of these, 844 originated in 5 adjacent counties (Norfolk, Elgin, Middlesex, Oxford and Brant) in locations of deep sandy soils. The balance (61 accessions) were located in more distant counties (Kent, Essex, Haldimand, Prince Edward, Hasting, Frontenac and Grey), but always in locations of deep sandy soils. This was an east-west collecting distance of approximately 650 km, representing the warmest and almost the coldest of present commercial wineries/vineyards in Ontario.

These individual clones were observed during collection (2012) and during 2013, 2014 for phenological markers: bud break, flowering, veraison, senescence as well as precocity, sex, robustness/vigour and pest tolerance. The fifteen selections targeted for advancement were chosen for late bud break, mid flowering, early veraison, early ripening, early periderm development and early senescence. During one greenhouse drought tolerance trial, high proline content was also used as a selection criterion. Seedlings of early fruiting selections were used for lime tolerance tests, but with little reaction and inconclusive results. (Rahemi, unpublished results). 

Rootstocks have traditionally been used to combat specific soil pests (phylloxera, nematodes) and/or conditions (salinity, drought, free lime), but less so for controlling vigour. The use of 'low vigour', traditional hybrid rootstocks, or the use of native, locally selected V. riparia rootstocks could reduce vine vigour/size, improve fall acclimation and potentially stabilize both yield and winter injury incidence. The present field trials consist of four traditional ‘low vigour’ rootstocks and 15 Ontario V. riparia rootstocks now planted as grafted vines at two sites (Simcoe Research Station (SRS), Simcoe and Burning Kiln Winery (BKW), St. Williams) to test this hypothesis.  

Pruning weights (kg/vine), standardized cane/bud numbers per vine, vine development (bud break (time), % shootless nodes), fertility (clu/sh), veraison (time), periderm development (nodes/cane), leaf senescence (Chl/SPAD, time, %), yield (kg/vine) and fruit quality (Brix, TA, pH, colour) will be determined systematically for these two sites. Weather data will be collected at each site. DTA of the scions will be determined three times during each dormant season. Vines will be managed as commercially acceptable. Harvest will be determined by the on-site winemaker at Burning Kiln. Three seasons are planned for this study.

Native Ontario riparia selections in a replicated variety-rootstock trial is unprecedented and absolutely unique in Ontario.

Ongoing - Continuation of project 2600.

Lead researcher: Dr. Helen Fisher

The continuing interest in grape growing and winery enterprises in Norfolk County means that production systems must be improved to modulate the issue of winter injury, especially with the onset of more unpredictable winters and variable spring conditions. Risks need to be modified by reducing excessive vine size on these deep sands, but also by influencing the acclimation /de-acclimation cycles of the scions. Riparia, as a general species, is far hardier than vinifera and its use as a rootstock can affect scion acclimation and mid-winter hardiness.(Fisher, 2021). This project will focus on effects on spring de-acclimation to determine whether this aspect of the overwintering hardiness curve can be delayed consistently using rootstocks.
Fifteen new riparia selections have been chosen for rootstock trials that are ongoing at Simcoe RS and BKW St. Williams. These genotypes have had some virus screening (Fisher 2021) but this needs to be repeated and verified. This virus screening is essential for entry into the CGCN clean plant programme (CGCN 2021) and may verify the lack of pathogenic viruses resident in wild riparia from these sources. Freedom from pathogenic virus is critical for the rootstock material to enter the micropropagation programme at Brock U (Poojari 2021) for the establishment of a clean germplasm repository for grapevine material as a backup for the CFIA/AAFC collection in Sydney, BC.
DNA profiling is proposed for the each of the fifteen new riparia rootstocks selections, so that they can be definitively identified. Visual identification of the rootstocks is virtually impossible as they are all genotypes/ecotypes within the wild V. riparia, having no obvious ampelographic differences and being essentially identical. This will protect the identity of these selections should they be pursued with Plant Breeders’ Rights in the future.
The resident germplasm collection will be actively screened for late budding and late de-acclimation clones to widen the search for appropriate selections to add to the field testing. This will include the USDA collection at Simcoe which has a much wider geography and may yield more variability. This collection has not been screened for these traits.

The existing field trials (4 cultivars X 4 rootstocks and Pinot noir X 15 rootstocks) will have DTA analysis expanded in spring to try and capture specific differences among the local riparia rootstocks in overwintering effects on the scion, particularly de-acclimation.

Completed.

Lead researcher: Dr. Wendy McFadden-Smith

Funded in collaboration with the Niagara Peninsula Fruit & Vegetable Growers' Association.

At the Ontario Fruit and Vegetable Convention 2023 grape session, Mark Krasnow presented his work on using a grape harvester to shake out trash in clusters as a way to reduce Botrytis bunch rot (https://drive.google.com/drive/folders/1YCri7iZ4qBkDYy3wAXfykznRo6t_w_2c).  The fruiting zone bars are removed.  The research also showed that the mechanical shaking of the clusters changed the chemistry of the skin, making it thicker and more resistant to splitting, which is a common issue in our rainy pre-harvest season.  A Beamsville Bench vineyard was approached with this idea and they are willing to trial it in their vineyard blocks.  They use a Collard leaf blower to remove trash in the cluster right after bloom (control treatment) so the harvester treatment would be applied after the Collard treatment, at lead shot to pea size.  The trial will be conducted in Pinot noir and Riesling.

The weight of debris remaining in 25 clusters per treatment row will be determined (replicated 4 times i.e. 4 rows with just Collard at postbloom and 4 rows of Collard plus Gregoire harvester).  The treatment may also decrease berry set so at cluster close, 25 clusters per treatment will be evaluated for cluster tightness and number of berries per cm of rachis.  At harvest, 25 clusters per treatment row will be evaluated for Botrytis bunch rot and sour rot.

Read the final report here.

Ongoing

Lead researcher: Dr. Malkie Spodek

CCOVI planted two research vineyards at commercial sites in 2018 using certified chardonnay vines from a California nursery. The chardonnay block at each site represented approximately ½ acre. The bundles of vines acquired from the nursery were randomly split between both sites at the time of planting, ensuring both sites had the same compilation of clone/rootstock combinations. The virus status of the vines were followed between 2020 and 2022. Initial composite testing using end point PCR found no evidence of grapevine red blotch virus (GRBV) in the initial vines. At site A, the chardonnay vines in all rows continued to test negative over the years, zero percent for GRBV. But at site B, the same lot of chardonnay vines that were planted at site A are testing positive for GRBV at 63% at site B, with some rows in the chardonnay block testing as high as 92% positive for red blotch as of 2022. Why is a variety from the same nursery testing positive for GRBV after just a couple years of planting at a site east of the canal on heavy clay with lots of weed pressure (bind weed and thistle) while the same lot of vines planted west of the canal on sandy loam with little weed pressure is testing negative?
The objective of this study will be to determine if insect vectors are responsible for the virus transmission at site B, specifically whether the planthoppers belonging to the genera Melanoliarus and Stictocephala are present or not and determine where they are living in the vineyard ecosystem. If the insects are present, PCR will be used to assess if GRBV is present within the insects. If the virus is present, the PCR amplicon will be sequenced via Sanger sequencing to document the virus strain. In addition, the remaining chardonnay vines that had tested negative at site B will be tested for GRBV via high throughput sequencing (HTS) to see if any further transmission has occurred since 2022. The virus sequence from the vines will be compared to any sequence detected in the insects to ascertain if the insects could be responsible for the transmission.

To confirm that the original vines at site A are still negative for GRBV, composite testing of vines at site A will be carried out using HTS to further confirm the presence or absence of GRBV. If virus is detected, the sequence of the virus will be acquired through this HTS testing and can be compared to any virus sequences gathered from site B insects or vines. If the vines test negative, it is further evidence that the origin of GRBV at Site B was not from the propagation material used to make the vines planted at both Site A and B, but rather from transmission from a source in close proximity to the research block at Site B.
This research will help determine if insects are vectoring this transmission. This research will contribute to the limited knowledge base that we have on insect vectors associated with GRBV and add to our broader understanding of GRBV epidemiology.

In March 2024, the Honourable Lawrence MacAulay, Minister of Agriculture and Agri-Food Canada announced $5.9 million to fund the Canadian Grape and Wine Science Cluster.

The Canadian Grapevine Certification Network (CGCN) will adminster the Canadian Grape and Wine Science Cluster, under the Sustainable Canadian Agricultural Partnership AgriScience funding program and OGWRI is providing the industry cash for all Ontario led research activities within the cluster.

Research activities within the cluster will end in 2028, with final report summaries to be inlcuded below. Details on Ontario led activities can be found here. For additional information on the cluster, please visit the CGCN website.

Below are descriptions of the 4 Ontario led research activities.

Activity 10b -  Grapevine trunk disease: an under-rated threat to the Ontario grape industry?

Lead: Wendy McFadden-Smith

Grapevine trunk diseases caused by fungi have been largely ignored in Ontario vineyards with assumptions that vine decline and death are due to cold injury rather than pathogenesis.  The goal of this project is to determine a baseline of incidence of grapevine trunk diseases, the pathogens responsible for them, the timing of inoculum presence (when infection could occur) relative to weather and vine development, and to identify possible cultural, chemical and biological management options.   

Baseline incidence will be determined by observing symptoms and collecting trunk samples in the early and late summer from Ontario vineyards of different ages.  Pathogens will be isolated and identified using molecular techniques.  The presence of inoculum (fungal spores) will be monitored using volumetric spore traps.  Spores will be sucked into tubes that will be collected weekly and analyzed using molecular techniques to identify which pathogens are present and the weather conditions that are associated with spore release.  Diagnostic tools will be developed to facilitate identification of infected vines by growers and consultants.

This project aims to shed light on a hidden problem in Ontario vineyards: the role of fungal trunk infections in the decline and death of grapevines, a problem previously attributed mainly to cold weather. Fungal trunk diseases can weaken grapevines, leading to reduced vigor, lower fruit yield, and poorer fruit quality, while also shortening the lifespan of the vines. Researchers are setting out to understand how widespread these fungal diseases are, identify the specific fungi responsible, and pinpoint the times these fungi are most likely to infect the vines. This includes exploring various ways to protect the vines, ranging from traditional farming practices to chemical treatments and biological controls.

To gather the necessary information, the team will examine grapevines at key growth stages during the growing season, collecting samples to identify the fungi using advanced lab techniques. They will also deploy spore traps to capture and identify fungal spores in the air, linking their presence to specific weather conditions that might trigger outbreaks. The ultimate goal is to develop easy-to-use tools for vineyard owners and consultants, enabling them to quickly detect infected plants. This research not only aims to protect Ontario's grapevines from these hidden threats but also to ensure the sustainability and productivity of the vineyards. 

Activity 11 -  Wine flavour modification through non-traditional yeasts, oenological treatments and taint remediation 

Lead: Debbie Inglis

The Ontario, and broader Canadian, wine industry is searching for ways to further improve wine quality through flavour modification to increase the competitiveness of domestic wines to capture a higher percentage of wine market share. Canadian wine has always competed on quality rather than price.  Our research program will focus on processes that will provide new and improved wine attributes, making our industry more resilient to the challenges of climate change that negatively impact fruit quality, and more resilient to market pressure requiring our wines to be price competitive but with added quality.   

Although it is widely accepted that making great wines begins in the vineyard with quality fruit, winemakers still require additional oenological tools to enhance the aroma profile of wines to offer resilience in winemaking to overcome threats from climate change. Those tools include non-traditional yeast strains that alter and improve the volatile aroma compounds in wine, oenological additives and fermentation temperature that allow yeast to create flavours that further enhance wine character. This program will use all of these tools to address industry priority issues facing winemakers.

This project has two main objectives in wine flavour modification, addressing key areas of concern in the Ontario grape and wine industry with application to industries in British Columbia, Quebec and Nova Scotia. 

Objective 1: Assess the commercial application of locally isolated S. uvarum strains to mitigate the impact of botrytis and sour rot taints in white grape varieties through consumption of acetic acid and assess their use to form volatile fatty acids and acetate esters that increase the fruity volatile aroma compounds in Riesling and Chardonnay wine.

Objective 2:  Increase volatile thiol concentrations in Vidal table wine through a yeast micronutrient additive, fermentation temperature and yeast strain to enhance the “Sauvignon blanc” characteristic of Vidal to diversify uses of the Vidal grape, improve marketability and increase the domestic wine market share.  

Activity 12 -  Selection of superior grapevine material using traditional field evaluations and genomic/metabolic signatures for cold resilience

Lead: Jim Willwerth

Climate change is a threat to the Canadian grape and wine industry and adaptation strategies are urgently needed.  The main objective of this research is to support the Canadian Grapevine Certification’s domestic clean plant program through accelerated selection of superior grapevine material for improved performance, cold resilience, and quality using traditional evaluations and genomic and metabolic signatures.

The goal is to improve the sustainability of grape production by greater cold tolerance resilience through identification of superior vine material and their genomic and metabolic signatures and mitigation strategies such as the use plant growth regulators such as Abscisic acid analogs. 

Activity 13 - Grapevine red blotch virus: insect vector biology and ecology

Lead: Justin Renkema

Red blotch disease caused by grapevine red blotch virus (GRBV) is a new and important problem in grapes in North America. Secondary spread of GRBV is occurring in some regions, but the ability of insects to transmit GRBV is not well understood, particularly in Ontario. In this proposal, we will build on our previous research showing that a planthopper, Melanoliarus, and buffalo treehoppers, Stictocephala, can acquire GRBV. We will focus on determining the ecology and biology of Melanoliarus, and whether grapes are feeding and reproductive hosts, including for its soil-dwelling/root-feeding immature stages. Research has focused on insect adults transmitting GRBV to grape leaves and stems, but acquisition of GRBV through root feeding may also occur for Melanoliarus.  We will conduct experiments with planthoppers and treehoppers to determine whether GRBV can be transmitted from GRBV-infected vines to uninfected vines, while focusing on insect-virus interactions that may inhibit the circulation of the virus within insects and thus it transmissibility. Finally, we will determine the phenology and movement of planthoppers and treehoppers to work towards recommendations for management of these potential GRBV vectors. Overall, the goal of the projects is to provide new insights about the secondary spread of GRBV by insects in Ontario so that the grape industry can take appropriate action to mitigate losses due to GRBV.