As we close the second fiscal year of the Canadian Agricultural Partnership, Grape & Wine Science Cluster each of the activities has provided a brief update on their research done so far. We thank Agriculture & Agri-Food Canada and British Columbia Wine and Grape Council, Grape Growers of Ontario, Ontario Grape and Wine Research Inc., Consiel des Vins Du Quebec, Nova Scotia Department of Agriculture and Grape Growers Association of Nova Scotia along with our Industry Partners for funding this research. We look forward to learning more over the next 3 years of the program. For more information, please contact us.
Activity 2 - Grape and Wine Viruses in British Columbia
Read the full Grapevine Viruses update here!
- Jose Urbez Torres, Tom Lowery, AAFC Summerland
Activity 3 - Grapevine Virus Diseases and Virus Vector Control
The project focuses on a survey of the major grapevine virus diseases (Grapevine leafroll-associated virus-3; GLRaV-3 and Grapevine red blotch virus; GRBV) and their insect vectors as well as estimating the impact of these viruses on vine health. In addition, the project aims to develop strategic mitigation practices for these viruses.
- The temporal and spatial distribution of grapevine leafroll and red blotch diseases was determined in red and white vinifera as well as hybrid variety blocks in the major grape growing areas using a medium-density sampling procedure.
- Intended outcomes were met.
- Justin Renkema and Wendy McFadden-Smith, AAFC Vineland and CCOVI at Brock University
Activity 4 - Evaluation of Viruses
Surveys to assess the incidence of grapevine viruses in Nova Scotia (NS) were conducted in 20 varietal blocks in 2019. A total of 380 composite samples from four varieties (Seyval Blanc, Osceola Muscat, Marquette, Leon Millot), were collected from vineyards and tested for the presence of Grapevine Leafroll associated Viruses (GLRaV-1 and GLRaV-3), Grapevine Red Blotch virus (GRBV), Grapevine Fan Leaf Virus (GFLV), and Grapevine Pinot Gris Virus (GPGV), using PCR and RT-PCR techniques. Testing was done in the plant health laboratory at the Kentville Research and Development Centre (KRDC). Results confirmed the presence of all viruses except GFLV. Of interest, the number of panels infected with GRBV has remained somewhat constant since first confirmed in NS in 2016, suggesting low or no risk of spreading by vectors. At this time, there are still no records for the known vector of GRBV in Canada. In contrast, confirmed numbers of GPGV infected panels continues to increase. Field observations and sequence data suggests that the strain detected in NS is asymptomatic and thought to have negligible impacts to vines. Published reports support the need for research on the potential GPGV vector, Erinea mite, and potential alternate hosts that may act as reservoirs for disease in and around vineyards. Efforts to determine presence and distribution of insect vectors and plant parasitic nematodes also continued in 2019. Risk of virus spread remains low due to small numbers and very localized populations of known vectors like grape mealybug and scale insects. Nematodes were confirmed in vineyards sampled in 2019 and included Ring, Dagger, Root Knot, Lesion, and Spiral nematode species. In most cases, counts were low and remain at levels that do not warrant concern. Efforts to evaluate individual vines to assess how viruses impact vine performance were initiated in commercial vineyards. A number of challenges were faced in efforts to monitor four commercial sites throughout the season and included poor vine health, issues associated with timing of sprays, and severe weather events for a second year in a row. Going forward, research on vine performance will re-focus on using potted plants for viruses of interest and a soon to be established virus (positive and negative) field site at KRDC. Local producers support the need for research to develop best practices for virus mitigation. Access to virus-free plant material and knowledge of sustainable vector management tools has become a major priority for our industry, especially given the current virus status and rapid expansion in acreage in NS, observed trends in regional climate change, and shifts to organic production systems. Research observations and preliminary trends have been shared with cooperating growers and industry stakeholders in annual reports and presentations to the Grape Growers Association of Nova Scotia, Nova Scotia Department of Agriculture, Canadian Grapevine Certification Network, and AAFC researchers and collaborators working on grapevine viruses across Canada.
- Debra Moreau, AAFC Summerland
Activity 5 - Cold Hardiness in Eastern Canada
Growing grapes in cold climates has several challenges to overcome. Cold injury to grapevines is an important problem, especially at the northern limits of culture where extensive damage to bud and cane tissues can result in severe economic losses. The main objective of this project is to improve knowledge of grapevine cold hardiness for hardy and semi-hardy hybrid and Vitis vinifera cultivars as well as to provide methods to reduce cold injury under climatic conditions of eastern Canada in order to support the development of the wine industry. To help understand cold resistance in grapevines, methods and models for evaluating bud resistance have been developed and utilized for several years. Following previous works, CRAM has set up a network of eleven vineyards across Quebec to monitor bud cold tolerance by means of Differential Thermal Analysis (DTA) during the winter and spring. The Low Temperature Exotherm (LTE) for each studied varietal can be derived in from DTA in order to demonstrate bud cold tolerance. The grape varieties that are followed from November to May are rustic hybrids, Frontenac, Marquette, St-Pepin, Frontenac blanc and Petite Perle. Then, from April on, V. vinifera (Chardonnay, Vidal and Pinot noir) are added. The first year of LTE monitoring in Quebec demonstrated that there was great variability in LTE values between vineyards and grape varieties. In addition, rustic hybrids do not seem to follow a standard curve of acclimation / maximum hardiness / deacclimation that is usually observed for V. vinifera. The LTEs are more variable during the winter and closely follow local outside temperature variations. Most notably, maximum hardiness was only attained at the end of February.
Winter protection methods have been developed to use concomitantly with tender and semi-hardy wine grapes that are less resistant to the cold in the northern regions. The use of geotextiles to protect semi-rustic and non-rustic vines is increasingly used in Quebec though without specific knowledge for optimal installation and outcome. The project evaluates three types of geotextiles (Hibertex 2.2 mm, Hibertex 3mm and Texel Arbo Pro) and four moments of installation/withdrawal (early installation/early withdrawal, early/late, late/early and late/late). Three grape varieties were followed: Vidal, Chardonnay and Pinot noir. The trials are carried out in seven vineyards across Quebec. A first site was installed in the fall of 2018 and the data was collected during the 2019 season. We can note that protecting the vines with geotextile maintains significantly higher temperatures under the geotextile, especially in presence of very cold weather. The later removal of the geotextile favoured the development of the vines in the spring, but very little effect was noted on the various parameters at harvest, except for a higher number of clusters for an early installation/early removal of the geotextiles comparatively to a late installation/late removal.
Several management practices can modulate the resistance to cold or vine acclimation, such as leaf removal, fertilization, pruning, training systems and rootstocks. Rootstocks can directly affect the biochemistry of grafts and tolerance to freezing or can affect cold tolerance indirectly by acting on the vigour of the vine and shade from the canopy. The effects of grafting for rustic grape varieties on various parameters have been monitored for several years. Thirty combinations including six grape varieties (Frontenac, Frontenac blanc, Frontenac gris, Marquette, Adalmiina, Baltica) and five root systems (pied franc, 3309, Riparia Gloire, 101-14, SO4) were studied. Grafting has little effect on bud survival rate during the winter, only a few non-constant differences are noted. Furthermore, after 5 years, vine development is also unaffected by grafting. Finally, grafting has variable effects on the parameters at harvest and some trends stand out. The most marked effect of grafting is in the wines produced. There is a general improvement in the appreciation of wines when the grapes come from grafted plants compared to grapes from own-rooted plants. Better understanding of physiology can lead to the development of new technology and adaptations to better protect grapevines against extreme winter temperatures. Important information will also be generated that could be used for more efficient management of frost protection systems, such as wind machines against spring frost.
La culture du raisin dans les climats froids doit relever plusieurs défis. Les dommages causés à la vigne par le froid constituent un problème important, en particulier aux limites septentrionales de la culture, où des dommages importants aux tissus du bourgeon et des tiges peuvent entraîner de graves pertes économiques. L’objectif principal de ce projet est d’améliorer les connaissances sur la résistance au froid des cépages hybrides (rustiques et semi-rustiques) et Vitis vinifera, ainsi que de proposer des méthodes permettant de réduire les dommages dus au froid dans les conditions de l’est du Canada, afin de soutenir le développement de l’industrie vinicole. Pour aider à comprendre la résistance au froid, des méthodes et des modèles d'évaluation de la résistance des bourgeons ont été développés. Le CRAM a mis en place un réseau de onze vignobles à travers le Québec afin de suivre la résistance des bourgeons au froid (LTE) durant la période hivernale et au printemps. Les cépages qui sont suivis de novembre à mai sont des hybrides rustiques, soit Frontenac, Marquette, St-Pepin, Frontenac blanc et Petite Perle, puis à partir du mois d’avril des non-rustiques sont évalués, soit Chardonnay, Vidal et Pinot noir. La première année de suivi des LTE au Québec a démontré qu’il y avait une grande variabilité des valeurs LTE entre les vignobles et les cépages. De plus, il a été observé que les hybrides rustiques ne semblent pas suivre une courbe standard du processus d’acclimatation/LTE optimale/désacclimatation que l’on peut observer pour les V. vinifera, les LTE sont beaucoup plus variables durant l’hiver et suivent les variations de la température extérieure.
Des méthodes de protection hivernale ont été mises au point pour utiliser des cépages moins résistants au froid (tendres, semi-rustiques) dans les régions nordiques. L’utilisation des toiles géotextiles pour protéger les vignes semi-rustiques et non-rustiques sont de plus en plus utilisées au Québec sans que l’on ait des connaissances spécifiques pour leur installation. Le projet évalue trois types de toiles (Hibertex 2.2 mm, Hibertex 3mm et Texel Arbo Pro) et quatre moments d’installation/retrait (installation tôt/ retrait tôt, tôt/tard, tard/tôt et tard/tard). Trois cépages sont utilisés : Vidal, Chardonnay et Pinot noir. Les essais sont réalisés dans sept vignobles à travers le Québec. Un premier site a été installé à l’automne 2018 et les données ont été collectées durant la saison 2019. On peut noter que la protection des vignes avec les toiles géotextiles permet d’augmenter la température sous les toiles de façon significative et ce surtout en présence de grands froids. Le retrait des toiles plus tardivement a favorisé le développement de la vigne au printemps, mais très peu d’effet a été noté sur les divers paramètres à la récolte, sauf un nombre de grappes plus élevé pour une installation et un retrait hâtif des toiles comparativement à une installation et un retrait tardif des toiles.
Plusieurs pratiques de gestion peuvent moduler la résistance au froid ou l'acclimatation de la vigne, telles que l'effeuillage, la fertilisation de la vigne, la taille, les systèmes de formation et les porte-greffes. Les porte-greffes peuvent influer directement la biochimie des greffons et la tolérance à la congélation ou peuvent affecter la tolérance au froid indirectement en agissant sur la vigueur de la vigne et l'ombrage du couvert. Les effets du greffage pour les cépages rustiques sur divers paramètres sont suivis depuis plusieurs années. Trente combinaisons incluant six cépages (Frontenac, Frontenac blanc, Frontenac gris, Marquette, Adalmiina, Baltica) et cinq systèmes racinaires (pied franc, 3309, Riparia Gloire, 101-14, SO4) sont étudiés. Le greffage a peu d’effet sur le taux de survie des bourgeons suite à l’hiver, seulement quelques différences non constantes sont notées. Le greffage n’affecte pas le développement de la vigne qui est établie depuis 5 ans. Enfin, le greffage a des effets variables sur les paramètres à la récolte et quelques tendances se démarquent. L’effet le plus marqué du greffage est au niveau des vins produits, on note une amélioration générale de l’appréciation des vins lorsque le raisin provient de plants greffés comparativement à du raisin de plants franc de pied. Une meilleure compréhension de la physiologie peut conduire au développement de nouvelles technologies et à des adaptations visant à mieux protéger les vignes contre les températures extrêmes en hiver. Des informations importantes seront générées dans le cadre du projet et elles pourraient être utilisées pour une gestion plus efficace des systèmes de protection contre le gel, tels que les éoliennes contre le gel printanier.
- Gaetan Bourgeois and Caroline Provost, AAFC Kentville and Centre de Recherche agroalimentaire de Mirabel
Activity 6 - Grape & Wine Grapevine Hardiness
In Activity 6 “Factors Affecting Grapevine Winter Hardiness” there are 6 objectives all with the common purpose of increasing our understanding of grapevine winter hardiness. This includes investigating the vulnerability of grapevine buds, canes, cordons, trunk and roots to sub-zero temperatures and to elucidating factors in vineyard management and site conditions that both positively and/or negatively affect grapevine hardiness. Work on all objectives is progressing as planned. The season for hardiness testing runs from leaf fall to bud break and data from year two of this project is still being tabulated and analyzed. Results and some preliminary analysis from this year are presented in this report: of note, is the development of a bud hardiness model for Merlot, the monthly mapping of phloem hardiness throughout an entire vine from roots to buds, and the initiation of a large field trial examining the effects of reduced early season irrigation on vine growth, fruit and wine quality and bud hardiness.
This activity is largely on track to complete all annual milestones for 2019 – 2020 (note: the closure of SuRDC beginning on March 17, 2020 due to covid-19 pandemic has prevented the collection and analysis of end of winter season data for some experiments, and further closure will probably cause all summer field experiments to be delayed until 2021.) For 2019 – 2020 all funds for this activity were spent as budgeted. Research and knowledge transfer to industry members regarding grapevine winter hardiness continues.
- Carl Bogdanoff, AAFC Summerland
Activity 7 - Grapevine evaluation and cold hardiness program
The purpose of this project is to provide grape growers with comparative levels of bud cold hardiness for key grape cultivars in different viticultural areas during grapevine dormancy. Monitoring bud cold hardiness throughout the dormant period is an invaluable tool to assist grape growers in avoiding freeze injury of their vines. The data collected is provided to grape growers through VineAlert’s web-accessible database which allows growers and researchers to see how cold tolerant cultivars are within a specific area at sampling times throughout the dormant period and hardiness responses based on changes in temperature during dormancy. Grapevine cold hardiness is not static but varies throughout the dormant period. Therefore, bud sampling and testing is done throughout the entire dormant season to monitor cold hardiness through the acclimation, maximum hardiness and deacclimation periods. This ever-changing bud hardiness data can be helpful in determining when wind machine use or other freeze avoidance methods are warranted to protect vines from cold temperature injury. Changes in cold tolerance can be very cultivar-specific and through this program we can learn how changing environmental conditions can impact not only maximum hardiness of a cultivar but also how quickly they gain and/or lose cold hardiness. Therefore, this project has important outreach and research aspects that are beneficial to the entire Ontario Grape and Wine sector.
Read the full Grapevine Evaluation update here!
- Harrison Wright and Jim Willwerth, AAFC Kentville and CCOVI at Brock University
Activity 8 - Canopy Management to reduce disease pressure
There is a general agreement among scientists and grape specialists that proper canopy and fruit zone management are essential practices to obtain qualitative grapes. Canopy management (CM) involves pruning, shoot thinning, sucker removal, shoot positioning, leaf and lateral removal, hedging and any other practice that manipulates shoots and leaves. Fruit zone management (FZM) involves de-leafing around the cluster. The ultimate objective of both CM and FZM is to improve grape aroma, flavour and pigment profiles, favour earlier maturity and reduce diseases. Practices of fruit zone management were evaluated for their effect on disease management during summer 2019. The practices were leafing around the cluster zone on 1) one side of the row at nouaison; 2) two sides of the row at nouaison ; 3) one side of the row at veraison; 4) two sides of the row at veraison; 5) no leafing (control). Microclimate (Temperature and relative humidity) was monitored within the fruit zone and fungicide penetration was measured with hydrosensitive paper. Downy mildew, powdery mildew, and botrytis bunch rot were assessed weekly and at harvest on clusters. Disease pressure (pathogen populations) was monitored using rotating-arms samples. The number of spores P. viticola, E. necator and B. cinerea per sampling period was determined using a previously developed qPCR assay (Carisse et al., 2014). Yield was assessed as the number of clusters, cluster weight and brix. Regardless of the treatment, the effect of fruit zone management practices was small but significant. For both timing of cluster zone leafing, nouaison and veraison, lower disease severity was observed when leaves were removed on both sides of rows. Overall, lowers disease severity was observed when leaves were removed at veraison as compare with nouaison. However, there was no significant difference in airborne inoculum. The difference in disease severity may be explained by lower humidity and better fungicide penetration in the canopy in sub-plots where leaves around the clusters were removed on both sides of rows at veraison. The removal of leaves from the fruiting area promotes the penetration of fungicides during a localized treatment but also of general coverage.
A portrait of the Quebec grape industry was made to evaluate the current canopy management practices including timing, level of exposure and the grower’s expected benefit. A questionnaire (survey) was developed to evaluate grape grower’s practices related to canopy and fruit zone management, equipment used, time required/ha, timing, impact on their disease management program, and their expected outcomes. Surveys was be conducted as a web version or in person with a follow up site on selected vineyards, based on CM and FZM practices used by the growers. Particular attention was paid to obtain vineyards in several regions (Québec), with different grape varieties and diversified cultural practices. Overall 62 grape growers from 11 growing regions of Quebec answered which allow us to make a very good portrait of the industry. Based on the survey, 55%, 80%, 15%, 74%, 69%, and 31% are doing shoot thinning, shoot positioning, fruit thinning (vendange en vert), hedging, lateral removal, and leafing around the cluster, respectively. These canopy management practices are done manually in 91%, 98%, 97%, 44%, 46%, 84% for shoot thinning, shoot positioning, vendange en vert, hedging, lateral removal, and leafing around the cluster, respectively.
Les scientifiques et les spécialistes de la vigne sont généralement d'accord sur le fait qu'une bonne gestion de la canopée et de la zone fruitière sont des pratiques essentielles pour obtenir des raisins de qualité. La gestion de la canopée (CM) implique l'éclaircissage fructifère, l’épamprage, le positionnement des tiges, le rognage et l’écimage et toute autre pratique qui manipule les pousses et les feuilles. La gestion de la zone fruitière (FZM) implique l’effeuillage autour de la grappe. L'objectif ultime du CM et du FZM est d'améliorer les profils d'arôme, de saveur et de pigment du raisin, de favoriser une maturité plus précoce et de réduire les maladies. Les pratiques de gestion de la zone fruitière ont été évaluées pour leur effet sur la gestion des maladies durant la saison 2019. Les essais comprenaient l’effeuillage autour de la zone de grappe sur 1) un côté du rang à la nouaison; 2) deux côtés du rang à la nouaison; 3) un côté du rang à la véraison; 4) deux côtés du rang à la véraison; 5) aucun feuillage (témoin). Le microclimat (température et humidité relative) a été collecté dans la zone fruitière et la pénétration du fongicide a été mesurée avec du papier hydrosensible. Le mildiou, l'oïdium et la pourriture liée à Botrytis ont été évalués chaque semaine et à la récolte sur les grappes. La pression des maladies (populations d'agents pathogènes) a été suivie en utilisant des capteurs de spores. Le nombre de spores de P. viticola, E. necator et B. cinerea par période d'échantillonnage a été déterminé en utilisant un test qPCR développé précédemment (Carisse et al., 2014). Le rendement a été évalué comme le nombre de grappes, le poids des grappes et le brix. Quel que soit le traitement, l'effet des pratiques de gestion de la zone fruitière était faible mais significatif. Pour les deux moments d’effeuillage, à la nouaison ou à la véraison, la gravité des maladies était moindre lorsque les feuilles ont été enlevées des deux côtés du rang. Dans l'ensemble, une gravité plus faible de la maladie a été observée lorsque les feuilles ont été enlevées à la véraison par rapport à la nouaison. Cependant, il n'y avait pas de différence significative dans l'inoculum en suspension dans l'air. La différence de l’incidence des maladies peut s'expliquer par une humidité plus faible et une meilleure pénétration des fongicides dans la canopée dans les sous-parcelles où les feuilles autour des grappes ont été enlevées des deux côtés du rang à la véraison. L'élimination des feuilles de la zone de fructification favorise la pénétration des fongicides lors d'un traitement localisé mais lors d’un traitement avec une couverture générale.
Un portrait de l’industrie du raisin au Québec a été dressé pour évaluer les pratiques actuelles de gestion de la canopée, y compris le moment, le niveau d’exposition et les avantages escomptés du producteur. Un questionnaire (enquête) a été élaboré pour évaluer les pratiques des viticulteurs en matière de gestion de la canopée et de la zone fruitière, l'équipement utilisé, le temps requis / ha, le calendrier, l'impact sur leur programme de gestion des maladies et leurs résultats escomptés. Les enquêtes ont été menées en version Web ou en personne avec un suivi sur des vignobles sélectionnés, sur la base des pratiques CM et FZM utilisées par les producteurs. Une attention particulière a été portée à l'obtention de vignobles dans plusieurs régions (Québec), avec des cépages différents et des pratiques culturales diversifiées. Au total, 62 viticulteurs de 11 régions productrices du Québec ont répondu, ce qui nous permet de dresser un très bon portrait de l'industrie. Sur la base de l'enquête, 55%, 80%, 15%, 74%, 69% et 31% effectuent respectivement l'épamprage, le positionnement des tiges, l’éclaircissage fructifère (vendange en vert), l’écimage, le rognage et l’effeuillage. Ces pratiques de gestion de la canopée sont effectuées manuellement dans 91%, 98%, 97%, 44%, 46%, 84% pour l'épamprage, le positionnement des tiges, l’éclaircissage fructifère (vendange en vert), l’écimage, le rognage et l’effeuillage, respectivement.
- Odile Carisse and Caroline Provost, AAFC CRDH and Centre de Recherche agroalimentaire de Mirabel
Activity 9 - Optimization of grape production in Eastern Canada
Accurate assessment of grape berry maturity during veraison and subsequent ripening period is critical for determining fruit readiness for harvest. While optimally mature grapes produce the highest quality vintage, important maturity-related measures (eg. brix, acidity) require destructive testing, can be time-consuming, and require laboratory-based equipment. Currently in the Nova Scotia (NS) grape-wine industry, there are no rapid, non-destructive methods available to accurately measure berry maturity for harvest decision-making. However, the development of such a method would facilitate a relatively quick assessment of the harvest potential in individual blocks of a specific grape cultivar enabling better management of the ripening variability within the vineyard. Recent developments of a rapid, non-destructive method for gauging maturity in other fruit crops like apples could be conceptually applied to the regional wine-grape industry. This technology could enable regional vineyard growers/managers to rapidly assess crop readiness for harvest at the end of the ripening period.
Exposure of fruit to natural light is critical for physiological ripening. As NS vineyards often have marginal heat units for V. vinifera vines and fruit growth, capturing light energy within the developing canopy is important for advancing the stages of grape berry/cluster maturity. Reflective fabrics have been shown to improve finished fruit quality in regionally-grown apples and in grapes in other regions and is associated with more reflected light energy (both directly and indirectly) being captured by the crop. The overall goals of the research work are twofold: i) To advance the harvest maturity of regionally significant wine-grape cultivars; and ii) To develop a non-destructive model for rapidly assessing grape berry maturity during veraison and the following ripening period.
In early August 2019, two research trials were established in two hybrid varietal blocks (L’Acadie Blanc and Leon Millot) at two commercial vineyards for each variety. Within each block, treatment plots of white reflective fabric (Extenday) and no fabric (control) were set up within the herbicide strip under the grapevines. Temperature & moisture loggers as well as a portable field spectroradiometer measured key environmental variables in the plots during the experiment. Between late August and late October, the juice of maturing grape berries within each treatment plot were measured each week for brix and acidity, while separated skins were analyzed for chlorophyll, phenolic and anthocyanin compound content. In addition, intact fruit were weekly analyzed using the light emission-based delta absorbance (DA) meter and Multiplex fluorescence meter technologies, which are being evaluated as rapid and non-destructive sensors of berry maturity via comparison to the conventional chemical measures. The 2019 data has been compiled with the initial analysis indicating that the fabric-treated Leon Millot grapes had marginally higher levels of phenolic and anthocyanin compound content than did the control fruit over the ripening period. The Multiplex fluorometer showed similar marginal anthocyanin increases in the fabric-exposed Leon Millot grapes. These data imply that compared with the control plots, the Extenday fabric reflected more light into the canopy which advanced fruit maturity to some degree; spectral irradiance data corroborate these findings. Plans for 2020 season include a fundamental replication of the 2019 experiment but may involve testing a different fabric to exacerbate maturity gains within the treated clusters. Grape cluster and berry selection methods will be re-evaluated for 2020 in order to minimize sampling variation among the many measurements taken after harvest. In addition, the purchase of a second field spectroradiometer will enable better light interception characterization of the plots. The 2020 trial may also include two V. vinifera cultivars which would depend upon willing grower participation and sufficient technical and labour capacity for the anticipated work. It is anticipated that this research will provide regional vineyard growers and managers the ability to rapidly and non-destructively assess the developing maturity of the wine-grape crop and provide a method for advancing berry maturity during the ripening period.
- John DeLong and Karine Pedneault, AAFC Kentville and University Sainte-Anne
Activity 10 - Water and Nutrient management strategies for grapevines and health promoting natural products
There is an increasing interest among grape growers for use of organic amendments (compost and biochar and vermicompost) and health promoting products (seaweed extract and vermicompost tea). The interactive effects of cover crops and charged biochar applications in the alleyways on yield and yield quality, vine’s N status and soil nitrogen dynamics were examined at a Merlot grape block and a newly established Riesling grape block located at Summerland Research and Development Centre. The effects of vermicompost, vermicompost tea and seaweed extract (Stella Maris) on grape yield, yield quality, vine growth, vine’s N status and soil nitrogen dynamics were evaluated in two commercial vineyards in Okanagan Valley, BC. The Interim data is reported here.
Cover crops were seeded in the alleyway in Merlot and Riesling experiments at SuRDC. Vines that did not establish or showed high level of winter damage in newly established Riesling block were replaced. Data vines with high level of winter damage were switched to their adjacent vine in vermicompost tea experiment in 2019. Stella Maris plots were re-established in a different location of vineyard in 2019, due to high variability observed in the 2018 location.
Yield parameters were not affected by the vermicompost rate, however, yeast assimilable nitrogen (YAN) concentrations amongst yield quality parameters were linearly increased with increase in compost application rates. Effect of vermicompost rate was significant (p<0.05) on soil mineral N during the growing season in 2019 and vine petiole N at veraison stage. Greater soil mineral N were measured in 28 and 14 tonnes per ha rates compared with 7 tonnes per ha and unfertilized control after harvest. Petiole N values were greater in 28 tonnes per ha compared with 14 and 7 tonnes per ha and control. Also petiole N values were greater at 14 and 7 tonnes per ha rates relative to unfertilized control. As the Riesling block is newly established, effect of treatments on yield and water or nutrient use efficiency will be examined in future years. Compost + biochar treatment increased cover crops and weeds biomass in the alleyways by 8% during 2019 growing season; which was the establishment year of the cover crops in both Merlot and Riesling blocks.
Vermicompost tea treatments were modified in 2019 based on 2018 data. Two rates of application (low and high) and 2 frequencies of application per season (4 vs. 8 applications) were evaluated. Effect of compost tea frequency of application was significant on yield. The interaction between frequency of application and rate was significant on berry mass. Slightly greater yields were measured for 8 times spray compared with 4 times. Greater compost tea concentrations increased the berry size at 4 times spray, while it reduced the berry size at 8 times spray compared with lower concentrations.
Effect of seaweed extract rate and frequency of spray per growing season on yield and yield quality parameters were investigated in a site in each of BC and NS provinces in 2019. No significant effects of treatments on measured parameters were observed; however several trends were observed: Seaweed
extract spray resulted in a trend towards larger number of clusters but smaller clusters compared with control in NS. Also, there was a trend towards greater YAN with 5 times application frequency compared with 3 times in NS. The 5 L/ha seaweed extract rate resulted in a trend towards lower juice pH in BC compared with control and 2.5 L/ha rate. No N benefits of seaweed extract application were detected in BC but there was trend towards higher leaf water potential in seaweed extract compared with control in BC.
Most of the trends were observed with 5L/ha and 5-6 time application of seaweed extract. Applications before bloom can be easily missed due to fast growth rate of vines. Therefore it make sense to have one application before full bloom and 5 application after full bloom. There is merit in including the soil application but not to replace foliar application. Possible effect on roots at 5-10 mL/L (Li and Mattson, 2015). The measurement to focus on are: clusters (number, size, looseness), Juice pH, YAN, LWP, trunk diameter, winter hardiness, mycorrhizae, cane analyses, and soil microbial activity. Due to high variability in the field it is recommended to increase the number of replications from 5 to 6.
- Mehdi Sharifi and Francisco Diez, AAFC Summerland and Perennia Agriculture and Food Inc.
Activity 11 - Grape & Wine Nitrogen Management
Activity objectives in the second year were completed successfully including the first series of aerial imaging. Field trials with Cabernet Sauvignon, Cabernet Franc, Sauvignon blanc and Pinot gris to evaluate the impact of foliar urea applications on vine and fruit N status were also used to begin development of remote sensing models for Plant N status. Wines were made from the trials and the chemical and sensory analysis are continuing on schedule. Differences are already being observed in fruit N content and developmental indicators. Red varieties had better uptake of foliar N compared to the white varieties and we find impacts on must and wine chemical composition due to the differences in N status of the must.
- Kevin Usher, AAFC Summerland
Activity 12 - TanninAlert: improving red wine quality and consumer acceptance
Over the last decade, the increasing popularity of red wines has driven consumer market growth in Ontario and Canada. However, foreign imports have profited the most from these recent trends, representing about 84% of red wine sales nationally in 2014-2015. Similar trends are reported in Ontario, with red wine representing 60% ($1.2 billion) of total wine sales, yet only 22% ($149 million) of red wines sold are from Ontario wineries (2014-2015 Liquor Control Board of Ontario, LCBO).
Consumers favour wine products/brands that demonstrate a consistent quality despite annual weather or vintage variations. The dominant market share by foreign imports emphasizes a clear challenge faced by many of Ontario’s wineries – that of producing consistent, high quality red wines. Given the overall trend of increased red wine consumption in Ontario and Canada, there is a tremendous opportunity for growth in Ontario’s red wine sales and production. However, given its smaller size, higher labour costs and cool climate, Ontario’s wine industry is unable to compete against imports on price alone. Therefore, strategic initiatives that are focused on developing product and process innovations to improve quality are the key to meeting consumer demands and subsequent growth of the industry.
Tannins are one of the most defining components of the quality of red wine. Knowledge of grape tannin concentration and composition at harvest and understanding how to best manage winemaking techniques accordingly are important steps towards improving red wine quality. Achieving the necessary colour, flavour and tannin for consumer acceptance of red wine can be a challenge during some growing seasons, which can lead to unfavourable characteristics in the final wine (less fruity flavours, lighter colour, more green flavours and increased astringency).
One solution to this problem is a unique precision oenology tool for winemakers that measures the maturation of red grapes, specifically TanninAlert. The tool analyzes tannin concentration in skins and seeds separately to evaluate phenolic levels in red grapes, then matches levels to winemaking technique.
The main objective of the overall Tannin project is to improve Ontario red wine quality by ensuring grape phenolic ripeness is incorporated into harvest decisions. Scientific knowledge for the Ontario wine industry regarding tannin concentrations in seeds and skins of varieties specific to wine style will be acquired. This will result in red winemaking guidelines tailored to tannin concentrations from the Ontario grape tannin database.
Read the full Tannin Alert update here!
- Debra Inglis, CCOVI at Brock University
Activity 13 - Improving wine quality through mixed and sequential fermentation with indigenous yeasts
Winemaking is a burgeoning industry in Nova Scotia, with many new opportunities to create regionally distinctive products. While commercial yeasts are usually added to grape juice to induce wine fermentation, many native yeasts reside naturally on grape skins and can noticeably influence wine flavour (the “microbial terroir”). There is therefore recent interest in natural, or spontaneous, fermentations that forgo the addition of commercial yeast and rely on native yeasts to produce wines that are more representative of the local region. Although a lack of control over the end product makes natural fermentations somewhat risky, this can be reduced by using both native and commercial yeasts simultaneously (mixed fermentation), or by allowing the native yeasts to ferment initially, followed by commercial yeast to ensure completion of the process (sequential fermentation).
This project aims to 1) document and characterize the native yeasts in Nova Scotia vineyards, 2) determine their influence on wine quality, alone or in combination with commercial yeast, and 3) grow and store promising native yeast strains to produce mixed starter cultures that can provide the benefits of native yeasts without the risks of fully natural fermentations.
Natural fermentations using grape musts from several Nova Scotia vineyards have been carried out, and the native yeasts identified by DNA sequencing and characterized with respect to their fermentative properties. The flavour and aroma of the products of the natural fermentations are also assessed by a wine panel in order to link the quality of the final products to the occurrence of specific assemblages of native yeasts.
Natural fermentations varied greatly in their content of residual sugars, ethanol, glycerol and certain phenolics. Musts containing small quantities of particular species of native yeasts produced vigorous fermentations, while those with different yeast species were sluggish. Promising native yeasts that were tolerant to both ethanol and sulfur dioxide were selected as potential components of mixed starter cultures.
The results of this research will allow local winemakers to begin utilizing the native yeasts found in their vineyards to create distinctive wines with qualities reflecting the Nova Scotia wine making region.
- Lihua Fan, Gavin Kernaghan, AAFC Kentville and Mount Saint Vincent University
Activity 14 - Improving sparkling and still wine quality: preventing high volatile acidity, honey off-flavour and other faults through Canadian yeast isolates
In wines, a limited amount of “sweet/honey” flavour contributes to the complexity of wine, but at high levels, is considered a fault (Campo et al. 2012). It has been observed by sparkling producers in Canada Ontario that sparkling wines in Ontario produced with Pinot noir grapes (susceptible to sour rot) can have an obvious “sweet/honey” flavour. With sparkling wine production on the rise across Ontario, it is critical that this issue is addressed. Recently, two specific aroma compounds have been identified in wine that cause this “sweet/honey” off-flavour, namely Ethylphenyl acetate (EPhA) and Phenylacetic acid PhAA (Campo et al. 2012). Both compounds have also been reported to contribute to “sweet/honey” off-flavour in wines made from grapes that contain some sour rot (Campo et al. 2012). It is unclear as to when these problem compounds originate, and the direct linkage to sour rot development in grapes. It could be that the grapes have high levels of the precursor, and the sour rot microbial complex acts on the precursor contributing to the “sweet/honey” off-flavour when sour rot develops in the fruit. Alternatively, commercial yeast could be forming these compounds during fermentation when acetic acid levels are high in the starting must (such as when sour rot grapes are present) through esterification reactions with other fermentation metabolites.
PhAA is a plant-growth regulator so it could possibly be produced in grapes susceptible to sour rot as a growth response to an alteration of the surface of the grapes. No studies to analyze the grapes before, and after, sour rot to measure the precursor PhAA and the metabolite EpHA have been carried out. We hypothesize that these compounds are high in grapes as they begin to break down internally from sour rot, and then are transferred to the must and ultimately the wine. Studies have not been carried out on Ontario varieties in Canada prone to sour rot used in red table wines and sparkling wines (Pinot noir). Consumer threshold levels have been identified in wines made from the Portuguese red grape variety Trincaderia. However, the “sweet/honey” off- flavour also appears to be increased by the common nitrogen additive Diammonium phosphate (DAP) during fermentation and lees aging. It is essential we test grapes harvested for sparkling wine that are known to be susceptible to sour rot, for the precursor and the metabolite (Torrea et al. 2011, Campo et al. 2012). The thin-skinned Pinot noir is particularly susceptible to sour rot, widely planted across Canada in Ontario and used in sparkling wine production.
The overall objectives of this project are to identify if two “sweet/honey” off-flavours caused by ethyl phenylacetate (EPhA) and phenylacetic acid (PhAA) are present in Pinot noir grapes as a result of sour rot infection as well as in sparkling and still wines fermented from those grapes. We will test consumer acceptance of the compounds in red and sparkling wines; and test if natural indigenous yeast isolates from Canadian vineyards can remove the compounds along with acetic acid. An indigenous yeast isolated from an Ontario vineyard will be trialed for commercial scale red wine production.
Read the full Improving sparkling and still wine quality update here!
- Belinda Kemp, CCOVI at Brock University
Activity 15 - Plant Parasitic Nematodes
Plant-parasitic nematodes (PPNs) are soil-dwelling microscopic roundworms that parasitize the roots of grapevines as well as many other horticultural crops. While PPNs are already well recognized as significant pests in most major grape-growing regions of the world, their impacts on grapevine health in the Okanagan Valley and other cool climate growing regions of Canada are not well known. PPNs generally affect overall vigour of grapevines but without presenting any more specific signs or symptoms that are easy to identify. Consequently, they are often overlooked or confused with other soil issues such as poor fertility or water-holding capacity. The overall goal of this project is to improve knowledge of the species of PPNs found in Canadian vineyards, their distribution among vineyards, and their relationships with other stresses on grapevines, notably water stress, and crown gall and trunk diseases.
Research activities conducted through 2018 and 2019 have revealed that the ring nematode (Mesocriconema xenoplax), as yet undetermined species of dagger nematodes (Xiphinema species), and at least two different species of root-lesion nematodes (Pratylenchus penetrans, P. neglectus) are widespread in British Columbia and Nova Scotia vineyards. Ongoing field and greenhouse experiments conducted in collaboration with AAFC plant physiologists and plant pathologists are assessing relationships between the presence and abundance of these nematodes, measurements of vine water stress in relation to irrigation practices, and the expression of crown gall and trunk diseases. Ongoing research is also confirming the species identity of the Xiphinema and Pratylenchus species found in Canadian vineyards, which is crucial for understanding their potential impacts on grapevine health.
- Tom Forge, AAFC Summerland
Activity 16 - Novel approaches to IPM strategies for climbing cutworm in grapevines
As reported in the first year (2018) summary, eggs and larvae of two winter climbing cutworm species, Noctua comes and Abagrotis orbis were obtained from Dr. Tom Lowery, AAFC, Summerland, in July 2018 and have been reared at 15 °C in rearing facilities and growth chambers at the laboratory of the Institute for Sustainable Horticulture (ISH), KPU since then. Larvae are fed McNeil’s Full diet with the addition of bok choy and kale grown at the ISH greenhouse facility. The efficacy of the entomopathogenic nematodes, EPNs, Heterorhabditis bacteriophora, Steinernema carpocapsae, and S. feltiae (Koppert Biological Systems) and the isolates of Beauveria bassiana (ISH-189, ISH-190, ISH-252, and ISH-272 from the coastal area of BC, OK-372 and OK-373 from the Okanagan region of BC, and one tropical isolate, ISH-171) against 2nd and 4th instar N. comes and A. orbis were evaluated in the laboratory. The bioassays were conducted at 15°C, 17°C, 20°C, and 25°C. In the second year, 2019, efficacy bioassays of the nematodes and B. bassiana isolates were continued and the optimal concentrations of the most efficacious nematodes and the isolates were selected to use in combination against the cutworm larvae.
- Deborah Henderson, Kwantlen Polytechnic University
Activity 17 - Grape & Wine Leafhopper Management
CGCN project activity #17, contains five research objectives contributing to the sustainable management of leafhopper pests of grapes. The aim of the Anagrus egg parasitoid studies conducted in ON and BC is to utilize morphological and molecular diagnostic techniques to identify alternate leafhopper hosts for the parasites, determine if a 3rd Anagrus wasp species has arrived in BC, and understand why Virginia creeper leafhopper (VCL) populations have decreased dramatically in certain areas of the Okanagan. Protocols have been developed and large numbers of leafhoppers and Anagrus parasitoids have been collected from the Niagara region of ON (Parent, Renkema) and from the Okanagan (Lowery) and Fraser Valleys (Abram) of BC. Molecular diagnostics (Gariepy) have been completed on a large number of leafhopper and Anagrus specimens; some Anagrus will now be sent to Dr. S. Triapitsyn, UC Riverside and leafhoppers to Ottawa (Kits), for species confirmation. The 2nd objective of this study, an extension of the 1st, is now to collect Anagrus and their leafhopper hosts from plants during the spring and summer with the goal to identify plants that might be used to enhance parasitism of VCL or western grape leafhoppers in Okanagan vineyards.
Building on previous research showing a strong feeding deterrent effect to leafhoppers for certain fungicides, feeding choice test bioassays have been completed (Lowery) to date on 9 surfactants, 9 plant essential oils, and 9 commercial products formulated from plant essential oils. Leafhopper control for those that were strongly deterrent to VCL nymphs in the lab will now be assessed in greenhouse and field spray trials. Supplies are in place and protocols developed for planned laboratory insecticide efficacy screening trials (Lowery). A replicated field spray trial was conducted in 2019 to assess the effectiveness of PureSpray Green horticultural oil in comparison to Vegol spray oil. Should restrictions be lifted in time, we hope to carry out additional spray trials in 2020. The final objective is to develop a model of leafhopper development and improve the accuracy of damage thresholds in relation to short periods of deficit irrigation. Leafhopper populations will be sampled from replicated deficit irrigation study plots established (Bowen and Bogdanoff) in 2019, and irrigation will be established for an additional deficit irrigation study in 2020 (Lowery). Temperature and phenology-based leafhopper development models are also being developed to help producers determine appropriate timing to apply control measures (leaf removal, sprays).
Variance – there are concerns that reduced levels of student assistance and quarantine restrictions related to the virus pandemic will prevent completion of all the outlined objectives.
Read the full Leafhopper update here!
- Tom Lowery, AAFC Summerland
Activity 18 - Mitigation of infestations of multi-coloured Asian lady beetle (MALB)
Multicoloured Asian lady beetle (MALB) is a serious pest in wine and juice grapes in North America as beetles enter vineyards in the autumn and are harvested along with the grapes. When disturbed or crushed during grape processing, MALB release methoxypyrazines that taint the juice. If a single MALB is observed in a vineyard at harvest, many wineries require that it be treated with insecticides. Methods for controlling MALB in vineyards are largely limited to the use of insecticides. The goal of this research project is to evaluate alternative methods for removing MALB from vineyards and harvested material. Before harvest, behavior-modifying chemicals, such as repellents, can be used to discourage MALB from aggregating in vineyards. Alternatively, removal of MALB during sorting is a possibility and technologies exist that promise to do so, but these have not been thoroughly evaluated for MALB or their impact on methoxypyrazines.
Read the full MALB update here!
- Wendy McFadden-Smith, CCOVI at Brock University
Activity 19 - Using ground cover to control soil bourne pathogens in grapevines
The role of groundcover in pathogen control is largely unknown, yet it is well known plants can alter the composition of soil fungal communities. Increasing the biodiversity of Canadian vineyards above ground may have advantages beyond pathogen suppression, including improved nutrient retention, improved soil structure, reduced herbivory. These ecosystem services will become increasingly important as growers experience the effects of future climate regimes. Although grape growers are eager to exploit cover crops as biofumigants there is insufficient evidence to recommend particular crops or combinations. We will test the role of plant identity in cover crops in viticulture on the incidence and abundance of common trunk fungal diseases.
Read the full groundcover update here!
- Miranda Hart, University of British Columbia-Okanagan
Activity 20 - Crown Gall Disease of grapevines: identification, bio-control and sustainable management strategies
Crown gall of grapevines, caused by the bacterium Agrobacterium vitis, is an economically important disease in grape-growing regions with a continental climate, particularly in those where winter freezing occurs. Crown gall significantly reduces plant vigor and the disease may cause partial or complete vine death, especially in young vines, resulting in significant economic losses for the grapevine industry. The disease is found in many vineyards in BC and ON and seems to be on the increase, likely due to introduction of A. vitis through contaminated nursery stock. The pathogen can also be present in vineyard soil, enters the vine through wounds in plant roots and trunks caused by winter freezing and survives systemically in grape plants. Galls can be formed in trunks or even in 1-year-old canes.
To determine the level of A. vitis contamination in nursery stock, a total of 536 vines representing 22 winery/nursery/cultivar variations were tested to quantify A. vitis abundance. More DNA isolated from nursery stock will be tested.
Because there is currently no chemical or biological control available for grapevine crown gall, soil from vineyards with crown gall in the Okanagan and from Ontario were sampled. Bacteria residing in the soil or in the roots of grapevines were isolated and tested for their potential to inhibit A. vitis. Fourty-six bacteria were able to inhibit growth of A. vitis on a plate to some extent. The bacteria will undergo more testing both in the laboratory and in greenhouse studies and may result in potential biocontrols to inhibit A. vitis.
Compost has been associated with prevention of crown gall in fruit trees and in vineyards. Mechanisms that explain the suppressive effects of composts include competition for nutrients and colonization sites, hyperparasitism, antibiosis, induced systemic resistance and systemic acquired resistance. Other benefits of compost amendment include improved water-use efficiency, increased soil carbon, reduced nitrous-oxide emission and pH stabilization. We have applied three different composts to a vineyard with a severe crown gall infection. Data analysed to date suggest that compost did not have an effect on A. vitis disease or vine performance, except that Glengrow compost increased berry TA when compared to Superior Peat compost. These results are not surprising as the effects of composts are usually not observed until at least three years after application.
In addition, plans to establish a new experimental site to test the effects of compost when healthy nursery stock is planted into contaminated soil are finalized and planting will commence May/June 2020.
- Louise Nelson, University of British Columbia - Okanagan
Activity 21 - Grape & Wine Trunk Diseases
The long term economic viability of the grapevine industry relies on healthy planting material and effective disease management strategies in vineyards. Nowadays, grapevine trunk diseases (GTD) are considered one of the most important biotic factors limiting both grapevine production and vineyards’ lifespan not only in Canada but worldwide. Currently, no chemical/biological products are registered in Canada against GTD fungi. In addition, there is a lack if information of the best cultural practices that can be used to minimize the impact that these diseases have on vineyards under Canadian environmental conditions. Accordingly, the overall objective of this research project is to develop and implement effective management strategies against GTD in both young and mature vineyards in Canada. Within this main objective we also aim to investigate the health status of ready-to-plant grapevine nursery material in Canada regarding GTD pathogens and to better understand different stress conditions that may contribute to disease development in young vineyards. Significant progress has been made in all the objectives during 2019-2020 work year.
Read the full Trunk Diseases update here!
- Jose Urbez-Torres, AAFC Summerland
Activity 22 - Grape & Wine Terroir and Precision
The Activity progressed on track this year with substantial work accomplished in all four objectives:
1. Vineyard soil carbon levels are being determined in all growing regions of the Okanagan and Similkameen valleys. Soil samples were collected from 10 vineyard sites and neighbouring natural sites and are being prepared for analysis. Sampling will continue in 2020-2021. Newly established vineyards were GPS mapped and their soils characterized for mapping. Descriptions of five geographical indications (GIs), based in part on the viticulture GIS, were developed for submission, and five GIs approved as official by the Province of BC.
2. An experiment was conducted to determine the interactive effects of irrigation rate and cluster exposure on canopy function and size, and fruit quality. Drone based thermal imagery was used to assess water stress.
3. Drone based thermal, multispectral, and hyperspectral images were developed in commercial vineyards to assess water stress and vine N status. Ground-truthing measurements enabled determination of relationships between imaged spectra and vine stress and N status.
4. An intense imaging campaign enabled exploration of relationships between reflected spectra and vine infections by leaf roll virus and red blotch virus. Ground truthing included measurements of leaf gas exchange, leaf spectra, and analyses of leaf pigments and N content. Data analysis developed a spectral signature for each infection for potential used as a diagnostic tool. The highest accuracy for a signature developed was 80%, sufficient to use only as a pre-screening diagnostic. Lab-based molecular diagnosis would be needed to verify virus infections.
- Pat Bowen, AAFC Summerland
Thank you to our funding Partners:
Agriculture & Agri-Food Canada through the Canadian Agricultural Partnership
