As we close the first 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., Conciel 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 4 years of the program. For more information, please contact us.
Activity 2 - Grape and Wine Viruses in British ColumbiaRead full Grapevine Leafroll 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 large-scale vineyard sampling and testing for GLRaV-3 and GRBV were completed as expected.
- The geolocation and testing of individual vines were completed as expected.
- The evaluation of the effects of solo and combined infections on cold hardiness was initiated and is being completed this spring.
- Justin Renkema and Wendy McFadden-Smith, AAFC Vineland and CCOVI at Brock University
Activity 4 - Evaluation of Viruses
A survey was conducted in 20 varietal blocks in 2018, to establish the status of grapevine viruses in 4 varieties currently grown in Nova Scotia (NS). A total of 410 composite samples (representing approximately 1800 individual vines) were collected from vineyards and tested for the presence of Grapevine Leafroll associated Virus-1 and -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 multiple viruses and also a new record for NS with samples positive for GPGV. Results further support the need for continued efforts towards best practices for virus mitigation. Given the virus status in NS and observed trends in regional climate change, sustainable vector management is now recognized as a major priority for our industry, especially given that the potential vector for GPGV is Erinea mite, a common vineyard pest in NS. Soil samples were also taken from the 20 varietal blocks surveyed for virus, to establish the composition of plant parasitic nematodes throughout the wine-grape regions in NS. Lesion, ring, dagger, root knot and pin nematodes were found. In general, nematode numbers may be impacting some NS vineyard blocks but not at serious levels. In preparation for the intensive vine performance study and fruit and wine evaluation, approximately 480 individual vines were sampled and tested for GLRaV-1 and GLRaV -3, GRBV, and Grapevine Rupestris Stem Pitting Virus. Testing methods were the same as was described earlier and done at the Cool Climate Oenology and Viticulture Institute, Brock, Ontario. Due to the uneven distribution of infected and not infected vines in the commercial blocks tested in 2018, cuttings have also been collected and have been propagated for use in potted plant trials at KRDC. Vector surveys, vine performance and fruit evaluations will begin in the 2019 field season. Results have been shared with wine-grape producers and regular progress updates will continue to be provided to industry stakeholders.
- 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. Grapevine health and productivity are a function of the site and climatic conditions during the growing season but also during the dormant period. To help understand cold hardiness, methods and models to evaluate bud freezing were developed. Screening cultivars under field conditions over several years in different regions provides information on cultivar suitability to growing site and environmental conditions that contribute to injury. Controlled freeze testing was developed in order to evaluate freezing tolerance under specific controlled conditions. Frozen supercooled tissues can be measured by differential thermal analysis (DTA). The temperature at which freezing occurs, referred to the low temperature exotherm (LTE), indicates the lethal temperature. Bud protection from winter freezing damage is essential for grapevine production in northern regions and is directly related to the dormant bud. Winter protection methods were developed in order to use cultivars with lower cold hardiness (tender, semi-hardy) in cold regions. Several methods are available such as wind machines, insulating with snow, mulch or soil, and geotextile to reduce winter injury. Moreover, several management practices can modulate cold hardiness or vine acclimation, such as leaf removal, vine nutrition, pruning, training systems and rootstock. Rootstock may influence scion biochemistry and freezing tolerance or indirectly impact freezing tolerance by influencing vine size and canopy shading. However, the use of these methods needs to be matched to specific regions or improved for specific cultivars. The main objective of this project is to improve knowledge of grapevine cold hardiness of hybrids (hardy and semi-hardy) and Vitis vinifera cultivars as well as to provide methods to reduce cold injury under eastern climatic conditions of Canada in order to support the development of the wine production industry. The specific objectives for these activities include: 1) the establishment of a monitoring system for periodic data acquisition on bud hardiness (LTE 10, 50, 90) in order to understand grapevine physiology related to cold hardiness and to support producers in optimizing the use of frost protection methods; 2) knowledge acquisition on winter protection systems with geotextile (or other material) in order to optimize grapevine winter protection and consequently to increase yield and fruit quality; and 3) evaluate of the impact of rootstocks on scion acclimation (by direct or indirect effect) that can modulate cold hardiness, yield and fruit quality. Data collected under different trials will allow an increase of knowledge of grapevine physiology and cold hardiness for several cultivars. 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. La santé et la productivité de la vigne sont fonction du site et des conditions climatiques pendant la saison de croissance, mais également pendant la période de dormance. Pour aider à comprendre la résistance au froid, des méthodes et des modèles d'évaluation de la résistance des bourgeons ont été développés. La sélection de cépages dans des conditions de terrain sur plusieurs années dans différentes régions fournit des informations sur l'adéquation des cépages au site de culture et sur les conditions environnementales contribuant aux dommages. Des tests de congélation contrôlée ont été mis au point afin d'évaluer la tolérance au gel dans des conditions contrôlées spécifiques. Les tissus en surfusion congelés peuvent être mesurés par analyse thermique différentielle (DTA). La température à laquelle cela se produit, appelée exothermie à basse température (LTE), indique la température mortelle. La protection des bourgeons contre les dommages dus au gel hivernal est essentielle pour la production de vigne dans les régions septentrionales et est directement liée au bourgeon dormant. Des méthodes de protection hivernale ont été mises au point pour utiliser des cépages moins résistants au froid (tendres, semi-rustiques) dans les régions froides. Plusieurs méthodes sont disponibles, telles que les machines à vent, l'isolation avec de la neige, du paillis ou de la terre et le géotextile pour réduire les dommages dus à l'hiver. De plus, 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. Cependant, l'utilisation des différentes méthodes doit être adaptée à des régions spécifiques ou améliorée pour des cépages spécifiques. 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. Les objectifs spécifiques de ces activités comprennent: 1) la mise en place d'un système de suivi pour l'acquisition périodique de données sur la résistance des bougeons (LTE 10, 50, 90) afin de comprendre la physiologie de la vigne liée à la résistance au froid et d'aider les producteurs à optimiser l'utilisation des méthodes de protection contre le gel; 2) l’acquisition de connaissances sur les systèmes de protection hivernale avec géotextile (ou autre matériau) afin d'optimiser la protection hivernale de la vigne et d'accroître le rendement et la qualité des fruits; et 3) l'évaluation de l'impact des porte-greffes sur l'acclimatation du greffon (par effet primaire ou secondaire) pouvant moduler la résistance au froid, le rendement et la qualité du fruit. Les données recueillies dans le cadre des différents essais permettront d’accroître les connaissances sur la physiologie de la vigne et la résistance au froid de plusieurs cépages. 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 également générées 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
Read full Grapevine Bud Hardiness Testing report here!
- Carl Bogdanoff, AAFC Summerland
Activity 7 - Grapevine evaluation and cold hardiness program
Jim Willwerth - This activity is based in Ontario but is in conjunction with sub-activities in Nova Scotia to support the Canadian Grapevine Certification Network (CGCN). The goal of this activity is to achieve research outcomes that can be integrated into decision-making processes of establishing clean, high performing plant material for the Canadian grape and wine industry and provide superior grapevine selections for Ontario and Nova Scotia’s diverse growing regions in order to optimize vine performance and fruit quality with distinct character. The main objectives of this activity include: 1) Maintaining formal variety x clone x rootstock evaluation blocks to ensure vines remain free of leaf roll associated and red blotch viruses and are ‘true to type’; 2) Determining the best combinations of clone x rootstocks for Ontario’s core V. vinifera cultivars for high performance in varied Ontario climate and diverse soils; 3) Understanding of scion x rootstock combinations and how they perform under various environmental conditions, both during the growing and winter seasons and; 4) Selection of clones that are superior with respect to cold tolerance and reduced freeze injury. Through these objectives we will help to improve vine health, consistency, quality and sustainability of VQA-approved varieties grown in Canada. This research activity will allow our industry to make informed choices for future plantings to reduce risk, increase profitability, and match vine material to site and consumer preference over the long term.
- 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. Despite the obvious advantages of CM and FZM on grape quality the precise impact on disease development is not so well documented. Consequently, these practices are considered as good practices but generally do not influence disease management. The effects of canopy and fruit zone management on disease management are expected to be variable and depend on timing of CM, cultivars, and climate. The aim of this project is to examine the influence of both canopy and fruit zone management on disease development and disease management decisions under climatic conditions of Eastern Canada. There are gaps in the understanding of when and how the practices should be applied and what effect they have on the development of grape diseases. During the first year of the project, a questionnaire (survey) was developed to evaluate grape grower practices related to canopy and fruit zone management, equipment usage, time required/ha, timing, impact on their disease management program and their expected outcomes. Data collection is currently in progress. This project evaluates some parameters of canopy and fruit zone management and results will be included in a comprehensive strategy developed to reduce disease occurrence and fungicide resistance development under northeastern conditions. This research will provide a better understanding of the best canopy and fruit zone management practices and the benefits for grape and wine producers.
Les scientifiques et les spécialistes du raisin s'entendent pour dire qu'une bonne gestion du couvert végétal et des zones fruitières est une pratique essentielle pour obtenir une bonne qualité de raisin. La gestion de la canopée (CM) comprend la taille, l’éclaircissage des pousses, l’élimination des gourmands, le positionnement des tiges, le rognage, l’écimage et toute autre pratique de manipulation des tiges et des feuilles. La gestion de la zone fruitière (FZM) implique l’élimination des feuilles autour de la grappe. L'objectif ultime de CM et de FZM est d'améliorer les profils d'arôme, de saveur et de pigments du raisin, de favoriser une maturité plus précoce et de réduire les maladies. Malgré les avantages évidents de la CM et de la FZM sur la qualité du raisin, l'impact précis sur le développement des maladies n'est pas aussi bien documenté. Par conséquent, ces pratiques sont considérées comme de bonnes pratiques mais n’influencent généralement pas la gestion de la maladie. Les effets de la gestion de la canopée et des zones fruitières sur la gestion de la maladie sont souvent variables et dépendent du moment de la pratique, des cépages et du climat. L'objectif de ce projet est d'examiner l'influence de la gestion de la canopée et de la zone fruitière sur le développement des maladies ainsi que sur les décisions de gestion des maladies dans des conditions climatiques de l'est du Canada. Plusieurs aspects sont manquant pour la compréhension du moment et de la manière dont les pratiques doivent être appliquées ainsi que de leurs effets sur le développement des maladies du raisin. Au cours de cette première année du projet, un questionnaire (enquête) a été mis au point pour évaluer les pratiques des vignerons en matière de gestion du couvert végétal et des zones fruitières, les équipements utilisés, le temps nécessaire / ha, le calendrier, l’impact sur leur programme de gestion des maladies et les résultats attendus. La collecte des données est en cours. Ce projet évalue certains paramètres de la gestion de la canopée et des zones fruitières et les résultats seront inclus dans une stratégie globale développée pour réduire l'apparition de maladies et le développement de la résistance aux fongicides dans les conditions du nord-est du Canada. Cette recherche permettra de mieux comprendre les meilleures pratiques de gestion du couvert végétal et des zones fruitières et de démontrer les avantages de ces pratiques pour les producteurs de raisin et de vin.
- Odile Carisse and Caroline Provost, AAFC CRDH and Centre de Recherche agroalimentaire de Mirabel
Activity 9 - Optimization of grape production in Eastern Canada
The primary objective of Activities 1 and 2 of Activity 9 is to have a thorough understanding of the maturation of berries in Vitis varieties grown in Eastern Canada using sensory, metabolomic and transcriptomic analysis of berries (Activity 1) and, on the other hand, to understand the impact of harvest date on wine quality for grape varieties grown in Eastern Canada (Activity 2). For these two activities, the objective of this first year of study was to develop analytical methods needed to monitor metabolites of interest in berries, including primary metabolites and free and bound volatile compounds. These methods have been developed. Calibration and validation steps are in progress.
- 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 health promoting products (i.e. seaweed extract (SWE) and high quality organic amendments (i.e. vermicompost (VC)). Seaweed extract has been used in wine grape production to improve plant establishment, rachis stretch, increase set, and to enhance yields. In addition visual improvements in color uniformity, wine quality with application of SWE have been observed. Lower number of pathogens and higher concentration of nutrients is reported for VC compared with traditional compost. Studies on use of VC in vineyards have reported that VC can increase grape yield, supply high amount of nutrients, enhance arbuscular mycorrhizae fungi colonization, and suppress populations of parasitic nematodes. The suppression of powdery mildew and botrytis bunch rot pathogens of grapevine with different biology and epidemiology by VC tea indicates the potential for its use as an integrated disease management sterategy. The recent detection and quantitation of cytokinins in VC tea provided direct evidence to explain the growth efficacy of applying VC tea in order to enhance plant growth and development. The effect of SWE, VC and VC tea on grape yield, yield quality and soil nitrogen dynamics were evaluated in two commercial vineyards in Okanagan Valley, BC. Interim data did not show any significant effects of above treatments on yield or yield quality parameters; however petiole N at veraison were significantly increased in order of 0.65, 0.80, 0.96, and 1.07% with VC application rate of 0, 15, 30 to 45 tons fresh weight basis ha-1 row, respectively. Preliminary data showed a positive trend in yield (14%), average numbers of clusters (7.3%) and berry size (2.7%) with application of VCT (5 applications at E-L growth stages of 13, 15, 19, 23, 28 and 31; 1:25 compost to water ratio; 800 L ha-1 spray rate) compared with control (distilled water). The SWE increased the berry size. A grape block for testing SWRT was established.
Ground cover in vineyards suppresses weeds and contributes to several essential ecosystem services, such as, water infiltration, carbon sequestration, nutrient retention, soil erosion control, and provision of habitat and biodiversity. Despite increasing interest in the adoption of cover crops in vineyard systems, there remains concern over the implications of competition between grapevines and cover crops for water and nutrient availability. The positive role of biochar on regulating water availability in vineyards with cover crops has been reported in Mediterranean climates, but the implications for fruit quality and yield are poorly understood. Charging biochar with compost can reduce subsequent nitrogen and carbon losses, enhance carbon sequestration, and increase mineral N through accelerated mineralization. The interactive effects of charged biochar and cover crop in the alleyways on grape yield and yield quality and cover crop biomass were examined of a Merlot (Vitis vinifera L.) vineyard in the semi-arid Okanagan Valley, British Columbia, Canada. Cover crop and charged biochar treatments were applied to the alleyways in a factorial design. Both alleyway cover crops and amendment with charged biochar increased fruit yield by ~ 42%; however, combination of the two treatments did not change the yield compared with vegetation-free, unamended control treatments.
- Mehdi Sharifi and Francisco Diez, AAFC Summerland and Perennia Agriculture and Food Inc.
Activity 11 - Grape & Wine Nitrogen Management
Activity objectives in the first year were completed successfully with the exception of the aerial imaging component which will begin next year. Field trials were successfully established to evaluate the impact of foliar urea applications on vine and fruit 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. We expect to find impacts on wine quality and 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. 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 and must look to quality improvements. 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). Ripe tannins are phenolic compounds found in the skins and seeds of grapes that impart many desirable qualities to red wine, but over-extraction of tannins can severely reduce quality. 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 red wine quality by ensuring grape phenolic ripeness is incorporated into harvest decisions. The Tannin Alert database has now been established with skin and seed data included for 6 red grape varieties: Pinot noir, Cabernet franc, Cabernet sauvignon, Gamay, Syrah and Merlot. For these six red varieties, the tannin profile in the skin and seed is available from veraison to harvest. The database at harvest now has skin and seed values input for the past four years for Pinot noir, Cabernet franc and Cabernet Sauvignon and for the past two years for Gamay, Syrah and Merlot. In year 1 of the CGCN project, winemaking techniques were compared among Pinot noir, Gamay, Cabernet franc and Cabernet sauvignon. Difference testing and consumer preference testing among the treatments for each variety are now underway.
- Debra Inglis, CCOVI at Brock University
Activity 13 - Improving wine quality through mixed and sequential fermentation with indigenous yeasts
The Nova Scotia wine industry is experiencing rapid growth, and with this comes a desire for distinctive wines that reflect attributes of the region and of individual vineyards. Local variation in wine characteristics has traditionally been thought to be due to physical factors such as soil type and climate. However, it is now becoming clear that there is also a biological aspect to wine variability, imparted by differences in local microbial communities - the “microbial terroir”. This includes native yeasts that reside in vineyard soils and on grape leaves and skins. These yeasts are active early in the fermentation process and can influence wine colour, acidity and viscosity, as well as alcohol, glycerol, sulphur and phenolic contents, potentially exerting strong positive or negative influences on wine flavour and aroma.
There has been a recent increase in interest in “natural” (spontaneous) fermentations that utilize only the native yeast already present in the vineyard, as this can produce better textured, more complex wines, with the added advantage of a product that is more representative of the local region. However, many winemakers feel that these benefits do not outweigh the risks related to the lack of control inherent in natural fermentations. A balance between the benefits of natural fermentation and the control offered by commercial yeast might be achieved by allowing the native yeasts to exert their influence initially, followed by addition of commercial yeast to ensure completion of the fermentation (sequential fermentation).
This project aims to investigate the native yeasts in Nova Scotia vineyards, and understand how they influence wine quality, especially in combination with commercial yeast. Another goal is to grow and store promising native yeast strains for the formulation of mixed starter cultures, that will also make the benefits of native yeasts available to winemakers without the risks involved in natural fermentation. Native yeasts are being identified by DNA sequencing and also tested for biochemical attributes. The sensory properties (flavour and aroma) of wines fermented with native yeasts are also being characterised so that this information can be related to the specific assemblages of native yeasts inhabiting individual Nova Scotia vineyards.
- 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
The overall objectives of this project will serve to identify if two “sweet/honey” flavours are present in Pinot noir grapes, still wine and sparkling wine due to sour rot infection. The thin-skinned Pinot noir is particularly susceptible to sour rot, widely planted across Canada, and used in sparkling and red still wine production. In wines, a limited amount of “sweet/honey” flavour contributes to the complexity of wine, but at high levels is considered a fault when it produces dusty, mouldy characteristics. Two specific aroma compounds have been identified in wine that cause this “sweet/honey” off-flavour, namely ethyl phenylacetate (EPhA) and phenylacetic acid (PhAA). This project will determine the detection and consumer threshold levels of the two compounds Pinot noir red and sparkling wines, establish the percent of the compounds in red and sparkling wines and investigate the use of indigenous yeast to reduce their concentrations.
- Belinda Kemp, CCOVI at Brock University
Activity 15 - Plant Parasitic Nematodes
Plant-parasitic nematodes (PPNs) are important pests in most major grape-growing regions of the world. PPNs are difficult to detect in early stages of infestation development, and their effects, which include chronic declines in productivity and predisposition to other stresses, are often misdiagnosed as soil quality issues. The impacts of PPNs on grapevine health in the Okanagan Valley and other cool climate grape-growing regions of Canada are less well-known than for most other major grape-growing regions of the world. The overall goal of this project is to improve understanding of the distribution and potential impacts of species of PPNs in Canadian vineyards. The project began in 2018 with surveys of PPN populations in vineyards throughout the Okanagan Valley and Nova Scotia. Nematodes were extracted, identified and counted from a total of 57 composite soil samples from Okanagan vineyard blocks, and from 37 composite samples from vineyards in Nova Scotia. In the Okanagan survey, ring nematodes (Mesocriconema xenoplax) were found in 82% of the blocks while root-lesion nematodes (Pratylenchus species) and dagger nematodes (Xiphinema species) were found in 81% and 77% of blocks, respectively; as well, northern root-knot nematodes (Meloidogyne hapla), and stubby root nematodes (Paratrichodorus species) were found in 25% and 23% of Okanagan blocks, respectively. In Nova Scotia, 74% of samples had ring nematodes, while root-lesion, dagger and root-knot nematodes were present in 84, 54 and 27% of samples. Previous research indicates that high population densities of ring nematodes can cause significant damage to grapevines, with 1000 ring nematodes per liter soil considered to be an approximate damage threshold for newly planted vines. The average ring nematode population density in Okanagan vineyards was 1030 per liter soil, and 28% of blocks had ring nematode population densities greater than 1000 per liter soil. Greenhouse experiments with an Okanagan population of the most widespread species of root-lesion nematode (Pratylenchus penetrans), indicate that grapevine is not a good host. We speculate that the species persists in Okanagan vineyards feeding on weeds and is not a concern for wine-grape production. In conclusion, results from 2018 indicate that ring nematodes are overall the most important nematode pests of grapevines in Canadian vineyards and deserve to be a primary focus of future research on the impacts and management of PPNs in Canada.
- Tom Forge, AAFC Summerland
Activity 16 - Novel approaches to IPM strategies for climbing cutworm in grapevines
Cutworm is a term that refers to numerous caterpillar species that survive in the soil overwinter and causes extensive damage to plant buds in the early spring. Cutworms can cause significant loss of high value fruit in vineyards due to their wasteful feeding habits and attack on developing buds. Due to the high crop value a low level of bud damage is acceptable in vineyards. Chemical insecticide applications are typically recommended when bud damage is in the range of 2 to 4%. However, chemical insecticides can negatively impact animal and human health, pollinators, natural enemies, fisheries, and lead to the development of resistance in insect pests. Alternatively, biological control makes use of naturally occurring organisms, including nematodes, fungi, viruses, and bacteria that can infect and kill pests.
The objective of our study is to examine the efficacy of nematode species and fungal isolates of Beauveria bassiana and combinations that are pathogenic to cutworm species as alternatives to chemical controls. Cold tolerant nematodes and fungal isolates would offer the most promise, since our aim is to target cutworms (Noctua comes and Abagrotis orbis) in the fall when larvae are small and most susceptible. Laboratory trials are currently being performed at temperatures ranging from 15 to 25°C on larvae of varying size. To date, preliminary results indicate that nematode species Steinernema feltiae is the most efficacious against cutworm species, N. comes and A. orbis at low temperatures. Mortality in N. comes and A. orbis larvae treated with Beauveria bassiana is in the range of 20%-50% at temperatures of 15 and 17°C. Higher temperatures increased mortality in both species. In addition, trials planned for 2019 and 2020 will target the use of combinations of these agents with the goal of increasing cutworm mortality. Lastly, trials using potted grape vines will begin this summer to examine the efficacy of these biological agents as an intermediate step. This work is the first stage in reducing the use of chemical insecticides for cutworm control in vineyards and enhancing the sustainability of management practices.
- Deborah Henderson, Kwantlen Polytechnic University
Activity 17 - Grape & Wine Leafhopper Management
Leafhoppers are economically important pests of grapevines in Canada. Feeding by nymphs and adults causes the death of individual leaf cells, resulting in reduced photosynthetic activity and delayed ripening of fruit. Control is currently achieved largely with applications of insecticides, but there is increasing interest in alternative control measures, including enhancement of the activity of predators and parasitoids, particularly Anagrus wasp parasitoids of leafhopper eggs; registration of oils and new insecticides as replacements to neonicotinoids that are of concern for their effects on non-target species; the use of antifeedants or repellants based on plant essential oils; and managed fertility and deficit irrigation. The various components of this proposed research will contribute to the development of a sustainable management program for leafhoppers on grapes in Canada.
Progress on this project was hindered during 2018-2019 due to the late arrival of funds and lack of technical assistance to Dr. Lowery. In spite of these hindrances, substantial progress was made on all objectives. Large numbers of Anagrus wasp parasitoids of leafhopper eggs were collected from dormant winter hosts during spring 2018 in ON and BC. Anagrus were also collected from parasitized leafhopper eggs on grapevines and Virginia creeper vines during the summer and preserved for identification by taxonomic and molecular means. Molecular sequences have been generated for these parasitoids, as well as for a large number of leafhoppers. Completion of a study that included plants that harbor an alternate leafhopper host was unsuccessful due to the unauthorized application of a pesticide spray. Plans to initiate new plantings of alternate host plants have been altered. Instead, research is being conducted to discover alternate early season leafhopper hosts of Anagrus parasitoids that would serve as ‘bridges’ between the time parasitoids emerge from winter hosts and when leafhopper eggs on grapevines are available. A Virginia creeper leafhopper colony has been established at SuRDC and discussions have been had with companies regarding provision of antifeedant materials and insecticides. Oils and other materials are on hand for upcoming field spray trials and laboratory bioassays, and recommendations have been made to the minor use program re. possible new registrations. Plans have been outlined and locations for field trials determined for the study of the effects of deficit irrigation on leafhopper population development. Due to the cost of materials and other factors, initiation of the project was delayed until spring 2019. It is hoped that all outlined objectives will be fully completed by the project end date.
- 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, most 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 harvest and 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.
Alternative compounds for managing MALB were initially evaluated under controlled laboratory conditions in 2017. Many of the products tested successfully reduced berry feeding activity by MALB when evaluated within 2 hours of treatment. Additional potential repellents were tested in 2018-2019 in the lab. Based on results from short-term repellency trials, the most repellent products were tested for long-term repellency (3 days) in the laboratory. Many of these products continued to reduce berry feeding activity by MALB with varying degrees of effectiveness. These results meet the intended outcome of research objective 1.
In 2018, an optical sorter was evaluated for efficacy in removing MALB from commercially harvested fruit artificially infested with MALB. The system reduced the number of MALB in “clean” fruit compared to the initial sample before sorting. These results are working towards meeting the intended outcome of research objective 2, although more trials must be completed.
- Wendy McFadden-Smith, CCOVI at Brock University
Activity 19 - Using ground cover to control soil bourne pathogens in grapevines
Disease control is a major issue for grapevine growers but current disease control is increasingly limited by growing restrictions on, and by resistance to, biocides. Groundcover in vineyards may reduce the incidence of soil borne pathogens in grapevine. Plant diversity and identity can greatly affect the composition of microbes in the soil, especially plant pathogens. Some plants, in particular those in the mustard family, are known to produce metabolites that inhibit the growth of fungi. We are testing the role of plant diversity and origin on the abundance of grapevine diseases in greenhouse and field studies in the Okanagan winegrowing region. We predict that diverse, locally adapted ground covers will be a sustainable way for growers to control vine disease and reduce overall inputs.
- 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 160 vines representing seven winery/nursery/cultivar variations were tested to quantify A. vitis abundance. More nursery stock will be tested when the plant material is received and donated in spring/early summer.
Because there is currently no chemical or biological control available for grapevine crown gall, soil from seven vineyards with crown gall in the Okanagan was sampled. Bacteria residing in the soil or in the roots of grapevines were isolated and tested for their potential to inhibit A. vitis. Sixteen bacteria were able to inhibit growth of A.vitis on a plate weakly, 14 showed medium and 4 showed strong inhibition properties. 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 identified a vineyard with a severe crown gall infection and will apply compost from three different sources to assess its effects on crown gall and vine performance. In addition, a new vineyard will be established and compost treatments to prevent crown evaluated.
- Louise Nelson, University of British Columbia - Okanagan
Activity 21 - Grape & Wine Trunk Diseases
Read full Grapevine Trunk Diseases in British Columbia: From Identification to Control report here!
- Jose Urbez-Torres, AAFC Summerland
Activity 22 - Grape & Wine Terroir and Precision
Substantial progress was made toward meeting Activity 22 objectives in the first year, including: updating the GIS database and developing sub-appellation proposals; completing three hyperspectral imaging campaigns to develop spectral signatures for leaf roll and red blotch viral diseases; completing drone-based IR imaging and ground-truthing measurements to develop guidelines for precision irrigation; and developing a leaf-trait database that defines relationships among leaf reflected spectra, leaf pigment and N contents, and physiological performance (photosynthesis, stomatal conductance, and transpiration). Development of precision N management guidelines, to be initiated in 2019, will be based on calibrations developed from leaf-trait data.
Read full GIS Tools for precision Terroir Management report here!
- Pat Bowen, AAFC Summerland
Thank you to our funding Partners:
Agriculture & Agri-Food Canada through the Canadian Agricultural Partnership