Andrew Reynolds

Grapevines are subjected to many physiological and environmental stresses that influence their vegetative and reproductive growth. Water stress, cold damage, and pathogen attacks are highly relevant stresses in many grape-growing regions. Precision viticulture can be used to determine and manage the spatial variation in grapevine health within a si...

The primary purpose of this study was to improve our understanding of remote sensing technologies and their potential application in vineyards to monitor yields and fruit composition, which could then be used for selective harvesting and winemaking. For yield and berry composition data collection, representative vines from the vineyard block were s...

An undesirable sensory attribute (“floral taint”) has recently been detected in red wines from some winegrowing jurisdictions in North America (e.g., Ontario, British Columbia, Washington), caused by the introduction of frost-killed leaves and petioles [materials-other-than-grapes (MOG)] during mechanical harvest and winemaking. It was hypothesized...

An undesirable sensory attribute (“floral taint”) has been recently detected in red wines in some winegrowing jurisdictions in North America (e.g. Ontario, British Columbia, Washington), caused by introduction of frost-killed leaves and petioles [materials-other-than-grapes (MOG)] during mechanical harvest and winemaking. It was hypothesized that t...

Volatile phenols impart particular aromas to wine. Due to their distinctive aroma characteristics and low sensory thresholds, volatile phenols can easily influence and modify the aroma of wine. Since these compounds can be formed in wines in various ways, it is necessary to clarify the possible sources of each volatile phenol to achieve management...

Grapevine leafroll associated virus 3 (GLRaV-3) is one of the most common viruses that adversely affect grape production quality around the world. Grapevine virus is usually detected by polymerase chain reaction (PCR) tests, but the main diagnostic challenges with the PCR are uneven distribution of symptoms, low virus titers in early stage, and the...

The ability to detect and respond to vineyard spatial variation can lead to improved management—a practice known as precision viticulture. The goal of this study was to determine if remote sensors can enhance precision viticulture applications by detecting vineyard spatial variation. The hypothesis was that differences in vine spectral reflectance,...

Individual vineyards can vary spatially for several viticultural attributes, including water stress, nutrient status, growth/vigour and disease—which can, in turn, impact berry composition and resulting wine products. The goal of this study was to determine if vineyard variability detected by remote sensing using an unmanned aerial vehicle (UAV) co...

“Floral taint”, a unique sensory defect that has been detected in red wines in North America, is caused by frozen leaves and petioles (materials other than grapes; MOG) introduced during mechanical harvest. Responsible volatiles are likely terpenes, norisoprenoids, and esters. Objectives of this study were to investigate volatile compounds that may...

An undesirable sensory attribute (“floral taint”) has been detected in red wines in North America, caused by leaves and petioles (materials other than grapes [MOG]) introduced during mechanical harvest after killing frosts. From 2017 to 2019, several harvest strategies were evaluated on Ontario Cabernet franc: hand harvest (HH), conventional machin...

This chapter discusses the impacts of various cultural practices on fruit composition and wine quality, with an emphasis on aroma compounds. It is framed within four basic pillars of the Cool Climate Paradigm of winegrowing: (1) keep the fruit warm; (2) keep the leaves exposed to sunlight; (3) achieve vine balance; (4) minimize water stress. Practi...

Winter hardiness may be influenced by vineyard terroir-driven factors, and vineyard zones with low water status [leaf water potential (ψ)] could be more winter hardy than vines with high water status (higher leaf ψ). Six Cabernet franc vineyards were chosen throughout the Niagara region in Ontario. Data were collected at fruit set, lag phase, and v...

Aim: The major focus of this research was to explain the so-called terroir effects that impact grapevine yield components, berry composition, and wine varietal character. To elucidate potential contributors to the terroir effect, vine water status [midday leaf water potential (ψ)] was chosen as a major determinant. The hypothesis of this component...

Spatial variability of berry composition was studied over a 3 year period in 10 Riesling vineyards in the Niagara Peninsula in Ontario. Vineyards were delineated using global positioning systems (GPS) and 75-80 sentinel vines were geo-referenced within a sampling grid for data collection. During 2005 to 2007, vine water status measurements [leaf wa...

Freezing-thawing events contribute to the unique aroma profile of icewines. Differences in key odor-active volatile compounds between ‘Beibinghong’ (Vitis amurensis × V. vinifera) icewines and dry wines were investigated by gas chromatography-olfactometry and gas chromatography-mass spectrometry. Acceptable agreement between the olfactometric and q...

Pinot gris, Riesling, Cabernet franc and Cabernet Sauvignon from a vineyard in Virgil, Ontario, Canada were subjected by cluster thinning to two crop-level treatments (full crop, half crop), combined with three harvest dates (commercial harvest (T0), three weeks after T0 (T1), six weeks after T0 (T2)) in a randomised experiment in 2011 and 2012, wi...

The hypothesis of this research was that the maps based on remotely-sensed images would create zones of different vigor, yield, water status, winter hardiness and berry composition and the wines from the unique zones would show different chemical and sensorial profiles. A second hypothesis was that titer of grapevine leafroll-associated virus (GLRa...

Aims: Determinants of the terroir effect in Riesling were sought by choosing vine water status as a major factor. It was hypothesized that consistent water status zones could be identified within vineyards, and, differences in wine sensory attributes could be related to vine water status. Methods and results: To test our hypothesis, 10 Riesling vin...

The polygalacturonase (PGU), hemicellulase (mannanase) and protease enzyme activities in commercial macerating, pectinase-enzyme preparations commonly used by wineries in Ontario (Scottzyme Color X and Color Pro) were measured under various simulated process conditions (temperature, pH, and ethanol concentration). Treatments included three temperat...

Pinot gris, Riesling, Cabernet franc, and Cabernet Sauvignon vines from a single vineyard in Virgil, Ontario were subjected to two crop levels, full crop (FC) and half crop (HC), in which crop was reduced in HC to one basal cluster per shoot at veraison. Crop level treatments were combined with three harvest dates: T0 (commer-cial harvest), T1 (thr...

Grapevine is one of the longest-domesticated species with evidence of winemaking found in Anatolia dating from ca. 6000 BCE. Its spread throughout the Near East and Europe relied upon: (1) cultivar and later clonal selection and (2) vegetative propagation. Both of these processes encouraged the spread of viruses and increased the potential for infe...

The effects of three irrigation levels [two regulated deficit irrigation treatments (RDI) at 25% and 50% replacement of water loss through crop evapotranspiration, ETc) and 100% ETc] combined with three timings of irrigation initiation [fruit set (FS), lag phase (LP), veraison (VRN)] on the French-American hybrid Baco noir grapes and wines were stu...

Irrigation experiments were conducted on French-American hybrid Baco noir in a vineyard in Virgil, Ontario, Canada, in 2005–2007. Effects on vine physiology, shoot growth, and yield components of three regulated deficit irrigation (RDI) levels [100%, 50%, 25% crop evapotranspiration (ETc)] combined in a factorial experiment with three timings of ir...

The objective of this study was to determine whether yield components and grape berry composition variables were related to and dependent upon soil texture and composition, vine water status (leaf water potential, Ψ), and vine size and to assess whether spatial patterns of leaf Ψ, vine size, and other field variables were temporally stable. Data we...

An irrigation trial was performed in a Chardonnay vineyard in Niagara-on-the-Lake, Ontario, Canada, between 2005 and 2008. Treatments were three irrigation levels based on% of crop evapotranspiration (ETc) [two deficit water regimes (50% ETc, 25% ETc) plus 100% ETc] combined with two times of irrigation imposition [fruit set (FS), veraison (VRN)] p...

Relationships among vine water status, soil texture, and vine size were observed in four Ontario Pinot noir vineyards in 2008 and 2009. The vineyards were divided into water status zones using geographic information systems to map the seasonal mean leaf water potential (Ψ) and cane pruning weight (vine size). Leaf Ψ zones were confirmed using k-mea...

The biosynthetic pathway of abscisic acid (ABA) is well known. The aim of this study was to investigate the relationship among various ABA catabolites in leaves and berries of Chardonnay grapevines grown under various irrigation regimes. An irrigation trial was set up in one vineyard, located in Niagara-on-the- Lake, ON, Canada, consisting of seven...

Precision agriculture is a term referring to a suite of technologies utilized for the optimisation of production in agronomic crops. The overall objective of this research project was to evaluate the usefulness of high spatial resolution proximally sensed observations acquired by the GreenSeeker™ technology for mapping important variables such as y...

The objective of this investigation was to verify usefulness of proximal sensing technology and unmanned aerial vehicles (UAVs) for mapping variables e.g., vine size (potential vigor), soil and vine water status, yield, fruit composition, and virus incidence in vineyards. Twelve Niagara Peninsula sites (six each of Riesling and Cabernet franc) were...

Cabernet Sauvignon (CS) and Cabernet franc (CF) vines were subjected to two crop levels (full, half) and three harvest dates (earliest to latest; T0, T1, T2) over two vintages. Wines were analyzed for anthocyanins, phenolics, and proanthocyanidins. Crop level increased CS hue (2011–2012), increased CS pH and reduced CS color intensity (2012), and r...

Gibberellic acid (GA; 0, 15, or 30 mg/L) and abscisic acid (ABA; 0, 150, and 300 mg/L) treatments were applied alone and in combination to Sovereign Coronation (Coronation) and Skookum Seedless (Skookum) table grapes in 2013 and 2014 to assess their effects on cluster and berry size, berry composition, and sensory characteristics, alone and in comb...

The study objective was to determine whether multispectral high spatial resolution airborne imagery could be used to segregate zones in Pinot noir vineyards to target highest quality fruit for premium winemaking. We hypothesized that remotely sensed data would be correlated with vine size and leaf water potential (ψ), and by extension with yield an...

The talents of French grape breeders were put to a great test in the late nineteenth century. European viticulture was faced with three major devastating crises beginning in the 1870s: first came phylloxera, and thereafter powdery and downy mildew. French breeders eventually settled on two distinct approaches: use of rootstocks resistant to phyllox...

The story of grape breeding in the eastern United States from the beginning of the twentieth century to present is essentially written by the history of the New York State Agricultural Experiment Station in Geneva, NY. The station was established in 1882 and shortly thereafter began work in tree fruit, small fruit, and grape breeding. Over the past...

Grape breeding in Canada has been performed primarily in Ontario and British Columbia, with some activity in Nova Scotia, Quebec and Saskatchewan. In Ontario, a grape-breeding programme was initially established by the Ontario Department of Agriculture Fruit Branch (later the Horticultural Research Institute of Ontario; HRIO) in 1913 under J. van H...

Composite samples of intact grape berries were collected weekly from veraison until harvest. Each sample comprised similar to 400 berries selected following the preharvest row sampling protocol specified by the vineyard manager. The grape cultivars and corresponding number of samples of each collected in 2009 and 2010 were as follows: Cabernet Sauv...

Objectives of this study were to quantify starch and soluble sugar concentrations in wine grape (Vitis sp.) scionwood and rootstock material, and to examine relationships between carbohydrate (CHO) metrics and both grafting success and shoot growth. CHOs of three wine grape scionwood cultivars [Merlot and Riesling (Vitis vinifera) and Vidal blanc (...

Icewine is a sweet dessert wine made from pressing grapes naturally frozen on the vines. It is likely that freeze/thaw cycles endured by icewine grapes change their chemical and sensory profiles due to climatic events. Our objective was to determine the influence of harvest date on icewine must and wine basic chemical variables and aroma compounds....

Potential terroir effects are described that might impact Riesling wine varietal character. In 2005, the Vintners Quality Alliance of Ontario created putative sub-appellations within the Niagara Peninsula based on soil and climate. The objective of this research was to determine differences that might validate sub-appellation designations. It was h...

Aim: The purpose of this study was to determine if multispectral high spatial resolution airborne imagery could be used to segregate zones in vineyards to target fruit of highest quality for premium winemaking. We hypothesized that remotely sensed data would correlate with vine size and leaf water potential (ψ), as well as with yield and berry comp...

Four grapevine cultivars ('Pinot gris', 'Riesling', 'Cabernet franc', 'Cabernet Sauvignon') were subjected to six different field treatments in 2011 [two crop loads (full, half) X three harvest dates [normal (TO), 3 weeks after TO, 6 weeks after TO] in a randomized block design with a factorialized treatment arrangement. All treatments were sampled...

Aim: The efficacy of partial root zone drying (PRD) and regulated deficit irrigation (RDI) on vine physiology, yield components, fruit composition and wine sensory profiles of ‘Cabernet-Sauvignon’ was investigated in a cool climate region in Ontario, Canada. Methods and results: Field experiments were conducted in a Cabernet-Sauvignon block in Niag...

The possible influence of vine water status upon berry composition was studied in ten commercial vineyard blocks of Vitis vinifera L. cv. Cabernet franc in the Niagara Peninsula, Ontario from 2005 to 2007. Soil texture, soil chemical composition, soil moisture and leaf water potential (φ), as an indicator of vine water status, were determined on. 8...

Relationships between vine water status and wine sensory attributes were investigated in four Ontario Pinot noir vineyards in 2008–2009. Vineyards were divided into water status zones based on leaf water potential, and fruit from each zone was vinified. Sensory analysis included multidimensional scaling (MDS) and descriptive analysis (DA). MDS (200...

The relationships among soil and plant water status, plant physiology and the hormonal profiles associated with it, were analyzed in leaves and berries from 'Chardonnay' cultivar. Data was collected during 2006 and 2007 growing seasons. The field trial consisted in seven irrigation treatments: control (non-irrigated), plus three water levels (100,...

Two Vitis labrusca cultivars [Bordô (Ives), Concord] grafted to two rootstocks (1103 Paulsen, VR043-43) were combined in a randomized complete block experiment with a factorialized treatment arrangement in southern Brazil. Clusters were sampled over two seasons (2012, 2013) and analyzed for Brix, titratable acidity (TA) and pH, sucrose, glucose and...

The possible influence of vine water status on grapevine yield components was studied in ten Vitis vinifera L. Cabernet franc vineyards in the Niagara Peninsula, Ontario from 2005-2007 using geomatic techniques. Soil texture, soil chemical composition, soil moisture and leaf water potential (ψ; vine water status), were determined on ≈ 80 sentinel v...

A simple method involving measurement of electrical conductivity of grapevine cane tissue was evaluated. ‘Sovereign Coronation’ vines on two sites were subjected to five irrigation treatments based upon reference evapotranspiration (ET0) and various crop coefficients (Kc): non-irrigated control; 100% ET0 × Kc = 0.75; 150% ET0 × Kc = 0.75 (ET0 × 1.1...

Spatial variability of vine water status and its relationship to soil moisture (SM) and physical properties was studied in ten vineyard blocks of Vitis vinifera L. Cabernet Franc in the Niagara Peninsula, Ontario, using geomatic techniques. Soil texture, soil chemical composition, SM, and leaf water potential (Ψ; vine water status), were determined...

Spatial variability of vine water status and its relationship to soil moisture (SM) and physical properties was studied in ten vineyard blocks of Vitis vinifera L. Cabernet Franc in the Niagara Peninsula, Ontario, using geomatic techniques. Soil texture, soil chemical composition, SM, and leaf water potential (ψ; vine water status), were determined...

The possible infl uence of vine water status on grapevine yield components was studied in ten Vitis vinifera L. Cabernet franc vineyards in the Niagara Peninsula, Ontario from 2005-2007 using geomatic techniques. Soil texture, soil chemical composition, soil moisture and leaf water potential (ψ; vine water status), were determined on ≈ 80 sentinel...

The possible infl uence of vine water status upon berry composition was studied in ten commercial vineyard blocks of Vitis vinifera L. cv. Cabernet franc in the Niagara Peninsula, Ontario from 2005 to 2007. Soil texture, soil chemical composition, soil moisture and leaf water potential (ψ), as an indicator of vine water status, were determined on ≈...

To understand the relationship among soil and plant water status, plant physiology, and the hormonal profiles associated with it, abscisic acid (ABA) and its catabolites [phaseic acid (PA), dihydrophaseic acid (DPA), 7-hydroxy-ABA, 8′-hydroxy-ABA, neophaseic acid, and abscisic acid glucose ester (ABA-GE)] in leaves and berries from wine grape culti...

p style="text-align: justify;"> Aim : The impacts of partial root zone drying (PRD) and regulated deficit irrigation (RDI) on soil moisture, vine water status, yield components, fruit composition and wine sensory profile of Sauvignon blanc were studied in a cool climate region. Methods and results : Field experiments were conducted in a commercial...

Five Chardonnay vineyards in the Niagara Peninsula were delineated according to soil texture using global positioning systems and geographic information systems (GPS/GIS). For three vintages, sentinel vines were classified based on weight of cane prunings (vine size) and the soil texture in which they were grown. Wines were made from vine size x so...

p style="text-align: justify;"> Aims : To investigate the impact of semi-permanent bird netting and timing of its application on Cabernet franc grapevine yield components and fruit, juice, and wine composition. Methods and results : Semi-permanent bird netting was installed over Cabernet franc grapevines at various times – post-bloom, bunch closure...

The main objective of this study was to determine if remote sensing could help segregate vines at harvest and, if treated separately, lead to wines of different sensory properties. A commercial Riesling vineyard, Thirty Bench Winemakers, located in Beamsville (Ontario, Canada) was used for the study. The vineyard was delineated using global positio...

Six irrigation treatments consisting of three reference evapotranspiration (ETo) values (100%, 50%, 25%) and two crop coefficients (K-c) estimated from canopy volume (0.6, or "fixed," and 0.2 to 0.9, or "variable") were imposed on Syrah/110R vines in the Dunnigan Hills (California) in a randomized block containing four replicates and 12 equally spa...

In the Niagara Peninsula, cool years delay veraison, thus shortening the growing season and adversely affecting grape maturity. Exogenous abscisic acid (ABA) could potentially hasten veraison, and improve grape composition in cool and wet years. Two experiments were conducted in a Cabernet Sauvignon block in Niagaraon-the-Lake, Ontario, in 2008 and...

This study aimed to elucidate the odor potency of aroma compounds in Riesling and Vidal blanc (syn. Vidal) table wines and icewines from the Niagara Peninsula using stir bar sorptive extraction-gas chromatography-olfactometry-mass spectrometry. Dilution analysis determined the most odor-potent compounds in Vidal and Riesling icewines (n = 2) and ta...

‘Syrah’ vines in the Dunnigan Hills, California were trained to one of three canopy systems [Smart-Dyson (SD); southern sprawl (SS); full sprawl (FS)] over 3 years. The canopy system had little impact on yield components. The SS had the smallest berries in 2005, and in 2006, both SS and FS had the smallest berries. Soluble solids were highest in SS...

Merlot, Cabernet franc, and Cabernet Sauvignon vines in Niagara-on-the-Lake, Ontario, were subjected to four treatments in a randomized complete block experiment: hedged control, cluster thinning at veraison (CT), basal leaf removal (BLR), and CT+BLR. Musts from each treatment replicate (CT+BLR excepted) were thereafter either left untreated or tre...

Merlot, Cabernet franc, and Cabernet Sauvignon vines in Niagara-on-the-Lake, Ontario, were subjected to four treatments in a randomized complete block experiment: hedged control, cluster thinning at veraison (CT), basal leaf removal (BLR), and CT+BLR. Musts from each treatment replicate (CT+BLR excepted) were thereafter either left untreated or tre...

This chapter discusses the impacts of various cultural practices on fruit composition and wine quality, with an emphasis on aroma compounds. It is framed within four basic pillars of the Cool Climate Paradigm of winegrowing: (i) keep the fruit warm; (ii) keep the leaves exposed to sunlight; (iii) achieve vine balance; (iv) minimize water stress. Pr...

p style="text-align: justify;"> Aim : To examine the impact of vine water status on sensory and chemical characteristics of Cabernet franc wines on non-irrigated sites in the Niagara Peninsula, Ontario, to assess whether vine water status might be a key factor in the determination of so-called terroir effects. Methods and results : The effects of v...

Many aspects of both grape production and winemaking influence wine sensory properties and stability. Progress in research helps to elucidate the scientific basis of quality variation in wine and suggest changes in viticulture and oenology practices. The two volumes of Managing wine quality review developments of importance to wine producers, resea...