Vine Age Research Articles

Occurrence of Grapevine leafroll associated virus-2, −3 and Grapevine fleck virus in Virginia, U.S.A., and factors affecting virus infected vines

A statewide survey of commercial vineyards in Virginia (VA), USA was conducted in 2009–2011 seasons to examine the occurences of Grapevine leafroll-associated virus-2 (GLRaV-2), Grapevine leafroll-associated virus-3 (GLRaV-3), Grapevine fleck virus (GFkV), and mealybugs. Out of 415 samples (comprising 41 wine grape cultivars) from 77 locations (vineyards), GLRaV-2, GLRaV-3 and GFkV were detected by RT-PCR in 8, 25, and 1 %, respectively, and 64 % of vineyards were positive for at least one of the three viruses. Samples from 100 wild Vitis sp. tested negative for the three viruses. Both the grape (Pseudococcus maritimus) and Gill’s (Ferrisia gilli) mealybug were found in VA vineyards. Although regional effect was not significant (P > 0.05), examination of variance showed higher variability of GLRaV-3 incidence at cultivar scale within a vineyard than at a smaller spatial scale (i.e., at sampling site). In addition, the probability of finding a GLRaV-3-infected vine was higher in the presence of mealybugs (P < 0.001) and with increased vine age (P < 0.001). These results also suggest movement of GLRaV-3 by mealybugs in VA vineyards. The high frequency of virus-infected vines emphasizes the importance of clean plant materials as well as management of mealybugs. This is the first study reporting the presence of Ferrisia gilli, GLRaV-2, GLRaV-3, and GFkV in VA vineyards.

Effects of biotic and abiotic factors on grape root borer (Lepidoptera: Sesiidae) infestations in commercial vineyards in Virginia.

Larval grape root borer, Vitacea polistiformis (Harris) (Lepidoptera: Sesiidae), feed on roots of wild Vitis and commercially important Vitis species and rootstocks in portions of the eastern United States. Grape root borer pupal exuviae sampling in Virginia vineyards from 2008 to 2012 revealed that infestation levels varied substantially among 48 vineyard blocks. Data on horticultural (cultivar, rootstock, vine age, and planting area), cultural (insecticide use, ground cover, weed control, and irrigation), and environmental variables (proximity to forest, soil composition, soil moisture holding capacity, pH, organic matter, bulk density, and cation exchange capacity) from each block were subjected to optimal quantification using categorical principal component analysis (CATPCA). Variables with component loading values ≥0.70 from the CATPCA were used as predictors and pupal exuviae density as the dependent variable in binary logistic regression. A prediction model was developed by including statistically significant variables in the logistic regression. CATPCA showed that seven vineyard factors (ground cover, soil texture, soil mass moisture, soil pH, clay/sand ratio, clay/silt ratio, and sand/silt ratio) based on three selected principal components were significant for subsequent regression analysis. Binary logistic regression showed that soil mass moisture and clay/sand ratio were statistically significant factors contributing to differences in infestation among vineyard blocks. Based on these two factors, a risk prediction model for calculating the probability of grape root borer infestation in vineyards was developed and validated using receiver operating characteristic curve. Results are discussed in relation to the practical implications of a predictive, risk assessment model for grape root borer management.

A Plant‐Level, Spatial, Bioeconomic Model of Plant Disease Diffusion and Control: Grapevine Leafroll Disease

AbstractGrapevine leafroll disease threatens the economic sustainability of the grape and wine industry in the United States and around the world. This viral disease reduces yield, delays fruit ripening, and affects wine quality. Although there is new information on the disease spatial‐dynamic diffusion, little is known about profit‐maximizing control strategies. Using cellular automata, we model the disease spatial‐dynamic diffusion for individual plants in a vineyard, evaluate nonspatial and spatial control strategies, and rank them based on vineyard expected net present values. Nonspatial strategies consist of roguing and replacing symptomatic grapevines. In spatial strategies, symptomatic vines are rogued and replaced, and their nonsymptomatic neighbors are virus‐tested, then rogued and replaced if the test is positive. Both nonspatial and spatial classes of strategies are formulated and examined with and without considering vine age. We find that spatial strategies targeting immediate neighbors of symptomatic vines dominate nonspatial strategies, increasing the vineyard expected net present value by 18% to 19% relative to the strategy of no disease control. We also find that age‐structured disease control is preferred to non‐age‐structured control but only for nonspatial strategies. Sensitivity analyses show that disease eradication is possible if either the disease transmission rate or the virus undetectability period is substantially reduced.

Dendro-Viticultural Applications

Twenty cross-sectional grapevine (Vitis vinifera L.) samples were used to explore the utility of using dendrochronological techniques to verify and reliably estimate vine age, and to determine the level of annual growth variability among vines for potential viticultural adoption. The annual xylem-growth rings from the study-site samples were easily discernable, and cross-sectional growth patterns were significantly associated among the samples. Samples from the site also revealed distinct pointer years, indicating a homogeneous environmental growth response. The impetus for the adoption of dendrochronological-based vineyard measurements is to increase the understanding of the relationships between climate and environmental variability on vine growth, and the associated effects on crop yields, to ultimately improve vineyard management methods and yields, and therefore enhance profitability.

The diversity of arbuscular mycorrhizal fungi amplified from grapevine roots (Vitis vinifera L.) in Oregon vineyards is seasonally stable and influenced by soil and vine age

The diversity of arbuscular mycorrhizal fungi (AMF) in 10 Oregon vineyards was assessed by examining spores in soil and amplifying mycorrhizal DNA from roots. Seventeen spore morphotypes were found in soil, including seven species in the Acaulosporaceae. Eighteen phylotypes were amplified from grape roots with AM1 and NS31 primers, and clones were dominated by Glomus spp. (> 99%). A few clones (< 1%) representing a single phylotype within Gigasporaceae, and a single clone within Archaeosporaceae were amplified from roots with AM1-NS31 primers. A separate experiment employing known proportions of grape roots colonized by Glomus intraradices or by Gigaspora rosea showed that fungi within Gigasporaceae might be underrepresented in clone abundance when Glomus spp. co-occur in roots. No clones representing fungi within the Acaulosporaceae were amplified from vineyards, although specific fungi within Acaulosporaceae were shown to colonize Pinot noir roots in sterilized soil and were amplified from these roots. Four Glomus phylotypes, including G. intraradices, were found in roots from all 10 vineyards, and these fungi accounted for 81% of clones. AMF phylotypes amplified from roots did not change during the growing season, although six phylotypes varied with soil type. The presence of three phylotypes was affected by vineyard age, and phylotype richness appeared to decline as vineyard age increased beyond 20 y. PCA analysis supported the hypothesis that the AMF community is different in red-hill soils than in valley soils and indicated certain phylotypes might be associated with lower soil and vine nutrient status. However, the changes in the AMF community in grape roots across vineyards were subtle because most root samples were dominated by the same three or four phylotypes. A separate analysis using primers to amplify AMF from the Archeasporaceae/Paraglomeraceae showed most root samples also were colonized by at least one Paraglomus or Archaeospora phylotype.

Influence of grapevine leafroll associated viruses (GLRaV-2 and -3) on the fruit composition of Oregon Vitis vinifera L. cv. Pinot noir: Phenolics

Some of the 10 known grapevine leafroll associated viruses (GLRaVs) have negative impacts upon vine productivity and grape quality, though these negative influences are dependent on factors such as GLRaV strain, cultivar, clone, rootstock, and vine age. This is the first study to report on GLRaV-2 and GLRaV-3 infected vines, with regard to phenolic compounds, and other fruit maturity indices, of ‘Pinot noir’ grapes, compared to berries from adjacent vines free of GLRaVs (same vineyards). Three different rootstock/scion combinations were included in this study. Clusters were collected for two growing seasons from commercial vineyards in the Willamette Valley of Oregon, and each vine sampled was tested for GLRaV-1, -2, -3 and Rupestris stem pitting-associated virus (RSPaV). All sampled vines were infected with RSPaV. Grapevine leafroll associated virus -infected vines tested positive for GLRaV-2 or GLRaV-3. Overall, fruit infected with GLRaV-2 and -3 had reduced percent soluble solids, decreased individual and total anthocyanins, and increased skin and pulp weight for all three ‘Pinot noir’ rootstock/scion combinations examined. Vitis riparia rootstock/‘Pinot noir’ clone 114 scion combination appeared to be the most sensitive to GLRaV-3 infection, having significant reduction of all five anthocyanins, total phenolics, and total tannins, with an increased cluster weight and 100-berry weight. No clear trends were observed in the polyphenolics analysed.

Interactions of Vine Age and Reflective Mulch Upon Berry, Must, and Wine Composition of Five Vitis vinifera Cultivars

ABSTRACT Four- and 14-year-old Cabernet Franc, Cabernet Sauvignon, Pinot Meunier, Pinot noir, and 15-year-old Riesling vines located at Thirty Bench Vineyards in Beamsville, Ontario, were assessed in terms of vine age (2002 and 2003) and reflective mulch treatments (2003) with respect to berry, must, and wine composition as well as wine sensory attributes. In 2002, but not 2003, old vines had higher yields, clusters per vine, cluster weights, and berry weights than young vines. Berries from young vines tended to have higher Brix and lower titratable acidity (TA), pH, and total phenols than those from old vines in 2002; in 2003, age showed little impact on berry composition. Wines made from young vines in 2002 were higher in TA, and often lower in pH, color intensity, and anthocyanins than those from old vines, while in 2003, young vines produced wines with lower TA, and higher pH, intensity, and total phenols. Reflective mulch showed few effects on the berry, must, and wine composition of the red wine cultivars; however, mulch increased free and bound terpenes in the Riesling berries. Wines produced from young Cabernet Sauvignon and Cabernet Franc vines exhibited more intense vegetal aromas and flavors than those from old vines in 2002 but not in 2003. The red wines made from the mulched vines generally exhibited the least amount of vegetal aroma and flavor. Reflective mulch also led to less perceived acidity in Riesling wines.

Regional sustainability in table grape production on saline soils

A study was done in South Africa to investigate the state of the soil salt content and its effect on plant growth on a regional rather than a point basis. The study site went through a development phase since 1996 of establishing new vineyards each year. This provided an excellent opportunity to investigate soil characteristics, plant vigour and their relationship since the start of development. Soil samples were taken and trunk circumferences were measured. The soil properties included in the investigation were soil clay percentage, ECe, soil pH value and time since initial irrigation. Exploratory data analyses were done and variograms were drawn for all data. Kriging was used to map the variables and multiple regression analysis was used to investigate their relationships on a regional basis. A number of useful observations were made. Trunk circumference as an index of growth showed a negative correlation with ECe and a positive correlation with soil pH. Trunk circumference reflected a positive growth cycle when compared with time since development. Regression analysis showed that trunk circumference as an indicator of vigour could be confidently predicted through knowledge of the vine age, soil pH and ECe and reflected upon measurement and prediction of sustainability in grape production. This approach has widespread applications for agriculture in terms of dealing with variation in a landscape and dealing with water supply problems. Methodology that uses a regional approach rather than a point approach in management could enhance the ability to increase profitability and ultimately improve water management.

Mycorrhizal Colonization in Dryland Vineyards of the Willamette Valley, Oregon

Abstract Arbuscular mycorrhizal fungi (AMF) enhance the growth of numerous plants, including grapevines, by increasing the absorptive surface area between roots and soil. A survey of commercial vineyards in Oregon was conducted to assess the levels of root colonization by AMF at two times during the growing season. Grapevines sampled, ranged in age from 2 to 29 years old and were growing in 10 different soil types from 3 soil orders. AMF colonization of fine (feeder) roots of vines was generally high, averaging 73% and 69% of root length colonized at bloom and veraison, respectively. Vine age, soil type, cultivar, trellis type and vine row aspect did not influence colonization of roots by AMF. In-row cultivation reduced AMF colonization at bloom, and foliar application of soluble phosphorus fertilizers reduced arbuscules (the site of nutrient transfer in mycorrhizas) in roots at veraison. The proportion of roots colonized by AMF at bloom was negatively correlated to leaf N concentrations and positively co...

Grapevine productivity and yield components: A case study using field vines of Zante currant

Yield components of the parthenocarpic cultivar Zante were analysed for five vineyards of diverse age and management. The data was obtained as part of an experiment to improve fruit set and yield by applying combinations of gibberellin and 2-chloroethyltrimethyl ammonium chloride or 4-chlorophenoxyacetic acid. Four of the vineyards were located in the Brockman valley north of Perth, Western Australia, two of these were irrigated, one was rain fed and one received supplementary flood irrigation. The fifth lay in an adjacent area of coastal sand plain, at the foot of the Darling scarp, and was irrigated. The vines were aged from 6 to 50 years. Principal component analysis showed that vine age was negatively correlated with vigour (pruning weight) and with berry number per bunch. Vine age however was not strongly related to either yield or yield components (bunch number and berry volume). Sugar concentration was negatively correlated with all yield components but imprecisely modelled based on any combination of the measured variables. Berry number per vine appeared to be the underlying factor determining 'sink' strength though this was inextricably confounded with bunch number per vine. Interpretation of the data leads to the conclusion that increased berry volume is an inefficient means of increasing dried yield. This conclusion argues for caution in the application of plant growth regulators that act primarily to increase berry volume. Yield of sugar per vine was accurately modelled based on second order relationships with bunch number per vine, berry number per bunch, berry volume and pruning weight. Vine age also showed a second order relationship to yield although the range was relatively small. The observations are considered in terms of developing strategies for maximising dried yield and devising mathematical models to account for photoassimilate (dry matter) partitioning in Vitis.

Kiwifruit fruit size distributions

Abstract The distribution of fruit weight at harvest from 0.5 ha blocks of kiwifruit in the Kerikeri district is shown to closely approximate a Normal distribution with a constant standard deviation of 20.5 g. The standard deviation changed less than 2 g between seasons despite wide variations in the mean fruit weight with crop loading and vine age. This Normal approximation provides a mathematically convenient assumption which should be considered when modelling the influence of management practices on yield or the effect of industry pricing schedules on grower returns.

Accumulation and partitioning of dry matter and mineral nutrients in developing kiwifruit vines.

Size, dry weight and mineral nutrient content of fruit, leaves, shoots, canes, leader, stem and roots of kiwifruit (Actinidia deliciosa (A. Chev.) C.F. Liang et A.R. Ferguson var. deliciosa) vines, aged from one to five years, were measured. The distribution of fruit yield among single canes was examined in three of the vines. Total dry weight increased from a mean of 1.29 kg vine(-1) for one-year-old vines to 29.2 kg vine(-1) for five-year-old vines. The proportion of total dry weight in roots declined from the first to the third year (55 to 40%) and then remained approximately constant, whereas the proportion of dry weight in fruits increased from the first to the third year before attaining a more or less constant value. The proportion of total canopy dry weight contained in the current season's growth (fruit, leaves and shoots) averaged 75% for all ages. Roots of five-year-old vines had only penetrated a small proportion of the total soil volume available. Total fruit yield increased linearly with number of floral shoots for whole vines and single canes within vines, but with cane size (length or dry weight) for whole vines only. The productivity of single canes declined from 2.5 kg m(-1) for canes shorter than 0.25 m to about 1.1 kg m(-1) for canes longer than 1.0 m, in accordance with a declining bud density with increasing cane length. For vines of all ages, mineral nutrient concentrations in various tissues were similar, except that Ca in leaves and S in leaves and shoots increased with vine age. Major sites of accumulation of N, Ca, Mg, S, Fe, Mn and B were the leaves, whereas P and K accumulated predominantly in the fruits, Zn in the leader, and Na and Cu in the roots. Estimated annual mineral nutrient uptake increased with vine size and fruit yield, and for five-year-old vines the values per hectare were 141 kg N, 19 kg P, 169 kg K, 161 kg Ca, 28 kg Mg, 32 kg S, and less than 2 kg for Na and all micronutrients. The nutrient content of the harvested fruit provided an inaccurate estimate of annual nutrient uptake of the developing vines.

Descriptive Analysis of Commercial Cabernet Sauvignon Wines from California

Twenty-one Cabernet Sauvignon wines were evaluated by descriptive analysis. The intensity of eleven flavor attributes differed significantly across wines. The largest differences between wines were the contrast between vegetative and fruity flavors as shown by principal component analysis (PCA). Vine age showed a significant positive correlation with intensity of berry aroma and significant negative correlations with the intensities of green bean aroma and vegetative flavor by mouth. Significant negative correlations were also found between the temperature zone of growing area and the intensities of eucalyptus aroma and vegetative flavor by mouth. Thus in this data set, younger vines and vines growing under cooler conditions produced wines which were more vegetative in flavor. By PCA, the first principal component contrasted `fruity9 with `vegetative9. The second axis was `phenolic9, and the third contrasted `wood/phenol9 with `eucalyptus9 and `fruit9 by mouth.

Effect of Grape Rootstocks on Chloride Accumulation in Leaves1

Abstract The effect of 5 rootstocks on chloride accumulation in ‘Cardinal’ and ‘Thompson Seedless’ scions was studied for 3 years in large sand cultures containing 12.5, 25, and 50 meq Cl-/liter of culture solution. Rootstock effects were unprecedentedly large. Scions on ‘Thompson Seedless’, ‘Dog Ridge’, 1613-3, and ‘Salt Creek’ roots consistently accumulated only one-half, one-third, one-tenth, and one-sixteenth as much chloride, respectively, on a leaf dry-weight basis as did scions on ‘Cardinal’ roots. Rootstock effects on chloride in canes and roots were similar to those in leaves, although differences were not as great. Leaves of ‘Cardinal’ scions accumulated more chloride than those of ‘Thompson Seedless’ on the 2 lower chloride treatments, apparently because of differential distribution of chloride between leaves and stems. Chloride accumulation tended to be proportional to substrate chloride concentrations for all rootstocks, and increases in chloride accumulation associated with advancing season and vine age also tended to be proportional. Because of extremely low chloride accumulation by vines on 1613-3 and ‘Salt Creek’ roots, the salt tolerance of grapevines on these roots would probably be limited by osmotic effects long before chloride accumulation reached toxic levels. Rootstock and chloride-treatment levels caused no other important nutritional or toxic effects.