Vine Plot Research Articles

Impact of Grape Maturity on Ester Composition and Sensory Properties of Merlot and Tempranillo Wines

The goal of this study was to evaluate how grape composition modifications linked to maturity level could affect the wine ester composition and aromatic expression. An experimental design has been developed from grapes of Vitis vinifera cv Merlot and cv Tempranillo. On each vine plot, grapes have been harvested at two maturity levels and have been fermented using a commercial yeast strain under standardized conditions, specifically after having the sugar and nitrogen concentrations adjusted to the same target values. Tempranillo wine ester content was not impacted by the maturity level, whereas Merlot wines from the highest maturity level showed lower concentrations for fatty acid ethyl esters and higher alcohol acetates but higher concentrations for substituted ethyl esters. Sensory analysis corroborated these analytical results: when Merlot maturity increased, wine fruity aromatic expression decreased (particularly its global intensity and the fresh, red-berry, and fermentative fruit characters). In addition, aromatic reconstitution experiments showed that esters were not, alone, responsible for the sensory differences linked to grapes' maturity. Globally, our results highlight the role of esters in the overall wine fruity aromatic expression associated to Merlot ripeness and show that their levels are impacted by other parameters than the grape content in sugars and amino acids, well known as being their precursors.

Spatial Distribution Patterns of Parthenolecanium corni (Hemiptera, Coccidae) and of the Ampelovirus GLRaV-1 and the Vitivirus GVA in a Commercial Vineyard.

Distribution patterns of the European fruit lecanium Parthenolecanium corni (Bouché) and of grapevine leafroll-associated virus-1 (GLRaV-1) and grapevine virus A (GVA) were monitored from 2003 to 2015 in a Riesling vine plot in the northeast of France. Virus spread was compared between two periods: 2003–2008 and 2009–2014. The percentage of infected vines increased from 54 to 78% for GLRaV-1 and from 14 to 26% for GVA. The spatial distribution of viruses and of P. corni was analysed using permutation tests and revealed an aggregative pattern. Virus distribution was not associated with the density of P. corni population on grapevines. However, GLRaV-1 and GVA spread mainly from initially infected vines. New GLRaV-1 and GVA infections were more frequent on vines near primarily infected vines, first anisotropically along the row, then between neighbouring rows. Virus spread was similar to those described in literature with grapevine mealybug species. This slow vine-to-vine progression suggests that P. corni was responsible for the virus spread, in accordance with the low mobility and low transmission capacities of its local population.

Model-checking precision agriculture logistics: the case of the differential harvest

The development, in the last decades, of technologies for precision agriculture allows the acquisition of crop data with a high spatial resolution. This offers possibilities for innovative control and raises new logistics issues that may be solved using discrete event models. In vineyards, some technologies make it possible to define zones with different qualities of grapes and sort the grapes at harvest to make different vintages. In this context, the Differential Harvest Problem (DHP) consists in finding a trajectory of the harvesting machine in the field in order to obtain at least a given quantity of higher quality grapes and minimising working time. In available literature, the DHP has been solved using Constraint Programming. In this paper, we investigate if it is possible to solve the DHP using the Cost Optimal Reachability Analysis feature of a model-checking tool such as UPPAAL-CORA. A model named DHP_PTA has been designed based on the priced timed automata formalism and the UPPAAL-CORA tool. The method made it possible to obtain the optimal trajectory of a harvesting machine for a vine plot composed of up to 14 rows. The study is based on real vineyard data. This paper is an extended version of a communication presented at WODES 2018 (Saddem-Yagoubi IFAC-PapersOnLine 51(7):57–63, 2018).

First record of the Japanese grape leafhopper Arboridia kakogawana (Matsumura, 1932) (Hemiptera: Cicadellidae) from Romania

A new invasive species, the Japanese grape leafhopper, Arboridia kakogawana (Matsumura). is reported for the first time in Romania. Arboridia kakogawana is a serious pest of grapevine (Vitis vinifera L.) in East Asia (South Korea and China) and in Southern Russia (Krasnodar and Rostov regions) and Ukraine. In 2018, very high numbers of A. kakogawana were caught on yellow sticky traps in a vine plot in Romania in Northern Bucharest. Adults were trapped from early June to the middle of November. The dynamics of the adult population were measured using yellow sticky traps, and in 2018 four peaks were observed in the middle of July, in the first 10 days of August, at the beginning of September and in the first 10 days of October. The first overwintering adults appeared from the beginning of June. Foliar symptoms associated with the trophic activity of the leafhopper were observed on grapevine and Virginia creeper (Parthenocissus quinquefolia (L.)). Yellow sticky traps used in prior studies in the Bucharest area were re‐examined and the Japanese leafhopper was discovered on these, which leads to the conclusion that the species has been present at least since 2016 in this area. This is the first report of A. kakogawana in Romania and in the European Union.

Quantitative and qualitative impact of Tomato Black Ring Virus (TBRV) on Merlot and Cabernet franc

Aim: Fifteen nepoviruses are able to induce fanleaf degeneration in grapes, which is the viral disease with the highest economic impact. Grapevine FanLeaf Virus (GFLV) is the main causal agent of this disease worldwide and in Europe, followed by Arabis Mosaic Virus (ArMV). A third nepovirus has been described in France: Tomato Black Ring Virus (TBRV), detected in vines for the first time in France on a multi-varietal plot in 2009. The aim of this work is to evaluate the effect of TBRV on grape yield and berry quality potential in two grapevine varieties.Methods and results: Quantitative and qualitative impact of TBRV was investigated in 2010 and 2011 in the vine plot where the virus was first detected in France. Over 200 vines were analyzed by ELISA tests in order to determine their status regarding viral diseases. Vines were distributed in four groups: TBRV positive versus virus free for Merlot and Cabernet franc respectively. For each vine, the presence of eleven other viruses was investigated. In 2010 and 2011 shoot length was measured. Grape composition was also analyzed to determine technological maturity and phenol content in grapes of each vine in relation to its virus status. Total pruning weight was reduced in TBRV infected vines, while lateral shoot number and length were increased. All yield components were affected by the presence of the virus. Vines positive to TBRV produced less bunches and berries and smaller berries compared to healthy vines. Yield loss was greater on Merlot compared to Cabernet franc. Grape quality parameters seemed to be not negatively affected by the presence of TBRV.Conclusions: The major impact of TBRV was a significant yield decrease. The enhanced development of lateral shoots may be considered as a second negative impact that could increase production cost.Significance and impact of the study: These results provide essential information on the impact of TBRV in vineyards. Consequences for management of the viral disease in the vineyard are discussed.

Gone with the wind: Aerial dispersal of Parthenolecanium corni crawlers in a newly planted grapevine plot

Soft scales nymphs are suspected to propagate grapevine leafroll viruses in the vineyard, while moving from vine to vine, but results of long distance dispersion, especially those due to wind, are poorly known. Thus, a net of sticky cylindrical traps was placed in a newly planted grapevine plot to evaluate aerial dispersal of Parthenolecanium corni (Hemiptera Coccidae) nymphs. The plot was surrounded by vine plots infested by this species. Number of crawlers collected on traps was generally higher on the trap side exposed downwind and depended on population density of neighbouring vines. Coloured glitters of size and weight similar to that of crawlers were used to simulate wind transport. The highest number of glitters was trapped at the prevailing wind sector. A majority of glitters was found on traps close to dispersion cups, and the most remote were collected up to 165 m away from glitter source. Wind dispersal of crawlers was confirmed by colonisation of the new vine plot by P. corni, 2 years after plantation. The settling of P. corni on the young plot displayed no significant structure, as expected from a wind dispersal. Although grapevine leafroll viruses and Grapevine virus A were detected by reverse transcription‐polymerase chain reaction in several batches of trapped nymphs, these viruses were not found in vines colonised by P. corni in the new plot within the 4 years following plantation.

New Approach for Differential Harvest Problem: The model checking way

The development, in the last decades, of technologies for precision agriculture allows the acquisition of crop data with a high spatial resolution. This offers possibilities for innovative control and raises new logistics issues that may be solved using discrete event models. In vineyards, some technologies make it possible to define zones with different qualities of grapes and sort the grapes at harvest to make different vintages. In this context, the Differential Harvest Problem (DHP) consists in finding a trajectory of the harvesting machine in the field in order to obtain at least a given quantity of higher quality grapes and minimising working time. In available literature, the DHP has been solved using Constraint Programming. In this paper, we investigate if it is possible to solve the DHP using the Cost Optimal Reachability Analysis feature of a model-checking tool such as UppAal-CORA. A model named DHP PTA has been designed based on the priced timed automata formalism and the UppAal-CORA tool. The method made it possible to obtain the optimal trajectory of a harvesting machine for a vine plot composed of up to 12 rows. The study is based on real vineyard data.

Imperfect knowledge and data-based approach to model a complex agronomic feature – Application to vine vigor

Vine vigor, a key agronomic parameter, depends on environmental factors but also on agricultural practices. The goal of this paper is to model vine vigor level according to the most influential variables.The approach was based upon a collected dataset in a French vineyard in the middle Loire valley and the available expert knowledge. The input features were related to soil, rootstock and inter-crop management, the output was an expert assessment of vine plot vigor. The approach included a data selection step, which was needed because of data imperfection and incompleteness. Usually implicit in the literature, data selection was carried out with explicit criteria. Then a fuzzy model was designed from the selected data. Owing to the fuzzy model interpretability, its structure and behavior were analyzed.Results showed that, despite the data imperfection, the approach was able to select data that yielded an informative model. Well-known relationships were identified, and some elements of new or controversial knowledge were discussed.This is an important step towards the design of a decision support tool aiming to adapt the agricultural practices to the environment in order to get a given vigor level.

EFFECTS OF NITROGEN, POTASSIUM FERTILIZERS AND CLUSTERS PER VINE ON YIELD AND ANTHOCYANIN CONTENT IN CABERNET SAUVIGNON GRAPE

The experiment was carried out in a humid subtropical climate located in the south of China, in Xichang, Sichuan province, (27oN, 102oE, and 1650 m above mean sea level) during the 2005 and 2006 seasons. Eight year old, irrigated Cabernet Sauvignon vines were planted at Xichang Chia Tai Wine & Spirits Co., Ltd. Vine plants were spaced 1.25 m apart with 2 vines and rows were 2.0 m apart and oriented approximately north/south. Vines were trained to a vertical shoot positioned training system (VSP), and were bilaterally cordon-trained, spur-pruned, and shoots were vertically positioned upright. Vines were irrigated by drip irrigation system. The 3 different levels of N-K were 0-0, 100-20, and 200-60 g/plant and the 3 different levels of clusters per vine were 10, 20, and 30 clusters per vine. Treatments were applied to 1 vine plot, each replicated 6 times in a split plot, in which the main plots were clusters per vine. Vine shoot lengths were maintained at 15 nodes by shoot trimming. It was found that the yield of grapes in year 2005 was higher than 2006. Increasing the rate of N-K in both years did not increase yields, but increased clusters increased yields in both years. Color and phenolic compounds in the berries were higher in year 2006 than 2005. At the 0-0 and 100-20 levels of N-K the phenolic compounds in the grape were lower than other treatments. It was also found that the Cabernet Sauvignon berry contained more malvidin than other anthocyanins.

Modelling nitrate transport under row intercropping system: Vines and grass cover

Summary In the context of reduction of agricultural non-point source pollution, an associated crop system often presents several advantages. The difficulty resides in the characterisation of each species’ contribution (dominant and dominated). This paper deals with the particular case of voluntary grass cover management between rows in a vine plot. We evaluate the spatial and temporal changes in the development of both crops: vine/grass cover system, in their ecological functioning and in the influences on water and nitrogen balances. We modify the SWMS_3D model to incorporate separate distribution of water and nitrogen demands for the two coexisting plant species. The parameterized model is then assessed using the measured data (water content, matrix potential and nitrogen content of the soil solution at depths of 30, 60, 90 and 120 cm) acquired from two monitored vine plots (vine “Tockay-Pinot Gris” plot grass covered every second row compared to a control plot that was chemically weeded vine “Riesling” plot, France, Alsace, Rouffach) between October 1998 and September 2000. The main results are the following. The vine’s mean total transpiration over the two growing seasons of 1998/1999 and 1999/2000 is simulated of 355 ± 9 mm per season. The matrix potential is reproduced accurately especially improving with depth and under the interrow. Despite a high variability due to soil heterogeneity, the nitrogen mass variations between measurements and simulations with the adapted model are coherent. Nevertheless we note that the model slightly underestimates the nitrogen mass for both types of observed cropping patterns, however the ratio between the two itineraries remains similar, yielding a reduction in nitrogen loss by at least 4-fold in favour of grass cover every second row plot during the period observed from 10/01/1998 to 09/30/2000.

Agroforestry management and phytoseiid communities in vineyards in the South of France

This study deals with the long-term effect of agroforestry management (trees within vine crops) on communities of phytoseiid mites. Several plots were considered: vineyards co-planted with Sorbus domestica or Pinus pinea, monocultures of vines and monocultures of S. domestica or P. pinea. All vine plots included two vine cultivars, Syrah and Grenache. Phytoseiid mites have been surveyed in these plots during several years within the previous 10 years. In 2010, samplings were again carried out in these same plots, from May to September, twice a month. Significantly higher densities of Phytoseiidae were observed on the cultivar Syrah (0.85 phytoseiids per leaf) than on Grenache (0.26 phytoseiids per leaf). Furthermore, significantly higher phytoseiid mite densities were observed in the monocultural grapevine plot than in the two co-planted ones. The main species found was Typhlodromus (Typhlodromus) exhilaratus in all vine plots considered. However, Kampimodromus aberrans was observed in the grapevine plots co-planted with the two trees, but never in the monocultural vine plot. Surprisingly, this phytoseiid species was not found on the co-planted trees, nor in the neighbouring uncultivated vegetation. Several hypotheses are discussed to explain such an unexpected distribution. Furthermore, contrary to what has been observed previously, agroforestry management did not seem to favour phytoseiid mite development, especially on the Grenache cultivar. Again, some hypotheses are developed to explain such observations and density modifications.

An Automatized Frequency Analysis for Vine Plot Detection and Delineation in Remote Sensing

<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> The availability of an automatic tool for vine plot detection, delineation, and characterization would be very useful for management purposes. An automatic and recursive process using frequency analysis (with Fourier transform and Gabor filters) has been developed to meet this need. This results in the determination of vine plot boundary determination and accurate estimation of interrow width and row orientation. To foster large-scale applications, tests and validation have been carried out on standard very high spatial resolution remotely sensed data. About 89% of vine plots are detected corresponding to more than 84% of vineyard area, and 64% of them have correct boundaries. Compared with precise on-screen measurements, vine row orientation and interrow width are estimated with an accuracy of 1<formula formulatype="inline"><tex>$^{\circ}$</tex></formula> and 3.3 cm, respectively. </para>

Immigration of Phytoseiid Mites from Surrounding Uncultivated Areas into a Newly Planted Vineyard

This study reports (1) a faunistic survey of phytoseiid mites observed inside a vine plot and in neighbouring vegetation (other vine plots and uncultivated areas) and (2) dispersal of phytoseiid mites into the plot studied. These data aim to raise some hypotheses concerning natural colonisation of a vineyard by predatory mites. The study was carried out over 3 years (1999, 2000 and 2001) in an experimental plot planted with two cultivars (Grenache and Syrah) and with Sorbus domestica in a framework of agroforestry investigations. Phytoseiid mites were collected in both cultivated and uncultivated areas surrounding the experimental plot, and their dispersal into the plot studied using "aerial" traps. Densities remained quite low compared to previous studies. The main species encountered in the uncultivated areas and in the traps was Typhlodromus phialatus. Despite the low numbers of phytoseiid mites trapped, densities of phytoseiid mites into the vine field increased during 3 years. Typhlodromus phialatus, the species mainly found in the neighbouring uncultivated areas, was rarely found in vineyards. Another morphologically close species was predominant on vines: Typhlodromus exhilaratus. However, Kampimodromus aberrans the main phytoseiid mite species in vineyards of Southern France was not found in the present survey. Hypotheses for this colonisation process are discussed.

Dispersal of Kampimodromus aberrans (Oudemans) between Uncultivated Areas and Grape Fields: Does Pesticide Application Affect the Settlement of Migrants?

Kampimodromus aberrans is a predatory mite species present in vineyards of South of France and also in uncultivated areas, from where great densities disperse into the neighbouring vine fields, mainly by aerial means. In order to determine the origin of migrants in an experimental vine plot, a molecular study using RAPD markers was performed. It was found that there exists genetic differentiation of populations collected in the experimental vineyard, and those collected, both from surrounding cultivated and uncultivated areas. No correlation between genetic and geographic distances was found. Thus, despite the dispersal of great densities of mites into the plot, selection pressures may affect their settlement. To determine the impact of pesticide application on mite settlement, we studied the insecticide resistance of K. aberrans populations collected in the vine field and on an oak located in a neighbouring uncultivated area. The insecticide tested, quinalphos, is the most frequently applied pesticide in the plot. High resistance levels were observed in both populations. However, at the recommended concentration, mortality rates (80 and 87 %) were quite the same for the two populations. Thus, the application of this pesticide seems not to be the major explanation of the poor settlement of migrants coming from woody areas into the plot, and other studies have to be conducted to determine other factors involved.

Colonization of vineyards by phytoseiid mites: their dispersal patterns in the plot and their fate.

The effect of wind and woody margins on the dispersal and population dynamics of phytoseiid mites was studied in a vine plot for a period of two years. Mites were sampled in the plot and in the surrounding vegetation (crops and natural vegetation) in order to determine phytoseiid mite abundance. The surrounding vegetation was considered to be a reservoir of phytoseiids from where the vine plot could be invaded. Directional and non-directional soil and aerial traps were placed in the plot to determine predatory mite exchange between the two areas. Colonization of the plot occurred in two stages: first, mite migration into the plot, followed by their establishment. The two-year study partially clarified the first of these two stages. Kampimodromus aberrans was the main species caught in the aerial traps. Phytoseiid mite dispersal within the vine plot seemed to be affected by both wind (direction, intensity and regularity) and phytoseiid mite density in the woody margin. However, the woody margin had a large effect only over a short distance. Some observations pointed towards an effect of other reservoir areas but it was not possible to characterize these. The population density of the phytoseiid mites in the plot increased from 1996 to 1998, but these increases are much smaller than one would expect on the basis of the number of mites migrating by air in the plot. Moreover, blocks where most mites were trapped were not the blocks where densities of phytoseiid mites on vine leaves were the largest. It therefore seems likely that not all migrants were able to develop. Their settlement pattern was not determined and this could constitute a potential research focus for the future.