Timing of cluster-zone leaf removal and its impact on canopy morphology, cluster structure and bunch rot susceptibility of grapes

OENO One ◽  
2011 ◽  
Vol 45 (3) ◽  
pp. 149 ◽  
Author(s):  
Daniel Molitor ◽  
Marc Behr ◽  
Serge Fischer ◽  
Lucien Hoffmann ◽  
Danièle Evers
Keyword(s):  
Cluster Structure ◽  
Grey Mould ◽  
Optimal Timing ◽  
Leaf Removal ◽  
Wine Quality ◽  
Microclimatic Conditions ◽  
Cluster Compactness ◽  
Bunch Rot ◽  
Efficient Option ◽  
Cool Climate

<p style="text-align: justify;"><strong>Aims</strong>: Leaf removal in the cluster-zone has proved to be an efficient option to reduce grey mould infestation. The aim of the present work was to determine the optimal timing of this measure in practical viticulture.</p><p style="text-align: justify;"><strong>Methods and results</strong>: Manual leaf removal in the cluster-zone was carried out at six time points between pre-bloom (BBCH 57) and veraison (BBCH 81) on the white varieties Sauvignon blanc (2009), Auxerrois (2009), Pinot gris (2010) and Riesling (2010). Leaf removal conducted between bloom and berries-touching led to a decreased number of interior clusters as well as a reduced cluster compactness and disease severity of <em>B. cinerea</em>. Prebloom and late (at veraison) leaf removal turned out to be less efficient.</p><p style="text-align: justify;"><strong>Conclusion</strong>: Leaf removal between bloom and berries-touching proved to be very efficient to control bunch rot due to (i) the disaggregation of the cluster structure and (ii) the improved microclimatic conditions and can be recommended in integrated as well as organic viticulture.</p><p style="text-align: justify;"><strong>Significance and impact of the study</strong>: The outcome of the present study constitutes an important tool for improving grape health status and, in consequence, wine quality under cool climate winegrowing conditions.</p>

Efficiency of different strategies for the control of grey mold on grapes including gibberellic acid (Gibb3), leaf removal and/or botrycide treatments

OENO One ◽  
2010 ◽  
Vol 44 (3) ◽  
pp. 151 ◽  
Author(s):  
Danièle Evers ◽  
Daniel Molitor ◽  
Melanie Rothmeier ◽  
Marc Behr ◽  
Serge Fischer ◽  
...  
Keyword(s):  
Gibberellic Acid ◽  
Control Strategies ◽  
Disease Incidence ◽  
Cluster Structure ◽  
Pinot Noir ◽  
Leaf Removal ◽  
Wine Quality ◽  
Additional Measure ◽  
Grey Mold ◽  
The Impact

<p style="text-align: justify;"><strong>Aim</strong>: The present work evaluated different strategies for the control of grey mold, caused by <em>Botrytis cinerea</em>, on wine grapes, including the use of the plant growth regulator Gibb3, leaf removal and/or botryticide treatments. The efficiency of the different control strategies (disease incidence and severity, yield) as well as the effect on the cluster structure was investigated.</p><p style="text-align: justify;"><strong>Methods and results</strong>: The trials were conducted in commercial vineyards in the Moselle Valley (Luxembourg) between the years 2007 and 2009, on the Pinot gris, Pinot blanc and Pinot noir grape varieties. The untreated control (T1) was compared to the following treatments : (T2) Gibb3, (T3) Gibb3 combined with leaf removal in the cluster zone after bloom, (T4) leaf removal after bloom combined with two times botryticides and (T5) Gibb3 combined with two times botryticides. The combination of Gibb3 with leaf removal or botryticide applications led to an efficiency level in grey mold reduction of around 60% and a decrease in cluster density when compared to the control. Moreover, we showed that the progression of grey mold disease was slowed down by the three treatments T3, T4 and T5.</p><p style="text-align: justify;"><strong>Conclusions</strong>: Gibberellic acid applied at full bloom as stand-alone treatment did not reduce in a significant way the compactness of the grape clusters and the impact on grey mold development was low. For a significant decrease of disease severity, gibberellic acid had to be combined with an additional measure, such as leaf removal or the use of botryticides. Based on its positive effect on cluster structure and microclimate, leaf removal can be recommended as a basic measure that can be further combined with an application of botryticides or gibberellic acid.</p><p style="text-align: justify;"><strong>Significance and impact of the study</strong>: All the tested strategies combining two measures have shown their potential to prolong the ripening period and therewith to improve wine quality. Moreover, the combined use of gibberellic acid and leaf removal represents a sustainable strategy for integrated viticulture due to its reduced input of organic-synthetic pesticides into the environment.</p>

scholarly journals Hand and Mechanical Fruit-zone Leaf Removal at Prebloom and Fruit-set Was More Effective in Reducing Crop Yield than Reducing Bunch Rot in ‘Riesling’ Grapevines

2018 ◽  
Vol 28 (3) ◽  
pp. 296-303 ◽  
Author(s):  
Bryan Hed ◽  
Michela Centinari
Keyword(s):  
Complex Disease ◽  
Fruit Set ◽  
Lower Percentage ◽  
Leaf Removal ◽  
Wine Quality ◽  
Significant Treatment ◽  
Canopy Density ◽  
Fruit Composition ◽  
Bunch Rot ◽  
Disease Pressure

Fruit-zone leaf removal is typically applied in cool and humid regions to improve grape and wine quality, while reducing disease pressure. When fruit-zone leaf removal is applied early in the season, before bloom [early leaf removal (ELR)], it also reduces fruit-set, cluster compactness, and susceptibility to bunch rot, a complex disease that involves fungi (Botrytis cinerea, Aspergillus sp., Penicillium sp.) and bacteria (Acetobacter sp.). Over 2 years (2015–16), we tested whether ELR applied mechanically [mechanical defoliation at stage E-L 18 (MD-I)] would mimic the effects of a hand removal [hand defoliation of the first six basal leaves and laterals at stage E-L 18 (Coombe, 1995) (HD-I)] with respect to ‘Riesling’ (Vitis vinifera) production parameters, canopy density and cluster sunlight exposure, fruit composition, and bunch rot control. We also compared the effects of mechanical defoliation applied either at prebloom (MD-I) or at fruit-set [mechanical defoliation at stage E-L 27 (MD-II)]. In both years, fruit-zone leaf removal, regardless of method and timing, reduced yield, cluster weight, and berries per cluster, while maintaining fruit composition and bud fruitfulness as compared with nondefoliated vines (control, C). In 2015, HD-I vines had a lower percentage of clusters infected by bunch rot as compared with the C and MD-II vines. However, severity of bunch rot was low in all treatments, and there was not significant treatment effect on bunch rot severity in either year. ELR consistently shortened cluster length, offsetting much of the intended cluster loosening effect induced by a lower number of berries per cluster—that would have reduced bunch susceptibility to late seasons rots. Despite removing only half the leaf area of HD-I, MD-I successfully mimicked the canopy improving effects of HD-I in terms of fewer interior clusters and leaves, fewer cluster-shading layers, and greater light available to clusters and leaves as compared with C vines.

scholarly journals Impacts of Pre-bloom Leaf Removal on Wine Grape Production and Quality Parameters: A Systematic Review and Meta-Analysis

2021 ◽  
Vol 11 ◽  
Author(s):  
Joshua VanderWeide ◽  
Chris Gottschalk ◽  
Steven R. Schultze ◽  
Esmaeil Nasrollahiazar ◽  
Stefano Poni ◽  
...  
Keyword(s):  
Management Practice ◽  
Meta Analysis ◽  
Quality Parameters ◽  
Soluble Solids ◽  
Extensive Literature ◽  
Wine Grape ◽  
Leaf Removal ◽  
Wine Quality ◽  
Bunch Rot ◽  
Rot Disease

Wine grape (Vitis vinifera L.) is the most widely cultivated fruit crop in the world. However, the climactic characteristics in some growing regions are suboptimal for grape production, including short season length and excess precipitation. Grape growers can utilize an array of methods to mitigate these issues, including “early leaf removal,” a management practice involving the removal of leaves from selected basal nodes along shoots around bloom. This meta-analysis reviews the extensive literature on this practice, with specific regards to application at “pre-bloom” (PB). One hundred seventy-five publications on the topic of “early leaf removal” were identified using key terms and subsequently narrowed via eight data curation steps. The comparison between treated (PB) and control plants in these studies revealed two important results. First, PB lowered bunch rot disease (−61%), partially through reducing the compactness of clusters. Second, PB promoted a significant increase in fruit total soluble solids (°Brix, +5.2%), which was related to the increase in the leaf-to-fruit ratio. Furthermore, cultivar and rootstock were found to have a large influence on the success of PB, while the contribution of climate was smaller. In conclusion, PB significantly lowers yield and bunch rot disease and increases °Brix, both of which improve grape and wine quality.

scholarly journals Prediction of Botrytis cinerea Risk in Vineyards Based on Weather Indicators

2020 ◽  
Vol 77 (2) ◽  
pp. 58
Author(s):  
Liliana PIRCALABU ◽  
Elena BRINDUSE ◽  
Marian ION
Keyword(s):  
High Risk ◽  
Botrytis Cinerea ◽  
Predictive Models ◽  
Meteorological Data ◽  
Grey Mould ◽  
Low Risk ◽  
Wine Quality ◽  
The Hours ◽  
Medium Risk ◽  
Positive Correlations

Botrytis cinerea causes grey mould, a major disease occurring in vineyards worldwide, resulting in loss of grape production and wine quality. Predictive models of favorability of Botrytis cinerea were used. Therefore, a series of meteorological data from 2010 to 2019 was used. The results showed that the frequency of years with low risk of Botrytis cinerea was 10%, medium risk 10%, high risk 80%. The disease can drastically reduce both yield and wine quality (Ribereau Gayon et al., 1980). The harvest years 2010, 2011, 2012, 2013 and 2014, favored the manifestation of an attack degree of 62.9% (2012) and 34.2% (2013). Positive correlations were observed in the case of Broome index and Bacchus index with the duration of sunlight (r2 = 0.935), respectively (r2 = 0.944) and the sum of the hours of moisture on the leaves (r2 = 0.833, r2 = 0.848). Based on the results a model for prediction of Botrytis cinerea risk will be developed.

Early Leaf Removal as a Strategy to Improve Ripening and Lower Cluster Rot in Cool Climate (Vitis vinifera L.) Pinot Grigio

2019 ◽  
Vol 71 (1) ◽  
pp. 70-79 ◽  
Author(s):  
Joshua VanderWeide ◽  
Tommaso Frioni ◽  
Zhongli Ma ◽  
Manfred Stoll ◽  
Stefano Poni ◽  
...  
Keyword(s):  
Vitis Vinifera ◽  
Vitis Vinifera L ◽  
Leaf Removal ◽  
Cool Climate

Gibberellin Application Improved Bunch Rot Control of Vignoles Grape, but Response to Mechanical Defoliation Varied between Training Systems

Plant Disease ◽  
2020 ◽  
pp. PDIS-06-20-1184
Author(s):  
Bryan Hed ◽  
Michela Centinari
Keyword(s):  
Soluble Sugar ◽  
Control Program ◽  
Titratable Acidity ◽  
Training System ◽  
Cluster Architecture ◽  
Training Systems ◽  
Positive Effects ◽  
Treatment Responses ◽  
Cluster Compactness ◽  
Bunch Rot

Late-season bunch rot causes significant crop loss for grape growers in wet and humid climates. For 3 years (2016 to 2018), we integrated prebloom mechanized defoliation (MD) in the fruit zone and bloom gibberellin (GA) applications, either alone or in combination, into the bunch rot control program of Vignoles, a commercially valuable grape variety that is highly susceptible to bunch rot. We hypothesized that both treatments would decrease bunch rot through modification of cluster architecture or fruit zone microclimate compared with vines treated with the standard chemical control program. Grapevines were trained to two popular training systems, four-arm Kniffin (4AK) and high-wire bilateral cordon (HWC). Treatment responses varied between training systems. MD, alone or in combination with GA, reduced bunch rot incidence and severity every year on 4AK-trained vines, an effect attributed mainly to fruit zone improvements. Conversely, MD alone did not reduce bunch rot incidence on HWC-trained vines, despite significant improvements in cluster architecture (reduced number of berries per cluster and cluster compactness). GA applications were more effective than MD at reducing cluster compactness, regardless of training system. As a result, GA reduced bunch rot incidence and severity when applied alone or with MD on 4AK- and HWC-trained vines. All treatments positively improved fruit-soluble sugar concentration on both training systems, while positive effects on titratable acidity were more consistent across training systems with MD.

Postponing First Shoot Topping Reduces Grape Cluster Compactness and Delays Bunch Rot Epidemic

2014 ◽  
Vol 66 (2) ◽  
pp. 164-176 ◽  
Author(s):  
Daniel Molitor ◽  
Nicole Baron ◽  
Timo Sauerwein ◽  
Christelle M. André ◽  
Anna Kicherer ◽  
...  
Keyword(s):  
Cluster Compactness ◽  
Bunch Rot

Canopy manipulation of Okanagan Riesling vines for improvement of winegrape quality

1992 ◽  
Vol 72 (2) ◽  
pp. 489-496 ◽  
Author(s):  
A. G. Reynolds ◽  
P. L. Sholberg ◽  
D. A. Wardle
Keyword(s):  
Untreated Control ◽  
Titratable Acidity ◽  
Leaf Removal ◽  
Basal Leaf ◽  
Bunch Rot ◽  
Canopy Management

Vigorous, Geneva Double Curtain-trained Okanagan Riesling vines were subjected over a 2-yr period (1987–1988) to four canopy manipulation practices: shoot positioning; shoot positioning plus postbloom hedging to 12 leaves per shoot; basal leaf removal; and an untreated control, in combination with the presence or absence of iprodione (Rovral 50WP) fungicide sprays. Shoot positioning and shoot positioning plus hedging reduced weight of cane prunings relative to control vines in 1988, but increased yield, cluster weight, and berries per cluster. Shoot positioning, shoot positioning plus hedging, and basal leaf removal reduced °Brix in 1988, but tended to reduce titratable acidity in both seasons. Shoot positioning plus hedging reduced pH in 1987, while shoot positioning and shoot positioning plus hedging reduced pH and potassium (K+) in 1988. Neither Rovral nor canopy manipulation appeared to have any significant impact on the percentage of bunch rot-affected clusters. Shoot positioning of Geneva Double Curtain-trained Okanagan Riesling is recommended as a method to reduce titratable acidity, pH and K+, hence improving potential winegrape quality.Key words: Vitis, grape, hedging, shoot positioning, leaf removal, canopy management

Fruit zone leaf removal influences vegetative, yield, disease, fruit composition, and wine sensory attributes of Vitis vinifera L. 'Optima' and 'Cabernet franc'

1997 ◽  
Vol 77 (1) ◽  
pp. 149-153 ◽  
Author(s):  
S. L. Staff ◽  
D. C. Percival ◽  
J. A. Sullivan ◽  
K. H. Fisher
Keyword(s):  
Vitis Vinifera ◽  
Botrytis Cinerea ◽  
Canopy Structure ◽  
Sensory Attributes ◽  
Vitis Vinifera L ◽  
Leaf Removal ◽  
Cabernet Franc ◽  
Fruit Composition ◽  
Wine Composition ◽  
Bunch Rot

The influence of fruit zone leaf removal treatments (0, 50, and 100%) on grapevine canopy structure, incidence of bunch rot (Botrytis cinerea Pers.:Fr.), yield components, fruit and wine composition and wine sensory attributes was studied on Vitis vinifera L. 'Optima' and 'Cabernet franc'. The 50 and 100% leaf removal reduced leaf layer number, percent interior leaves and percent interior clusters. Yield was reduced between 29 and 46%. Severity of bunch rot in Optima and incidence and severity for Cabernet franc were reduced by leaf removal. Leaf removal improved colour, aroma and palatability of both Optima and Cabernet franc wines. Key words: Botrytis cinerea, defoliation, canopy management

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