Leaf Removal for Nonchemical Control of the Summer Bunch Rot Complex of Wine Grapes in the San Joaquin Valley

Plant Disease ◽  
1992 ◽  
Vol 76 (2) ◽  
pp. 205 ◽  
Author(s):  
James J. Stapleton
Keyword(s):  
San Joaquin Valley ◽  
Leaf Removal ◽  
Wine Grapes ◽  
Bunch Rot

scholarly journals Utilizing Pruning and Leaf Removal to Optimize Ripening of Vitis riparia-Based ‘Frontenac Gris’ and ‘Marquette’ Wine Grapes in the Northern Great Plains

Horticulturae ◽  
2020 ◽  
Vol 6 (1) ◽  
pp. 18 ◽  
Author(s):  
Andrew Aipperspach ◽  
James Hammond ◽  
Harlene Hatterman-Valenti
Keyword(s):  
North Dakota ◽  
Great Plains ◽  
Fruit Quality ◽  
Management Practices ◽  
Soluble Solids ◽  
Northern Great Plains ◽  
Wine Grape ◽  
Leaf Removal ◽  
Wine Grapes ◽  
Production Region

Experiments were conducted to evaluate the effects of three pruning levels (20, 30 and 40 nodes per vine) and three fruit-zone leaf removal levels (0%, 50%, and 100%) on the yield and fruit quality of Frontenac gris and Marquette wine grapes in a northern production region. The study was conducted at three North Dakota vineyards located near Buffalo, Clifford, and Wahpeton, North Dakota, in 2011 and 2012. Increasing the number of buds retained increased yields and reduced pruning weights in both cultivars. Frontenac gris and Marquette yields were greatest when vines had 50% of the fruit-zone leaves removed due to heavier clusters, suggesting that the 100% fruit-zone leaf removal level was too severe. Individual berries in clusters were also heavier when vines were pruned to retain 40 buds. Frontenac gris fruit quality was similar both years and was not influenced by pruning or leaf removal levels. Marquette fruit total soluble solids content was greater in 2012 due to the warmer and longer growing season. Marquette fruit titratable acidity was lower when 100% of the fruit-zone leaves were removed. These results suggest that for the two cold-hardy hybrid wine grapes used in this study, greater bud retention levels should be investigated. Results also warrant further research into cultivar adaptiveness to northern Great Plains conditions. With further research, it is anticipated that wine grape cultivars and management practices will be identified to produce acceptable yields and fruit quality for commercial wine grape production.

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

scholarly journals IPM: Leaf removal for pest management in wine grapes

1990 ◽  
Vol 44 (5) ◽  
pp. 15-17 ◽  
Author(s):  
James Stapleton ◽  
William W. Barnett ◽  
James J. Marois ◽  
W. Douglas Gubler
Keyword(s):  
Pest Management ◽  
Leaf Removal ◽  
Wine Grapes

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.

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