scholarly journals 800 PB 080 IMPROVED DOWNY MILDEW CONTROL IN WINE GRAPES WITH VOSSEN BLUE

HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 547g-547
Author(s):  
Gary C. Pavlis ◽  
Joseph A. Fiola
Keyword(s):  
Downy Mildew ◽  
Statistical Difference ◽  
Leaf Tissue ◽  
Economic Loss ◽  
Plasmopara Viticola ◽  
Experimental Plot ◽  
Wine Grapes ◽  
Yield Data ◽  
Grape Cultivars ◽  
Downy Mildew Disease

Downy Mildew, Plasmopara viticola, causes major damage and economic loss to many wine grape cultivars grown in the Northeast. The purpose of this experiment was to test the efficacy of Vossen Blue (VB; iron pigment) in association with fungicides for the control of Downy Mildew disease of wine grapes in New Jersey. The experimental plot was a planting of Chancellor (10th leaf). Treatments (applied via back-pack sprayer) included no fungicide (NF), full fungicide (FF) (RCE commercial recs. half fungicide (HF), FF + 8%VB (FF8), HF + 8% VB (HF8), 88V B. Subjective (l-9) disease score for leaf tissue showed no statistical difference between the FF, FF8, HF and HF8 treatments however all showed superior Downy Mildew control to the 8% VB and the no fungicide control. Yield data indicated that the FF8 treatment resulted in higher yield (p is ≤ 0.01) than FF, HF and HF8. The NF and 8VB treatments resulted in the lowest yield. Compared to normal full fungicide, superior Downy Mildew control on the fruit was achieved by adding VB to full fungicide. These results are consist with previous experiments conducted on Seyval Blanc.

scholarly journals IMPROVED DOWNY MILDEW CONTROL IN WINE GRAPES WITH VOSSEN BLUE

HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 605d-605
Author(s):  
Joseph A. Fiola ◽  
Gary C. Pavlis
Keyword(s):  
Downy Mildew ◽  
Disease Incidence ◽  
Total Yield ◽  
Economic Loss ◽  
Plasmopara Viticola ◽  
Wine Grapes ◽  
Incidence Data ◽  
Average Cluster ◽  
Grape Cultivars ◽  
Downy Mildew Disease

Downy Mildew, Plasmopara viticola, causes major damage and economic loss to many wine grape cultivars grown in the Northeast. The purpose of the experiment was to test the efficacy of Vossen Blue (VB; iron pigment) in association with fungicides for the control of Downy Mildew disease of wine grapes in New Jersey. The experimental plot was a planting of `Seyval Blanc' (5th leaf). Treatments (applied via back-pack sprayer) included no fungicide (control I), full fungicide (FF) (RCE commercial recs; control II), FF + 4%VB, FF + 8%VB, 8%VB, Half Rate Fungicide (HF) + 4%VB, HF + 8%VB. There were no significant differences between treatments for total yield, average cluster weight, average berry weight, Brix %, and pH. Spectrophotometric (Hunter's Lab) analysis of foliage samples revealed that leaf samples from the VB treatments had greater green color (correlate: increased chlorophyll). Analysis of subjective (1-9) disease incidence data: FF8 significantly lower disease score that FF; FF4, HF4, HF8, and FF no difference. Compared to normal full fungicide: superior Downy Mildew control was achieved by adding VB to full fungicide; equal control was achieved with half fungicide and VB.

scholarly journals Isolation of Plasmopara viticola from Grapevine Leaves

Proceedings ◽  
2019 ◽  
Vol 29 (1) ◽  
pp. 34
Author(s):  
Camelia Ungureanu ◽  
Liliana Cristina Soare ◽  
Diana Vizitiu ◽  
Mirela Calinescu ◽  
Irina Fierascu ◽  
...  
Keyword(s):  
Downy Mildew ◽  
Plasmopara Viticola ◽  
Grapevine Downy Mildew ◽  
Grapevine Leaves ◽  
Downy Mildew Disease

In order to test some biofungicides, the isolation of Plasmopara viticola was carried out.Plasmopara viticola is a fungus that causes the grapevine downy mildew disease [...]

scholarly journals Susceptibility of Cold-Climate Wine Grape Cultivars to Downy Mildew, Powdery Mildew, and Black Rot

Plant Disease ◽  
2017 ◽  
Vol 101 (7) ◽  
pp. 1077-1085 ◽  
Author(s):  
David S. Jones ◽  
Patricia S. McManus
Keyword(s):  
Powdery Mildew ◽  
Downy Mildew ◽  
Management Strategies ◽  
Plasmopara Viticola ◽  
Cold Climate ◽  
Black Rot ◽  
Wine Grape ◽  
Plant Host ◽  
Northern United States ◽  
Grape Cultivars

Lack of knowledge regarding the susceptibility of cold-climate hybrid wine grape cultivars may be leading to the overuse of fungicides and underutilization of plant host resistance to combat disease in the northern United States. To provide new insights on diseases of cold-climate cultivars and to update management recommendations, disease was evaluated in three vineyards containing eight cultivars that were not sprayed with fungicides in 2015 and 2016. Disease severity or incidence of downy mildew (Plasmopara viticola), powdery mildew (Erysiphe necator), and black rot (Guignardia bidwellii) were measured from bud break until 2 weeks after harvest. Cold-climate cultivars ranged widely in susceptibility to different diseases and, although several cultivars were relatively resistant to two diseases, no cultivar was highly resistant to all three diseases. Additionally, a difference between foliar and fruit susceptibility for all three diseases was noted in several cultivars. These data provide a foundation for developing low-spray and certified organic disease management strategies for cold-climate wine grape cultivars based on susceptibility to disease.

scholarly journals Vapor Activity and Systemic Movement of Mefenoxam Control Grapevine Downy Mildew

Plant Disease ◽  
2007 ◽  
Vol 91 (10) ◽  
pp. 1260-1264 ◽  
Author(s):  
Megan M. Kennelly ◽  
David M. Gadoury ◽  
Wayne F. Wilcox ◽  
Robert C. Seem
Keyword(s):  
Downy Mildew ◽  
Leaf Tissue ◽  
Plasmopara Viticola ◽  
Post Inoculation ◽  
Complete Suppression ◽  
Stem Tissue ◽  
Grapevine Downy Mildew ◽  
Systemic Movement ◽  
Closed Systems ◽  
Vapor Activity

Metalaxyl is translocated from roots to leaves to control a number of oomycete pathogens, but systemic movement from vegetative organs into fruit and vapor activity against Plasmopara viticola, the causal agent of grapevine downy mildew, has not been examined experimentally. We inoculated fruit clusters of grapevines with P. viticola at prebloom, bloom, or 1 week postbloom. We then selectively applied mefenoxam (288 mg/liter), the active enantiomer of metalaxyl, to the leaves or stem tissue 12 to 48 h after inoculation. Little to no downy mildew developed on fruit when mefenoxam was applied to leaf tissue, stem tissue, or both. In contrast, downy mildew symptoms were severe on inoculated clusters on untreated shoots. When potential vapor activity was blocked, we observed fungicidal activity on seedling foliage in response to apparent systemic movement from treated stems and soil, but not from leaves. However, when vapor activity was permitted, mefenoxam residues on treated leaves controlled disease on other, untreated leaves. In subsequent vineyard experiments, vapor and systemic activity provided equivalent and near-complete suppression of downy mildew on clusters 48 h post inoculation. Furthermore, inoculated grape seedlings that were placed near mefenoxam-treated seedlings in open and closed systems developed nil to trace levels of downy mildew compared with controls, further indicating that the material has strong vapor activity.

scholarly journals The effect of Saccharomyces cerevisiae on antioxidant system of grape leaves infected by downy mildew

2020 ◽  
Vol 25 ◽  
pp. 06006
Author(s):  
Alisa Mishko ◽  
Eugene Lutsky
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Immune Response ◽  
Downy Mildew ◽  
Plasmopara Viticola ◽  
Stilbene Synthase ◽  
Resistant Cultivar ◽  
Susceptible Cultivar ◽  
Defense System ◽  
Pre Treatment ◽  
Downy Mildew Disease

In this article, results of the comparative analysis and assessment of resistance of two grape cultivars Vostorg and Muscat blanc against downy mildew disease (Plasmopara viticola) with or without the symbiote Saccharomyces cerevisiae (vine yeast) were shown. The highly resistant cultivar Vostorg with yeast pre-treatment demonstrated a high defensive capability to the pathogen due to the fast immune response. On the first day after inoculation with downy downy mildew the rapid increase in the hydrogen peroxide, which is involved the first step of the grape’s defense system induction, was observed. At the same time, the upregulation of the relative expression of the PR2 protein (β-1,3-gluconase), a key gene involved in the plant’s resistance to pathogens. The oxidative burst was not detected in the susceptible cultivar Muscat blanc for the couple of hours after inoculation with downy mildew pathogen. The significant increase of the total phenols content and expression of stilbene synthase, which is an enzyme involved in the synthesis of phytoalexins, was observed in leaves of Muscat blanc. It was shown that pre-treatment of grape leaves with natural symbiote S. cerevisiae enhanced the immune response of the resistant cultivar Vostorg and inducted phytoalexins synthesis in the susceptible cultivar Muscat blanc.

scholarly journals Eucalyptus staigeriana essential oil can control downy mildew in grapevine

2021 ◽  
Vol 28 (1) ◽  
pp. 1-14
Author(s):  
Carine Pedrotti ◽  
Clarissa Franzoi ◽  
Rafael Nicolas Sandi ◽  
Daniel Santos Grohs ◽  
Joséli Schwambach
Keyword(s):  
Downy Mildew ◽  
Conventional Treatment ◽  
Yield Loss ◽  
Plant Protection ◽  
Plasmopara Viticola ◽  
Study Objective ◽  
Severity Of Disease ◽  
Downy Mildew Disease

Downy mildew (Plasmopara viticola) is the primary disease in viticulture worldwide, and your control requires synthetic fungicides applications to avoid quality and yield loss in the grapevines. However, alternatives to reduce synthetic fungicides are needed to ensure the consumer’s health and the environment. Essential oils (EOs) are amongst the most promising natural plant protection alternatives because of their antifungal properties on several crop diseases. The present study objective was to determine the effect of Eucalyptus staigeriana EO in vitro and in vivo against P. viticola. The EO exhibited the highest activity in vitro, inhibiting 90% of the incidence and severity of disease caused by P. viticola in leaves of grapevines in the greenhouse. In the field (in vivo), treatment with EO could not control the disease; however, treatment with EO in consortium with conventional treatment reduced approximately 50% of the incidence and more than 90% of the severity of downy mildew disease in leaves, decreasing the application of synthetic fungicides by 50%.

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