scholarly journals Indirect effect of fungicide treatments on chasmothecia of Erysiphe necator Schwein overwintering on grapevine bark

2012 ◽  
Vol 48 (No. 1) ◽  
pp. 21-30 ◽  
Author(s):  
P. Hoffmann ◽  
I. Füzi ◽  
F. Virányi
Keyword(s):  
Powdery Mildew ◽  
Field Trials ◽  
Vitis Vinifera L ◽  
Significant Activity ◽  
Erysiphe Necator ◽  
Large Numbers ◽  
Leaf Infection ◽  
Autumn Leaf ◽  
Powdery Mildew Infection ◽  
Made In

Erysiphe necator Schwein overwinters in Hungary primarily as large numbers of chasmothecia providing primary inoculum for grapevine (Vitis vinifera L.) infection in the next year. In two field trials, the effect of fungicide treatments on powdery mildew severity and the number of chasmothecia produced on leaves and washed to the bark were studied. In 2005, the number of chasmothecia harvested from the bark showed a limited correlation with disease severity (r = 0.553) and number of chasmothecia on leaves (r = 0.600). In 2006, using a refined sieving technique, a substantial increase in the number of harvested chasmothecia could be achieved resulting in a much closer correlation between the variables above (r = 0.750 and r = 0.886, respectively). Among the fungicides applied, boscalid and fluquinconazole (SC formulation) showed the most significant activity by decreasing both the autumn leaf infection and the formation of chasmothecia on the leaves and providing the lowest number of chasmothecia on bark. The research underlined the importance of fungicide applications made in the previous year to decrease the amount of overwintering inoculum and to help protect grapevines from powdery mildew infection in the next year.  

scholarly journals Fitness of Erysiphe necator with G143A-Based Resistance to Quinone Outside Inhibitors

Plant Disease ◽  
2014 ◽  
Vol 98 (11) ◽  
pp. 1494-1502 ◽  
Author(s):  
Lynn Esther E. Rallos ◽  
Nels G. Johnson ◽  
David G. Schmale ◽  
Aaron J. Prussin ◽  
Anton B. Baudoin
Keyword(s):  
Powdery Mildew ◽  
Quantitative Polymerase Chain Reaction ◽  
Field Trials ◽  
Resistance Development ◽  
Erysiphe Necator ◽  
Potted Plants ◽  
Sterol Demethylation Inhibitors ◽  
Quinone Outside Inhibitors ◽  
Competition Assays ◽  
Qoi Resistance

Management of grape powdery mildew (Erysiphe necator) using quinone outside inhibitors (QoIs) has eroded in an increasing number of regions due to resistance development. To determine persistence of resistance when QoIs are withdrawn, competition assays were conducted on unsprayed grape plants (Vitis vinifera ‘Chardonnay’) by cycling mixtures of resistant and sensitive isolates characterized as genetically diverse based on microsatellite analyses. Under laboratory conditions, %G143A, quantified by quantitative polymerase chain reaction (qPCR), increased significantly, indicating competitiveness of the resistant fraction. To confirm competitiveness in the field, trials using potted plants were conducted. Percent G143A tended to decrease in one growing season, probably due to spore migration and mixing of populations with natural background inoculum. In a second season, QoI resistance persisted at high frequency for 4 weeks. Resistant populations were also found to persist in one vineyard without QoI application for four consecutive years. The frequency was still about 25% in the fourth year, with higher frequency (36%) in a hotspot section. QoI-resistant populations with >5% G143A also harbored Y136F in the cyp51 gene that confers some resistance to sterol demethylation inhibitors, another fungicide class for powdery mildew control. Double resistance could have been partly responsible for persistence of QoI resistance at this location.

scholarly journals Powdery mildew infection dependent on weather factors in vineyards near Keszthely in 2008

2010 ◽  
Vol 16 (2) ◽  
Author(s):  
P. Taksony ◽  
E. Tarczal ◽  
K. Maráczi ◽  
I. J. Holb ◽  
L. Kocsis
Keyword(s):  
High Temperature ◽  
Powdery Mildew ◽  
Vitis Vinifera ◽  
Meteorological Data ◽  
Weather Conditions ◽  
Vitis Vinifera L ◽  
Weather Factors ◽  
Vegetative Period ◽  
Favorable Conditions ◽  
Powdery Mildew Infection

Weather conditions are extremely influential on grapevine productivity and quality. High temperature and humidity makes favorable conditions for powdery mildew infection respectively. The meteorological data around Keszthely, Hungary show the vegetative period is dryer and warmer than it was closely hundred years ago. We examined the development of powdery mildew infection  on  two variet ies Vitis vinifera L. cv Italian Riesling and cv Merlot in relation with meteorological data. No primer infections were appeared in the vineyard. The year of 2008 was quite ideal for the accumulation of Erysiphe necator in the experimental vineyard. Although the dry summer can lower the infection, but if the high temperature is coupling with rainfall, the possibilities of powdery mildew infection is going to grow higher during the upcoming years.

scholarly journals Evaluation of Quinoxyfen Resistance of Erysiphe necator (Grape Powdery Mildew) in a Single Virginia Vineyard

Plant Disease ◽  
2018 ◽  
Vol 102 (12) ◽  
pp. 2586-2591 ◽  
Author(s):  
Xuewen Feng ◽  
Mizuho Nita ◽  
Anton B. Baudoin
Keyword(s):  
United States ◽  
Powdery Mildew ◽  
Disease Control ◽  
Low Dose ◽  
Disease Incidence ◽  
The United States ◽  
Field Trials ◽  
Erysiphe Necator ◽  
Late Season ◽  
Grape Powdery Mildew

The protectant fungicide quinoxyfen has been used against grape powdery mildew (Erysiphe necator) in the United States since 2003. In 2013, isolates of grape powdery mildew with reduced quinoxyfen sensitivity (here designated as quinoxyfen lab resistance or QLR) were detected in a single vineyard in western Virginia, USA. Field trials were conducted in 2014, 2015, and 2016 at the affected vineyard to determine to what extent quinoxyfen might still contribute to disease control. Powdery mildew control by quinoxyfen was similar to, or only slightly less than, that provided by myclobutanil and boscalid in all three years. In 2016, early- versus late-season applications of quinoxyfen were compared to test the hypothesis that early-season applications were more effective, but differences were small. A treatment with two early quinoxyfen applications, at bloom and 2 weeks later, followed by a myclobutanil-boscalid plus a low dose of sulfur rotation provided slightly better control of foliar disease incidence than treatments containing four quinoxyfen applications or two midseason or two late quinoxyfen applications supplemented by myclobutanil and boscalid applications; severity differences were small and nonsignificant. Metrafenone and benzovindiflupyr generally provided excellent powdery mildew control. The frequency of QLR in vines not treated with quinoxyfen slowly declined from 65% in 2014 to 46% in 2016. Further research is needed to explain how, despite this QLR frequency, quinoxyfen applied to grapes in the field was still able to effectively control powdery mildew.

scholarly journals Testing of paraffin oil efficiency against grape powdery mildew in Eger wine region

2016 ◽  
pp. 73-80
Author(s):  
Xénia Pálfi ◽  
Dénes Bisztray ◽  
Szabolcs Villangó ◽  
Zita Pálfi ◽  
Tamás Deák ◽  
...  
Keyword(s):  
Powdery Mildew ◽  
Downy Mildew ◽  
Plasmopara Viticola ◽  
Field Trials ◽  
Intensity Of Infection ◽  
Erysiphe Necator ◽  
Regular Treatment ◽  
Paraffin Oil ◽  
Wine Region ◽  
Grape Varieties

The aim of the present study was to examine the efficiency of paraffin oil against powdery mildew in Eger wine region. The experiment has been carried out in 2013 and 2014 with Chardonnay and Kékfrankos grape varieties, which have different resistance against powdery mildew. The effectiveness of the oil was examined on leaves and clusters (frequency and intensity). This oil was effective against Erysiphe necator infection on field trials in Chile and Brazil. The spread of downy mildew (Plasmopara viticola) was also inhibited by this material in some experiments conducted in Spain and France. The differences between oil treatments represented the sensitivity of the grape varieties in accordance with the applied dosages. The oil was effective against powdery mildew with different extent as a result of the so called ”vintage effect”. In 2013, the treatment of the highest dosage (D3) didn’t differed significantly in frequency and intensity of infection from the regular treatment (clusters of Kékfrankos, leaves of Chardonnay). In 2014, the oil was not so effective against powdery mildew compared to 2013. No remarkable differences were detected between the treatments due to the strong pressure of powdery mildew. Furthermore, no any effect of the lowest dosage (D1) was detected in the case of the sensitive clusters of Chardonnay and leaves of Kékfrankos in both experimental years. In summary, the oil treatment has an effect against powdery mildew, however this efficiency largely depends on the vintage characteristics and the pressure of powdery mildew. Further investigations are neccessary, for example field trials with combinations of other sprays. The oil can be useable as fungicide with proper care in eco-friendly integrated and bio (ecological) viticulture.

scholarly journals Segregation of powdery mildew (Podosphaera leucotricha [Ell. et Ev. /Salm./]) resistance within 54 apple progenies

2011 ◽  
Vol 31 (No. 3) ◽  
pp. 81-87
Author(s):  
J. Blažek ◽  
J. Křelinová ◽  
H. Drahošová
Keyword(s):  
Powdery Mildew ◽  
Partial Resistance ◽  
First Generation ◽  
Growth Habit ◽  
Columnar Growth ◽  
Monogenic Resistance ◽  
Complete Resistance ◽  
Close Relationship ◽  
Powdery Mildew Infection ◽  
Made In

The occurrence of powdery mildew after heavy spontaneous infections was evaluated on 2,500 apple seedlings of 54 progenies that were derived from crosses made in 1993 and 1994. At the same time, the response to mildew was also assessed on 47 cultivars or selections that were used as parents for the crosses. Scores of the strongest infestation were used for final ranking of every seedling or parent. The highest proportions (33 and 28%) of seedlings with complete resistance to mildew were attained in 2 progenies involving parents transmitting monogenic resistance to the pathogen. A few seedlings with this resistance were also found in other 7 progenies. Seedlings with partial resistance to mildew were distributed in the highest proportions (about 30%) among 7 progenies. In 6 out of these progenies, always one parent was derived from partially resistant selections that were selected in the first generation from the cross Spätblühender Taffetapfel × Court Pendu Plat. A very close relationship was found between mid-scores of parents and mean response to powdery mildew infection in progenies. Seedlings on average were significantly more infested than their parents. Progenies determined to have a columnar growth habit were somewhat less infested than progenies possessing a standard growth pattern only. This study revealed considerable improvement of some donors transmitting partial resistance to powdery mildew.  

scholarly journals Control of winter forage pea diseases by pea-oat intercropping under field conditions

2014 ◽  
Vol 29 (2) ◽  
pp. 131-136 ◽  
Author(s):  
Dalibor Zivanov ◽  
Radivoje Jevtic ◽  
Sonja Tancic ◽  
Sanja Vasiljevic ◽  
Stevan Masirevic
Keyword(s):  
Powdery Mildew ◽  
Ascochyta Blight ◽  
Control Treatment ◽  
Vegetable Crops ◽  
Plant Seed ◽  
Positive Effects ◽  
Leaf Infection ◽  
Moderate Effect ◽  
Novi Sad ◽  
Powdery Mildew Infection

A field experiment was conducted at the experimental field of the Institute of Field and Vegetable Crops in Novi Sad to investigate the effect of forage winter pea and winter oat intercropping on ascochyta blight and powdery mildew infections. Seeding rations of pea and oat in Treatment 1 (50:50%) and Treatment 2 (75:25%, respectively) reduced ascochyta leaf infection by 32.5% and 12.8%, and powdery mildew infection by 12.3% and 17.5%, respectively, compared to pea monoculture used as a control (Treatment 3). The same seeding rations in Treatment 1 and 2 reduced ascochyta blight on pea plants by 37.2% and 18.3%, respectively. However, there were no significant differences between the treatments in reducing powdery mildew on plants. The effects of different treatments on the average number of pods per plant, seed per pod, shriveled pods and seed weight were analyzed using Spearman?s correlation coefficient. Negative but not statistically significant effects on those measured parameters were registered in Treatments 2 and 3, while Treatment 1 showed positive effects on all parameters except shriveled pods. According to all data obtained in this research, the intercropping mixture of pea and oat at 50:50% seeding ratio had the best effect on the measured parameters while the intercropping mixture of pea and oat at 75:25% seeding ratio had low to moderate effect in comparison with pea monocrop.

scholarly journals Construction of a high-density genetic map and detection of a major QTL of resistance to powdery mildew (Erysiphe necator Sch.) in Caucasian grapes (Vitis vinifera L.)

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Tyrone Possamai ◽  
Sabine Wiedemann-Merdinoglu ◽  
Didier Merdinoglu ◽  
Daniele Migliaro ◽  
Gloria De Mori ◽  
...  
Keyword(s):  
Powdery Mildew ◽  
Vitis Vinifera ◽  
Central Asia ◽  
Genetic Relationships ◽  
High Density ◽  
Vitis Vinifera L ◽  
Resistance Locus ◽  
Phenotypic Variance ◽  
Mycelium Growth ◽  
Erysiphe Necator

Abstract Background Vitis vinifera L. is the most cultivated grapevine species worldwide. Erysiphe necator Sch., the causal agent of grape powdery mildew, is one of the main pathogens affecting viticulture. V. vinifera has little or no genetic resistances against E. necator and the grape industry is highly dependent on agrochemicals. Some Caucasian V. vinifera accessions have been reported to be resistant to E. necator and to have no genetic relationships to known sources of resistance to powdery mildew. The main purpose of this work was the study and mapping of the resistance to E. necator in the Caucasian grapes ‘Shavtsitska’ and ‘Tskhvedianis tetra’. Results The Caucasian varieties ‘Shavtsitska’ and ‘Tskhvedianis tetra’ showed a strong partial resistance to E. necator which segregated in two cross populations: the resistant genotypes delayed and limited the pathogen mycelium growth, sporulation intensity and number of conidia generated. A total of 184 seedlings of ‘Shavtsitska’ x ‘Glera’ population were genotyped through the Genotyping by Sequencing (GBS) technology and two high-density linkage maps were developed for the cross parents. The QTL analysis revealed a major resistance locus, explaining up to 80.15% of the phenotypic variance, on ‘Shavtsitska’ linkage group 13, which was associated with a reduced pathogen infection as well as an enhanced plant necrotic response. The genotyping of 105 Caucasian accessions with SSR markers flanking the QTL revealed that the resistant haplotype of ‘Shavtsitska’ was shared by ‘Tskhvedianis tetra’ and a total of 25 Caucasian grape varieties, suggesting a widespread presence of this resistance in the surveyed germplasm. The uncovered QTL was mapped in the region where the Ren1 locus of resistance to E. necator, identified in the V. vinifera ‘Kishmish vatkana’ and related grapes of Central Asia, is located. The genetic analysis conducted revealed that the Caucasian grapes in this study exhibit a resistant haplotype different from that of Central Asian grape accessions. Conclusions The QTL isolated in ‘Shavtsitska’ and present in the Caucasian V. vinifera varieties could be a new candidate gene of resistance to E. necator to use in breeding programmes. It co-localizes with the Ren1 locus but shows a different haplotype from that of grapevines of Central Asia. We therefore consider that the Caucasian resistance locus, named Ren1.2, contains a member of a cluster of R-genes, of which the region is rich, and to be linked with, or possibly allelic, to Ren1.

scholarly journals Construction of A High-Density Genetic Map And Detection of A Major QTL of Resistance To Powdery Mildew (Erysiphe Necator Sch.) In Caucasian Grapes (Vitis Vinifera L.)

2021 ◽  
Author(s):  
Tyrone Possamai ◽  
Sabine Wiedemann-Merdinoglu ◽  
Didier Merdinoglu ◽  
Daniele Migliaro ◽  
Gloria De Mori ◽  
...  
Keyword(s):  
Powdery Mildew ◽  
Vitis Vinifera ◽  
Central Asia ◽  
High Density ◽  
Vitis Vinifera L ◽  
Resistance Locus ◽  
Phenotypic Variance ◽  
Sources Of Resistance ◽  
Mycelium Growth ◽  
Erysiphe Necator

Abstract BackgroundVitis vinifera L. is the most cultivated grapevine species worldwide. Erysiphe necator Sch., the causal agent of grape powdery mildew, is one of the main pathogens affecting viticulture. V. vinifera has little or no genetic resistance against E. necator and the grape industry is highly dependent on agrochemicals. Some Caucasian V. vinifera accessions have been reported to be resistant to E. necator and to have no genetic relationship to known sources of resistance to powdery mildew. The main purpose of this work was the study and mapping of the resistance to E. necator in the Caucasian grapes ‘Shavtsitska’ and ‘Tskhvedianis tetra’.ResultsThe Caucasian varieties ‘Shavtsitska’ and ‘Tskhvedianis tetra’ showed a strong partial resistance to E. necator which segregated in two cross populations: the resistant genotypes delayed and limited the pathogen mycelium growth, sporulation intensity and number of conidia generated. A total of 184 seedlings of ‘Shavtsitska’ x ‘Glera’ population were genotyped through the Genotyping by Sequencing (GBS) technology and two high-density linkage maps were developed for the cross parents. The QTL analysis revealed a major resistance locus, explaining up to 80.15% of the phenotypic variance, on ‘Shavtsitska’ linkage group 13, which was associated with a reduced pathogen infection as well as an enhanced plant necrotic response. The genotyping of 105 Caucasian accessions with SSR markers flanking the QTL revealed that the resistant haplotype of ‘Shavtsitska’ was shared by ‘Tskhvedianis tetra’ and a total of 24 Caucasian grape varieties, suggesting a widespread presence of this resistance in the surveyed germplasm. The uncovered QTL was mapped in the region where the Ren1 gene of resistance to E. necator, identified in the V. vinifera ‘Kishmish vatkana’ and related grapes of Central Asia, is located. The genetic analysis conducted revealed that the Caucasian grapes in this study exhibit a resistant haplotype different from that of Central Asian grape accessions.ConclusionsThe QTL isolated in ‘Shavtsitska’ and present in the Caucasian V. vinifera varieties could be a new candidate gene of resistance to E. necator to use in breeding programmes. It co-localizes with the Ren1 locus but shows a different haplotype from that of grapevines of Central Asia. We therefore consider this gene, named Ren1-2, a member of a cluster of R genes, of which the region is rich, and linked with, or possibly allelic, to the Ren1.

Changes in protein abundance during powdery mildew infection of leaf tissues of Cabernet Sauvignon grapevine (Vitis vinifera L.)

PROTEOMICS ◽  
2010 ◽  
Vol 10 (10) ◽  
pp. 2057-2064 ◽  
Author(s):  
Ellen Marsh ◽  
Sophie Alvarez ◽  
Leslie M. Hicks ◽  
W. Brad Barbazuk ◽  
Wenping Qiu ◽  
...  
Keyword(s):  
Powdery Mildew ◽  
Vitis Vinifera ◽  
Vitis Vinifera L ◽  
Cabernet Sauvignon ◽  
Protein Abundance ◽  
Leaf Tissues ◽  
Powdery Mildew Infection

scholarly journals The Perfect Stage of Powdery Mildew of Grapevine Caused by Erysiphe necator Found in Peru

Plant Disease ◽  
2012 ◽  
Vol 96 (5) ◽  
pp. 768-768 ◽  
Author(s):  
M. V. Bendezú-Euribe ◽  
L. A. Alvarez
Keyword(s):  
Powdery Mildew ◽  
Genetic Recombination ◽  
First Record ◽  
Vitis Vinifera L ◽  
Erysiphe Necator ◽  
Host Genus ◽  
Table Grapes ◽  
Grapevine Powdery Mildew ◽  
New Races ◽  
Grape Varieties

Grapevine (Vitis vinifera L.) has been cultivated in Peru since the sixteenth century to produce wine and grape brandy called “Pisco”. Grapevine powdery mildew caused by Erysiphe necator (Schwein.) (formerly Uncinula necator [Schw.] Burr.; anamorph Oidium tuckeri) is currently the most important disease of grapevine in Peru. Table grape producers rely heavily on fungicide applications to manage powdery mildew infections. In Peru, the pathogen is normally found in the anamorphic state, except for one report of the teleomorphic state in 1972 (2) on wine grape varieties. In July 2011, ascomata were observed on table grapevine leaves cv. Sugraone in a commercial field near Huaral in the central coast of Peru. Abundant, mature (black) and immature (brown), globose ascocarps were visible on the abaxial leaf surfaces covered by the anamorphic state of the fungus. The chasmothecia were epiphyllous and ranged from 93.3 to 157.5 μm in diameter. The appendages were hyaline, variable in number (9 to 17), septate, with the apex helicoid when mature, and measuring 310 to 480 μm long. Each ascocarp contained four to seven subglobose asci (55.3 to 76.7 × 36.3 to 52.0 μm) with two to six (mostly three) ascospores. The ascospores were elliptical, hyaline, and measured 20.2 to 25.0 μm long by 11.1 to 17.3 μm wide. The pathogen was identified as E. necator on the basis of the host genus and morphology of the teleomorph (1). The teleomorphic state of E. necator could be a source of primary inoculum before infection by anamorphic conidia occurs, provide the basis for genetic recombination, and lead to more frequent appearance of new races. This could have serious implications for managing fungicide resistance in the pathogen population and may also result in the development of virulence to the resistance of some grape varieties tolerant to powdery mildew infections. In South America, the teleomorph of E. necator has been recently detected in Chile (3), and has caused great concern among grape producers. To our knowledge, this finding represents a first record of the presence of the ascigenous state of the pathogen on table grapes in Peru. References: (1) U. Braun. A Monograph of the Erysiphales (powdery mildews). J. Cramer, Berlin-Stuttgart, 1987. (2) S. L. Dongo and M. E. Arestegui. Fitopatologia 8:35, 1973. (3) F. Riveros et al. Aconex 83:24, 2004.

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