Diversity, Pathogenicity, and Fungicide Sensitivity of Fungal Species Associated with Late-Season Rots of Wine Grape in the Mid-Atlantic United States

Plant Disease ◽  
2021 ◽  
Author(s):  
Scott David Cosseboom ◽  
Mengjun Hu
Keyword(s):  
United States ◽  
Detrimental Effect ◽  
Field Trials ◽  
Fungal Species ◽  
Wine Grape ◽  
Wine Grapes ◽  
Phenological Stages ◽  
Fungicide Sensitivity ◽  
Late Season ◽  
Higher Sensitivity

Late-season bunch rots cause major losses in grape production every year in the Mid-Atlantic United States, but the causal agents are not well characterized. In this study, 265 fungal isolates were collected from rotten grapes from 2014 to 2020 and identified to the genus level according to ITS sequences. The most prevalent of the 15 genera were Botrytis, Colletotrichum, Aspergillus, Alternaria, Pestalotiopsis, and Neopestalotiopsis. Of these, isolates within three prevalent, yet understudied genera were identified to be Aspergillus uvarum, Alternaria alternata, and Neopestalotiopsis rosae. The pathogenicity of these three fungal species was evaluated in two field trials by artificially inoculating wounded and non-wounded grapes of four cultivars at the phenological stages of bloom, veraison, and pre-harvest. Upon ripening, fruit were weighed and assessed for severity of multiple diseases. On non-wounded fruit, A. uvarum caused significantly higher disease severity than the control in both seasons. On wounded fruit, each inocula caused significantly higher disease than the respective controls in the first season, but only A. uvarum and B. cinerea caused this in the second season. Also, wounding was found to have a detrimental effect on cluster weight, which was significantly influenced by inoculation timing and cultivar. Lastly, A. uvarum and N. rosae were tested for sensitivity to azoxystrobin, boscalid, and difenoconazole. The A. uvarum isolates were found to be more sensitive to boscalid and difenoconazole in general, with varying sensitivity to azoxystrobin. N. rosae isolates were resistant to boscalid and azoxystrobin but displayed much higher sensitivity to difenoconazole. Evidence from the isolate collection and field trials demonstrates that A. uvarum could be a significant pathogen of wine grapes in the Mid-Atlantic. Results from this study will be useful for the identification and management of the understudied Alternaria, Aspergillus, and Neopestalotiopsis fruit rots of wine grapes.

scholarly journals Evaluation of Exclusion Netting for Spotted-Wing Drosophila (Diptera: Drosophilidae) Management in Minnesota Wine Grapes

2019 ◽  
Vol 112 (5) ◽  
pp. 2287-2294 ◽  
Author(s):  
Dominique N Ebbenga ◽  
Eric C Burkness ◽  
William D Hutchison
Keyword(s):  
The United States ◽  
Field Trials ◽  
Spotted Wing Drosophila ◽  
Wine Grape ◽  
Fruit Crops ◽  
Drosophila Suzukii ◽  
Wine Grapes ◽  
High Fecundity ◽  
Untreated Check ◽  
The Impact

Abstract Spotted-wing drosophila, Drosophila suzukii (Matsumura), an economically damaging invasive species of numerous fruit crops, was first detected in Minnesota in 2012. High fecundity, and short generation times facilitated a rapid rise in the global pest status of D. suzukii, particularly in North America and Europe. To date, the majority of crop injury research has focused on fruit crops such as blueberries, raspberries, and cherries. However, little is known regarding the impact of D. suzukii on the wine grape industry in the upper Midwest region of the United States. Field trials were conducted in Minnesota during the summers of 2017–2018 to examine season-long phenology of D. suzukii in wine grape vineyards and wineries, and to assess the efficacy of exclusion netting for control of D. suzukii. Four treatments were evaluated, 1) open plot check (control), 2) open plot treated with an insecticide, 3) exclusion netting, and 4) exclusion netting, with artificial infestations of D. suzukii adults. Exclusion netting was applied at véraison and removed at harvest. On each sample date, 20 berries (10 intact and 10 injured) were collected from each plot for dissection. The number of larvae and adults were recorded for each berry to determine infestation levels. As shown by mean larval infestations and injured berries across treatments, exclusion netting provided a significant reduction in the level of D. suzukii infested berries when compared with the untreated check. These results indicate that exclusion netting could provide an effective alternative management strategy for D. suzukii in wine grapes.

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.

Monitoring of Drosophila suzukii (Diptera: Drosophilidae) in Okanagan Valley vineyards, British Columbia, Canada, and assessment of damage to table and wine grapes (Vitaceae)

2020 ◽  
Vol 152 (4) ◽  
pp. 415-431
Author(s):  
Susanna Acheampong ◽  
Etienne Lord ◽  
D. Thomas Lowery
Keyword(s):  
British Columbia ◽  
Weather Conditions ◽  
Wine Grape ◽  
Drosophila Suzukii ◽  
Wine Grapes ◽  
Apple Cider ◽  
Table Grapes ◽  
Soft Fruit ◽  
Grape Cultivars ◽  
Okanagan Valley

AbstractSpotted-wing drosophila, Drosophila suzukii, (Matsumura) (Diptera: Drosophilidae), has become a serious pest of soft fruit in the Okanagan Valley of British Columbia, Canada since its detection in 2009. The study was conducted to determine the distribution of D. suzukii and damage levels in grapes. Apple cider vinegar-baited traps placed in table and wine grape (Vitis vinifera Linnaeus; Vitaceae) vineyards during 2011–2013 demonstrated that D. suzukii was numerous in all sites, with earliest emergence and highest numbers recorded in 2013. Drosophila suzukii were reared from intact and damaged table grapes and damaged wine grapes collected from the field, but not from intact wine grapes. Drosophila suzukii were reared in low numbers in 2011 from intact fruit of 11 wine grape cultivars exposed artificially in the laboratory. Susceptibility of intact wine grapes under laboratory conditions in 2011 when sour rot was widespread might relate in part to undetected infections of berries due to weather conditions. Identification of Drosophila Fallén species revealed that D. suzukii comprised a small portion of the total. Our results demonstrate that healthy wine grapes in the Okanagan Valley of British Columbia are largely undamaged by D. suzukii, while certain table grape cultivars should be protected from attack.

scholarly journals Fungicide Sensitivity of Pythium spp. Associated with Cavity Spot of Carrot in California and Michigan

Plant Disease ◽  
2012 ◽  
Vol 96 (3) ◽  
pp. 384-388 ◽  
Author(s):  
Xiao Hong Lu ◽  
R. Michael Davis ◽  
S. Livingston ◽  
J. Nunez ◽  
Jianjun J. Hao
Keyword(s):  
United States ◽  
Growth Inhibition ◽  
Active Ingredient ◽  
Mycelial Growth ◽  
The United States ◽  
Fungicide Sensitivity ◽  
First Report ◽  
Cavity Spot ◽  
Pythium Violae

The identity of 172 isolates of Pythium spp. from cavity spot lesions on carrot produced in California and Michigan was determined, and their sensitivity to three fungicides was examined. Pythium violae accounted for 85% of California isolates, with P. irregulare, P. dissotocum (the first report as a carrot pathogen in the United States), P. ultimum, and P. sulcatum making the balance. P. sulcatum, P. sylvaticum, and P. intermedium were the most commonly recovered (85%) species in Michigan; others from Michigan included P. intermedium, P. irregulare, and an unclassified strain, M2-05. On fungicide-amended media, 93% of isolates were sensitive to mefenoxam (inhibition of mycelial growth was >60% at 10 μg active ingredient [a.i.]/ml); however, two of five isolates of P. irregulare from California were highly resistant (≤60% inhibition at 100 μg a.i./ml); about half of the isolates of P. intermedium and P. sylvaticum and a single isolate of P. violae were highly or intermediately resistant to mefenoxam (>60% inhibition at 100 μg a.i./ml, or ≤60% inhibition at 10 μg a.i./ml). P. dissotocum, P. irregulare, P. sulcatum, M2-05, and three of seven isolates of P. intermedium were insensitive to fluopicolide (effective concentrations for 50% growth inhibition [EC50] were >50 μg a.i./ml), while P. sylvaticum, P. ultimum, P. violae, and some isolates in P. intermedium were sensitive (EC50 < 1 μg a.i./ml). All isolates were sensitive to zoxamide (EC50 < 1 μg a.i./ml). Sensitivity baselines of P. violae to zoxamide and fluopicolide were established.

Fungicide efficacy on tar spot and yield of corn in the Midwestern United States

2022 ◽  
Author(s):  
Darcy E. P. Telenko ◽  
Martin I. Chilvers ◽  
Adam Byrne ◽  
Jill Check ◽  
Camila Rocco Da Silva ◽  
...  
Keyword(s):  
United States ◽  
Growth Stage ◽  
Field Trials ◽  
Corn Belt ◽  
Yield Losses ◽  
Single Application ◽  
Midwestern United States ◽  
Tar Spot ◽  
Significant Yield ◽  
Foliar Fungicide

Tar spot of corn caused by Phyllachora maydis has recently led to significant yield losses in the eastern corn belt of the Midwestern United States. Foliar fungicides containing quinone outside inhibitors(QoI), demethylation inhibitors(DMI), and succinate dehydrogenase inhibitors(SDHI) are commonly used to manage foliar diseases in corn. To mitigate the losses from tar spot thirteen foliar fungicides containing single or multiple modes of action (MOA/FRAC groups) were applied at their recommended rates in a single application at the standard tassel/silk growth stage timing to evaluate their efficacy against tar spot in a total of eight field trials in Illinois, Indiana, Michigan, and Wisconsin during 2019 and 2020. The single MOA fungicides included either a QoI or DMI. The dual MOA fungicides included a DMI with either a QoI or SDHI, and fungicides containing three MOAs included a QoI, DMI, and SDHI. Tar spot severity estimated as the percentage of leaf area covered by P. maydis stroma of the non-treated control at dent growth stage ranged from 1.6 to 23.3% on the ear leaf. Averaged across eight field trials all foliar fungicide treatments reduced tar spot severity, but only prothioconazole+trifloxystrobin, mefentrifluconazole+pyraclostrobin+fluxapyroxad, and mefentrifluconazole+pyraclostrobin significantly increased yield over the non-treated control. When comparing fungicide treatments by the number of MOAs foliar fungicide products that had two or three MOAs decreased tar spot severity over not treating and products with one MOA. The fungicide group that contained all three MOAs significantly increased yield over not treating with a fungicide or using a single MOA.

scholarly journals Fungicide Sensitivity of U.S. Genotypes of Phytophthora infestans to Six Oomycete-Targeted Compounds

Plant Disease ◽  
2015 ◽  
Vol 99 (5) ◽  
pp. 659-666 ◽  
Author(s):  
Amanda Saville ◽  
Kim Graham ◽  
Niklaus J. Grünwald ◽  
Kevin Myers ◽  
William E. Fry ◽  
...  
Keyword(s):  
United States ◽  
Phytophthora Infestans ◽  
The United States ◽  
Effective Concentration ◽  
Response Curves ◽  
Baseline Sensitivity ◽  
Fungicide Sensitivity ◽  
The Past ◽  
The Us

Phytophthora infestans causes potato late blight, an important and costly disease of potato and tomato crops. Seven clonal lineages of P. infestans identified recently in the United States were tested for baseline sensitivity to six oomycete-targeted fungicides. A subset of the dominant lineages (n = 45) collected between 2004 and 2012 was tested in vitro on media amended with a range of concentrations of either azoxystrobin, cyazofamid, cymoxanil, fluopicolide, mandipropamid, or mefenoxam. Dose-response curves and values for the effective concentration at which 50% of growth was suppressed were calculated for each isolate. The US-8 and US-11 clonal lineages were insensitive to mefenoxam while the US-20, US-21, US-22, US-23, and US-24 clonal lineages were sensitive to mefenoxam. Insensitivity to azoxystrobin, cyazofamid, cymoxanil, fluopicolide, or mandipropamid was not detected within any lineage. Thus, current U.S. populations of P. infestans remained sensitive to mefenoxam during the displacement of the US-22 lineage by US-23 over the past 5 years.

WELCOMING REMARKS

PEDIATRICS ◽  
1969 ◽  
Vol 44 (5) ◽  
pp. 791-792
Author(s):  
Merritt Low
Keyword(s):  
United States ◽  
American Academy ◽  
One Health ◽  
The United States ◽  
Field Trials ◽  
Accident Prevention ◽  
American Academy Of Pediatrics ◽  
Job Safety ◽  
Developing Area ◽  
Made In

The American Academy of Pediatrics has long been interested in the control of Childhood Injuries; its first formal committee was the Committee on Accident Prevention. The pediatrician is a primary accident preventer and should indeed have a big stake and commitment here. He is basically a "consumer," yet he must be convinced of the product he uses and in turn passes on. Though he has the humility of an amateur, he is allied with the expert and begs for his help. He sees the great strides made by industry, even in the newly developing area of "off-the-job" safety, and the advances made in the therapeutic but not the prophylactic responsibilities of accident prevention as he surveys the situation. Yet, is he truly convinced? If so, he could do more. We exhort ourselves to immunize our children with a safety vaccine, but is this just borrowed jargon? What are the ingredients of the vaccine? Are they dead or alive? Where are the field trials? Where are the proving figures of effectiveness? A hard look shows us that this number one health problem is not being solved. (I scarcely need remind this group of the statistics and facts: 15,000 children under 15, including 5,000 pre-school children, die of accidents in the United States each year; 15 million children go to doctors for care of accidents in a year; all accidents cost the country over 15 billion dollars a year). In our primary reliance on the tool of "education," we fall victims to the fact-of-life fallacy-if we provide facts we automatically get results.

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.

DSM-5 Field Trials in the United States and Canada, Part II: Test-Retest Reliability of Selected Categorical Diagnoses

2013 ◽  
Vol 170 (1) ◽  
pp. 59-70 ◽  
Author(s):  
Darrel A. Regier ◽  
William E. Narrow ◽  
Diana E. Clarke ◽  
Helena C. Kraemer ◽  
S. Janet Kuramoto ◽  
...  
Keyword(s):  
United States ◽  
The United States ◽  
Field Trials ◽  
Retest Reliability ◽  
Dsm 5 ◽  
Test Retest Reliability
Sign in / Sign up

Export Citation Format

Share Document