scholarly journals Effects of Relative Humidity on the Vector of Rose Rosette Disease, Phyllocoptes fructiphilus (Eriophyidae), and Incidence of Disease Symptoms

2021 ◽  
Vol 104 (3) ◽  
Author(s):  
Alejandra Monterrosa ◽  
Fanny B. Iriarte ◽  
Mathews L. Paret ◽  
Shimat V. Joseph
Keyword(s):  
Relative Humidity ◽  
Disease Symptoms ◽  
Rose Rosette ◽  
Rose Rosette Disease

scholarly journals First Report of Rose rosette virus Associated with Rose Rosette Disease in Rosa hybrida in Minnesota

2017 ◽  
Vol 18 (2) ◽  
pp. 102-103
Author(s):  
Sara Bratsch ◽  
David Zlesak ◽  
Dimitre Mollov ◽  
Benham Lockhart
Keyword(s):  
Reverse Transcription ◽  
Rosa Hybrida ◽  
Disease Symptoms ◽  
First Report ◽  
Reverse Transcription Pcr ◽  
Rose Rosette ◽  
Hybrida Plant ◽  
Rose Rosette Disease

A Rosa hybrida plant was identified with rose rosette disease symptoms and was positive for Rose rosette virus (RRV) by reverse transcription PCR. It is important to monitor routinely roses for RRV symptoms and to test and rogue symptomatic plants. This is the first report of RRV infecting roses in Minnesota.

Impact of Foliar Application of Acibenzolar S-Methyl on Rose Rosette Disease and Rose Plant Quality

Plant Disease ◽  
2021 ◽  
Author(s):  
Binoy Babu ◽  
Mathews L Paret ◽  
Xavier Martini ◽  
Gary Knox ◽  
Barron Riddle ◽  
...  
Keyword(s):  
Plant Growth ◽  
Disease Severity ◽  
Untreated Control ◽  
Systemic Acquired Resistance ◽  
Foliar Application ◽  
Acquired Resistance ◽  
Water Control ◽  
Knock Out ◽  
Rose Rosette ◽  
Rose Rosette Disease

Rose rosette disease (RRD) caused by rose rosette emaravirus (RRV) is a major issue in the U.S. rose industry with no effective method for its management. This study evaluated the effect of foliar application of Acibenzolar S-methyl (ASM), a plant systemic acquired resistance inducer in reducing RRD disease severity on Rosa species cv. Radtkopink (Pink Double Knock Out®) under greenhouse condition, and the effect of ASM on plant growth under commercial nursery production conditions. ASM at 50 or 100 mg/L at weekly intervals significantly reduced RRD severity compared to the untreated control in two of the three greenhouse trials (P < 0.05). The plants in these trials were subsequently pruned and observed for symptoms, which further indicated that application of ASM at 50 or 100 mg/L lowered disease severity compared to the untreated control (P < 0.05) in these two trials. Plants treated with ASM at 50 or 100 mg/L had delayed incidence of RRD compared to the non-treated controls. Plants treated with ASM at 50 or 100 mg/L rate in all three trials either did not have RRV present or the virus was present in fewer leaf samples than untreated controls as indicated by RT-qPCR analysis. Overall, plants treated with ASM at 50 mg/L had 36-43% reduced RRD incidence compared to the water control. The treatment of two cultivars of rose, ‘Radtkopink’ and ‘Meijocos’ (Pink Drift®), with weekly foliar applications of ASM at three rates (0.5, 0.75 and 1.0 oz/A) indicated that ASM had no negative effect on flowering or plant growth at even the highest rate.

scholarly journals Effects of Temperature, Relative Humidity, and Plant Age on Bacterial Disease of Onion Plants

2019 ◽  
Vol 20 (4) ◽  
pp. 200-206
Author(s):  
Kim E. Tho ◽  
Elizabeth Brisco-McCann ◽  
Prissana Wiriyajitsomboon ◽  
Mary K. Hausbeck
Keyword(s):  
Relative Humidity ◽  
Management Strategies ◽  
Bacterial Pathogen ◽  
Plant Age ◽  
Effect Of Temperature ◽  
Bacterial Disease ◽  
Disease Symptoms ◽  
Foliar Disease ◽  
Progress Curve ◽  
Effects Of Temperature

Foliar disease of onion in Michigan, caused by Pantoea agglomerans, Pantoea ananatis, or Enterobacter cowanii, has recently become a concern to producers. The objective of this study was to determine the effect of temperature, relative humidity (RH), and plant age in growth chamber and greenhouse experiments on onion plants inoculated with each pathogen. A significant level of disease resulted from each pathogen at 25 to 30°C, with strong positive associations detected using regression analysis between the area under the disease progress curve (AUDPC) and temperature. RH also significantly influenced symptom development. Foliar disease symptoms developed sooner and were more severe when RH was high (80 to 100%) but was limited at RH < 60%. Significant positive associations between RH and AUDPC, as described by linear regression, were also detected. When 6- to 14-week-old plants were inoculated with each bacterial pathogen, susceptibility increased significantly with age. These results provide insight into the epidemiology of P. agglomerans, P. ananatis, and E. cowanii bacterial pathogens of onions in Michigan and can assist in the development and timing of management strategies.

scholarly journals Botrytis Blossom Blight of Southern Blueberries: Cultivar Susceptibility and Effect of Chemical Treatments

Plant Disease ◽  
1998 ◽  
Vol 82 (8) ◽  
pp. 924-927 ◽  
Author(s):  
Barbara J. Smith
Keyword(s):  
Relative Humidity ◽  
Gibberellic Acid ◽  
Conidial Suspension ◽  
Full Bloom ◽  
Disease Symptoms ◽  
Chemical Treatments ◽  
Severity Scores ◽  
Flower Stage ◽  
Southern Highbush ◽  
Cultivar Susceptibility

The susceptibility of blueberry flowers at each developmental stage was evaluated by inoculating potted blueberry bushes of the rabbiteye cultivars Climax, Premier, and Tifblue, and the southern highbush cultivars Gulfcoast and Cooper, during bloom with a conidial suspension of Botrytis cinerea and incubating in a dew chamber for 2 days at 20°C and 100% relative humidity. Flower stage was rated at the beginning of each study and at 2 and 4 weeks after inoculation. The efficacy of five fungicides (benomyl, captan, cyprodinil, cyprodinil + CGA173506, and propiconazole) and a surfactant for control of Botrytis blossom blight was evaluated by inoculating Climax and Gulfcoast plants 2 days before or 2 days after treatment with each fungicide. The effect of chemicals used during bloom on the severity of Botrytis blossom blight was evaluated by treating Tifblue and Cooper plants with gibberellic acid, surfactant, and fungicide combinations 1 day prior to inoculation. Botrytis disease symptoms were scored 2 and 4 weeks after inoculation on a visual scale of 0 to 7. Flower susceptibility increased as flower stage at inoculation increased. Tifblue flowers at or near full bloom (stages 5 and 6) at the time of inoculation were very susceptible to Botrytis blossom blight. Flowers treated with benomyl, cyprodinil, and cyprodinil + CGA173506 2 days after inoculation had lower Botrytis severity scores than inoculated flowers not treated with fungicides. Flowers treated with gibberellic acid 1 day prior to inoculation had lower Botrytis scores 2 and 4 weeks later than untreated flowers, while flowers treated with a nonionic surfactant received the same Botrytis severity scores as untreated flowers.

IDENTIFICATION OF THE ROSE ROSETTE DISEASE AGENT

2015 ◽  
pp. 295-298 ◽  
Author(s):  
P.L. Di Bello ◽  
T. Ho ◽  
I.E. Tzanetakis
Keyword(s):  
Disease Agent ◽  
Rose Rosette ◽  
The Rose ◽  
Rose Rosette Disease

scholarly journals Evaluation of Rosa Species Accessions for Resistance to Eriophyid Mites1

2019 ◽  
Vol 37 (4) ◽  
pp. 108-112
Author(s):  
K. M. Solo ◽  
S. B. Collins ◽  
L. G. Schneider ◽  
M. R. Hajimorad ◽  
F. A. Hale ◽  
...  
Keyword(s):  
High Variability ◽  
Rosa Rugosa ◽  
Eriophyid Mite ◽  
Chestnut Rose ◽  
Rosa Roxburghii Tratt ◽  
Rosa Roxburghii ◽  
Rose Rosette ◽  
Rosa Species ◽  
Forest Farm ◽  
Rose Rosette Disease

Abstract Rose rosette disease, caused by rose rosette virus (RRV), is an epidemic affecting nearly every rose cultivar in the United States. The only hosts for Phyllocoptes fructiphilus, the eriophyid mite that vectors RRV, are Rosa species. Eighteen Rosa species were evaluated for mite resistance by collecting foliage samples from July to November in 2016 and 2017, from which mites were extracted. Mites were isolated through a series of sieves and counted using a stereomicroscope. The response variable was expressed as the number of mites per gram of optimal rose tissue. Mite data were evaluated to determine the peak week for mite populations for each year. The mite populations varied by rose species (α = 0.05) in 2016 but not 2017. Due to high variability in mite counts, the species were not as clearly distinguishable as expected. This high variability is likely due to factors such as differential growth rates of the roses, weather, presence of RRV in the rose, and the quality of the tissue collected throughout the season. Experimental design revisions are proposed for future studies looking at Rosa species resistance to eriophyid mite populations. Index words: rose rosette virus, rose rosette disease, Phyllocoptes fructiphilus Keifer, virus, vector. Species used in this study: Phyllocoptes fructiphilus (Keifer), Prairie Rose [Rosa arkansana (Porter), Forest Farm]; Carolina Rose [Rosa carolina (L.), Forest Farm]; Rosa clinophylla (Thory), Rogue Valley Rose; White Prairie Rose [Rosa foliolosa (Nutt.), Rogue Valley Rose]; White Prairie Rose [Rosa foliolosa (Nutt.) Antique Rose Emporium]; Father Hugo Rose [Rosa hugonis, Rogue Valley Rose]; Musk Rose [Rosa moschata (J. Herrm.), Antique Rose Emporium]; Multiflora Rose [Rosa multiflora (Thunb.)]; Shining Rose [Rosa nitida (Willd.), Rogue Valley Rose]; Shining Rose [Rosa nitida (Willd.), Antique Rose Emporium]; Nootka Rose [Rosa nutkana (C. Presl.), Rogue Valley Rose]; Tea Rose [Rosa odorata (Andrews), Foundation Plant Services, Davis, CA]; Swamp Rose [Rosa palustris (Marshall), Antique Rose Emporium]; Swamp Rose [Rosa palustris (Marshall), Ever Blooming Antique Rose Emporium]; Chestnut Rose [Rosa roxburghii (Tratt.), Antique Rose Emporium]; ‘Plena' Chestnut Rose [Rosa roxburghii (Tratt.), Rogue Valley Rose]; Rugosa Rose [Rosa rugosa (Thunb.), Bailey's Nursery]; ‘Alba' Rugosa Rose [Rosa rugosa (Thunb.), Bailey's Nursery]; Climbing Prairie Rose [Rosa setigera (Michx.), Antique Rose Emporium]; Rosa soulieana (Crép.), Ralph Moore; Virginia Rose [Rosa virginiana (Mill.), Forest Farm]; Porterfolia Memorial Rose [Rosa wichuraiana (Crép.), Antique Rose Emporium]; Mountain Woods' Rose [Rosa woodsii (Lindl.), Rogue Valley Rose].

scholarly journals Rose Rosette Disease: Recent Advances on Molecular Diagnostic Tools

HortScience ◽  
2018 ◽  
Vol 53 (5) ◽  
pp. 596-600 ◽  
Author(s):  
Binoy Babu ◽  
Gary Knox ◽  
Mathews L. Paret ◽  
Francisco M. Ochoa-Corona
Keyword(s):  
The United States ◽  
Molecular Diagnostic ◽  
Diagnostic Tools ◽  
Department Of Agriculture ◽  
Specialty Crop ◽  
Detection And Identification ◽  
Research Initiative ◽  
Highly Sensitive ◽  
Rose Rosette ◽  
Rose Rosette Disease

Rose rosette emaravirus (RRV, genus Emaravirus), the causal agent of rose rosette disease, is the topmost pathogen of concern for the rose industry in the United States. The only strategy available for disease management is early identification and eradication of the infected plants. Highly reliable, specific, and sensitive detection assays are thus required to test and confirm the presence of RRV in suspected plant samples. RRV is only a recently characterized virus and hence limits the diagnostic tools available for its early detection. With a U.S. Department of Agriculture (USDA) Specialty Crop Research Initiative (SCRI) project sponsorship, several diagnostic tools including end-point reverse transcription-polymerase chain reaction (RT-PCR) and RT-qPCR assays targeting single and multiple genes targets were developed for routine diagnostics. This review introduces an overall view of the different diagnostic tools developed, which are reliable, highly sensitive, and can be easily implemented for detection and identification in laboratories providing diagnostic services and confirmation of RRV-infected samples.

scholarly journals Effects of morning vs. evening inoculation on the development of Neonectria ditissima lesions

2018 ◽  
Vol 71 ◽  
pp. 353
Author(s):  
Emma Patrick ◽  
Anthea Garmey ◽  
Lauren Turner ◽  
Rebecca E. Campbell ◽  
Monika Walter
Keyword(s):  
Relative Humidity ◽  
Environmental Conditions ◽  
Weather Conditions ◽  
Symptom Expression ◽  
Symptom Development ◽  
Apple Trees ◽  
Successful Development ◽  
Disease Symptoms ◽  
Average Daily Temperature ◽  
Daily Relative Humidity

The study of Neonectria ditissima causing European canker in apple trees is often dependent on controlled inoculation of tree wounds and development of canker lesions. This makes the success of the initial inoculation crucial for time-efficient research. The effect of morning vs. evening inoculation on the successful development of canker lesions was investigated. Ninety-six ‘Royal Gala’ trees were inoculated on six different days (February—March 2017), which covered several different weather conditions. On each inoculation day, 16 trees were inoculated on four rasp and four picking wounds, at 10:00 and 19:00 hours. These were then assessed over the following 8 months for presence of disease symptoms. Irrespective of rain (0—4.5 mm rainfall at the day of inoculation), temperature (average daily temperature of 14.8—21.3˚C), and humidity (average daily relative humidity of 59.8—94.2% rH), neither the day nor the hour of inoculation affected symptom development. However, more inoculated wounds developed symptoms in rasp wounds (91%) than in picking wounds (63%). Under the environmental conditions tested, inoculation timing (date and hour) had little effect on N. ditissima symptom expression.

scholarly journals First Report of Rose Rosette Disease Caused by Rose rosette virus on Knock Out Roses in Louisiana

2016 ◽  
Vol 17 (3) ◽  
pp. 195-196
Author(s):  
Raghuwinder Singh ◽  
Rodrigo Valverde ◽  
Madeline Cook ◽  
Allen Owings
Keyword(s):  
The State ◽  
Knock Out ◽  
First Report ◽  
Rose Rosette ◽  
Rose Rosette Disease

To the authors' knowledge, this is the first report of rose rosette disease caused by Rose rosette virus on Knock Out roses in Louisiana. It is difficult to assess the total value of roses in Louisiana but this disease has the potential to negatively impact the thriving rose industry in the state. Accepted for publication 23 August 2016.

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