scholarly journals Evaluation of the Risk of Spreading Fire Blight in Apple Orchards with a Mechanical String Blossom Thinner

HortScience ◽  
2009 ◽  
Vol 44 (3) ◽  
pp. 862-865 ◽  
Author(s):  
Henry K. Ngugi ◽  
James R. Schupp
Keyword(s):  
Field Experiment ◽  
Fire Blight ◽  
Erwinia Amylovora ◽  
Apple Orchards ◽  
Severe Fire ◽  
Greenhouse Experiments ◽  
History Of Disease ◽  
History Of ◽  
Mechanical Thinning ◽  
Rotating String

The risk of spreading fire blight in apples after mechanical thinning with a rotating string blossom thinner was evaluated in field and potted-tree experiments. In the field experiment, using the mechanical thinner on noninoculated trees immediately after operating the equipment on inoculated trees significantly (P < 0.01) increased fire blight incidence resulting in 90 ± 20.01 (mean ± SE) infected shoots compared with 23.5 ± 8.97 diseased shoots in similar trees that were not thinned mechanically. A similar result was obtained in greenhouse experiments whereby healthy apple plants positioned adjacent to diseased plants before the group was subjected to the mechanical thinner developed more than twice the number of infected shoots as that on similar plants that were not thinned. These results indicate that under conditions conducive to infection, the mechanical blossom thinner significantly increases the risk of spreading Erwinia amylovora. The use of the thinner should therefore be limited to orchards with no history of disease in the last 3 years and on days when predicted weather is not suitable for tree infection by E. amylovora; otherwise, a severe fire blight epidemic could develop in the orchard.

Assessing and minimizing the development and spread of fire blight following mechanical thinning and pruning in apple orchards

Plant Disease ◽  
2020 ◽  
Author(s):  
Anna Wallis ◽  
Mario R. Miranda-Sazo ◽  
Kerik Cox
Keyword(s):  
Point Source ◽  
Fire Blight ◽  
New York State ◽  
Low Risk ◽  
Apple Orchards ◽  
Disease Progress ◽  
Progress Curve ◽  
Bud Set ◽  
Terminal Bud ◽  
Mechanical Thinning

The adoption of mechanical thinning and pruning in commercial apple orchards has largely been limited by the risk of development and spread of fire blight. This devastating disease, caused by the bacterial pathogen Erwinia amylovora, may be transmitted by mechanical injury such as pruning, especially under warm, moist conditions conducive to bacterial growth, infection, and disease development. However, risk may be mitigated by avoiding highest risk times and applying a bactericide, such as streptomycin, following mechanical thinning or pruning. In ‘Gala’ and ‘Idared’ orchards, we evaluated the risk of fire blight development and spread following mechanical thinning early in bloom (20% bloom), when seasonal temperatures are cooler and there are few open flowers available for infection. In both orchards, we also evaluated the spread and development of fire blight by mechanical pruning in July and in August, before and after terminal bud set when shoot growth is slowed and less susceptible to infection. We also assessed the potential efficacy of a streptomycin or Bacillus subtilis biopesticide application following mechanical thinning and pruning to mitigate the spread of fire blight. In the ‘Gala’ orchard, disease never developed beyond the inoculated tree following thinning or pruning, which was unexpected for this highly susceptible cultivar. In the ‘Idared’ orchard, incidence of blossom or shoot blight from the point source, represented as relative area under the disease progress curve (rAUDPC) was rarely different for trees that received mechanical thinning or mechanical pruning compared to untreated trees, and was frequently eliminated or reduced when the antibiotic streptomycin or the B. subtilis biopesticide was applied within 24 h of mechanical thinning or pruning. For both thinning and pruning, incidence of fire blight dropped off quickly beyond the inoculated tree in the ‘Idared’ orchard and generally was not observed in trees beyond 10-15 m from the inoculated point source or predicted beyond 10 m by exponential and power law models fit to the disease progress curves. The results of this work demonstrate the low risk for fire blight development and spread by mechanical thinning and pruning when practiced under low-risk conditions—early in bloom for mechanical thinning, and after terminal bud set (in August) for mechanical pruning—especially when paired with a subsequent bactericide application. This study demonstrates the safe use of mechanical thinning and pruning in commercial apple production, corroborated by anecdotal evidence from apple growers in Western New York State.

scholarly journals Draft Genome Sequences of Four Streptomycin-Sensitive Erwinia amylovora Strains Isolated from Commercial Apple Orchards in Ohio

2021 ◽  
Vol 10 (50) ◽  
Author(s):  
A. M. Jimenez Madrid ◽  
T. Klass ◽  
V. Roman-Reyna ◽  
J. Jacobs ◽  
M. L. Lewis Ivey
Keyword(s):  
Causative Agent ◽  
Fire Blight ◽  
Erwinia Amylovora ◽  
Draft Genome ◽  
Apple Orchards ◽  
Genome Sequences ◽  
Apple Trees ◽  
Content Type

Erwinia amylovora is the causative agent of fire blight, a devastating disease of apples and pears worldwide. Here, we report draft genome sequences of four streptomycin-sensitive strains of E. amylovora that were isolated from diseased apple trees in Ohio.

scholarly journals Prevalence of Streptomycin-Resistant Erwinia amylovora in New York Apple Orchards

Plant Disease ◽  
2016 ◽  
Vol 100 (4) ◽  
pp. 802-809 ◽  
Author(s):  
K. A. Tancos ◽  
S. Villani ◽  
S. Kuehne ◽  
E. Borejsza-Wysocka ◽  
D. Breth ◽  
...  
Keyword(s):  
United States ◽  
New York ◽  
Fire Blight ◽  
Erwinia Amylovora ◽  
The United States ◽  
Streptomycin Resistance ◽  
Apple Orchards ◽  
Wayne County ◽  
The Past ◽  
Shoot Blight

Resistance to streptomycin in Erwinia amylovora was first observed in the United States in the 1970s but was not found in New York until 2002, when streptomycin-resistant (SmR) E. amylovora was isolated from orchards in Wayne County. From 2011 to 2014, in total, 591 fire blight samples representing shoot blight, blossom blight, and rootstock blight were collected from 80 apple orchards in New York. From these samples, 1,280 isolates of E. amylovora were obtained and assessed for streptomycin resistance. In all, 34 SmR E. amylovora isolates were obtained from 19 individual commercial orchards. The majority of the resistant isolates were collected from orchards in Wayne County, and the remaining were from other counties in western New York. Of the 34 resistant isolates, 32 contained the streptomycin resistance gene pair strA/strB in the transposon Tn5393 on the nonconjugative plasmid pEA29. This determinant of streptomycin resistance has only been found in SmR E. amylovora isolates from Michigan and the SmR E. amylovora isolates discovered in Wayne County, NY in 2002. Currently, our data indicate that SmR E. amylovora is restricted to counties in western New York and is concentrated in the county with the original outbreak. Because the resistance is primarily present on the nonconjugative plasmid, it is possible that SmR has been present in Wayne County since the introduction in 2002, and has spread within and out of Wayne County to additional commercial growers over the past decade. However, research is still needed to provide in-depth understanding of the origin and spread of the newly discovered SmR E. amylovora to reduce the spread of streptomycin resistance into other apple-growing regions, and address the sustainability of streptomycin use for fire blight management in New York.

scholarly journals Sensitivity of Erwinia amylovora in Illinois Apple Orchards to Streptomycin, Oxytetracyline, Kasugamycin, and Copper

Plant Disease ◽  
2013 ◽  
Vol 97 (11) ◽  
pp. 1484-1490 ◽  
Author(s):  
A. G. Jurgens ◽  
M. Babadoost
Keyword(s):  
Fire Blight ◽  
Erwinia Amylovora ◽  
Field Trials ◽  
Luria Bertani ◽  
Apple Orchard ◽  
Streptomycin Resistance ◽  
Colony Development ◽  
Apple Orchards ◽  
Shoot Blight ◽  
Prohexadione Calcium

In 2008 and 2009, severe fire blight (Erwinia amylovora) occurred in Illinois apple orchards, leading to speculation that streptomycin-resistant strains of E. amylovora might be present in some orchards. Statewide surveys were conducted in 2010, 2011, and 2012, and 117, 129, and 170, E. amylovora isolates were collected, respectively, from 20 counties. None of the 416 E. amylovora isolates tested were resistant to streptomycin (Agri-Mycin 17WP) at 50 mg/liter. Seven non-E. amylovora bacterial isolates were collected from E. amylovora-infected shoots that contained both a strA-strB streptomycin resistance gene and IS1133 on transposon Tn5393, which could be a potential source of streptomycin resistance for E. amylovora in Illinois in the future. Colony development of all 84 E. amylovora isolates tested was inhibited on Luria-Bertani medium amended with oxytetracycline at 50 mg/liter and kasugamycin (Kasumin 2L) at 100 mg/liter. Similarly, colony development of the 84 E. amylovora isolates was inhibited on casitone-yeast extract medium amended with copper sulfate at 0.16 mM. In 2011 and 2012, field trials were conducted to evaluate the efficacy of oxytetracycline (Mycoshield 17WP), kasugamycin (Kasumin 2L and ARY-4016-06), copper hydroxide (Kocide-3000 41.6DF), Bacillus subtilis (Serenade Max, QST713), and Pseudomonas fluorescens (Blight Ban A506) for management of fire blight in an apple orchard. Only kasugamycin (Kasumin 2L and ARY-4016-06) reduced blossom infection significantly. There was a significant interaction of kasugamycin (Kasumin 2L) with prohexadione calcium (Apogee 27.5DF) in reducing shoot blight incidence in the field in 2012.

Voices and Visions: Mind, Body and Affect in Medieval Writing

2018 ◽  
Author(s):  
Corinne Saunders
Keyword(s):  
Medical Humanities ◽  
Family Care ◽  
Literary Texts ◽  
Cultural Perspective ◽  
Historical Sources ◽  
Disease Treatment ◽  
History Of Disease ◽  
Health And Illness ◽  
History Of ◽  
Cultural Texts

A properly critical medical humanities is also a historically grounded medical humanities. Such historical grounding requires taking a long cultural perspective, going beyond traditional medical history – typically the history of disease, treatment and practice – to trace the origins and development of the ideas that underpin medicine in its broadest sense – ideas concerning the most fundamental aspects of human existence: health and illness, body and mind, gender and family, care and community. Historical sources can only go so far in illuminating such topics; we must also look to other cultural texts, and in particular literary texts, which, through their imaginative worlds, provide crucial insights into cultural and intellectual attitudes, experience and creativity. Reading from a critical medical humanities perspective requires not only cultural archaeology across a range of discourses, but also putting past and present into conversation, to discover continuities and contrasts with later perspectives. Medical humanities research is illuminated by cultural and literary studies, and also brings to them new ways of seeing; the relation is dynamic. This chapter explores the ways mind, body and affect are constructed and intersect in medieval thought and literature, with a particular focus on how voice-hearing and visionary experience are portrayed and understood.

Fire Blight Susceptibility in Pyrus Germplasm from Eastern Europe

HortScience ◽  
1990 ◽  
Vol 25 (5) ◽  
pp. 566-568 ◽  
Author(s):  
T. van der Zwet ◽  
R.L. Bell
Keyword(s):  
Eastern Europe ◽  
Fire Blight ◽  
Erwinia Amylovora ◽  
Breeding Program ◽  
Plant Germplasm ◽  
Plant Exploration ◽  
Moderately Resistant

During 1976-1980, three plant exploration trips were made throughout eastern Europe in search of native Pyrus germplasm. A total of 384 accessions (231 from Yugoslavia, 86 from Romania, 43 from Poland, and 12 each from Hungary and Czechoslovakia) were collected as budwood and propagated at the National Plant Germplasm Quarantine Center in Glenn Dale, Md. Following 8 years of exposure to the fire blight bacterium [Erwinia amylovora (Burr.) Winsl. et al.], 17.49” of the accessions remained uninfected, 11.2% rated resistant, 6.8% moderately resistant, and 64.6% blighted severely (26% to 100% of tree blighted). Some of the superior accessions have been released for use in the pear breeding program.

Corticosteroids in Inflammatory Bowel Disease patients: a practical guide for physicians.

2020 ◽  
Vol 15 ◽  
Author(s):  
Maria Carla Di Paolo ◽  
Cristiano Pagnini ◽  
Maria Giovanna Graziani
Keyword(s):  
Severe Disease ◽  
Unknown Etiology ◽  
History Of Disease ◽  
Bowel Diseases ◽  
Literature Evidence ◽  
History Of ◽  
Inflammatory Bowel ◽  
Favorable Safety ◽  
Pass Metabolism

: Inflammatory bowel diseases (IBDs) are chronic conditions characterized by unknown etiology and pathogenesis with deregulation of mucosal immunity. Among possible treatments, corticosteroids, already available from the 50’, are still the mainstay of treatment for moderate-severe disease. Nonetheless, the use of steroids is still largely empirical and solid evidence about therapeutic schemes are lacking. Moreover, due to the important side-effects and for the unsatisfactory impact on long-term natural history of disease, the steroid sparing has become an important therapeutic goal in IBD management. Besides conventional steroids, the so called “low bioavailability” steroids, which are steroids with high affinity for peripheral receptors and elevated hepatic first-pass metabolism, have demonstrated efficacy and more favorable safety profile. In the present review of the literature evidence of efficacy and safety of conventional and low bioavailability steroids in IBD patients are evaluated, and practical suggestions for a correct use in clinical practice are presented according to the current clinical guidelines.

The Great Influenza

2018 ◽  
Author(s):  
Samuel K. Cohn, Jr.
Keyword(s):  
Social Behaviour ◽  
East Coast ◽  
World History ◽  
Collective Violence ◽  
Large Cities ◽  
Surgeon General ◽  
The Us ◽  
History Of Disease ◽  
The World ◽  
History Of

This chapter examines evidence principally from the US that the Great Influenza provoked profiteering by landlords, undertakers, vendors of fruit, pharmacists, and doctors, but shows that such complaints were rare and confined mostly to large cities on the East Coast. It then investigates anti-social advice and repressive decrees on the part of municipalities, backed by advice from the US Surgeon General and prominent physicians attacking ‘spitters, coughers, and sneezers’, which included state and municipal ordinances against kissing and even ‘big talkers’. It then surveys legislation on compulsory and recommended mask wearing. Yet this chapter finds no protest or collective violence against the diseased victims or any other ‘others’ suspected of disseminating the virus. Despite physicians’ and lawmakers’ encouragement of anti-social behaviour, mass volunteerism and abnegation instead unfolded to an extent never before witnessed in the world history of disease.

scholarly journals Isolation and efficacy of two bacterial strains antagonists of Erwinia amylovora and Pectobacterium carotovorum

2021 ◽  
Vol 31 (1) ◽  
Author(s):  
M’hamed BENADA ◽  
Boualem BOUMAAZA ◽  
Sofiane BOUDALIA ◽  
Omar KHALADI
Keyword(s):  
Fire Blight ◽  
Erwinia Amylovora ◽  
Bacterial Species ◽  
Crop Protection ◽  
Soft Rot ◽  
Causal Agent ◽  
Plant Diseases ◽  
Ecological Niches ◽  
Pectobacterium Carotovorum ◽  
Bacterial Strains

Abstract Background The development of ecofriendly tools against plant diseases is an important issue in crop protection. Screening and selection process of bacterial strains antagonists of 2 pathogenic bacterial species that limit very important crops, Erwinia amylovora, the causal agent of the fire blight disease, and Pectobacterium carotovorum, the causal agent of bacterial potato soft rot, were reported. Bacterial colonies were isolated from different ecological niches, where both pathogens were found: rhizosphere of potato tubers and fruits and leaves of pear trees from the northwest region of Algeria. Direct and indirect confrontation tests against strains of E. amylovora and P. carotovorum were performed. Results Results showed a significant antagonistic activity against both phytopathogenic species, using direct confrontation method and supernatants of cultures (p<0.005). In vitro assays showed growth inhibitions of both phytopathogenic species. Furthermore, results revealed that the strains of S. plymuthica had a better inhibitory effect than the strains of P. fluorescens against both pathogens. In vivo results on immature pear fruits showed a significant decrease in the progression of the fire blight symptoms, with a variation in the infection index from one antagonistic strain to another between 31.3 and 50%, and slice of potato showed total inhibition of the pathogen (P. carotovorum) by the antagonistic strains of Serratia plymuthica (p<0.005). Conclusion This study highlighted that the effective bacteria did not show any infection signs towards plant tissue, and considered as a potential strategy to limit the fire blight and soft rot diseases.

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