scholarly journals Impact of Fungicide Inputs on the Severity of Entomosporium Leaf Spot on Selections of Dwarf Indian Hawthorn

2003 ◽  
Vol 21 (1) ◽  
pp. 16-19
Author(s):  
A.K. Hagan ◽  
J.R. Akridge ◽  
M.E. Rivas-Davila
Keyword(s):  
Disease Severity ◽  
Leaf Spot ◽  
Untreated Control ◽  
Snow White ◽  
Disease Resistant ◽  
Bay Breeze ◽  
A Minor ◽  
The Impact ◽  
Indian Princess

Abstract In a simulated landscape planting in Brewton, AL, the impact of fungicide treatments on severity of Entomosporium leaf spot was assessed on 13 selections of Indian hawthorn, which range from highly susceptible to resistant to this disease. Chlorothalonil [Daconil 2787 4.17F] at 1.25 g ai/liter was applied at 2-and 4-week intervals to a randomly selected plant in each plot. The remaining plant in each plot was not sprayed and was the untreated control. From mid-winter to mid-spring in 1997, 1998, and 1999, fungicide applications were made over a 13-to 15-week period. When compared to unsprayed controls, reductions in the severity of Entomosporium leaf spot were noted on the fungicide-treated plants of nearly all selections, regardless of their susceptibility to Entomosporium leaf spot. As expected, disease severity was usually lower on those plants sprayed at 2-week rather than 4-week intervals. While chlorothalonil significantly reduced disease severity on the Entomosporium leaf spot resistant selections ‘Indian Princess’®, ‘Clara’, ‘Snow White’, ‘Olivia’™, and ‘Eleanor Tabor’™, only a limited reduction in the number of infected leaves in the canopy and perhaps a minor reduction in premature leaf loss were seen. In contrast, substantially less leaf spotting and defoliation on the selections such as ‘Spring Rapture’®, ‘White Enchantress’®, ‘Enchantress’®, ‘Heather’, ‘Harbinger of Spring’®, ‘Pinkie’, and ‘Bay Breeze’® were obtained with chlorothalonil, particularly when this fungicide was applied at 2-week intervals. When treated with chlorothalonil at 2-week intervals, disease severity on susceptible selections was, however, comparable to the damage levels observed on the unsprayed leaf spot resistant selections. When compared with costly and labor-intensive fungicide inputs, production and establishment of disease resistant selections is the preferred strategy for preventing destructive outbreaks of Entomosporium leaf spot on Indian hawthorn in the nursery and landscape.

scholarly journals Evaluation of the TOM-CAST Forecasting Model in Asparagus for Management of Stemphylium Leaf Spot in Ontario, Canada

Plant Disease ◽  
2018 ◽  
Vol 102 (11) ◽  
pp. 2253-2257 ◽  
Author(s):  
Jennifer M. Foster ◽  
Mary Ruth McDonald
Keyword(s):  
Disease Severity ◽  
Leaf Spot ◽  
Untreated Control ◽  
Day Treatment ◽  
Field Trials ◽  
The Other ◽  
Forecasting Model ◽  
Stemphylium Vesicarium ◽  
Forecasting Models ◽  
Foliar Pathogen

In the last 5 years, asparagus acreage in Canada has increased by over 25%. Stemphylium leaf spot, caused by Stemphylium vesicarium, has emerged as the predominant foliar pathogen of asparagus. Typically, contact fungicides are applied every 14 days; however, regardless of the number of applications, growers are not achieving adequate control of the disease. The TOM-CAST forecasting model is used widely in Michigan asparagus fields, but it has never been assessed for suitability in Ontario or in the popular cultivar, Guelph Millennium. Six field trials were conducted in 2012 and 2013 to evaluate the TOM-CAST forecasting model in two asparagus cultivars. The fungicides chlorothalonil or azoxystrobin/difenoconazole were applied according to the forecasting model or on a 14-day interval. The effectiveness of the forecasting model differed between sites and cultivars. Even though TOM-CAST is used in all cultivars in Michigan, TOM-CAST was not effective on Guelph Millennium. In the cultivar Jersey Giant, however, TOM-CAST with a 20 disease severity value spray interval improved control of Stemphylium leaf spot without increasing the number of sprays, compared with a 14-day treatment. The results in Guelph Millennium differed between sites. At one site, TOM-CAST maintained similar levels of Stemphylium leaf spot, but increased the number of applications, compared with a 14-day application interval. Of more concern, none of the fungicide treatments differed greatly from the untreated control at the other site. Our results show that forecasting models need to be validated locally in asparagus cultivars relevant to production today.

scholarly journals Improving the Cercospora Leaf Spot Management Model for Sugar Beet in Minnesota and North Dakota

Plant Disease ◽  
2007 ◽  
Vol 91 (9) ◽  
pp. 1105-1108 ◽  
Author(s):  
J. Khan ◽  
L. E. del Río ◽  
R. Nelson ◽  
M. F. R. Khan
Keyword(s):  
Sugar Beet ◽  
North Dakota ◽  
Disease Severity ◽  
Leaf Spot ◽  
Management Model ◽  
Initial Symptom ◽  
Cercospora Leaf Spot ◽  
Progress Curve ◽  
Management Recommendations ◽  
The Impact

Management of Cercospora leaf spot, caused by Cercospora beticola, is necessary for the economic production of sugar beet (Beta vulgaris). The objectives of this study were to evaluate the impact of two relative humidity thresholds (87 and 90%) on the daily infection values (DIVs) used to determine when fungicide applications were required, to determine whether current Cercospora management recommendations for northern areas of Minnesota and North Dakota could be used by growers in the southern areas of these states, and to compare the utility of calendar-based fungicide applications with the Cercospora management model. Research was conducted in Breckenridge, MN and St. Thomas, ND in 2003 and 2004. Fungicide applications significantly (P = 0.05) reduced maximum disease severity (ymax) and area under the disease progress curve (AUDPC) when compared with the nontreated control at both locations during 2003 and 2004. Fungicides applied according to DIVs calculated at RH ≥ 87% or RH > 90% gave similar results. The mandatory second fungicide application 14 days after the first application for southern areas did not significantly decrease disease severity or AUDPC, or improve root yield or recoverable sucrose compared with treatments without the mandatory application. This research illustrates that a DIV calculated at RH ≥ 87% would result in similar timing of fungicide applications compared with DIVs calculated at RH > 90%. The results further show that the recommendation of fungicide applications at initial symptom and subsequent applications based on DIV and disease severity should be used for both northern and southern growers. Finally, this research showed that fungicide applications based on the Cercospora management model provided similar, effective disease control with fewer fungicide applications compared with calendar-based applications.

scholarly journals Resistance of Selected Cultivars of Indian Hawthorn to Entomosporium Leaf Spot, Fireblight, and Anthracnose in Alabama

2001 ◽  
Vol 19 (1) ◽  
pp. 43-46
Author(s):  
A. K. Hagan ◽  
J. R. Akridge ◽  
K. L. Bowen ◽  
J. W. Olive ◽  
K. M. Tilt
Keyword(s):  
Disease Severity ◽  
Leaf Spot ◽  
Erwinia Amylovora ◽  
Test Period ◽  
Leaf Damage ◽  
Trial Period ◽  
Indian Princess

Abstract Resistance of 19 cultivars of Indian hawthorn (R. umbellata and R. × delacourii) to the diseases Entomosporium leaf spot (Entomosporiummespili), fireblight (Erwinia amylovora), and anthracnose (Colletotrichium gloeosporioides) was evaluated in a simulated landscape planting in Brewton, AL. Although symptoms of Entomosporium leaf spot were observed each year on the foliage of all cultivars, significant differences in disease severity were noted. Over the four-year test period, the lowest level of leaf spotting and premature leaf shed was consistently seen on Indian Princess® and Olivia™. Significant differences in the susceptibility of Indian hawthorn cultivars to fireblight, particularly in 1997 and 1998, were also noted. ‘Janice’ and ‘Jack Evans’, which proved particularly susceptible to this disease, resulted in the death on nearly all plants. In those same years, minor fireblight damage was also seen on Olivia™. Noticeable anthracnose-induced leaf damage and premature defoliation was recorded in 1997 only on Majestic Beauty®. Among the cultivars of Indian hawthorn screened, Indian Princess® suffered the least damage due to Entomosporium leaf spot, fireblight, and anthracnose over the four-year trial period. Olivia™ has excellent resistance to Entomosporium leaf spot but may prove sensitive to fireblight.

Impact of influenza virus during pregnancy: from disease severity to vaccine efficacy

2020 ◽  
Vol 15 (7) ◽  
pp. 441-453
Author(s):  
Ana Vazquez-Pagan ◽  
Rebekah Honce ◽  
Stacey Schultz-Cherry
Keyword(s):  
Influenza Virus ◽  
Virus Infection ◽  
Immune Responses ◽  
Pregnant Women ◽  
Disease Severity ◽  
Influenza A ◽  
Antiviral Treatment ◽  
Influenza Virus Infection ◽  
Severe Influenza ◽  
The Impact

Pregnant women are among the individuals at the highest risk for severe influenza virus infection. Infection of the mother during pregnancy increases the probability of adverse fetal outcomes such as small for gestational age, preterm birth and fetal death. Animal models of syngeneic and allogeneic mating can recapitulate the increased disease severity observed in pregnant women and are used to define the mechanism(s) of that increased severity. This review focuses on influenza A virus pathogenesis, the unique immunological landscape during pregnancy, the impact of maternal influenza virus infection on the fetus and the immune responses at the maternal–fetal interface. Finally, we summarize the importance of immunization and antiviral treatment in this population and highlight issues that warrant further investigation.

scholarly journals Updated overview on the interplay between obesity and COVID-19

Diagnosis ◽  
2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Diletta Onorato ◽  
Giovanni Carpenè ◽  
Giuseppe Lippi ◽  
Mairi Pucci
Keyword(s):  
Disease Severity ◽  
Clinical Characteristics ◽  
Literature Search ◽  
Scientific Literature ◽  
Population Sample ◽  
Obese Patients ◽  
Health Crisis ◽  
Keywords Obesity ◽  
Negative Prognostic Factor ◽  
The Impact

AbstractThe worldwide spread of coronavirus disease 2019 (COVID-19) has generated a global health crisis and more than a million deaths so far. Epidemiological and clinical characteristics of COVID-19 are increasingly reported, along with its potential relationship with overweight and/or obesity. Therefore, we aim here to review the current scientific literature on the impact of overweight and/or obesity among hospitalized patients who have developed severe or critical forms of COVID-19. Following PRISMA guidelines, our literature search identified over 300 scientific articles using the keywords “obesity” and “COVID-19”, 22 of which were finally selected for reporting useful information on the association between overweight/obesity and disease severity. In particular, in 11 out of the 14 studies (79%) which evaluated the association between obesity and disease severity providing also a risk estimate (i.e., the odd ratio; OR), the OR value was constantly >2. Although the studies were found to be heterogeneous in terms of design, population, sample size and endpoints, in most cases a significant association was found between obesity and the risk of progressing to severe COVID-19 illness, intensive care unit admission and/or death. We can hence conclude that an increased body mass index shall be considered a negative prognostic factor in patients with COVID-19, and more aggressive prevention or treatment shall hence be reserved to overweight and/or obese patients.

scholarly journals The Impact of Metabolic Scion–Rootstock Interactions in Different Grapevine Tissues and Phloem Exudates

Metabolites ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 349
Author(s):  
Sara Tedesco ◽  
Alexander Erban ◽  
Saurabh Gupta ◽  
Joachim Kopka ◽  
Pedro Fevereiro ◽  
...  
Keyword(s):  
Agronomic Traits ◽  
Phloem Exudate ◽  
Graft Union ◽  
Reciprocal Effect ◽  
Metabolic Markers ◽  
Interaction Studies ◽  
Metabolic Interactions ◽  
A Minor ◽  
The Impact ◽  
Related Compounds

In viticulture, grafting is used to propagate Phylloxera-susceptible European grapevines, thereby using resistant American rootstocks. Although scion–rootstock reciprocal signaling is essential for the formation of a proper vascular union and for coordinated growth, our knowledge of graft partner interactions is very limited. In order to elucidate the scale and the content of scion–rootstock metabolic interactions, we profiled the metabolome of eleven graft combination in leaves, stems, and phloem exudate from both above and below the graft union 5–6 months after grafting. We compared the metabolome of scions vs. rootstocks of homografts vs. heterografts and investigated the reciprocal effect of the rootstock on the scion metabolome. This approach revealed that (1) grafting has a minor impact on the metabolome of grafted grapevines when tissues and genotypes were compared, (2) heterografting affects rootstocks more than scions, (3) the presence of a heterologous grafting partner increases defense-related compounds in both scion and rootstocks in shorter and longer distances from the graft, and (4) leaves were revealed as the best tissue to search for grafting-related metabolic markers. These results will provide a valuable metabolomics resource for scion–rootstock interaction studies and will facilitate future efforts on the identification of metabolic markers for important agronomic traits in grafted grapevines.

scholarly journals Improving the Biocontrol Potential of Bacterial Antagonists with Salicylic Acid against Brown Rot Disease and Impact on Nectarine Fruits Quality

Agronomy ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 209
Author(s):  
Nadia Lyousfi ◽  
Rachid Lahlali ◽  
Chaimaa Letrib ◽  
Zineb Belabess ◽  
Rachida Ouaabou ◽  
...  
Keyword(s):  
Salicylic Acid ◽  
Disease Severity ◽  
Mycelial Growth ◽  
Brown Rot ◽  
Antagonistic Bacteria ◽  
Biological Treatments ◽  
Rot Disease ◽  
The Impact

The main objective of this study was to evaluate the ability of both antagonistic bacteria Bacillus amyloliquefaciens (SF14) and Alcaligenes faecalis (ACBC1) used in combination with salicylic acid (SA) to effectively control brown rot disease caused by Monilinia fructigena. Four concentrations of salicylic acid (0.5%, 2%, 3.5%, and 5%) were tested under in vitro and in vivo conditions. Furthermore, the impact of biological treatments on nectarine fruit parameters’ quality, in particular, weight loss, titratable acidity, and soluble solids content, was evaluated. Regardless of the bacterium, the results indicated that all combined treatments displayed a strong inhibitory effect on the mycelial growth of M. fructigena and disease severity. Interestingly, all SA concentrations significantly improved the biocontrol activity of each antagonist. The mycelial growth inhibition rate ranged from 9.79% to 88.02% with the highest reduction rate recorded for bacterial antagonists in combination with SA at both concentrations of 0.5% and 3.5%. The in vivo results confirmed the in vitro results with a disease severity varying from 0.00% to 51.91%. A significant biocontrol improvement was obtained with both antagonistic bacteria when used in combination with SA at concentrations of 0.5% and 2%. The lowest disease severity observed with ACBC1 compared with SF14 is likely due to a rapid adaptation and increase of antagonistic bacteria population in wounded sites. The impact of all biological treatments revealed moderate significant changes in the fruit quality parameters with weight loss for several treatments. These results suggest that the improved disease control of both antagonistic bacteria was more likely directly linked to both the inhibitory effects of SA on pathogen growth and induced fruit resistance.

scholarly journals The interplay between environmental exposures and COVID-19 risks in the health of children

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Peter D. Sly ◽  
Brittany A. Trottier ◽  
Catherine M. Bulka ◽  
Stephania A. Cormier ◽  
Julius Fobil ◽  
...  
Keyword(s):  
Air Pollution ◽  
Air Quality ◽  
Disease Severity ◽  
Research Effort ◽  
Severe Disease ◽  
Environmental Exposures ◽  
Research Strategy ◽  
Lessons Learned ◽  
Research Questions ◽  
The Impact

Abstract Background An unusual feature of SARS-Cov-2 infection and the COVID-19 pandemic is that children are less severely affected than adults. This is especially paradoxical given the epidemiological links between poor air quality and increased COVID-19 severity in adults and that children are generally more vulnerable than adults to the adverse consequences of air pollution. Objectives To identify gaps in knowledge about the factors that protect children from severe SARS-Cov-2 infection even in the face of air pollution, and to develop a transdisciplinary research strategy to address these gaps. Methods An international group of researchers interested in children’s environmental health was invited to identify knowledge gaps and to develop research questions to close these gaps. Discussion Key research questions identified include: what are the effects of SAR-Cov-2 infection during pregnancy on the developing fetus and child; what is the impact of age at infection and genetic susceptibility on disease severity; why do some children with COVID-19 infection develop toxic shock and Kawasaki-like symptoms; what are the impacts of toxic environmental exposures including poor air quality, chemical and metal exposures on innate immunity, especially in the respiratory epithelium; what is the possible role of a “dirty” environment in conveying protection – an example of the “hygiene hypothesis”; and what are the long term health effects of SARS-Cov-2 infection in early life. Conclusion A concerted research effort by a multidisciplinary team of scientists is needed to understand the links between environmental exposures, especially air pollution and COVID-19. We call for specific research funding to encourage basic and clinical research to understand if/why exposure to environmental factors is associated with more severe disease, why children appear to be protected, and how innate immune responses may be involved. Lessons learned about SARS-Cov-2 infection in our children will help us to understand and reduce disease severity in adults, the opposite of the usual scenario.

scholarly journals Epidemiology and management of bacterial leaf spot on watermelon caused byPseudomonas syringae

Plant Disease ◽  
2017 ◽  
Vol 101 (7) ◽  
pp. 1222-1229 ◽  
Author(s):  
E. A. Newberry ◽  
L. Ritchie ◽  
B. Babu ◽  
T. Sanchez ◽  
K. A. Beckham ◽  
...  
Keyword(s):  
Disease Severity ◽  
Pseudomonas Syringae ◽  
Leaf Spot ◽  
Negative Relationship ◽  
Disease Outbreaks ◽  
Field Trials ◽  
Multiple Regression Model ◽  
Bacterial Leaf Spot ◽  
Progress Curve ◽  
Cool Conditions

Bacterial leaf spot of watermelon caused by Pseudomonas syringae has been an emerging disease in the southeastern United States in recent years. Disease outbreaks in Florida were widespread from 2013 to 2014 and resulted in foliar blighting at the early stages of the crop and transplant losses. We conducted a series of field trials at two locations over the course of two years to examine the chemical control options that may be effective in management of this disease, and to investigate the environmental conditions conducive for bacterial leaf spot development. Weekly applications of acibenzolar-S-methyl (ASM) foliar, ASM drip, or copper hydroxide mixed with ethylene bis-dithiocarbamate were effective in reducing the standardized area under the disease progress curve (P < 0.05). Pearson’s correlation test demonstrated a negative relationship between the average weekly temperature and disease severity (–0.77, P = 0.0002). When incorporated into a multiple regression model with the square root transformed average weekly rainfall, these two variables accounted for 71% of the variability observed in the weekly disease severity (P < 0.0001). This information should be considered when choosing the planting date for watermelon seedlings as the cool conditions often encountered early in the spring season are conducive for bacterial leaf spot development.

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