Survival of Fusarium oxysporum f. sp. lactucae on crop residue in soil

Plant Disease ◽  
2020 ◽  
Author(s):  
Kelley Rose Paugh ◽  
Thomas Gordon
Keyword(s):  
Fusarium Oxysporum ◽  
Crop Residue ◽  
Soil Surface ◽  
Soil Inoculum ◽  
Residue Decomposition ◽  
Soil Persistence ◽  
Long Run ◽  
One Year ◽  
Drying Conditions ◽  
Over Time

Fusarium oxysporum f. sp. lactucae, the cause of Fusarium wilt of lettuce, can survive on crop residue in soil. Persistence of the pathogen over time will be influenced by the rate at which residue decomposes. We evaluated the effect of drying and fragmenting crop residue on the rate of decomposition and survival of F. oxysporum f. sp. lactucae. In a controlled experiment that represented optimal drying conditions, fragmenting and oven-drying infested lettuce taproots at 30°C significantly reduced the frequency of recovery of the pathogen, compared to untreated tissue. However, in a field experiment, drying infested crop residue on the soil surface prior to incorporation did not significantly reduce survival of F. oxysporum f. sp. lactucae after one year. Regardless of treatment, there was not a significant decrease in soil inoculum density between one and 12 months after residue was incorporated. In a greenhouse experiment, fragmenting crop residue prior to incorporation in pathogen-free soil resulted in significantly higher inoculum densities of F. oxysporum f. sp. lactucae after one year. The increase in inoculum levels was associated with a faster rate of residue decomposition, which may be beneficial in the long run but not where lettuce will be replanted within the next year.

scholarly journals Crop residue decomposition in Minnesota biochar-amended plots

Solid Earth ◽  
2014 ◽  
Vol 5 (1) ◽  
pp. 499-507 ◽  
Author(s):  
S. L. Weyers ◽  
K. A. Spokas
Keyword(s):  
Microbial Biomass ◽  
Crop Residue ◽  
Crop Residues ◽  
Soil Surface ◽  
Microbial Dynamics ◽  
Wood Pellet ◽  
First Order ◽  
Residue Decomposition ◽  
Continuous Corn ◽  
Crop Residue Decomposition

Abstract. Impacts of biochar application at laboratory scales are routinely studied, but impacts of biochar application on decomposition of crop residues at field scales have not been widely addressed. The priming or hindrance of crop residue decomposition could have a cascading impact on soil processes, particularly those influencing nutrient availability. Our objectives were to evaluate biochar effects on field decomposition of crop residue, using plots that were amended with biochars made from different plant-based feedstocks and pyrolysis platforms in the fall of 2008. Litterbags containing wheat straw material were buried in July of 2011 below the soil surface in a continuous-corn cropped field in plots that had received one of seven different biochar amendments or a uncharred wood-pellet amendment 2.5 yr prior to start of this study. Litterbags were collected over the course of 14 weeks. Microbial biomass was assessed in treatment plots the previous fall. Though first-order decomposition rate constants were positively correlated to microbial biomass, neither parameter was statistically affected by biochar or wood-pellet treatments. The findings indicated only a residual of potentially positive and negative initial impacts of biochars on residue decomposition, which fit in line with established feedstock and pyrolysis influences. Overall, these findings indicate that no significant alteration in the microbial dynamics of the soil decomposer communities occurred as a consequence of the application of plant-based biochars evaluated here.

scholarly journals Crop residue decomposition in Minnesota biochar amended plots

2014 ◽  
Vol 6 (1) ◽  
pp. 599-617 ◽  
Author(s):  
S. L. Weyers ◽  
K. A. Spokas
Keyword(s):  
Microbial Biomass ◽  
Crop Residue ◽  
Crop Residues ◽  
Soil Surface ◽  
Wood Pellet ◽  
First Order ◽  
Residue Decomposition ◽  
Continuous Corn ◽  
Crop Residue Decomposition ◽  
Charred Wood

Abstract. Impacts of biochar application at laboratory scales are routinely studied, but impacts of biochar application on decomposition of crop residues at field scales have not been widely addressed. The priming or hindrance of crop residue decomposition could have a cascading impact on soil processes, particularly those influencing nutrient availability. Our objectives were to evaluate biochar effects on field decomposition of crop residue, using plots that were amended with biochars made from different feedstocks and pyrolysis platforms prior to the start of this study. Litterbags containing wheat straw material were buried below the soil surface in a continuous-corn cropped field in plots that had received one of seven different biochar amendments or a non-charred wood pellet amendment 2.5 yr prior to start of this study. Litterbags were collected over the course of 14 weeks. Microbial biomass was assessed in treatment plots the previous fall. Though first-order decomposition rate constants were positively correlated to microbial biomass, neither parameter was statistically affected by biochar or wood-pellet treatments. The findings indicated only a residual of potentially positive and negative initial impacts of biochars on residue decomposition, which fit in line with established feedstock and pyrolysis influences. Though no significant impacts were observed with field-weathered biochars, effective soil management may yet have to account for repeat applications of biochar.

scholarly journals Particulate soil organic carbon and stratification ratio increases in response to crop residue decomposition under no-till

2012 ◽  
Vol 36 (5) ◽  
pp. 1483-1490 ◽  
Author(s):  
Clever Briedis ◽  
João Carlos de Moraes Sá ◽  
Roberto Simão De-Carli ◽  
Erielton Aparecido Pupo Antunes ◽  
Lucas Simon ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Crop Residue ◽  
Soil Surface ◽  
Residue Decomposition ◽  
No Till ◽  
Dry Biomass ◽  
Particulate Soil ◽  
Crop Residue Decomposition ◽  
Biomass Decomposition

In soils under no-tillage (NT), the continuous crop residue input to the surface layer leads to carbon (C) accumulation. This study evaluated a soil under NT in Ponta Grossa (State of Paraná, Brazil) for: 1) the decomposition of black oat (Avena strigosa Schreb.) residues, 2) relation of the biomass decomposition effect with the soil organic carbon (SOC) content, the particulate organic carbon (POC) content, and the soil carbon stratification ratio (SR) of an Inceptisol. The assessments were based on seven samplings (t0 to t6) in a period of 160 days of three transects with six sampling points each. The oat dry biomass was 5.02 Mg ha-1 at t0, however, after 160 days, only 17.8 % of the initial dry biomass was left on the soil surface. The SOC in the 0-5 cm layer varied from 27.56 (t0) to 30.07 g dm-3 (t6). The SR increased from 1.33 to 1.43 in 160 days. There was also an increase in the POC pool in this period, from 8.1 to 10.7 Mg ha-1. The increase in SOC in the 0-5 cm layer in the 160 days was mainly due to the increase of POC derived from oat residue decomposition. The linear relationship between SOC and POC showed that 21 % of SOC was due to the more labile fraction. The results indicated that the continuous input of residues could be intensified to increase the C pool and sequestration in soils under NT.

scholarly journals Trends in mortality, co-morbidity and treatment after acute myocardial infarction in patients with rheumatoid arthritis 1998–2013

2020 ◽  
Vol 9 (8) ◽  
pp. 931-938 ◽  
Author(s):  
Mattias Skielta ◽  
Lars Söderström ◽  
Solbritt Rantapää-Dahlqvist ◽  
Solveig W Jonsson ◽  
Thomas Mooe
Keyword(s):  
Rheumatoid Arthritis ◽  
Myocardial Infarction ◽  
Heart Failure ◽  
Atrial Fibrillation ◽  
Acute Myocardial Infarction ◽  
Congestive Heart Failure ◽  
Cox Regression Analysis ◽  
Co Morbidity ◽  
One Year ◽  
Over Time

Aims: Rheumatoid arthritis may influence the outcome after an acute myocardial infarction. We aimed to compare trends in one-year mortality, co-morbidities and treatments after a first acute myocardial infarction in patients with rheumatoid arthritis versus non-rheumatoid arthritis patients during 1998–2013. Furthermore, we wanted to identify characteristics associated with mortality. Methods and results: Data for 245,377 patients with a first acute myocardial infarction were drawn from the Swedish Register of Information and Knowledge about Swedish Heart Intensive Care Admissions for 1998–2013. In total, 4268 patients were diagnosed with rheumatoid arthritis. Kaplan-Meier analysis was used to study mortality trends over time and multivariable Cox regression analysis was used to identify variables associated with mortality. The one-year mortality in rheumatoid arthritis patients was initially lower compared to non-rheumatoid arthritis patients (14.7% versus 19.7%) but thereafter increased above that in non-rheumatoid arthritis patients (17.1% versus 13.5%). In rheumatoid arthritis patients the mean age at admission and the prevalence of atrial fibrillation increased over time. Congestive heart failure decreased more in non-rheumatoid arthritis than in rheumatoid arthritis patients. Congestive heart failure, atrial fibrillation, kidney failure, rheumatoid arthritis, prior diabetes mellitus and hypertension were associated with significantly higher one-year mortality during the study period 1998–2013. Conclusions: The decrease in one-year mortality after acute myocardial infarction in non-rheumatoid arthritis patients was not applicable to rheumatoid arthritis patients. This could partly be explained by an increased age at acute myocardial infarction onset and unfavourable trends with increased atrial fibrillation and congestive heart failure in rheumatoid arthritis. Rheumatoid arthritis per se was associated with a significantly worse prognosis.

scholarly journals A Central Element of Europe’s Football Ecosystem: Competitive Intensity in the “Big Five”

2021 ◽  
Vol 13 (6) ◽  
pp. 3097
Author(s):  
Fabio Wagner ◽  
Holger Preuss ◽  
Thomas Könecke
Keyword(s):  
Big Five ◽  
Central Element ◽  
Quantitative Approach ◽  
Competitive Intensity ◽  
Entrepreneurial Ecosystems ◽  
Long Run ◽  
The Future ◽  
European Football ◽  
Over Time

This study perceives professional European football as one of the most relevant event-related entrepreneurial ecosystems (EEs) worldwide. It also identifies a healthy sporting competition in the five most popular European football leagues (Spain, England, Germany, Italy, and France), the “big five,” as a key pillar for the functioning of this ecosystem. By applying a quantitative approach, competitive intensity (CI) is measured for all big five leagues for 21 seasons (1998/99 to 2018/19). The chosen method does not only convey an overall indication of the competitive health of the entire league but also provides detailed information on the four important sub-competitions (championship race, qualification for Champions League or Europa League, and the fight against relegation). In all five leagues, seasonal CI tends to decrease over time, and especially over the last decade. The main reason is a decline in the intensity of the championship race while all other sub-competitions show relatively robust CI values. Overall, it can be concluded that the competitive health of the big five is intact, but the dwindling CI of the championship races can harm the EE of professional European football in the long run. Accordingly, it should be closely monitored in the future.

Seed dormancy in four Tibetan Plateau Vicia species and characterization of physiological changes in response of seeds to environmental factors

2013 ◽  
Vol 23 (2) ◽  
pp. 133-140 ◽  
Author(s):  
Xiaowen Hu ◽  
Tingshan Li ◽  
Juan Wang ◽  
Yanrong Wang ◽  
Carol C. Baskin ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Seed Dormancy ◽  
Germination Rate ◽  
Soil Surface ◽  
The Tibetan Plateau ◽  
Physical Dormancy ◽  
High Germination ◽  
One Year ◽  
Hydrotime Model ◽  
Aba Biosynthesis

AbstractAlthough seed dormancy of temperate legumes is well understood, less is known about it in species that grow in subalpine/alpine areas. This study investigated dormancy and germination of four Vicia species from the Tibetan Plateau. Fresh seeds of V. sativa were permeable to water, whereas those of V. angustifolia, V. amoena and V. unijuga had physical dormancy (PY). One year of dry storage increased the proportion of impermeable seeds in V. angustifolia, but showed no effect on seed coat permeability in V. amoena or V. unijuga. Seeds of all four species also had non-deep physiological dormancy (PD), which was especially apparent in the two annuals at a high germination temperature (20°C). After 1 year of storage, PD had been lost. The hydrotime model showed that fresh seeds obtained a significantly higher median water potential [Ψb(50)] than stored seeds, implying that PD prevents germination in winter for seeds dispersed without PY when water availability is limited. After 6 months on the soil surface in the field, a high proportion of permeable seeds remained ungerminated, further suggesting that PD plays a key role in preventing germination after dispersal. Addition of fluridone, an inhibitor of abscisic acid (ABA) biosynthesis, evened-out the differences in germination between fresh and stored seeds, which points to the key role of ABA biosynthesis in maintaining dormancy. Further, fresh seeds were more sensitive to exogenous ABA than stored seeds, indicating that storage decreased embryo sensitivity to ABA. On the other hand, the gibberellic acid GA3 increased germination rate, which implies that embryo sensitivity to GA is also involved in seed dormancy regulation. This study showed that PY, PD or their combination (PY+PD) plays a key role in timing germination after dispersal, and that different intensities of dormancy occur among these four Vicia species from the Tibetan Plateau.

scholarly journals Incidence, Characteristics, and Prognosis of Incidentally Discovered Hepatocellular Carcinoma after Liver Transplantation

2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Walid El Moghazy ◽  
Samy Kashkoush ◽  
Glenda Meeberg ◽  
Norman Kneteman
Keyword(s):  
Hepatocellular Carcinoma ◽  
Liver Transplantation ◽  
Tumor Recurrence ◽  
Patient Survival ◽  
Steady Increase ◽  
Liver Transplants ◽  
Significant Difference ◽  
One Year ◽  
Over Time

Background. We aimed to assess incidentally discovered hepatocellular carcinoma (iHCC) over time and to compare outcome to preoperatively diagnosed hepatocellular carcinoma (pdHCC) and nontumor liver transplants.Methods.We studied adults transplanted with a follow-up of at least one year. Patients were divided into 3 groups according to diagnosis of hepatocellular carcinoma.Results.Between 1990 and 2010, 887 adults were transplanted. Among them, 121 patients (13.6%) had pdHCC and 32 patients (3.6%) had iHCC; frequency of iHCC decreased markedly over years, in parallel with significant increase in pdHCC. Between 1990 and 1995, 120 patients had liver transplants, 4 (3.3%) of them had iHCC, and only 3 (2.5%) had pdHCC, while in the last 5 years, 263 patients were transplanted, 7 (0.03%) of them had iHCC, and 66 (25.1%) had pdHCC (P<0.001). There was no significant difference between groups regarding patient survival; 5-year survival was 74%, 75.5%, and 77.3% in iHCC, pdHCC, and non-HCC groups, respectively (P=0.702). Patients with iHCC had no recurrences after transplant, while pdHCC patients experienced 17 recurrences (15.3%) (P=0.016).Conclusions.iHCC has significantly decreased despite steady increase in number of transplants for hepatocellular carcinoma. Patients with iHCC had excellent outcomes with no tumor recurrence and survival comparable to pdHCC.

Changes in commitment to change among leaders in home help services

2015 ◽  
Vol 28 (3) ◽  
pp. 216-227 ◽  
Author(s):  
Kristina Westerberg ◽  
Susanne Tafvelin
Keyword(s):  
Organizational Change ◽  
Structured Interviews ◽  
Change Initiatives ◽  
Commitment To Change ◽  
Content Type ◽  
Team Meetings ◽  
Home Help ◽  
Home Help Services ◽  
One Year ◽  
Over Time

Purpose – The purpose of the this study was to explore the development of commitment to change among leaders in the home help services during organizational change and to study this development in relation to workload and stress. During organizational change initiatives, commitment to change among leaders is important to ensure the implementation of the change. However, little is known of development of commitment of change over time. Design/methodology/approach – The study used a qualitative design with semi-structured interviews with ten leaders by the time an organizational change initiative was launched and follow-up one year later. Thematic content analysis was used to analyze the interviews. Findings – Commitment to change is not static, but seems to develop over time and during organizational change. At the first interview, leaders had a varied pattern reflecting different dimensions of commitment to change. One year later, the differences between leaders’ commitment to change was less obvious. Differences in commitment to change had no apparent relationship with workload or stress. Research limitations/implications – The data were collected from one organization, and the number of participants were small which could affect the results on workload and stress in relation to commitment to change. Practical implications – It is important to support leaders during organizational change initiatives to maintain their commitment. One way to accomplish this is to use management team meetings to monitor how leaders perceive their situation. Originality/value – Qualitative, longitudinal and leader studies on commitment to change are all unusual, and taken together, this study shows new aspects of commitment.

scholarly journals Survival and Inoculum Production of Gibberella zeae in Wheat Residue

Plant Disease ◽  
2004 ◽  
Vol 88 (7) ◽  
pp. 724-730 ◽  
Author(s):  
S. A. Pereyra ◽  
R. Dill-Macky ◽  
A. L. Sims
Keyword(s):  
Management Strategies ◽  
Soil Surface ◽  
Triticum Aestivum L ◽  
Gibberella Zeae ◽  
Effective Management ◽  
Head Blight ◽  
Fusarium Spp ◽  
Residue Decomposition ◽  
Inoculum Production ◽  
Mesh Bags

Survival and inoculum production of Gibberella zeae (Schwein.) Petch (anamorph Fusarium graminearum (Schwabe)), the causal agent of Fusarium head blight of wheat and barley, was related to the rate of wheat (Triticum aestivum L.) residue decomposition. Infested wheat residue, comprising intact nodes, internodes, and leaf sheaths, was placed in fiberglass mesh bags on the soil surface and at 7.5- to 10-cm and 15- to 20-cm depths in chisel-plowed plots and 15 to 20 cm deep in moldboard-plowed plots in October 1997. Residue was sampled monthly from April through November during 1998 and every 2 months through April to October 1999. Buried residue decomposed faster than residue placed on the soil surface. Less than 2% of the dry-matter residue remained in buried treatments after 24 months in the field, while 25% of the residue remained in the soil-surface treatment. Survival of G. zeae on node tissues was inversely related to the residue decomposition rate. Surface residue provided a substrate for G. zeae for a longer period of time than buried residue. Twenty-four months after the initiation of the trial, the level of colonization of nodes in buried residue was half the level of colonization of residue on the soil surface. Colonization of node tissues by G. zeae decreased over time, but increased for other Fusarium spp. Ascospores of G. zeae were still produced on residue pieces after 23 months, and these spores were capable of inducing disease. Data from this research may assist in developing effective management strategies for residues infested with G. zeae.

scholarly journals A longitudinal study on emotional distress among local government staff seven years after the 2008 Wenchuan earthquake in China

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Yunge Fan ◽  
Lili Guan ◽  
Hu Xiang ◽  
Xianmei Yang ◽  
Guoping Huang ◽  
...  
Keyword(s):  
Longitudinal Study ◽  
Local Government ◽  
Wenchuan Earthquake ◽  
Emotional Distress ◽  
Early Stage ◽  
2008 Wenchuan Earthquake ◽  
The 2008 Wenchuan Earthquake ◽  
One Year ◽  
Self Reporting Questionnaire ◽  
Over Time

Abstract Background The current study examined the change in local government staff’s emotional distress over 7 years after the 2008 Wenchuan earthquake, and the influence of earthquake exposure and professional quality of life (ProQOL) on emotional distress. Methods This longitudinal study assessed 250 participants at 1 year after the earthquake; 162 (64.8%) were followed up at 7 years. Emotional distress was assessed with the Self-Reporting Questionnaire (SRQ) at both time points. We assessed ProQOL, including compassion satisfaction, burnout, and secondary traumatic stress, and earthquake exposure at 1 year. Wilcoxon signed-rank tests were performed to test longitudinal changes in emotional distress. Hierarchical multiple regression was conducted to examine the effect of earthquake exposure and ProQOL. Results The positive screening rate of emotional distress (SRQ ≥ 8) was 37.6 and 15.4% at one and 7 years, respectively. Emotional distress scores declined over time (p < 0.001). Earthquake exposure and ProQOL predicted one-year (ps < 0.05) but not seven-year emotional distress, whereas burnout predicted both one-year (p = 0.018) and seven-year (p = 0.047) emotional distress. Conclusions Although emotional distress can recover over time, it persists even 7 years later. Actions to reduce burnout during the early stage of post-disaster rescue have long-term benefits to staff’s psychological outcomes.

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