Reduction of Phellinusweirii inoculum in Douglas-fir stumps by the fumigant Telone ll-B

1995 ◽  
Vol 25 (1) ◽  
pp. 63-68 ◽  
Author(s):  
R.G. Fraser ◽  
J.D. Beale ◽  
R.J. Nevill
Keyword(s):  
Root Biomass ◽  
Control Measure ◽  
Large Diameter ◽  
Root Diameter ◽  
Douglas Fir ◽  
Soil Samples ◽  
Effective Control ◽  
Residual P ◽  
Diameter Classes

Two dosages of Teione II-B (1,3-dichloropropene) at 3.4 and 6.7 mL/kg of stump and root biomass were tested to determine the efficacy in reducing Phellinusweirii (Murr.) Gilb. inoculum in infected Douglas-fir, Pseudotsugamenziesii (Mirb.) Franco, stumps. After 21 months, both doses of Teione II-B proved equally effective and significantly (p < 0.05) reduced residual P. weirii mycelium in infected roots. Fumigation reduced residual endotrophic P. weirii in the large-diameter root classes nearest the stump, but survival of the fungus was less affected with increasing distance from the stump and in the smaller root diameter classes. Treated stumps also had significantly (p < 0.05) fewer roots with ectotrophic mycelium than untreated stumps. Four weeks after application, soil samples taken near treated stumps revealed no evidence of the fumigant. These findings suggest that application of Teione II-B could be used as an effective control measure for P. weirii.

Quantification of Root Biomass in Post-Mining Areas in the Municipality of Capitão Poço – PA, Brazil

2021 ◽  
pp. 84-92
Author(s):  
Jamilie Brito De Castro ◽  
Renisson Neponuceno De Araújo Filho ◽  
Victor Casimiro Piscoya ◽  
Cristiane Maria Gonçalves Crespo ◽  
Renata de Oliveira Fernandes ◽  
...  
Keyword(s):  
Soil Quality ◽  
Fine Roots ◽  
Root Biomass ◽  
Soil Samples ◽  
Soil Sampling ◽  
Root Density ◽  
Native Forest ◽  
Mining Areas ◽  
Degraded Area ◽  
Diameter Classes

The present work aimed to quantify the concentrations and biomass stock of fine andthick roots, in three areas in the municipality of Capitão Poço-PA, Brazil. The areas used were degraded area, recovery area and native forest. For soil sampling, 24 trenches were opened, measuring 70 x 70 x 100 cm. In these trenches, soil samples were taken at depths 0-10, 10-20, 20-30, 30-40, 40-50, 50-60, 60-80 and 80-100 cm and sieving was carried out.All roots and other underground plant structures that remained in the sieve were collected by manual collection. The roots were separated into two diameter classes: fine roots ≤ 5 mm and thick roots > 5 mm, kiln dried and weighed.In the analysis, higherconcentrationsofthickand fine roots were observed in an area of native forest at depths of 0-10 and 10-20 cm. In the areas analyzed in this study, the root density in the topsoil of 0-10 cm was mainly composed of fine roots.In the three areas analyzed in this study, it was observed that from a depth of 10-20 cm there were decreases in theconcentrationsofthick roots. The area under recovery approached the area of native forest in the concentration of fine roots, demonstrating possible improvements in soil quality and recovery is probably actually taking place.

Estimating coarse root biomass of balsam fir

2007 ◽  
Vol 37 (6) ◽  
pp. 991-998 ◽  
Author(s):  
M.B. Lavigne ◽  
M.J. Krasowski
Keyword(s):  
New Brunswick ◽  
Root Biomass ◽  
Abies Balsamea ◽  
Belowground Biomass ◽  
Root Diameter ◽  
Balsam Fir ◽  
Stand Age ◽  
Coarse Root ◽  
The Relationship ◽  
Diameter Classes

Root systems of 31 balsam fir ( Abies balsamea (L.) Mill.) trees were excavated at five sites in central New Brunswick. Sites ranged from 10 to >80 years in stand age; most had been thinned at least once, and densities ranged from 750 to 44 000 trees·ha–1. The relationship between diameter at breast height and coarse root biomass in the present investigation was similar to one reported for balsam fir in northern New Brunswick but differed from two other published biomass equations. Coarse root biomass per hectare ranged from 3 to 30 Mg·ha–1 among studied sites. Coarse root biomass in the smaller root diameter classes was similar at all sites, but biomass in diameter classes >50 mm increased with stand age. Precommercial thinning added 3 Mg coarse root biomass·ha–1 to the detrital pool. The ratio of coarse root biomass to stem biomass averaged 0.36 (±0.02 SE). These results show that there is more belowground biomass in balsam fir ecosystems than would be expected from the generic ratio of belowground to aboveground biomass often applied to coniferous ecosystems, pointing to a need for using ratios that are more specific.

scholarly journals Thinning effects on biomass and element concentrations of roots in adjacent hornbeam and oak stands in Istanbul, Turkey

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Serdar Akburak ◽  
Ender Makineci
Keyword(s):  
Fine Roots ◽  
Root Biomass ◽  
Fine Root ◽  
Basal Area ◽  
Fine Root Biomass ◽  
Root Diameter ◽  
Coarse Roots ◽  
Coarse Root ◽  
Element Concentrations ◽  
Diameter Classes

Abstract Background Thinning is a commonly used treatment in forest management which affects the tree root systems. The effects of thinning on element concentrations and seasonal change of roots were evaluated in adjacent oak (Quercus frainetto Ten.) and hornbeam (Carpinus betulus L.) stands according to the different root diameter classes. Method Two replicated control and thinning plots (50 m × 50 m) were set for each species (hornbeam and oak). Thinning treatments (November 2010) reduced 50% of the basal area in both oak and hornbeam stands. Roots were assessed by seasonal collection over 2 years (from October 2010 to October 2012). The roots were then sorted into diameter classes of 0–2 mm (fine roots), 2–5 mm (small roots) and > 5 mm (coarse roots). C, N, P, K, Ca, Na, Mg, S, Mn, Fe, Al, Zn, Pb, Ni, Cu and Cd were analyzed. Results Except coarse roots, the highest root biomasses were determined in April-2011 in all plots. Fine-root biomass in oak was found significantly higher in control plots. In contrast to the oak, the fine-root biomass in the thinned hornbeam plots was higher than in the controls. The small-root biomass did not significantly differ between the thinned and the control plots in both oak and hornbeam stands. However, the coarse-root biomass showed significant differences between the control (1989 g∙m− 2) and thinned plots (1060 g∙m− 2) in oak, while no difference was detected in hornbeam. The concentrations of C, Al, Pb, Cd, Ni, Zn, Mn, Na, K, Mg and P in the fine roots of oak were significantly higher in the thinned plots. However, the concentration of Pb, Cd and Fe in the fine roots was significantly higher in the thinned plots of hornbeam. Significant differences were observed between the species for all elements in the fine roots except for C, N and P. In particular, elements in the fine roots tended to increase in July in the oak. In the hornbeam, all element concentrations in the fine roots (except C, N, and S) in the thinned plots showed a tendency to increase in April. The concentrations of Pb, Ni, Al, Fe, Cu, Ca, Na, K, Mg and P in the hornbeam control plots increased during the April 2011 period. Conclusion The results indicated that thinning effects on temporal changes and concentrations of elements in the roots could be attributed to species-specific characteristics.

Control of Bulking in an Extended Aeration Sewage Treatment Plant

1972 ◽  
Vol 7 (1) ◽  
pp. 13-20
Author(s):  
D.D.P. Cane ◽  
G.J. Farguhar
Keyword(s):  
Dissolved Oxygen ◽  
Control Measure ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Effective Control ◽  
Organic Loading Rate ◽  
Organic Loading ◽  
Mixed Liquor ◽  
Air Supply

Abstract A case of filamentous activated sludge bulking was investigated at an extended aeration plant treating wastes from a highway service centre. The purpose of the study was to find an effective control measure for the bulking and, if possible, to determine the cause of the bulking condition. Experiments were conducted to determine the effects upon bulking of: (a) a controlled copper dosage to the mixed liquor, (b) variations in the organic loading rate, and (c) maintenance of high and low dissolved oxygen concentrations in the mixed liquor. The microorganism responsible for the bulking condition was tentatively identified as Sphaerotilus natans. Extensive growths of these bacteria occurred in the sludge when the mixed liquor dissolved oxygen concentration dropped below 0.5 mg/1. Such dissolved oxygen levels had frequently occurred at this plant due to the use of timed aeration cycles and the use of insufficient air supply during peak loading periods. Variations in organic loading rates were found to have no adverse effect on sludge settleability. When bulking was slight, the condition could be improved by increasing the dissolved oxygen level to 1.5 mg/1, or more. The rate at which the filamentous growths could be eliminated from a highly filamentous sludge by increased aeration was very slow, but could be greatly increased by the simultaneous feeding of copper to the mixed liquor at a dosage rate of 1.0 mg/1, based on the raw sewage flows.

Characterizing the effectiveness of COVID-19 mitigation measures: A data-centric approach (Preprint)

2020 ◽  
Author(s):  
Lukman Olagoke ◽  
Ahmet E. Topcu
Keyword(s):  
Control Measure ◽  
Control Measures ◽  
World Health ◽  
Mitigation Measures ◽  
Effective Control ◽  
The World ◽  
Decision Making Processes ◽  
And Performance ◽  
Health Organization ◽  
The Impact

BACKGROUND COVID-19 represents a serious threat to both national health and economic systems. To curb this pandemic, the World Health Organization (WHO) issued a series of COVID-19 public safety guidelines. Different countries around the world initiated different measures in line with the WHO guidelines to mitigate and investigate the spread of COVID-19 in their territories. OBJECTIVE The aim of this paper is to quantitatively evaluate the effectiveness of these control measures using a data-centric approach. METHODS We begin with a simple text analysis of coronavirus-related articles and show that reports on similar outbreaks in the past strongly proposed similar control measures. This reaffirms the fact that these control measures are in order. Subsequently, we propose a simple performance statistic that quantifies general performance and performance under the different measures that were initiated. A density based clustering of based on performance statistic was carried out to group countries based on performance. RESULTS The performance statistic helps evaluate quantitatively the impact of COVID-19 control measures. Countries tend show variability in performance under different control measures. The performance statistic has negative correlation with cases of death which is a useful characteristics for COVID-19 control measure performance analysis. A web-based time-line visualization that enables comparison of performances and cases across continents and subregions is presented. CONCLUSIONS The performance metric is relevant for the analysis of the impact of COVID-19 control measures. This can help caregivers and policymakers identify effective control measures and reduce cases of death due to COVID-19. The interactive web visualizer provides easily digested and quick feedback to augment decision-making processes in the COVID-19 response measures evaluation. CLINICALTRIAL Not Applicable

scholarly journals Transcriptome-based identification and characterization of genes responding to imidacloprid in Myzus persicae

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Jianyu Meng ◽  
Xingjiang Chen ◽  
Changyu Zhang
Keyword(s):  
Genetic Basis ◽  
Expression Profiles ◽  
Control Measure ◽  
Effective Control ◽  
Agricultural Pest ◽  
Functional Classification ◽  
Quantitative Real Time Pcr ◽  
Underlying Mechanisms ◽  
Identification And Characterization

Abstract Myzus persicae is a serious and widespread agricultural pest, against which, imidacloprid remains an effective control measure. However, recent reports indicate that this aphid has evolved and developed resistance to imidacloprid. This study aimed to elucidate the underlying mechanisms and genetic basis of this resistance by conducting comparative transcriptomics studies on both imidacloprid-resistant (IR) and imidacloprid-susceptible (IS) M. persicae. The comparative analysis identified 252 differentially expressed genes (DEGs) among the IR and IS M. persicae transcriptomes. These candidate genes included 160 and 92 genes that were down- and up-regulated, respectively, in the imidacloprid-resistant strain. Using functional classification in the GO and KEGG databases, 187 DEGs were assigned to 303 functional subcategories and 100 DEGs were classified into 45 pathway groups. Moreover, several genes were associated with known insecticide targets, cuticle, metabolic processes, and oxidative phosphorylation. Quantitative real-time PCR of 10 DEGs confirmed the trends observed in the RNA sequencing expression profiles. These findings provide a valuable basis for further investigation into the complicated mechanisms of imidacloprid resistance in M. persicae.

Le système radiculaire dans les érablières du Québec. I. Nouvelle méthode d'estimation du volume et de la masse des radicelles

1992 ◽  
Vol 22 (10) ◽  
pp. 1562-1567 ◽  
Author(s):  
Fernand Pagé ◽  
Bady Badibanga ◽  
Annie Sauvesty ◽  
Colette Ansseau
Keyword(s):  
Standard Deviation ◽  
Sugar Maple ◽  
Soil Samples ◽  
Diameter Class ◽  
Thin Sections ◽  
Truncated Cone ◽  
The Mean ◽  
Diameter Classes

A method for rapidly estimating the rootlet volume and mass in sugar maple groves was developed in relation with the rootlet size. Soil samples were obtained with corers and cut in 2-cm thick slices. The number of rootlets of diameter classes <0.3, 0.3–0.5, 0.5–0.8, and 0.8–1.0 mm were determined under microscope (× 150) on the upper surface of slices. Rootlet surface for each class was measured on thin sections of soil, with an optic microscope connected to a digitalizing board. Mean rootlet surface [Formula: see text] showed a small standard deviation within each diameter class. The rootlet surface (S) on a surface of soil St can be estimated as [Formula: see text], where N is the number of rootlets observed in nc fields of observation, each field having a surface So. If two soil slices are located at depths h1 and h2, respectively, and if the rootlet surfaces of those slices are S1 and S2, the rootlet volume V of the first slice corresponds approximately to the volume of a truncated cone, and can be calculated as V = [S1 + S2 + (S1S2)0,5] (h2–h1)/3. The rootlet density (g•cm−3 of root) was also determined for each diameter class. The standard deviation from [Formula: see text], the mean density for each diameter class was small. Thus, the rootlet mass M was determined as [Formula: see text]. Estimated and real rootlet volume and mass values were compared. A difference of about 10% was found between estimated and real values.

scholarly journals Challenges of influenza A viruses in humans and animals and current animal vaccines as an effective control measure

2018 ◽  
Vol 7 (1) ◽  
pp. 1 ◽  
Author(s):  
Sung J. Yoo ◽  
Taeyong Kwon ◽  
Young S. Lyoo
Keyword(s):  
Influenza A ◽  
Control Measure ◽  
Effective Control ◽  
Influenza A Viruses

scholarly journals Occurrence of Soil-transmitted Helminths from Selected Dumpsites and Farmlands in Calabar, Nigeria

2021 ◽  
pp. 14-22
Author(s):  
Edema Enogiomwan Imalele ◽  
Effanga Emmanuel Offiong ◽  
Usang Anok Ukam ◽  
Aramushu Willington Urimaneh ◽  
Henshaw Victoria Utibe
Keyword(s):  
Strongyloides Stercoralis ◽  
Dry Season ◽  
Soil Samples ◽  
Effective Control ◽  
Soil Nematode ◽  
Helminth Parasites ◽  
Wet Season ◽  
Potential Health ◽  
Soil Transmitted Helminths ◽  
Farmland Soils

Aims: The present study investigated the prevalence and intensity of soil-transmitted helminth contamination in dumpsite and farmland soils in Calabar, Cross River State, Nigeria. Methodology: Soil samples were randomly collected from selected dumpsites and farmlands from July to December 2019. 200 soil samples (100 samples each from dumpsites and farmland) were collected. Soil samples were analysed using Zinc sulphate flotation technique whereas soil nematode extraction for hookworm and Strongyloides larvae was carried out using the modified Baermann technique. Results: Of the 200 soil samples examined, 131 (65.5%) were positive for ova/larvae of one or more parasites. Dumpsite soils were highly contaminated with ova/larvae of soil-transmitted helminths than farmland soils with a prevalence of 79% (n=79) and 52% (n=52) respectively (P=.02). Farmlands had the highest mean intensity (6.75±1.88) of contamination with ova/larvae of soil-transmitted helminths compared to dumpsite soils (1.68±0.14). Ascaris lumbricoides recorded the highest occurrence (35.5%) (P=.003) in soil samples examined. A. lumbricoides (40%) and Trichuris trichiura (6%) contamination was higher in dumpsite soils, while Strongyloides stercoralis larvae (34%) and hookworm (10%) contamination was higher in farmland soils. Dumpsite soils recorded the highest number of parasites (84%) in the wet season, while farmland soils recorded the highest number of parasites (92%) in the dry season (P=.11). Generally, parasitic ova/larvae were more prevalent in the dry season (91%) than in the wet season (73%) (P=.33). S. stercoralis (33%) was more prevalent in the wet season followed while A. lumbricoides (43%) recorded highest occurrence in the dry season. Conclusion: This study revealed the potential health risk of contracting soil-transmitted helminth parasites in soils around farmlands and dumpsites in Calabar, Nigeria. It is therefore important that a combination of sanitation and health education be put in place for effective control of soil-transmitted helminths.

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