scholarly journals Synergistic Interaction between the Entomopathogenic Fungus Akanthomyces attenuatus (Zare & Gams) and the Botanical Insecticide Matrine against Megalurothrips usitatus (Bagrall)

2021 ◽  
Vol 7 (7) ◽  
pp. 536
Author(s):  
Jianhui Wu ◽  
Bo Yang ◽  
Xiaochen Zhang ◽  
Andrew G. S. Cuthbertson ◽  
Shaukat Ali
Keyword(s):  
Synergistic Effect ◽  
Entomopathogenic Fungus ◽  
Control Strategies ◽  
Germination Rate ◽  
Experimental Period ◽  
Colony Growth ◽  
Synergistic Interaction ◽  
Natural Ecosystem ◽  
Botanical Insecticide ◽  
Mortality Effect

The excessive use of synthetic chemicals for Megalurothrips usitatus (Bagrall) management has resulted in the development of insecticide resistance as well as adverse effects to the natural ecosystem. This has driven the need to develop alternative pest control strategies. This study reports a synergistic interaction between the entomopathogenic fungus Akanthomyces attenuatus (Zare & Gams) and the botanical insecticide matrine against M. usitatus. The results revealed that the germination rate and colony growth of A. attenuatus were inhibited by higher matrine concentrations. Percentage mortalities of M. usitatus following application of A. attenuatus and matrine showed a dose mortality effect. After five days of treatment, all concentrations of matrine combined with different concentrations of A. attenuatus, except one combination (matrine 0.25 mg/mL + 1 × 107 conidia/mL), showed synergistic effect. The activities of acetylcholinesterase and antioxidant enzymes (superoxide dismutase, catalase and peroxidase) in M. usitatus, in response to individual or combined application of A. attenuatus and matrine at the end of the experimental period, were significantly lower than controls. The findings confirm the synergistic action of A. attenuatus and matrine against M. usitatus along with the biochemical phenomenon possibly regulating the synergistic effect.

Effect of Environmental Factors on Germination and Emergence of Shortawn Foxtail (Alopecurus aequalis)

Weed Science ◽  
2017 ◽  
Vol 66 (1) ◽  
pp. 47-56 ◽  
Author(s):  
Ning Zhao ◽  
Qi Li ◽  
Wenlei Guo ◽  
Lele Zhang ◽  
Lu’an Ge ◽  
...  
Keyword(s):  
Seed Germination ◽  
Osmotic Potential ◽  
Control Strategies ◽  
Abiotic Factors ◽  
Germination Rate ◽  
Seedling Emergence ◽  
Soil Surface ◽  
Burial Depth ◽  
Effective Measure ◽  
Wide Range

Shortawn foxtail is an invasive grass weed infesting winter wheat and canola production in China. A better understanding of the germination ecology of shortawn foxtail would help to develop better control strategies for this weed. Experiments were conducted under laboratory conditions to evaluate the effects of various abiotic factors, including temperature, light, pH, osmotic stress, salt concentration, and planting depth, on seed germination and seedling emergence of shortawn foxtail. The results showed that the seed germination rate was greater than 90% over a wide range of constant (5 to 25C) and alternating (15/5 to 35/25C) temperatures. Maximum germination occurred at 20C or 25/15C, and no germination occurred at 35C. Light did not appear to have any effect on seed germination. Shortawn foxtail germination was 27% to 99% over a pH range of 4 to 10, and higher germination was obtained at alkaline pH values ranging from 7 to 10. Seed germination was sensitive to osmotic potential and completely inhibited at an osmotic potential of −0.6 MPa, but it was tolerant to salinity: germination even occurred at 200 mM NaCl (5%). Seedling emergence was highest (98%) when seeds were placed on the soil surface but declined with the increasing burial depth. No seedlings emerged when seeds were buried 6-cm deep. Deep tillage could be an effective measure to limit seed germination from increased burial depth. The results of this study will lead to a better understanding of the requirements for shortawn foxtail germination and emergence and will provide information that could contribute to its control.

scholarly journals Effect of Environmental Factors on Seed Germination and Early Seedling Emergence of Carolina geranium (Geranium carolinianum)

2018 ◽  
Vol 36 ◽  
Author(s):  
X. LIU ◽  
T. ZONG ◽  
Y. LI ◽  
X. ZHOU ◽  
L. BAI
Keyword(s):  
Control Strategies ◽  
Germination Rate ◽  
Seedling Emergence ◽  
Burial Depth ◽  
Invasive Weed ◽  
Temperature Regimes ◽  
Dark Regime ◽  
Early Seedling ◽  
Effects Of Temperature ◽  
And Control

ABSTRACT: Carolina geranium (Geranium carolinianum) is an emerging invasive weed in rape and wheat fields in China. A better understanding of its germination and emergence ecology will enable the development of integrated weed control strategies. In this study, we investigated the effects of temperature, photoperiod, soil water content, salinity, and burial depth, on germination and emergence of Carolina geranium. Germination percentages were over 74% under 15/20 and 20/25 oC night/day temperature regimes. Germination rate was independent of light/dark regime. Increasing salinity reduced germination of Carolina geranium from 81.1% at 0 mM to 0% at 160 mM NaCl. Seeds germination was peaked at 50% soil moisture, but was completely inhibited at < 20% and > 90%. The seedling emergence above 82.2% was observed when seeds were placed at a depth from 0 to 1 cm, and no seedlings emerged from seeds placed at a depth of 7 cm. Current work provide the basic information to effectively prevent and control this invasive weed in Chinese rape and wheat fields.

Effects of environmental factors on germination and emergence ofAmaranthus retroflexus

Weed Science ◽  
1999 ◽  
Vol 47 (5) ◽  
pp. 505-510 ◽  
Author(s):  
R. Ghorbani ◽  
W. Seel ◽  
C. Leifert
Keyword(s):  
Seed Germination ◽  
Control Strategies ◽  
Germination Rate ◽  
Soil Surface ◽  
Dry Weight ◽  
Amaranthus Retroflexus ◽  
Nitrogen Supply ◽  
Biological Weed Control ◽  
Detailed Knowledge ◽  
Different Temperatures

Detailed knowledge about the environmental conditions required for weed seed germination and establishment in soil is an important prerequisite for the development of integrated and biological weed control strategies. Germination and establishmentof Amaranthus retroflexuswere studied at different temperatures, planting depths, soil types, nitrogen supply, and water potentials. The minimum temperature for seed germination was > 5 C; maximum germination occurred between 35 and 40 C. At temperatures between 25 and 35 C, an additive effect on germination rate was observed when temperature and water availability were increased. For all soils tested, the percentage emergence of seeds placed on the soil surface and 4 cm deep was significantly lower than seeds placed between 0.5 and 3 cm. Emergence in the four sandy soils was generally greater than in the two heavier soils included in the study. There was a highly significant interaction between seed depth and soil type. Plant growth was also greatest in the lighter soils. Plant height, number of leaves, leaf area, fresh and dry weight, and nitrogen and carbon percentage in plant tissues ofA. retroflexusincreased significantly with increasing soil nitrogen supply.

SYNERGISTIC EFFECT OF INBREEDING ON VIABILITY IN DROSOPHILA VIRILIS

Genetics ◽  
1972 ◽  
Vol 72 (3) ◽  
pp. 461-468
Author(s):  
Kazuhiko Kosuda
Keyword(s):  
Synergistic Effect ◽  
Synergistic Interaction ◽  
Drosophila Virilis ◽  
Wide Range

ABSTRACT The effect of inbreeding on egg to adult viability was determined for Drosophila virilis over a wide range of inbreeding levels (0 &lt; F &lt;.734). The quantity —loge (Viability) was found to be a curvilinear function of F, indicating synergistic interaction among loci. The curvature was not evident, however, below F =.500. The values of A and B (Morton et al. 1956) were calculated to be.06 and.77-.86, respectively. This extremely small value of A yielded a very large value for the B/A ratio i.e., 12.51-14.99.

Synergistic Effect of High Temperature and High pH on the Destruction of Salmonella enteritidis and Escherichia co1i O157:H7

1996 ◽  
Vol 59 (10) ◽  
pp. 1023-1030 ◽  
Author(s):  
YEOW-LIM TEO ◽  
TIMOTHY J. RAYNOR ◽  
KAMESWAR R. ELLAJOSYULA ◽  
STEPHEN J. KNABEL
Keyword(s):  
Escherichia Coli ◽  
High Temperature ◽  
Synergistic Effect ◽  
Foodborne Pathogens ◽  
Salmonella Enteritidis ◽  
Synergistic Interaction ◽  
Escherichia Coli O157 ◽  
Gram Negative ◽  
High Ph ◽  
E Coli

This study was undertaken to determine if high temperature and high pH interact synergistically to enhance the rate of destruction of two important gram-negative foodborne pathogens, Escherichia coli O157:H7 and Salmonella enteritidis. The rates of destruction in NaHCO3-NaOH buffers at pH 7.0, 10.0, and 11.0 were determined at 35, 40, 45, 50, 55, 60, and 65°C. Use of an improved heating protocol eliminated a “tailing effect” at longer exposure times. The present study demonstrated that the combination of high pH and high temperature resulted in a highly significant synergistic interaction (P &gt; F = 0.0001), which caused rapid death of both E. coli O157:H7 and S. enteritidis. This “alka-therm” technology might be used commercially to destroy gram-negative foodborne pathogens on various raw agricultural commodities.

Repellency and Contact Irritancy Responses of Aedes aegypti (Diptera: Culicidae) Against Deltamethrin and Permethrin: A Cross-Regional Comparison

2020 ◽  
Author(s):  
Jin-Jia Yu ◽  
Lee-Jin Bong ◽  
Amonrat Panthawong ◽  
Theeraphap Chareonviriyaphap ◽  
Kok-Boon Neoh
Keyword(s):  
Aedes Aegypti ◽  
Control Strategies ◽  
Experimental Period ◽  
Test System ◽  
Resistance Ratio ◽  
Innate Response ◽  
Regional Comparison ◽  
Significant Difference ◽  
The Mean ◽  
Traditional Approaches

Abstract Control strategies exploiting the innate response of mosquitoes to chemicals are urgently required to complement existing traditional approaches. We therefore examined the behavioral responses of 16 field strains of Aedes aegypti (L.) from two countries, to deltamethrin and permethrin by using an excito-repellency (ER) test system. The result demonstrated that the escape percentage of Ae. aegypti exposed to pyrethroids did not vary significantly between the two countries in both contact and noncontact treatment despite the differing epidemiological patterns. Deltamethrin (contact: 3.57 ± 2.06% to 31.20 ± 10.71%; noncontact: 1.67 ± 1.67% to 17.31 ± 14.85%) elicited relatively lower responses to field mosquitoes when compared with permethrin (contact: 16.15 ± 4.07% to 74.19 ± 4.69%; noncontact: 3.45 ± 2.00% to 41.59 ± 6.98%) in contact and noncontact treatments. Compared with field strains, the mean percentage of escaping laboratory susceptible strain individuals were significantly high after treatments (deltamethrin contact: 72.26 ± 6.95%, noncontact: 61.10 ± 12.31%; permethrin contact: 78.67 ± 9.67%, noncontact: 67.07 ± 7.02%) and the escaped individuals spent significantly shorter time escaping from the contact and noncontact chamber. The results indicated a significant effect of resistance ratio on mean escape percentage, but some strains varied idiosyncratically compared to the increase in insecticide resistance. The results also illustrated that the resistance ratio had a significant effect on the mortality in treatments. However, the mortality in field mosquitoes that prematurely escaped from the treated contact chamber or in mosquitoes that stayed up to the 30-min experimental period showed no significant difference.

Biology and control of Reseda lutea L. 1. Seed biology and seedling growth

1997 ◽  
Vol 48 (4) ◽  
pp. 511 ◽  
Author(s):  
J. W. Heap
Keyword(s):  
Seedling Growth ◽  
Control Strategies ◽  
Germination Rate ◽  
South Australia ◽  
Effective Control ◽  
Temperate Climate ◽  
Perennial Weed ◽  
Seed Biology ◽  
Early Seedling ◽  
And Control

Reseda lutea L. is a major perennial weed of alkaline cropping soils in South Australia. Seed biology and early seedling growth of R. lutea were studied in field and laboratory experiments to gain information needed for effective control strategies. Recovery of intact seeds buried for 4 years in the field at 50 and 150 mm was 77–96%. Germination of this seed was 33–63% (50 mm) and 0% (150 mm). Germination patterns differed markedly between seed collected from 2 populations. Seed germinated at all constant and fluctuating temperatures between 10 and 35° C with the maximum (88%) at 25°C constant. Mean temperature, rather than constancy or fluctuation, determined the germination rate. Light strongly inhibited germination. Seedling shoot growth was slow but tap root growth was rapid, reaching 350 mm within 28 days of emergence. Secondary roots arose 3–7 days after emergence and shoot buds formed on the roots within 28 days. R. lutea was found to be well adapted for persistence in cultivated fields with a temperate climate.

Comparison of the Combined Effects of Hyperthermia with Ionizing Radiation or Cisplatin on Yeast and Mammalian Cells

2017 ◽  
pp. 21-28 ◽  
Author(s):  
М. Пронкевич ◽  
M. Pronkevich ◽  
Е. Евстратова ◽  
E. Evstratova ◽  
С. Белкина ◽  
...  
Keyword(s):  
Ionizing Radiation ◽  
Synergistic Effect ◽  
Exposure Time ◽  
Mammalian Cells ◽  
Synergistic Interaction ◽  
Yeast Cells ◽  
Simultaneous Action ◽  
Optimal Temperature ◽  
Combined Action ◽  
Combined Actions

Purpose: To compare radiation responses of yeast and mammalian cells to combined actions of various agents and on this basis to draw a conclusion about the possibility of synergy ideas application in medical radiology. Material and methods: The yeast cells of Saccharomyces cerevisiae were exposed to the combined action of hyperthermia (22–58 °C, exposure time 0–9 hrs) with ionizing radiation (25 MeV bremsstrahlung 5 and 25 Gy/min or γ-rays 60Co, 2, 10, and 80 Gy/min, acute irradiation) or anti-tumor drug cisplatin (0,05 or 0,25 mg/ml, exposure time 0–3 hrs). The result of synergistic interaction for yeast cells was assessed by the survival curves obtained by the authors after separate exposure to hyperthermia, ionizing radiation, cisplatin and after combined action of hyperthermia with ionizing radiation or cisplatin. To quantify the synergistic interaction of similar combined actions on mammalian cells, the data published by other authors have been used who did not evaluate the synergistic effect themselves. Results: The synergistic interaction of hyperthermia with ionizing radiation or cisplatin was established for yeast and mammalian cells. It is shown that the synergistic effect of the simultaneous action of these agents is observed only within a certain temperature range, within which there is an optimal temperature at which the greatest synergism occurs. This optimal temperature is shifted to lower values with a decrease in the dose rate of ionizing radiation or concentration of cisplatin. For sequential application of hyperthermia and ionizing radiation the effect of combined action increases with an increase in acting temperature up to a certain limit, after which it remains constant. These results are interpreted using the mathematical models previously proposed, in accordance with which the synergism is determined by the formation of additional damage due to the interaction of sub-damage that are not effective after separate application of agents. Despite the fact that all of the data presented were obtained at temperatures far beyond the ambient temperature, it is not excluded that there could be optimal intensities of harmful agents existing in the biosphere and capable of interacting with physiological heat of animals and man in a synergistic manner. Hence, the assessment of health or environmental risks from numerous natural and man-made agents at the level of intensities found in environmental and occupational settings should take into account synergistic interaction between harmful agents. Conclusion: The general regularities of synergistic effects of combined action of hyperthermia with ionizing radiation or with cisplatin for yeast and mammalian cells have been established – the existence of optimal parameters for acting agents providing the highest synergy and its dependence on the intensity of agents applied.

scholarly journals Does Cattle Milieu Provide a Potential Point to Target Wild ExophilicAnopheles arabiensis(Diptera: Culicidae) with Entomopathogenic Fungus? A Bioinsecticide Zooprophylaxis Strategy for Vector Control

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Issa N. Lyimo ◽  
Kija R. Ng'habi ◽  
Monica W. Mpingwa ◽  
Ally A. Daraja ◽  
Dickson D. Mwasheshe ◽  
...  
Keyword(s):  
Vector Control ◽  
Malaria Transmission ◽  
Entomopathogenic Fungus ◽  
Anopheles Arabiensis ◽  
Control Strategies ◽  
Field Conditions ◽  
Small Scale ◽  
Kilombero Valley ◽  
Scale Field ◽  
First Time

Background.Anopheles arabiensisis increasingly dominating malaria transmission in Africa. The exophagy in mosquitoes threatens the effectiveness of indoor vector control strategies. This study aimed to evaluate the effectiveness of fungus againstAn. arabiensiswhen applied on cattle and their environments.Methods. Experiments were conducted under semi-field and small-scale field conditions within Kilombero valley. The semi-field reared females of 5–7 days oldAn. arabiensiswere exposed to fungus-treated and untreated calf. Further, wildAn. arabiensiswere exposed to fungus-treated calves, mud-huts, and their controls. Mosquitoes were recaptured the next morning and proportion fed, infected, and survived were evaluated. Experiments were replicated three times using different individuals of calves.Results. A high proportion ofAn. arabiensiswas fed on calves (>0.90) and become infected (0.94) while resting on fungus-treated mud walls than on other surfaces. However, fungus treatments reduced fecundity and survival of mosquitoes.Conclusion. This study demonstrates for the first time the potential of cattle and their milieu for controllingAn. arabiensis. Most ofAn. arabiensiswere fed and infected while resting on fungus-treated mud walls than on other surfaces. Fungus treatments reduced fecundity and survival of mosquitoes. These results suggest deployment of bioinsecticide zooprophylaxis against exophilicAn. arabiensis.

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