scholarly journals Time to cut: population models reveal how to mow invasive common ragweed cost-effectively

NeoBiota ◽  
2018 ◽  
Vol 39 ◽  
pp. 53-78 ◽  
Author(s):  
Suzanne T. E. Lommen ◽  
Eelke Jongejans ◽  
Melinda Leitsch-Vitalos ◽  
Barbara Tokarska-Guzik ◽  
Mihály Zalai ◽  
...  
Keyword(s):  
Plant Height ◽  
Demographic Data ◽  
Seed Viability ◽  
Population Level ◽  
Cost Effective ◽  
Population Models ◽  
Plant Performance ◽  
Adult Plant ◽  
Common Ragweed ◽  
Female Flowering

Roadsides are an important habitat for invasive common ragweed, Ambrosiaartemisiifolia L., by facilitating seed dispersal. Reducing the size of roadside populations is therefore essential for confining this highly allergenic species. Here, we aim to determine the cost-effectiveness of mowing regimes varying in frequency and timing, by analysing population-level effects and underlying demographic processes. We constructed population models of A.artemisiifolia parameterised by demographic data for four unmanaged reference populations across Europe in two years. We integrated the effects of four experimental mowing regimes along Austrian road sides on plant performance traits of five years and experimental data on seed viability after cutting. All four experimental regimes reduced the projected intrinsic population growth rates (r) compared to the unmanaged controls by reducing plant height and seed viability, thereby counteracting increased size-dependent fecundity. The prevailing 2-cut regime in Austria (cutting during vegetative growth, here in June and just before seed ripening, here in September) performed least well and the reduction in r was mainly due to reduced seed viability after the second cut. The efficacy of the two best experimental regimes (alternative schemes for 2 or 3 cuts) was mainly due to cutting just before female flowering (here in August) by decreasing final adult plant height dramatically and thereby reducing seed numbers. Patterns were consistent across reference populations and years. Whether regimes reduced r below replacement level, however, varied per population, year and the survival rate of the seeds in the soil bank. Our model allowed projecting effects of five theoretical mowing regimes with untested combinations of cuts on r. By plotting r-cost relationships for all regimes, we identified the most cost-effective schemes for each cutting frequency (1–3 cuts). They all included the cut just before female flowering, highlighting the importance of cutting at this moment (here in August). Our work features i) the suitability of a modelling approach for the demography of an annual species with a seed bank, ii) the importance of seed viability in assessing mowing effects, iii) the use of population models in designing cost-effective mowing regimes.

scholarly journals Larger workers outperform smaller workers across resource environments: an evaluation of demographic data using functional linear models

2020 ◽  
Author(s):  
Natalie Kerr ◽  
Rosemary Malfi ◽  
Neal Williams ◽  
Elizabeth Crone
Keyword(s):  
Linear Models ◽  
Demographic Data ◽  
Social Groups ◽  
Scale Up ◽  
Population Level ◽  
Plant Performance ◽  
Environmental Drivers ◽  
Functional Linear Models ◽  
Positive Effects ◽  
Manipulative Experiments

1. Behavior and organization of social groups is thought to be vital to the functioning of societies, yet the contributions of various roles within social groups towards population growth and dynamics have been difficult to quantify. A common approach to quantifying these role-based contributions is evaluating the number of individuals conducting certain roles, which ignores how behavior might scale up to effects at the population-level. Manipulative experiments are another common approach to determine population-level effects, but they often ignore potential feedbacks associated with these various roles. 2. Here, we evaluate the effects of worker size distribution in bumblebee colonies on worker production in 24 observational colonies across three environments, using functional linear models. Functional linear models are an underused correlative technique that has been used to assess lag effects of environmental drivers on plant performance. We demonstrate potential applications of this technique for exploring high-dimensional ecological systems, such as the contributions of individuals with different traits to colony dynamics. 3. We found that more larger workers had mostly positive effects and more smaller workers had negative effects on worker production. Most of these effects were only detected under low or fluctuating resource environments suggesting that the advantage of colonies with larger-bodied workers becomes more apparent under stressful conditions. 4. We also demonstrate the wider ecological application of functional linear models. We highlight the advantages and limitations when considering these models, and how they are a valuable complement to many of these performance-based and manipulative experiments.

DIFFERENTIAL EFFECT OF SALINITY ON GROWTH, NUTRIENT CONCENTRATION AND CHLOROPHYLL IN SUGARCANE VARIETIES MEX 69-290 AND CP 72-2086

Agrociencia ◽  
2021 ◽  
Vol 55 (7) ◽  
pp. 597-610
Author(s):  
Odón Castañeda Castro ◽  
Miriam Cristina Pastelín Solano ◽  
Libia Iris Trejo Téllez ◽  
Eduardo Ariel Solano Pastelín ◽  
Fernando Carlos Gómez Merino
Keyword(s):  
Plant Height ◽  
Plant Performance ◽  
Saccharum Spp ◽  
Sugarcane Varieties ◽  
Randomized Design ◽  
Affected Plant ◽  
Nacl Concentration ◽  
Irrigation Solution ◽  
Completely Randomized Design ◽  
Better Than

Sugarcane (Saccharum spp. hybrids) is moderately sensitive to salinity and the effects on plant performance vary according to stress level and genotype. This study aimed to evaluate the effect of salt stress induced by application of different NaCl levels in the irrigation solution on plant height, indirect index of chlorophylls (SPAD), and macronutrients concentration (N, P, K, Ca, Mg and S) and Na in leaves of two sugarcane varieties: CP 72-2086 and Mex 69-290. The experiment was set in a completely randomized design with a 2×5 factorial arrangement. The study factors were sugarcane variety (CP 72-2086 and Mex 69-290) and NaCl concentration (0.0, 71.8, 143.6, 215.4 and  282.7 mM NaCl). Salinity as a single factor negatively affected plant height, SPAD units and N and P concentration in leaves; Ca concentrations increased, while K, Mg and S remained unaffected by the tested NaCl levels. Mex 69-290 grew higher and concentrated greater levels of N and K. Interactions of factors showed that salinity reduced growth in both varieties, but this reduction was more pronounced in CP 72-2086. SPAD units were also significantly reduced by salinity in both varieties. Concentrations of N and P in leaves decreased in both varieties in response to NaCl, while those of K and Ca increased in Mex 69-290. Concentration of Na was higher in Mex 69-290 which exhibited better performance than CP 72-2086. Sodium concentrations in leaves increased in direct relation to the tested NaCl concentrations. Mex 69-290 reached higher concentrations of Na in leave tissues but displayed better health than CP 72-2086. Thus, the variety Mex 69-290 showed more efficient Na-tolerance mechanisms related to Ca and K concentrations, and an indirect chlorophyll index better than CP 72-2086.

scholarly journals Penampilan Fenotipik Populasi Dasar Jagung Pulut Lokal Sulawesi Selatan dengan Seleksi Back Cross

2019 ◽  
Vol 19 (2) ◽  
Author(s):  
Junyah Leli Isnaini
Keyword(s):  
Plant Height ◽  
Total Sample ◽  
Back Cross ◽  
South Sulawesi ◽  
Plant Samples ◽  
Female Flowering ◽  
Waxy Corn ◽  
Cross Test

This research aims to see the phenotypic appearance of selected families from the basic population of  local waxy corn of South Sulawesi which is back cross with the parents. The technique of crosses used is repeated selection that is to make a cross between selected families (recombination) by means of free crossing. The number of cross-test of 5 selected families and 5 varieties of comparison (parents) with 2 replications. Each replica was planted with 10 lines of  20 lines of with 20 cm x 50 cm spacing), the total number of plants in this research were 400 plants. Each line represented 5 sample plants, so the total sample of 200 plants. The results showed that from 5 selected families who crossed with their parents as a whole can improve the phenotype character. The selected local waxy corn has a superior appearance of the phenotype character. Of the 200 plant samples, there are 75 plants that have superior appearance (better phenotype appearance than their parents) on the character : plant height , the height of cob location, male flowering, female flowering, and  husk cover.

scholarly journals Effect of Salicylic Acid in the Yield of Ricinine in Ricinus communis under Greenhouse Condition

Plants ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1902
Author(s):  
Carlos Eduardo Zavala-Gómez ◽  
Eloy Rodríguez-deLeón ◽  
Mamadou Moustapha Bah ◽  
Ana Angélica Feregrino-Pérez ◽  
Juan Campos-Guillén ◽  
...  
Keyword(s):  
Salicylic Acid ◽  
Plant Height ◽  
Castor Bean ◽  
Ricinus Communis ◽  
Cost Effective ◽  
Control Group ◽  
Effective Technique ◽  
Greenhouse Condition ◽  
Cost Effective Technique

Castor bean (Ricinus communis) seeds contain ricinine, an alkaloid with insecticidal and insectistatic activities. Elicitation with salicylic acid (SA) has proven to stress R. communis and might modify the ricinine concentration. The aim of this study was to evaluate the concentration of ricinine in the bagasse of seeds from R. communis elicited with exogenous SA under greenhouse conditions. Plants were grown and divided into five groups, which were sprayed with SA and drench with 50 mL 60 days after sowing with concentrations of SA (0, 100, 300, 600 and 900 µM). Clusters were mixed and separated according to the treatment, and dried. The seeds were ground, the oil was extracted by Soxhlet with hexane, and then the bagasse was extracted with methanol. Ricinine was determined by HPLC. Elicitation did not change the plant height or diameter; the control group had 9.17 µg mL−1 of ricinine; and the concentrations followed a hormesis curve with the peak at 300 µM of SA that had a ricinine concentration of 18.25 µg mL−1. Elicitation with SA might be a cost-effective technique to increase ricinine from R. communis bagasse.

scholarly journals Seed viability of common ragweed (Ambrosia artemisiifolia L.) is affected by seed origin and age, but also by testing method and laboratory

NeoBiota ◽  
2021 ◽  
Vol 70 ◽  
pp. 193-221
Author(s):  
Rea Maria Hall ◽  
Bernhard Urban ◽  
Hana Skalova ◽  
Lenka Moravcová ◽  
Ulrike Sölter ◽  
...  
Keyword(s):  
Seed Viability ◽  
Ambrosia Artemisiifolia ◽  
Testing Methods ◽  
Triphenyltetrazolium Chloride ◽  
Viability Test ◽  
Common Ragweed ◽  
Testing Procedures ◽  
Testing Method ◽  
Seed Origin ◽  
Set Up

Common ragweed (Ambrosia artemisiifolia L.) is an annual Asteraceae species native to North America which is highly invasive across Europe and has harmful impacts, especially on human health and agriculture. Besides its wide ecological range, particularly its high reproductive power by seeds is promoting its spread to various habitats and regions. To prevent further spread and to control the plant, the European Commission funded projects and COST-Actions involving scientists from all over Europe. A joint trial was set up comprising eight different laboratories from Europe to study seed viability variation in different seed samples. Three different testing methods (viability test with 2,3,5-triphenyltetrazolium chloride (TTC), a germination test combined with a subsequent TTC test and a crush test) were tested within the EU-COST-Action SMARTER network to four different seed origins. The viability test results from different laboratories were compared for variation amongst tests and laboratories. The main aim was to optimise the reliability of testing procedures, but results revealed not only significant effects of seed origin and seed age on seed viability, but also considerable differences between the output of the individual testing methods and furthermore between laboratories. Due to these significant differences in the results of the testing labs, additionally a second test was set up. Twelve Austrian ragweed populations were used for TTC testing to obtain a precise adjustment of the testing method as well as a tight guideline for interpreting the results, particularly for the TTC state “intermediate” since a proper classification of TTC-intermediate coloured seeds is still a challenge when determining viability rates.

The value of red light at night for increasing basil yield

2018 ◽  
Vol 98 (6) ◽  
pp. 1321-1330
Author(s):  
Jaimin S. Patel ◽  
Leora Radetsky ◽  
Mark S. Rea
Keyword(s):  
Plant Height ◽  
Red Light ◽  
Leaf Size ◽  
Cost Effective ◽  
Dry Weight ◽  
Photosynthetic Photon Flux Density ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Light At Night ◽  
Sweet Basil

Sweet basil (Ocimum basilicum L.) is primarily used for culinary purposes, but it is also used in the fragrance and medicinal industries. In the last few years, global sweet basil production has been significantly impacted by downy mildew caused by Peronospora belbahrii Thines. Nighttime exposure to red light has been shown to inhibit sporulation of P. belbahrii. The objective of this study was to determine if nighttime exposure to red light from light-emitting diodes (λmax = 625 nm) could increase plant growth (plant height and leaf size) and yield (number and weight of leaves) in basil plants. In two sets of greenhouse experiments, red light was applied at a photosynthetic photon flux density of 60 μmol m−2 s−1 during the otherwise dark night for 10 h (from 2000 to 0600). The results demonstrate that exposure to red light at night can increase the number of basil leaves per plant, plant height, leaf size (length and width), and leaf fresh and dry weight compared with plants in darkness at night. The addition of incremental red light at night has the potential to be cost-effective for fresh organic basil production in controlled environments.

Guidance for Using State-and Prediction-Based Theory

2020 ◽  
pp. 93-122
Keyword(s):  
Population Level ◽  
Population Models ◽  
Dynamic State ◽  
Trade Off ◽  
State Variable

This chapter outlines the guidance on using state- and prediction-based theory (SPT) to build models of populations and communities of adaptive individuals, detailing five steps unique to SPT. The most important aspect of SPT to remember is that one is not trying to build optimal, or even necessarily accurate, models of how an organism's behavior affects its future fitness. Instead, one is trying to find simplistic models that produce realistic behavior in contexts where optimization is impossible. While SPT can be used like dynamic state variable modeling (DSVM), as a framework for thinking about and modeling how an individual makes a particular decision, its main purpose is to model adaptive trade-off decisions in individual-based population models. Thus, using SPT is part of the larger process of developing, analyzing, and applying an IBM to address population-level questions, and the five steps therefore include that process.

scholarly journals Smart Sanitation—Biosensors as a Public Health Tool in Sanitation Infrastructure

2020 ◽  
Vol 17 (14) ◽  
pp. 5146 ◽  
Author(s):  
Emma Rary ◽  
Sarah M. Anderson ◽  
Brandon D. Philbrick ◽  
Tanvi Suresh ◽  
Jasmine Burton
Keyword(s):  
Public Health ◽  
Health Monitoring ◽  
Disease Surveillance ◽  
Population Level ◽  
Cost Effective ◽  
Small Scale ◽  
Individual Level ◽  
Emergent Technologies ◽  
The Individual ◽  
Sanitation Infrastructure

The health of individuals and communities is more interconnected than ever, and emergent technologies have the potential to improve public health monitoring at both the community and individual level. A systematic literature review of peer-reviewed and gray literature from 2000-present was conducted on the use of biosensors in sanitation infrastructure (such as toilets, sewage pipes and septic tanks) to assess individual and population health. 21 relevant papers were identified using PubMed, Embase, Global Health, CDC Stacks and NexisUni databases and a reflexive thematic analysis was conducted. Biosensors are being developed for a range of uses including monitoring illicit drug usage in communities, screening for viruses and diagnosing conditions such as diabetes. Most studies were nonrandomized, small-scale pilot or lab studies. Of the sanitation-related biosensors found in the literature, 11 gathered population-level data, seven provided real-time continuous data and 14 were noted to be more cost-effective than traditional surveillance methods. The most commonly discussed strength of these technologies was their ability to conduct rapid, on-site analysis. The findings demonstrate the potential of this emerging technology and the concept of Smart Sanitation to enhance health monitoring at the individual level (for diagnostics) as well as at the community level (for disease surveillance).

scholarly journals Pharmacist prescribing and care improves cardiovascular risk, but is it cost-effective? A cost-effectiveness analysis of the RxEACH study

2019 ◽  
Vol 152 (4) ◽  
pp. 257-266 ◽  
Author(s):  
Yazid N. Al Hamarneh ◽  
Karissa Johnston ◽  
Carlo A. Marra ◽  
Ross T. Tsuyuki
Keyword(s):  
Cost Effectiveness ◽  
Health Outcomes ◽  
Usual Care ◽  
Population Level ◽  
Cost Effective ◽  
Pharmacist Intervention ◽  
Sensitivity Analyses ◽  
Pharmacist Prescribing ◽  
Canadian Health Care System ◽  
Life Years

Background: The RxEACH randomized trial demonstrated that community pharmacist prescribing and care reduced the risk for cardiovascular (CV) events by 21% compared to usual care. Objective: To evaluate the economic impact of pharmacist prescribing and care for CV risk reduction in a Canadian setting. Methods: A Markov cost-effectiveness model was developed to extrapolate potential differences in long-term CV outcomes, using different risk assessment equations. The mean change in CV risk for the 2 groups of RxEACH was extrapolated over 30 years, with costs and health outcomes discounted at 1.5% per year. The model incorporated health outcomes, costs and quality of life to estimate overall cost-effectiveness. It was assumed that the intervention would be 50% effective after 10 years. Individual-level results were scaled up to population level based on published statistics (29.2% of Canadian adults are at high risk for CV events). Costs considered included direct medical costs as well as the costs associated with implementing the pharmacist intervention. Uncertainty was explored via probabilistic sensitivity analysis. Results: It is estimated that the Canadian health care system would save more than $4.4 billion over 30 years if the pharmacist intervention were delivered to 15% of the eligible population. Pharmacist care would be associated with a gain of 576,689 quality-adjusted life years and avoid more than 8.9 million CV events. The intervention is economically dominant (i.e., it is both more effective and reduces costs when compared to usual care). Conclusion: Across a range of 1-way and probabilistic sensitivity analyses of key parameters and assumptions, pharmacist prescribing and care are both more effective and cost-saving compared to usual care. Canadians need and deserve such care.

scholarly journals Mortierella elongata Increases Plant Biomass among Non-Leguminous Crop Species

Agronomy ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 754 ◽  
Author(s):  
Kaile Zhang ◽  
Gregory Bonito ◽  
Chih-Ming Hsu ◽  
Khalid Hameed ◽  
Rytas Vilgalys ◽  
...  
Keyword(s):  
Glycine Max ◽  
Leaf Area ◽  
Plant Height ◽  
Molecular Mechanisms ◽  
Plant Biomass ◽  
Citrullus Lanatus ◽  
Plant Performance ◽  
Future Research ◽  
Crop Species ◽  
Leguminous Crop

Recent studies have shown that M. elongata (M. elongata) isolated from Populus field sites has a dual endophyte–saprotroph lifestyle and is able to promote the growth of Populus. However, little is known about the host fidelity of M. elongata and whether M. elongata strains differ from one another in their ability to promote plant growth. Here, we compared the impacts of three Populus-associated M. elongata isolates (PMI 77, PMI 93, and PMI 624) on the growth of seven different crop species by measuring plant height, plant dry biomass, and leaf area. M. elongata isolates PMI 624 and PMI 93 increased the plant height, leaf area, and plant dry weight of Citrullus lanatus, Zea mays, Solanum lycopersicum, and Cucurbita to a much greater degree than PMI 77 (33.9% to 14.1%). No significant impacts were observed for any isolate on the growth of Abelmoschus esculentus or Glycine max. On the contrary, Glycine max significantly decreased in height by 30.6% after the inoculation of M. elongata PMI 77. In conclusion, this study demonstrates that M. elongata generally promoted metrics of the plant performance among a diverse set of importantly non-leguminous crop species. Future research on understanding the molecular mechanisms that underlie strain and host variability is warranted.

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