scholarly journals Field site analysis of giant salvinia nitrogen content and salvinia weevil density

2021 ◽  
Author(s):  
Julie Nachtrieb
Keyword(s):  
Nitrogen Content ◽  
Biocontrol Agent ◽  
Field Site ◽  
Salvinia Molesta ◽  
Plant Nitrogen ◽  
Site Analysis ◽  
Growing Seasons ◽  
Giant Salvinia ◽  
Adult Weevil

In 2012, a giant salvinia (Salvinia molesta Mitchell) biological control project was initiated in Louisiana. Although similar quantities of salvinia weevils (Cyrtobagous salviniae Calder and Sands) were released at all sites, weevil densities were highly variable among sites. Additionally, signs of plant nitrogen depletion (yellowing plants) were observed at some sites. Because it is well known that plant nutrition can affect the success of a biocontrol agent because of slowed development and/or reduced fecundity, the correlation between giant salvinia nitrogen content and Salvinia weevil density was investigated during the growing seasons of the second and fourth years. During 2013, weevils were reintroduced to sites, and the magnitude of adult weevil density increase varied by site. Giant salvinia nitrogen content varied among sites and sampling dates. Upper Big Break plants had greater nitrogen than all other sites during 75% of sampling dates. Additionally, adult and larval densities were significantly correlated to plant nitrogen content. During 2015, trends were less distinct and weevil densities and nitrogen content varied based on the interaction between sampling date and site, but a significant correlation was not detected. Results from 1-yr of a 2-yr study confirmed published reports of the importance of plant nitrogen content to salvinia weevil productivity. Additional studies are warranted to evaluate and understand the role of nitrogen at giant salvinia biocontrol field sites.

scholarly journals Role of carbon and nitrogen in the improvement of corrosion resistance of new powder metallurgy Co-Cr-Mo alloys

2020 ◽  
Vol 38 (3) ◽  
pp. 273-286 ◽  
Author(s):  
Cristina Garcia-Cabezon ◽  
Celia Garcia-Hernandez ◽  
Maria L. Rodriguez-Mendez ◽  
Gemma Herranz ◽  
Fernando Martin-Pedrosa
Keyword(s):  
Mechanical Properties ◽  
Corrosion Resistance ◽  
Powder Metallurgy ◽  
Nitrogen Content ◽  
Powder Metallurgy Technique ◽  
Carbon And Nitrogen ◽  
Physiological Conditions ◽  
Carbon And Nitrogen Content ◽  
Astm F75

AbstractMicrostructural changes that result in relevant improvements in mechanical properties and electrochemical behavior can be induced using different sintering conditions of ASTM F75 cobalt alloys during their processing using powder metallurgy technique. It has been observed that the increase in carbon and nitrogen content improves corrosion resistance and mechanical properties as long as the precipitation of carbides and nitrides is avoided, thanks to the use of rapid cooling in water after the sintering stage. In addition, the reduction of the particle size of the powder improves hardness and resistance to corrosion in both acid medium with chlorides and phosphate-buffered medium that simulates the physiological conditions for its use as a biomaterial. These results lead to increased knowledge of the role of carbon and nitrogen content in the behavior displayed by the different alloys studied.

scholarly journals Myco-Suppression Analysis of Soybean (Glycine max) Damping-Off Caused by Pythium aphanidermatum

Plants ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 788
Author(s):  
Shaban R. M. Sayed ◽  
Shaimaa A. M. Abdelmohsen ◽  
Hani M. A. Abdelzaher ◽  
Mohammed A. Elnaghy ◽  
Ashraf A. Mostafa ◽  
...  
Keyword(s):  
Glycine Max ◽  
Biocontrol Agent ◽  
Lateral Roots ◽  
Dry Weight ◽  
Pythium Aphanidermatum ◽  
Damping Off ◽  
Pythium Oligandrum ◽  
Rdna Its ◽  
Half Strength

The role of Pythium oligandrum as a biocontrol agent against Pythium aphanidermatum was investigated to avoid the harmful impacts of fungicides. Three isolates of P. oligandrum (MS15, MS19, and MS31) were assessed facing the plant pathogenic P. aphanidermatum the causal agent of Glycine max damping-off. The tested Pythium species were recognized according to their cultural and microscopic characterizations. The identification was confirmed through sequencing of rDNA-ITS regions including the 5.8 S rDNA. The biocontrol agent, P. oligandrum, isolates decreased the mycelial growth of the pathogenic P. aphanidermatum with 71.3%, 67.1%, and 68.7% through mycoparasitism on CMA plates. While the half-strength millipore sterilized filtrates of P. oligandrum isolates degrade the pathogenic mycelial linear growth by 34.1%, 32.5%, and 31.7%, and reduce the mycelial dry weight of the pathogenic P. aphanidermatum by 40.1%, 37.4%, and 36.8%, respectively. Scanning electron microscopy (SEM) of the most effective antagonistic P. oligandrum isolate (MS15) interaction showed coiling, haustorial parts of P. oligandrum to P. aphanidermatum hyphae. Furthermore, P. oligandrum isolates were proven to enhance the germination of Glycine max seedling to 93.3% in damping-off infection using agar pots and promote germination of up to 80% during soil pot assay. On the other hand, P. oligandrum isolates increase the shoot, root lengths, and the number of lateral roots.

Kaolin impacts on hormonal balance, polyphenolic composition and oenological parameters in red grapevine berries during ripening

2021 ◽  
pp. 1-15
Author(s):  
Sara Bernardo ◽  
Lia-Tânia Dinis ◽  
Nelson Machado ◽  
Ana Barros ◽  
Marta Pitarch-Bielsa ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Growing Season ◽  
Growing Seasons ◽  
Polyphenolic Composition ◽  
Berry Ripening ◽  
Hormonal Balance ◽  
Summer Stress ◽  
Fruit Damage ◽  
Stress Signals

BACKGROUND: Kaolin particle-film application is a well-known strategy to avoid fruit damage. However, its putative role in balancing berry ripening under a changing climate remains poorly explored. OBJECTIVE: We assessed kaolin treatment effect on several ripening berry components, hormonal balance and oenological parameters of the field-grown Touriga-Franca (TF) and Touriga–Nacional (TN) grapevine varieties at veraison (EL35) and ripening (EL38) during two growing seasons (2017 and 2018). RESULTS: Under the adverse summer conditions (two heatwave events) of 2017, kaolin application increased 211.2 %and 51.4 %the salicylic acid (SA) and abscisic acid (ABA) levels in TF berries at EL38, while no significant differences were observed in TN. Conversely, TF, and TN kaolin treated berries showed lower SA and ABA accumulation in 2018, respectively. Tartaric acid content increased about 17.2 %, and 24.2 %in TF and TN treated berries at stage EL35 in the 2017 growing season. Though kaolin treatment had no consistent effect on anthocyanins accumulation, flavonoids, ortho-diphenols and tannins increased in kaolin treated grapevines in 2017. CONCLUSIONS: This study highlights the key role of climate in triggering ripening related processes and fruit quality potential. Nevertheless, kaolin treated grapevines displayed an improved response to oxidative stress signals by increasing secondary metabolites accumulation in warm vintages. Kaolin application promoted different varietal responses, with a possible ripening delaying effect in TF, reinforcing its efficiency in alleviating severe summer stress impacts.

scholarly journals Role of glutathione in tolerance to arsenite in Salvinia molesta, an aquatic fern

2017 ◽  
Vol 31 (4) ◽  
pp. 657-664 ◽  
Author(s):  
Adinan Alves da Silva ◽  
Juraci Alves de Oliveira ◽  
Fernanda Vidal de Campos ◽  
Cleberson Ribeiro ◽  
Fernanda dos Santos Farnese
Keyword(s):  
Salvinia Molesta ◽  
Aquatic Fern

scholarly journals Pay it forward: refuse dump from leaf-cutting ants promotes caterpillar digestive performance by increasing plant nitrogen content

2018 ◽  
Vol 44 (1) ◽  
pp. 40-49
Author(s):  
Maria Natalia Lescano ◽  
Carolina Quintero ◽  
Alejandro Gustavo Farji-Brener ◽  
Esteban Balseiro
Keyword(s):  
Nitrogen Content ◽  
Plant Nitrogen ◽  
Refuse Dump ◽  
Leaf Cutting

scholarly journals Effects of Fire and Large Herbivores on Canopy Nitrogen in a Tallgrass Prairie

2019 ◽  
Vol 11 (11) ◽  
pp. 1364 ◽  
Author(s):  
Bohua Ling ◽  
Edward J. Raynor ◽  
Douglas G. Goodin ◽  
Anthony Joern
Keyword(s):  
Spatial Variability ◽  
Nitrogen Content ◽  
Tallgrass Prairie ◽  
High Nitrogen Content ◽  
High Nitrogen ◽  
Grazing History ◽  
One Year ◽  
Canopy Nitrogen

This study analyzed the spatial heterogeneity of grassland canopy nitrogen in a tallgrass prairie with different treatments of fire and ungulate grazing (long-term bison grazing vs. recent cattle grazing). Variogram analysis was applied to continuous remotely sensed canopy nitrogen images to examine the spatial variability in grassland canopies. Heterogeneity metrics (e.g., the interspersion/juxtaposition index) were calculated from the categorical canopy nitrogen maps and compared among fire and grazing treatments. Results showed that watersheds burned within one year had higher canopy nitrogen content and lower interspersions of high-nitrogen content patches than watersheds with longer fire intervals, suggesting an immediate and transient fire effect on grassland vegetation. In watersheds burned within one year, high-intensity grazing reduced vegetation density, but promoted grassland heterogeneity, as indicated by lower canopy nitrogen concentrations and greater interspersions of high-nitrogen content patches at the grazed sites than at the ungrazed sites. Variogram analyses across watersheds with different grazing histories showed that long-term bison grazing created greater spatial variability of canopy nitrogen than recent grazing by cattle. This comparison between bison and cattle is novel, as few field experiments have evaluated the role of grazing history in driving grassland heterogeneity. Our analyses extend previous research of effects from pyric herbivory on grassland heterogeneity by highlighting the role of grazing history in modulating the spatial and temporal distribution of aboveground nitrogen content in tallgrass prairie vegetation using a remote sensing approach. The comparison of canopy nitrogen properties and the variogram analysis of canopy nitrogen distribution provided by our study are useful for further mapping grassland canopy features and modeling grassland dynamics involving interplays among fire, large grazers, and vegetation communities.

scholarly journals Effects of duck feed supplemented with invasive giant salvinia(Salvinia molesta) on duck meat characteristics

2015 ◽  
Vol 39 ◽  
pp. 668-675 ◽  
Author(s):  
Bambang DWILOKA ◽  
Agus SETIADI ◽  
Siswanto IMAM SANTOSO ◽  
Edjeng SUPRIJATNA ◽  
Siti SUSANTI
Keyword(s):  
Salvinia Molesta ◽  
Giant Salvinia

Boron and Magnesium Fertilization of a Coastal Douglas-Fir Plantation

1993 ◽  
Vol 8 (2) ◽  
pp. 48-53 ◽  
Author(s):  
R. N. Green ◽  
R. E. Carter
Keyword(s):  
Height Growth ◽  
Douglas Fir ◽  
Boron Deficiency ◽  
Growing Seasons ◽  
Foliar Symptoms ◽  
Foliar Concentrations ◽  
A Site ◽  
Coastal British Columbia ◽  
Severe Growth

Abstract This study examines the role of boron and magnesium nutrition in the occurrence of severe growth distortion symptoms in Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) in the Skwawka River valley of south coastal British Columbia. Four fertilizer treatments including boron (2.25 kg B/ha), magnesium (42 kg Mg/ha), boron plus magnesium, and a control, were applied in conjunction with planting on a site believed to be deficient in these nutrients. After 5 growing seasons, only treatments containing boron (B and B+Mg) showed improved height growth over the control trees. The incidence of leader dieback, swollen leading shoots, and foliage distortion was significantly related to treatment with virtually no occurrence in plots treated with boron. Seedling uptake of applied boron was high, with foliar concentrations of 45 ppm found after the second growing season. Foliar B levels declined to 13-15 ppm after 5 growing seasons. No significant increase in foliar magnesium levels was detected for either of the magnesium treatments. The reduction in the incidence of leader dieback and shoot and foliar symptoms in seedlings treated with B indicate that these symptoms were the result of boron deficiencies. This is the first study to verify boron deficiency in coastal Douglas-fir through fertilizer trials. West. J. Appl. For. 8(2):48-53.

Promising Role of Wolbachia as Anti-parasitic Drug Target and Eco-Friendly Biocontrol Agent

2019 ◽  
Vol 14 (1) ◽  
pp. 69-79 ◽  
Author(s):  
Tooran Nayeri Chegeni ◽  
Mahdi Fakhar
Keyword(s):  
Drug Target ◽  
Biocontrol Agent ◽  
Pathogen Transmission ◽  
Parasitic Diseases ◽  
Pests And Diseases ◽  
Filarial Nematodes ◽  
Reproductive Incompatibility ◽  
Vector Borne ◽  
Potential Strategy

Background: Wolbachia is the most common endosymbiotic bacteria in insectborne parasites and it is the most common reproductive parasite in the world. Wolbachia has been found worldwide in numerous arthropod and parasite species, including insects, terrestrial isopods, spiders, mites and filarial nematodes. There is a complicated relationship between Wolbachia and its hosts and in some cases, they create a mutual relationship instead of a parasitic relationship. Some species are not able to reproduce in the absence of infection with Wolbachia. Thus, the use of existing strains of Wolbachia bacteria offers a potential strategy for the control of the population of mosquitoes and other pests and diseases. Methods: We searched ten databases and reviewed published papers regarding the role of Wolbachia as a promising drug target and emerging biological control agents of parasitic diseases between 1996 and 2017 (22 years) were considered eligible. Also, in the current study several patents (WO008652), (US7723062), and (US 0345249 A1) were reviewed. Results: Endosymbiotic Wolbachia bacteria, which are inherited from mothers, is transmitted to mosquitoes and interferes with pathogen transmission. They can change the reproduction of their host. Wolbachia is transmitted through the cytoplasm of eggs and have evolved different mechanisms for manipulating the reproduction of its hosts, including the induction of reproductive incompatibility, parthenogenesis, and feminization. The extensive effects of Wolbachia on reproduction and host fitness have made Wolbachia the issue of growing attention as a potential biocontrol agent. Conclusion: Wolbachia has opened a new window to design a costly, potent and ecofriendly drug target for effective treatment and elimination of vector-borne parasitic diseases.

Sign in / Sign up

Export Citation Format

Share Document