Development of simple models for agrichemical uptake into plant foliage

2003 ◽  
Vol 56 ◽  
pp. 61-65
Author(s):  
J.A. Zabkiewicz ◽  
W.A. Forster
Keyword(s):  
Vicia Faba ◽  
Initial Dose ◽  
Plant Leaves ◽  
Linear Relationships ◽  
Plant Foliage ◽  
Mass Uptake ◽  
Uptake Mechanisms ◽  
Simple Models

Pesticide uptake into plants is typically reported as percentage uptake of the amount applied but in studies of the mechanism of cuticular penetration this approach has not been helpful It can be shown that relating percentage uptake to initial dose of bentazone applied to Vicia faba foliage cannot provide pertinent relationships that can be used to explain cuticular uptake mechanisms However applying the principles of Ficks Law and using mass or molar quantities does provide excellent linear relationships between mass uptake and initial dose applied Universal equations can be derived that relate dose uptake to initial dose applied onto plant leaves

scholarly journals Influence of dose and molecular weight on foliar mass uptake of surfactant

2005 ◽  
Vol 58 ◽  
pp. 174-178
Author(s):  
C.M. Nielsen ◽  
K.D. Steele ◽  
W.A. Forster ◽  
J.A. Zabkiewicz
Keyword(s):  
Molecular Weight ◽  
Initial Dose ◽  
Unit Area ◽  
Active Ingredients ◽  
Constant Concentration ◽  
Model Compounds ◽  
Area Basis ◽  
Plant Foliage ◽  
Mass Uptake ◽  
Positive Determinant

Foliar uptake of model xenobiotics and active ingredients on a unit area basis can be related to the initial dose of compound applied per unit area Current concepts propose that ideally surfactants and active ingredients copenetrate into plants Other evidence has shown that this is not always the case with pesticides and surfactants influencing each others behaviour Hence it is relevant to determine whether surfactants follow a similar mass uptake relationship This study determined the uptake of five surfactants differing in structure and molecular weight (2901350) into two plant species (fathen and wheat) The results showed that surfactants follow the same mass uptake relationship found previously for model compounds and active ingredients ie the initial dose (nmol/mm2) of surfactant applied to plant foliage is a strong positive determinant of uptake per unit area However at the constant concentration () studied surfactant molecular weight also played a role in uptake

Ectodesmata as Revealed By Freeze-Etch Preparations of Plant Epidermal Cell Walls

1973 ◽  
Vol 31 ◽  
pp. 468-469
Author(s):  
N.C. Lyon ◽  
W. C. Mueller
Keyword(s):  
Electron Microscopy ◽  
Acetic Acid ◽  
Nitric Acid ◽  
Oxalic Acid ◽  
Light Microscopy ◽  
Epidermal Cell ◽  
Cell Walls ◽  
Plant Viruses ◽  
Plant Leaves ◽  
Thin Sections

Schumacher and Halbsguth first demonstrated ectodesmata as pores or channels in the epidermal cell walls in haustoria of Cuscuta odorata L. by light microscopy in tissues fixed in a sublimate fixative (30% ethyl alcohol, 30 ml:glacial acetic acid, 10 ml: 65% nitric acid, 1 ml: 40% formaldehyde, 5 ml: oxalic acid, 2 g: mecuric chloride to saturation 2-3 g). Other workers have published electron micrographs of structures transversing the outer epidermal cell in thin sections of plant leaves that have been interpreted as ectodesmata. Such structures are evident following treatment with Hg++ or Ag+ salts and are only rarely observed by electron microscopy. If ectodesmata exist without such treatment, and are not artefacts, they would afford natural pathways of entry for applied foliar solutions and plant viruses.

Big data and simple models used to track the spread of COVID-19 in cities

Nature ◽  
2020 ◽  
Vol 589 (7840) ◽  
pp. 26-28
Author(s):  
Kevin C. Ma ◽  
Marc Lipsitch
Keyword(s):  
Big Data ◽  
Simple Models

Incompatibilité unilatérale chez Vicia faba L. I. Analyse globale de croisements intraspécifiques entre quatre sous-espèces

Agronomie ◽  
1983 ◽  
Vol 3 (5) ◽  
pp. 443-449 ◽  
Author(s):  
Joël LE GUEN ◽  
Gérard MORIN ◽  
Jeanine POISSON
Keyword(s):  
Vicia Faba ◽  
Vicia Faba L

Acute Deep Vein Thrombosis Treated with Porcine Plasmin

1974 ◽  
Vol 32 (02/03) ◽  
pp. 468-482 ◽  
Author(s):  
O Storm ◽  
P Ollendorff ◽  
E Drewsen ◽  
P Tang
Keyword(s):  
Deep Vein Thrombosis ◽  
Lower Limb ◽  
Initial Dose ◽  
Treated Group ◽  
Allergic Reactions ◽  
Double Blind ◽  
Vein Thrombosis ◽  
Thrombolytic Effect ◽  
Acute Deep Vein Thrombosis ◽  
Deep Vein

SummaryThe thrombolytic effect of pig plasmin was tested in a double blind trial on patients with deep venous thrombosis in the lower limb. Only patients with not more than three days old thrombi were selected for this study. The diagnosis of deep vein thrombosis was made clinically and confirmed by phlebography. Lysofibrin Novo (porcine plasmin) or placebo (porcine plasminogen) was administered intravenously to the patients. The enzyme and the placebo were delivered as lyophilized powder in labelled bottles - the contents of the bottles were unknown to the doctor in charge of the clinical administration of the trial. An initial dose of plasmin/plasminogen of 30 unit per kg body weight given slowly intravenously (1-1% hours infusion) was followed by a maintenance dosis of 15 per cent the initial dose per hour for the following 5-7 hours. In most cases a similar maintenance dosis was given the next day. In all patients heparin was administered after ending the plasmin/plasminogen infusion. The results of the treatment was evaluated clinically as well as by control phlebo- grams the following days.A statistically significant improvement was found in the plasmin treated group compared with the placebo (plasminogen) treated group. Thrombolysis was obtained clinically and phlebographically in 65 per cent of the plasmin treated group, but only in 15 per cent of the control patients were improvements found.This study has thus demonstrated that plasmin treatment according to a standard scheme was able to induce thrombolysis. There were only a few and insignificant side effects. Allergic reactions have not been seen and only very simple tests are required.

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