نتایج جستجو برای: synthetic pyrethrins

تعداد نتایج: 141927  

2017
Federico Tacoli Nicola Mori Alberto Pozzebon Elena Cargnus Sarah Da Vià Pietro Zandigiacomo Carlo Duso Francesco Pavan

The leafhopper Scaphoideus titanus is the vector of 'Candidatus Phytoplasma vitis', the causal agent of Flavescence dorée (FD) a key disease for European viticulture. In organic vineyards, the control of S. titanus relies mostly on the use of pyrethrins that have suboptimal efficacy. During 2016, three field trials were conducted to evaluate the efficacy of kaolin, orange oil, insecticidal soap...

2003

Pyrethrum is the natural extract that occurs in the flowers of Chrysanthemum cinerariaefolium and Chrysanthemum cineum. Pyrethrum has long been recognized as possessing insecticidal properties; over the years, first the chemical extracts of pyrethrum, and then more recently, the specific synthetic chemical analogs have been produced. The six active insecticidal compounds of pyrethrum are called...

Journal: :Environmental Health Perspectives 1980
J E Casida

The natural pyrethrins from the daisy-like flower, Tanacetum or Chrysanthemum cinerariifolium, are nonpersistent insecticides of low toxicity to mammals. Synthetic analogs or pyrethroids, evolved from the natural compounds by successive isosteric modifications, are more potent and stable and are the newest important class of crop protection chemicals. They retain many of the favorable propertie...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه ولی عصر (عج) - رفسنجان - دانشکده علوم پایه 1389

در این تحقیق، ویژگی‎های شیمیایی فن‎والریت، سنتز و روش‎های تجزیه‎ای در تعیین مقدار آن مرور گردید. در ضمن یک روش اسپکتروفتومتری ساده برای تعیین فن‎والریت پیشنهاد شد، این روش بر اساس هیدرولیز فن‎والریت با هیدروکسید پتاسیم متانولی است تا 3- فنوکسی بنزالدهید تشکیل شود و با استفاده از روش مذکور فن‎والریت در آب، خاک و فرمولاسیون مورد اندازه گیری قرار گرفت. این گروه آلدهیدی با 4،2- دی نیترو فنیل هیدرا...

Journal: :Pest management science 2008
Raul Narciso C Guedes James F Campbell Frank H Arthur George P Opit Kun Yan Zhu James E Throne

BACKGROUND The psocids Liposcelis bostrychophila Badonnel and L. entomophila (Enderlein) (Liposcelididae) are emerging pests of stored products. Although their behavior, particularly their high mobility, may contribute to the reported relatively low efficacy of insecticides against them, studies to investigate this have not been conducted. The present study aimed to assess the label rate effica...

2017
Ciaran McCarthy

Pyrethrins are a class of natural terpenoid pesticides produced by Tanacetum cinerariifolium, commonly known as chrysanthemum. Here we present evidence that cannabis may be able to produce pyrethrins endogenously. Flower from a cannabis plant grown in a closed hydroponic environment contained 2.48 parts per million pyrethrin I by weight. A comparison of the genetics of T. cinerariifolium and Ca...

Journal: :Molecular biotechnology 2016
Maged E Mohamed Khomaizon A K Pahirulzaman Colin M Lazarus

Pyrethrins are natural insecticides, which accumulate to high concentrations in pyrethrum (Chrysanthemum cinerariaefolium) flowers. Synthetic pyrethroids are more stable, more efficacious and cheaper, but contemporary requirements for safe and environmentally friendly pesticides encourage a return to the use of natural pyrethrins, and this would be favoured by development of an efficient route ...

2017
Alan Wong Jan A Glinski

Pyrethrins are natural pesticides present in the oil extracted from the flowers of Chrysanthemum cinerariaefolium. They are potent ion-channel neurotoxins which have higher selective toxicity for insects compared to mammals. These phytochemicals have an exceptionally safe environmental profile and are an attractive natural alternative to organophosphate insecticides currently used in agricultur...

2012
Josef Velisek Alzbeta Stara Zdenka Svobodova

Worldwide pesticide usage has increased dramatically during the past two decades, coinciding with changes in farming practices and increasingly intensive agriculture. Environmental pollution caused by pesticides, especially in aquatic ecosystems, has become a serious problem. Contamination of water by pesticides, either directly or indirectly, can lead to fish kills, reduced fish productivity, ...

Journal: :The Plant cell 2012
Aldana M Ramirez Geert Stoopen Tila R Menzel Rieta Gols Harro J Bouwmeester Marcel Dicke Maarten A Jongsma

Glandular trichomes are currently known only to store mono- and sesquiterpene compounds in the subcuticular cavity just above the apical cells of trichomes or emit them into the headspace. We demonstrate that basipetal secretions can also occur, by addressing the organization of the biosynthesis and storage of pyrethrins in pyrethrum (Tanacetum cinerariifolium) flowers. Pyrethrum produces a div...

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