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Field dodder (Cuscuta campestris yuncker) is an important parasitic weed that has negative impacts on the growth and yield of alfalfa (Medicago sativa L.). Effective control of field dodder in alfalfa crops is necessary to reduce yield losses. Field studies were conducted to evaluate the efficacy of various herbicides on field dodder in a new-seeded alfalfa crop at three locations (Karaj, Jiroft, and Urmia) in Iran during 2020–2021. The herbicides evaluated were imazethapyr (100 g a.i. ha−1), glyphosate (six doses ranging from 143 to 348 g a.i. ha−1 + ammonium sulfate at 8 kg ha−1), and propyzamide (1250, 1500, and 1750 g a.i. ha−1). The results demonstrated that propyzamide at 1750 g a.i. ha−1 provided complete control of field dodder in terms of percentage change in biomass at first (100%) and second (99%) cuttings of alfalfa in Urmia. The imazethapyr at 100 g a.i. ha−1 provided 96 and 87% control at the first and second cuttings, respectively, whereas propyzamide at 1750 g a.i. ha−1 showed the best efficacy in increasing alfalfa biomass at the first (up to 82%) and the second cuttings (up to 81%), depending on the location. Glyphosate provided reasonable control of the field dodder at the first (73%) and the second cutting (82%). However, at higher rates (307 and 348 g a.i. ha−1), it caused significant reductions in alfalfa biomass due to crop injury, especially at the first cutting. The use of propyzamide at 1750 g a.i. ha−1 is recommended for highly effective control of field dodder in alfalfa crops without compromising the crop yield. [ABSTRACT FROM AUTHOR]

Open access new approach methods (NAM) in the US EPA ToxCast program and NTP Integrated Chemical Environment (ICE) were used to investigate activities of four neurotoxic pesticides: endosulfan, fipronil, propyzamide and carbaryl. Concordance of in vivo regulatory points of departure (POD) adjusted for interspecies extrapolation (AdjPOD) to modelled human Administered Equivalent Dose (AEDHuman) was assessed using 3-compartment or Adult/Fetal PBTK in vitro to in vivo extrapolation. Model inputs were from Tier 1 (High throughput transcriptomics: HTTr, high throughput phenotypic profiling: HTPP) and Tier 2 (single target: ToxCast) assays. HTTr identified gene expression signatures associated with potential neurotoxicity for endosulfan, propyzamide and carbaryl in non-neuronal MCF-7 and HepaRG cells. The HTPP assay in U-2 OS cells detected potent effects on DNA endpoints for endosulfan and carbaryl, and mitochondria with fipronil (propyzamide was inactive). The most potent ToxCast assays were concordant with specific components of each chemical mode of action (MOA). Predictive adult IVIVE models produced fold differences (FD)

Ultrasound as a green and efficient process gains special attention in wastewater treatment. The ultrasound-assisted degradation of azoxystrobin, methoxyfenozide, and propyzamide as widely used pesticides for vine treatment was investigated. A wide range of ultrasonic power (40 to 140 W) and a single frequency (20 kHz) were applied. Degradation experiments were carried out according to the parameters set by a central composite design (CCD) under response surface methodology (RSM) via JMP software. The treatment efficiency was quantified using degradation rates and hydrogen peroxide (H2O2) measurements. Results indicated that the pesticide's degradation was negligible at 40 W but by increasing the power setting from 80 to 140 W, the degradation rate constants of azoxystrobin, methoxyfenozide, and propyzamide increased from 3.6 × 10−2 min−1 to 0.2 min−1, from 6.1 × 10−2 min−1 to 0.3 min−1, and from 3.1 × 10−2 min−1 to 0.1 min−1, respectively. The hydrogen peroxide (H2O2) measurements confirmed this trend. Besides, electric energy per order of pollutant removal (EE/O) was also evaluated for the same treatment duration and results revealed that treatment conditions of 20 kHz and 140 W were the less energy-guzzling. Finally, profiles obtained with RSM illustrated linear degradation kinetics for azoxystrobin and propyzamide. Indeed, treatment efficiency increased when increasing both studied parameters. However, both linear and quadratic degradation kinetics occurred for methoxyfenozide degradation indicating a parameter threshold beyond which the trend is reversed. Overall, this study confirms the effectiveness of ultrasound for the degradation of pesticides in aqueous medium. [ABSTRACT FROM AUTHOR]

Microtubules are cytoskeletal cell elements that also build flagella and cilia. Moreover, these structures participate in spermatogenesis and form a microtubular manchette during spermiogenesis. The present study aims to assess the influence of propyzamide, a microtubule-disrupting agent, on alga Chara vulgaris spermatids during their differentiation by means of immunofluorescent and electron microscopy methods. Propyzamide blocks the functioning of the β-tubulin microtubule subunit, which results in the creation of a distorted shape of a sperm nucleus at some stages. Present ultrastructural studies confirm these changes. In nuclei, an altered chromatin arrangement and nuclear envelope fragmentation were observed in the research as a result of incorrect nucleus–cytoplasm transport behavior that disturbed the action of proteolytic enzymes and the chromatin remodeling process. In the cytoplasm, large autolytic vacuoles and the dilated endoplasmic reticulum (ER) system, as well as mitochondria, were revealed in the studies. In some spermatids, the arrangement of microtubules present in the manchette was disturbed and the structure was also fragmented. The observations made in the research at present show that, despite some differences in the manchette between Chara and mammals, and probably also in the alga under study, microtubules participate in the intramanchette transport (IMT) process, which is essential during spermatid differentiation. In the present study, the effect of propyzamide on Chara spermiogenesis is also presented for the first time; however, the role of microtubule-associated proteins in this process still needs to be elucidated in the literature. [ABSTRACT FROM AUTHOR]

Tedera is a drought-tolerant perennial forage legume introduced in Australia in 2006. In October 2018, T15-1218 Lanza®, the world's first tedera variety, was released by the Department of Primary Industries and Regional Development and Meat & Livestock Australia for commercial use. A key agronomic practise for the successful establishment and adoption of tedera is to have a robust herbicide package to control a range of grass and broadleaf weeds well tolerated by tedera. A total of 9 pre-emergent and 44 post-emergent herbicide treatments were evaluated in eight experiments from 2017 to 2021. To control grasses such as annual ryegrass (Lolium rigidum Gaud.), propyzamide and carbetamide can be recommended for pre- or post-emergent applications and butroxydim, clethodim, and haloxyfop for post-emergent applications. The broadleaf pre-emergent herbicides recommended are clopyralid to control emerged capeweed (Arctotheca calendula (L.) Levyns), fomesafen to control pre-emergent wild radish (Raphanus raphanistrum L.), and the double mix of fomesafen + diuron, flumetsulam + diuron, and the triple mix of fomesafen + diuron + flumetsulam to control pre-emergent capeweed, pre- and post-emergent wild radish, and other broadleaf weeds. The most consistently well tolerated post-emergent herbicides by tedera seedlings and adult plants were diflufenican, diuron, flumetsulam, fomesafen, and their two- or three-way mixes that will provide good control of capeweed and wild radish. Desiccants such as paraquat or diquat were also well tolerated by 1-year-old tedera plants that recovered after being desiccated. [ABSTRACT FROM AUTHOR]

Abstract The conclusions of the European Food Safety Authority (EFSA) following the peer review of the initial risk assessment carried out by the competent authority of the rapporteur Member State Sweden, for the pesticide active substance propyzamide are reported. The context of the peer review was that requested by the European Commission following the submission and evaluation of confirmatory information in the areas of mammalian toxicology and residues. The conclusions were reached on the basis of the evaluation of the representative uses of propyzamide as an herbicide on lettuce and winter oilseed rape. The reliable endpoints concluded as being appropriate for use in regulatory risk assessment, derived from the available studies and/or literature in the dossier peer reviewed, are presented. Concerns are identified.

The conclusions of the European Food Safety Authority (EFSA) following the peer review of the initial risk assessment carried out by the competent authority of the rapporteur Member State Sweden, for the pesticide active substance propyzamide are reported. The context of the peer review was that requested by the European Commission following the submission and evaluation of confirmatory information in the areas of mammalian toxicology and residues. The conclusions were reached on the basis of the evaluation of the representative uses of propyzamide as an herbicide on lettuce and winter oilseed rape. The reliable endpoints concluded as being appropriate for use in regulatory risk assessment, derived from the available studies and/or literature in the dossier peer reviewed, are presented. Concerns are identified. [ABSTRACT FROM AUTHOR]

The European Food Safety Authority (EFSA) was asked by the European Commission to provide scientific assistance with respect to the risk assessment for an active substance in light of confirmatory data requested following approval in accordance with Article 6(1) of Directive 91/414/EEC and Article 6(f) of Regulation (EC)No 1107/2009. In this context EFSA's scientific views on the specific points raised during the commenting phase conducted with Member States, the applicant and EFSA on the confirmatory data and their use in the risk assessment for propyzamide are presented. The current report summarises the outcome of the consultation process organised by the rapporteur Member State Sweden and presents EFSA's scientific viewsand conclusions on the individual comments received. [ABSTRACT FROM AUTHOR]

MilestoneTM herbicide contains the active substance propyzamide (500 g/L) and aminopyralid (5.3 g a.e./L) and is formulated as a suspension concentrate (SC). Registration for Milestone for the use in winter oilseed rape was granted in Germany in July 2014. The active substance propyzamide is well known from the product KerbTM FLO (containing 500 g/L propyzamide, suspension concentrate, SC) which is widely used in winter oilseed rape (WITTROCK et al., 2008). Aminopyralid is formulated in the commercial product Runway (clopyralid + picloram + aminopyralid). Milestone is applied with a use rate of 1.5 L/ha as a post-emergence herbicide from growth stage BBCH 14 of the crop at the beginning of November until February. Kerb FLO is applied with a use rate of 1.875 L/ha at the same timing. The efficacy of Milestone and Kerb FLO was tested in randomised and replicated plot trials in Germany, France and the United Kingdom. Milestone and Kerb FLO showed comparable and very high control levels against monocotyledonous species such as Alopecurus myosuroides, Apera spica-venti, Bromus species and volunteer cereals. Milestone shows a broader spectrum of activity vs. Kerb FLO against dicotyledonous weeds such as Matricaria chamomilla, Papaver rhoeas and Centaurea cyanus. The use of Milestone in dense crops (as the situation was in autumn 2014 for many areas in Germany) shows very high efficacy levels as well. The comparison of various application timings between end of October until beginning of December confirms the application date early November for best results. Milestone controls herbicide-resistant weed populations and can be considered an important part of a resistance management program not only in winter oilseed rape but as a component of an integrated weed management strategy in cropping systems.

Dodder (Cuscuta campestris) control is a challenge and dodder is one of the factors limiting the cultivation of sugar beet in many regions of Iran. New herbicides can be useful in chemical control of dodder. This study was conducted to evaluate the effect of new mixture of herbicides on dodder control in sugar beet field. Results showed that the Propyzamide (3 L ha-1) had the highest effect on dodder weed weight loss% and this treatment led to 99.59% reduction in its fresh and dry weight. In addition, herbicide treatments were significant at 0.01 significance level within 15 and 30 days; after this time application of Propyzamide 3 L ha-1 led to 90.63 and 100% reduction in dodder weed, respectively. The Propyzamide 3 L ha-1 led to 80.63% increase in sugar beet foliage dry weight within 30 Days After Herbicide Application (DAHA). In addition, between treatments the highest increase percentage of sugar beet yield was obtained by Ethofumesate (2 L ha-1) along with Gallant Supper (1 L ha-1) and the removal of broad leaf about 86.55% compared to control. Totally, Propyzamide (1.9 L ha-1) along with Gallant Supper (0.75 L ha-1) showed the best results with the lowest dosages. [ABSTRACT FROM AUTHOR]

Plant protection products (PPPs) have been found increasingly in the environment. They pose a huge threat to bees, contributing to honeybee colony losses and consequently to enormous economic losses. Therefore, this field investigation was designed to determine whether their active ingredients (AIs) were transferred from raspberry plants to beehives located in the immediate neighbourhood of the crop and to what extent they were transferred. Every week for 2 months, samples of soil, raspberry leaves, flowers and fruits, worker bees, honeybee brood, and honey were collected and analysed for the presence of propyzamide, chlorpyrifos, iprodione, pyraclostrobin, boscalid, cypermethrin, difenoconazole, azoxystrobin, and pyrimethanil residues. Five of these substances were found in the worker bee bodies. Chlorpyrifos, applied to only the soil through the irrigation system, also was detected in the brood. A small amount of boscalid was noted in the honey, but its residues did not exceed the maximum residue level. For chlorpyrifos, boscalid, and pyrimethanil, a positive correlation between the occurrence of PPPs in the crops and the beehives was found. Statistical methods confirmed that the application of PPPs on a raspberry plantation, as an example of nectar-secreting plants, was linked to the transfer of their AIs to beehives. [ABSTRACT FROM AUTHOR]

Copyright of Julius-Kühn-Archiv is the property of Julius Kuehn Institut and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The effects of field dodder on physiological and anatomical processes in untreated sugar beet plants and the effects of propyzamide on field dodder were examined under controlled conditions. The experiment included the following variants: N—noninfested sugar beet plants (control); I - infested sugar beet plants (untreated), and infested plants treated with propyzamide (1500 g a.i. ha−1(T1) and 2000 g a.i. ha−1(T2)). The following parameters were checked: physiological—pigment contents (chlorophylla, chlorophyllb, total carotenoids); anatomical -leaf parameters: thickness of epidermis, parenchyma and spongy tissue, mesophyll and underside leaf epidermis, and diameter of bundle sheath cells; petiole parameters: diameter of tracheid, petiole hydraulic conductance, xylem surface, phloem cell diameter and phloem area in sugar beet plants. A conventional paraffin wax method was used to prepare the samples for microscopy. Pigment contents were measured spectrophotometrically after methanol extraction. All parameters were measured: prior to herbicide application (0 assessment), then 7, 14, 21, 28 and 35 days after application (DAA). Field dodder was found to affect the pigment contents in untreated sugar beet plants, causing significant reductions. Conversely, reduction in the treated plants decreased 27% to 4% for chlorophylla, from 21% to 5% for chlorophyllb, and from 28% to 5% for carotenoids (T1). Also, in treatment T2,reduction decreased in infested and treated plants from 19% to 2% for chlorophylla, from 21% to 2% for chlorophyllb, from 23% to 3% for carotenoids and stimulation of 1% and 2% was observed 28 and 35 DAA, respectively. Plants infested (untreated) by field dodder had lower values of most anatomical parameters, compared to noninfested plants. The measured anatomical parameters of sugar beet leaves and petiole had significantly higher values in noninfested plants and plants treated with propyzamide than in untreated plants. Also, the results showed that propyzamide is an adequate herbicide for control of field dodder at the stage of early infestation. [ABSTRACT FROM PUBLISHER]

The roles of multiple GRAS transcription factors (TFs), which play key roles in diverse processes of growth and development, have been characterized in detail. However, the regulatory functions of one third of the GRAS members remain unknown. Here, we characterized the role of SCARECROW-LIKE 28 (SCL28) in the Arabidopsis root; nuclear localization and transcriptional activity indicated that SCL28 likely acts as a TF in the root. SCL28 overexpression ( SCL28-OX) promoted cell division and suppressed cell elongation in a zone-specific manner along the root axis. In the presence of the microtubule-destabilizing chemical propyzamide, SCL28-OX exhibited straight root growth, while scl28 roots showed left-handed helical growth similar to the wild type. Under salt and propyzamide treatments, scl28 roots grew straight, while SCL28-OX roots displayed exaggerated right-handed growth. Thus, SCL28 likely plays a role in the root growth response to stressinduced microtubule organization. Additionally, transcriptome analysis revealed that SCL28 regulated the transcription of diverse growth- and development-related genes in plants. In particular, SCL28 regulated the expression of various stressresponse genes. Taken together, our findings provide insight into the regulatory role of SCL28, which orchestrates the linked activity of cell division and elongation under various environmental conditions to achieve root growth plasticity. [ABSTRACT FROM AUTHOR]

Abstract The conclusions of EFSA following the peer review of the initial risk assessments carried out by the competent authorities of the rapporteur Member State, Sweden, and co‐rapporteur Member State, the United Kingdom, for the pesticide active substance propyzamide are reported. The context of the peer review was that required by Commission Implementing Regulation (EU) No 844/2012. The conclusions were reached on the basis of the evaluation of the representative uses of propyzamide as a herbicide on lettuce and winter oilseed rape. The reliable end points, appropriate for use in regulatory risk assessment are presented. Missing information identified as being required by the regulatory framework is listed. Concerns are identified.

Experiments compared sorption and leaching behaviour for the herbicide propyzamide when applied to two soils either as technical material or in the commercial formulation Kerb® Flo. Sorption was investigated in batch systems as well as using a centrifugation technique to investigate changes in pesticide concentration in soil pore water over incubation periods of up to 28 days. Studies with small soil columns compared leaching of technical and formulated pesticide for irrigation events (6 pore volumes) 1, 7, 14, 21 and 28 days after treatment. There were no differences in sorption of technical and formulated propyzamide when measured by batch systems. Sorption of technical material was significantly greater than that of formulated pesticide in sandy loam (p < 0.05), but not in sandy silt loam when measured by centrifugation of soil incubated at field capacity. Partition coefficients measured by batch and centrifugation methods were similar after 1 day and those measured by centrifugation increased by factors of 5.3 to 7.5 over the next 4 weeks. The mass of propyzamide leached from soil columns ranged between 1.1 ± 0.33% and 14.4 ± 3.2% of the applied amount. For all time intervals and in both soils, the mass of propyzamide leached was significantly greater (two-sided t-tests, p < 0.001) for the formulated product than for the technical material. Leached losses decreased consistently with time in the sandy loam soil (losses after 28 days were 14–17% of those after 1 day), but with less consistency in the sandy silt loam. There was a highly significant effect of formulation on the leaching of propyzamide through soil (two-way ANOVA, p < 0.001) as well as highly significant effects of time and soil type (p < 0.001). Results are consistent with modelling studies where leaching from commercial products in the field could only be simulated by reducing sorption coefficients relative to those measured with technical material in the laboratory. [ABSTRACT FROM AUTHOR]

In accordance with Article 6 of Regulation ( EC) No 396/2005, the evaluating Member State ( EMS), the United Kingdom, received an application from Agriculture and Horticulture Development Board to modify the existing maximum residue level ( MRL) for the active substance pyraclostrobin in beet leaves (chards). To accommodate for the intended use of pyraclostrobin, the United Kingdom proposed to raise the existing MRL from 0.5 to 1.5 mg/kg. According to EFSA, the data are sufficient to derive an MRL proposal of 1.5 mg/kg on beet leaves (chards). Adequate analytical enforcement methods are available to control the residues of pyraclostrobin in the commodity under consideration. Based on the risk assessment results, EFSA concludes that the use of pyraclostrobin in beet leaves (chards) will not result in a consumer exposure exceeding the toxicological reference values and therefore is unlikely to pose a consumer health risk. [ABSTRACT FROM AUTHOR]

The conclusions of EFSA following the peer review of the initial risk assessments carried out by the competent authorities of the rapporteur Member State, Sweden, and co-rapporteur Member State, the United Kingdom, for the pesticide active substance propyzamide are reported. The context of the peer review was that required by Commission Implementing Regulation ( EU) No 844/2012. The conclusions were reached on the basis of the evaluation of the representative uses of propyzamide as a herbicide on lettuce and winter oilseed rape. The reliable end points, appropriate for use in regulatory risk assessment are presented. Missing information identified as being required by the regulatory framework is listed. Concerns are identified. [ABSTRACT FROM AUTHOR]

BACKGROUND A substantial fraction of the applied crop protection products on crops is lost to the atmosphere. Models describing the prediction of volatility and potential fate of these substances in the environment have become an important tool in the pesticide authorisation procedure at the EU level. The main topic of this research is to assess the rate and extent of volatilisation of ten pesticides after application on field crops. RESULTS For eight of the ten pesticides, the volatilisation rates modelled with PEARL (Pesticide Emission Assessment at Regional and Local scales) corresponded well to the calculated rates modelled with ADMS (Atmospheric Dispersion Modelling System). For the other pesticides, large differences were found between the models. Formulation might affect the volatilisation potential of pesticides. Increased leaf wetness increased the volatilisation of propyzamide and trifloxystrobin at the end of the field trial. The reliability of pesticide input parameters, in particular the vapour pressure, is discussed. CONCLUSION Volatilisation of propyzamide, pyrimethanil, chlorothalonil, diflufenican, tolylfluanid, cyprodinil and E- and Z-dimethomorph from crops under realistic environmental conditions can be modelled with the PEARL model, as corroborated against field observations. Suggested improvements to the volatilisation component in PEARL should include formulation attributes and leaf wetness at the time of pesticide application. © 2015 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Copyright of Julius-Kühn-Archiv is the property of Julius Kuehn Institut and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In accordance with Article 6 of Regulation (EC) No 396/2005, Germany, herewith referred to as the evaluating Member State (EMS), received an application from the Landesanstalt für Landwirtschaft Forsten und Gartenbau Sachsen-Anhalt to modify the existing MRLs for the propyzamide in herbal infusions. In order to accommodate for the intended use of propyzamide in Germany, the EMS proposed to raise the existing MRLs in leaves and flowers of herbal infusions to 0.4 mg/kg and in roots of herbal infusions to 0.15 mg/kg. According to EFSA, the residue data are sufficient to support the extrapolation of residue data on dried peppermint, lemon balm leaves, narrow leaf plantain and camomile flowers to the whole group of dried leaves and flowers of herbal infusions with a MRL proposal of 0.4 mg/kg. The submitted residue data on black snakeroot can be extrapolated to dried roots of herbal infusions with a MRL proposal of 0.02 mg/kg (the LOQ). The applicant has to confirm the applicability of the enforcement method to analyse propyzamide residues in dried herbs. A minor data gap was identified regarding the freezer storage stability of propyzamide in dry matrices. Based on the risk assessment results, EFSA concludes that the intended use of propyzamide on the crops under consideration and the use of dried plant parts (leaves, flowers and roots) in herbal infusions will not result in a consumer exposure exceeding the toxicological reference value and therefore is unlikely to pose a public health concern.

Propyzamide is a widely used benzamide herbicide for controlling weeds in lettuce, soybeans, cotton and other crops. An efficient propyzamide-degrading strain W1 was firstly isolated from activated sludge and identified as Comamonas testosteroni . A metabolite of propyzamide by strain W1 was firstly identified. The novel gene camH encoding a hydrolase that catalyzed the amide bond cleavage of propyzamide was cloned from strain W1. The gene contained an open reading frame of 1452 bp, the deduced amino acid sequence showed low identity with other amidases. The recombinant enzyme CamH was expressed in Escherichia coli BL21 and purified. CamH displayed the highest activity at 30 °C and pH 8.0 with propyzamide as the substrate. These results provide important knowledge on the fate of propyzamide in the biodegradation, and elucidate the biodegradation mechanism of propyzamide by the strain W1. [ABSTRACT FROM AUTHOR]

The binding action of PRO associated with calf thymus DNA (ctDNA) was determined using multispectroscopic methods combined with parallel factor analysis (PARAFAC) and molecular docking. The fluorescence titration suggested a static fluorescence quenching of PRO was induced by ctDNA. The positive values of enthalpy changes and entropy changes suggested that the binding reaction was predominantly driven by hydrophobic interactions. Increases in melting temperature and viscosity of ctDNA and decrease in iodide-quenching effect indicated that an intercalative binding of PRO to ctDNA occurred. Moreover, the three-way synchronous fluorescence spectra data from the competitive interaction between PRO and fluorescence probe acridine orange (AO) with ctDNA were resolved by PARAFAC modeling to provide the concentration information and spectra of the three components (PRO, AO and ctDNA–AO complex) for the reaction system, which further supported the intercalation of PRO molecule into ctDNA double-helix by replacing bound AO probe. The molecular docking predicted that the A–T base pairs of ctDNA were the main binding sites for PRO, which was confirmed by Fourier transform infrared analysis, and the conformational change of ctDNA from B-form to A-form induced by PRO was inferred from the circular dichroism spectra studies. [ABSTRACT FROM AUTHOR]

Water suppliers in parts of Europe currently face occasional Drinking Water Directive compliance challenges for a number of pesticide active substances including metaldehyde, clopyralid and propyzamide. Water Framework Directive (WFD) Article 7 promotes a prevention-led (catchment management) approach to such issues. At the same time, European pesticide legislation is driving reduced active substance availability. In this context, embedding agronomic drivers of pesticide use into catchment management and regulatory decision making processes can help to ensure that water quality problems are addressed at source without imposition of disproportionate cost on either agriculture or potable water suppliers. In this study agronomist knowledge, perception and expectations of current and possible future pesticide use was assessed and the significance of this knowledge to other stakeholders involved with pesticide catchment management was evaluated. This was then used to provide insight into the possible impacts of active substance restrictions and associated adaptation options. For many arable crops, further restrictions on the range of pesticides available may cause increased use of alternatives (with potential for 'pollution swapping'). However, in many cases alternatives are not available, too costly or lack a proven track record and other adaptation options may be selected which catchment managers need to be able to anticipate. [ABSTRACT FROM AUTHOR]

In accordance with Article 6 of Regulation (EC) No 396/2005, Germany, herewith referred to as the evaluating Member State (EMS), received an application from the Landesanstalt für Landwirtschaft Forsten und Gartenbau Sachsen-Anhalt to modify the existing MRLs for the propyzamide in herbal infusions. In order to accommodate for the intended use of propyzamide in Germany, the EMS proposed to raise the existing MRLs in leaves and flowers of herbal infusions to 0.4 mg/kg and in roots of herbal infusions to 0.15 mg/kg. According to EFSA, the residue data are sufficient to support the extrapolation of residue data on dried peppermint, lemon balm leaves, narrow leaf plantain and camomile flowers to the whole group of dried leaves and flowers of herbal infusions with a MRL proposal of 0.4 mg/kg. The submitted residue data on black snakeroot can be extrapolated to dried roots of herbal infusions with a MRL proposal of 0.02 mg/kg (the LOQ). The applicant has to confirm the applicability of the enforcement method to analyse propyzamide residues in dried herbs. A minor data gap was identified regarding the freezer storage stability of propyzamide in dry matrices. Based on the risk assessment results, EFSA concludes that the intended use of propyzamide on the crops under consideration and the use of dried plant parts (leaves, flowers and roots) in herbal infusions will not result in a consumer exposure exceeding the toxicological reference value and therefore is unlikely to pose a public health concern [ABSTRACT FROM AUTHOR]

Abstract: Pesticide losses to water can present problems for environmental management, particularly in catchments where surface waters are abstracted for drinking water supply. The relative role of different transfer pathways (spray drift, spills, overland flow and leaching from soils) is often uncertain, and there is a need for experimental observation and modelling to ensure that processes are understood under a range of conditions. Here we examine the transport of propyzamide and carbetamide in a small (15.5ha) headwater sub-catchment dominated by an artificially drained field with strongly undulating topography (topographic gradients >1:10). Specifically, we explore the validity of the “field-scale lysimeter” analogy by applying the one dimensional mathematical model MACRO. Although one dimensional representation has been shown to be reasonable elsewhere, the scale and topography of the monitored system challenge many of the underlying assumptions. MACRO considers two interacting flow domains: micropores and macropores. The effect of subsurface drains can also be included. A component of the outflow from the main drain was identified as originating from an upslope permeable shallow aquifer which was represented using a simple groundwater model. Predicted herbicide losses were sensitive to drain spacing and the organic carbon to water partition coefficient, KOC . The magnitude of the peak water and herbicide transport and their timing were simulated satisfactorily, although model performance was poor following a period of one month when snow covered the ground and precipitation was underestimated by the rain gauge. Total herbicide loads were simulated adequately by MACRO, suggesting that the field-scale lysimeter analogy is valid at this scale, although baseflow contributions to flow needed to be accounted for separately in order to adequately represent hydrological response. [Copyright &y& Elsevier]

Abstract: Propyzamide and carbetamide are essential for blackgrass control in oilseed rape production. However, both of these compounds can contaminate surface waters and pose compliance problems for water utilities. The transport of propyzamide and carbetamide to an instrumented field drain in a small clay headwater tributary of the Upper Cherwell catchment was monitored over a winter season. Despite having very different sorption and dissipation properties, both herbicides were transported rapidly to the drain outlet in the first storm event after application, although carbetamide was leached more readily than propyzamide. A simple conceptual model was constructed to represent solute displacement from mobile pore water and preferential flow to drains. The model was able to reproduce the timing and magnitude of herbicide losses well, lending support to its conceptual basis. Measured losses in drainflow in the month following application were 1.1 and 8.1%, respectively, for propyzamide and carbetamide. Differences were due to a combination of differences in herbicide mobility and due to the fact that the monitoring period for carbetamide was hydrologically more active. For both compounds, losses were greater than those typically reported elsewhere for other herbicides. The data suggest that drainflow is the dominant pathway for the transfer of these herbicides to the catchment outlet, where water is abstracted for municipal supply. This imposes considerable constraints on the management options available to reduce surface water concentrations of herbicides in this catchment. [Copyright &y& Elsevier]

Low doses of microtubule-interacting drugs cause wild-type Arabidopsis thaliana seedling roots to twist in a left-handed helical direction. We here report molecular characterization of an A. thaliana tubulin mutant whose roots twist in a right-handed direction and have shallow left-handed cortical microtubule arrays when challenged with low doses of microtubule drugs. In the absence of the drug, growth and development of the mutant was apparently normal. In this conditional twisting mutant, Cys213 of α-tubulin6 was exchanged with Tyr. The mutant tubulin was incorporated into the microtubule polymer with wild-type tubulins, and thus acted as a dominant-negative mutation. These results suggest that compromised microtubules in wild-type and mutant roots are qualitatively distinct and affect skewing direction differently. [ABSTRACT FROM AUTHOR]

Abstract: The organisation of membrane proteins into certain domains of the plasma membrane (PM) has been proposed to be important for signalling in yeast and animal cells. Here we describe the formation of a very distinct pattern of the K+ channel KAT1 fused to the green fluorescent protein (KAT1::GFP) when transiently expressed in guard cells of Vicia faba. Using confocal laser scanning microscopy we observed a radially striped pattern of KAT1::GFP fluorescence in the PM in about 70% of all transfected guard cells. This characteristic pattern was found to be cell type and protein specific and independent of the stomatal aperture and the cytoskeleton. Staining of the cell wall of guard cells with Calcofluor White revealed a great similarity between the arrangement of cellulose microfibrils and the KAT1::GFP pattern. Furthermore, the radial pattern of KAT1::GFP immediately disappeared when turgor pressure was strongly decreased by changing from hypotonic to hypertonic conditions. The pattern reappeared within 15min upon reestablishment of high turgor pressure in hypotonic solution. Evaluation of the staining pattern by a mathematical algorithm further confirmed this reversible abolishment of the radial pattern during hypertonic treatment. We therefore conclude that the radial organisation of KAT1::GFP depends on the close contact between the PM and cell wall in turgid guard cells. These results offer the first indication for a role of the cell wall in the localisation of ion channels. We propose a model in which KAT1 is located in the cellulose fibrils intermediate areas of the PM and discuss the physiological role of this phenomenon. [Copyright &y& Elsevier]

Abstract: Good crop selectivity makes the use of graminicides an attractive proposition for use in tree establishment. However when compared to the agricultural situations upon which most graminicide recommendations are currently based, regenerating woodlands usually contain larger specimens of a wider range of grass weed species. For this reason, five field experiments were set up to investigate the relative susceptibility of young and established plants of 29 grass weed species and Juncus effusus to the graminicides cycloxydim, fluazifop-p-butyl and propaquizafop in comparison with glyphosate and propyzamide. Graminicide applications were made 6, 12 and 18 months after establishing small plants in early autumn. Generally, a wider range of grass species appeared to be susceptible, and at later growth stages, than currently recommended by manufacturers. Cycloxydim was the most effective graminicide on perennial grasses giving good long term control of Anthoxanthum oderatum, Cynosurus cristatus, Dactylis glomerata, Festuca arundinacea, Lolium perenne, Molinia caerulea, Phleum pratense and Poa trivialis at all application dates and Agrostis gigantea, Agrostis stolonifera, Arrhenathrum elatius in spring only. Fluazifop-p-butyl was the most effective on Festuca pratensis. Autumn applications of cycloxydim and fluazifop-p-butyl controlled Holcus lanatus and cycloxydim controlled Agrostis capillaris, Deschampsia caespitosa and Nardus stricta. Propaquizafop was the most effective graminicide on Elytrigia repens. Festuca longifolia, Festuca ovina, Festuca rubra ssp. rubra and J. effusus were not susceptible to these herbicides. The graminicides were generally very effective on annual species except Poa annua, although cycloxydim gave poorer control of older plants of Anisantha sterilis and Anisantha diandra and propaquizafop of Apera spica-venti. Possible factors affecting susceptibility of grass species to these herbicides are reviewed. [Copyright &y& Elsevier]

Chlorthal-dimethyl 7.5 and 11.25 kg ha-1 applied preemergence, propyzamide 1.0 and 1.5 kg ha-1 incorporated into the soil at the depth of 4–6 cm and trifluralin 0.75 and 1.0 kg ha-1 incorporated into the soil at the depth of 5–10 cm did not affect the fresh weight of shoots, length of main shoot nor the diameter of inflorescence of Carthamus tinctorius, Helichrysum bracteatum, Helipterum roseum and Lonas annua and controlled about 40 to 75% of weeds growing during eight weeks after seed sowing in 3-years experiment.

Previous studies showed that sub-micromolar concentrations of the microtubule-targeting herbicide propyzamide cause a right-handed helical arrangement of cortical microtubule arrays and left-handed twisting in elongating Arabidopsis epidermal cells. When seedlings were grown in the presence of 1–2 µM propyzamide or 50–100 nM oryzalin, we show that microtubules spent more time in a paused state in which they exhibited little net change in length. The drug treatment also resulted in slower growth and shortening velocities, increased catastrophe, and an overall decrease in microtubule turnover. A reduction in microtubule dynamic turnover may underlie the drug-induced rearrangement of cortical arrays. [ABSTRACT FROM AUTHOR]

We aimed to analyze the rheological characteristics during elongation of the root segments in Lemna minor. The elastic component of segment elongation (EC) increased for the first 6 h, and then almost stopped. However, the plastic component of the segment elongation (PC) began to rapidly increase from 6 h onwards. Uniconazole-P, a gibberellin biosynthesis inhibitor, inhibited the total elongation of root segments (TE), and this inhibition was mainly caused by suppression of the rapid increase in the PC after 6 h. Concomitant with this inhibition, the cortical microtubule (CMT) array within root epidermal cells became disorganized in the presence of uniconazole-P from 6 h onwards. Adding GA3 abolished the inhibition of TE by uniconazole-P treatment, and this recovery was caused not by the increase in the EC but by an increase in the PC. Furthermore, the CMT arrays also recovered their characteristic organization in the presence of GA3. These findings suggest that endogenous gibberellin accelerates TE by activating the PCviacontrol of CMT arrays. This conclusion is also supported by rheological analysis where propyzamide was used to disrupt microtubules. We suggest that endogenous gibberellin controls the PCviaits influence over the transverse arrangement of CMTs. [ABSTRACT FROM PUBLISHER]

Synchronous cell systems are highly desirable for investigating various aspects of plant cell biology. However, to date, the tobacco BY-2 cell line is the only plant cell line which can be synchronized to high levels. A cell synchrony starting from S phase is obtained after release of BY-2 cells from aphidicolin treatment, while that from M phase is available after release from a sequential treatment of aphidicolin followed by propyzamide. A high level of synchrony is only attained by using rapidly growing tobacco BY-2 cells that propagate ca. 100-fold in a week. Reduced levels of synchrony result if the growth rate becomes lower. Technical notes for maintaining the high growth rate of the tobacco BY-2 cell are described. Using this highly synchronous system it has been possible to demonstrate the cell cycle-dependent oscillation of many genes, such as cyclins, and characterize their role during the cell cycle. Furthermore, this system has facilitated the structural and biochemical analysis of cell cycle specific events such as the development of the phragmoplast and the formation of cortical microtubules. Other potential uses of this highly synchronized cells are also described. [ABSTRACT FROM AUTHOR]

In suspension cultures of Phytolacca americana, betacyanin accumulation was reduced when cell division was inhibited by treatment with various inhibitors of DNA synthesis or anti-microtubule drugs. Aphidicolin (APC), an inhibitor of DNA synthesis, reduced the incorporation of radioactivity from labeled tyrosine into betacyanin, but the incorporation of radioactivity from labeled 3,4-dihydroxyphenylalanine (DOPA) into betacyanin was not affected by similar treatments. Propyzamide, another anti-microtubule drug, reduced incorporation of radioactivity from tyrosine and DOPA into betacyanin. However, the rate of incorporation from DOPA was higher than that from tyrosine. The results suggest that inhibition of betacyanin accumulation in Phytolacca americana cells by APC and propyzamide is due to suppression of the reaction converting tyrosine to DOPA, which may be closely related to cell division. [ABSTRACT FROM AUTHOR]

The reorganization of microtubules (MTs) from cytokinesis to interphase was examined in protonemal cells of the fern Adiantum capillus-veneris. During the reorganization, many MTs fanned out from the nuclear envelope towards the cell periphery. Newly formed cortical MTs were located only near the nucleus and were arranged randomly. The randomly arranged cortical MTs were then replaced by an interphase array of cortical MTs that were oriented predominantly parallel to the cell axis. At the boundary between the new and the old cell wall, clusters of MTs were observed after the formation of cortical MTs.Re-formation of MTs after depolymerization of MTs was also examined. Clusters of short MTs appeared only at the nuclear envelope when MTs had been depolymerized by exposure of cells to 100 μM propyzamide at 0°C. Few MTs were formed at the boundary between the new and old cell walls. These results suggest that, even in fern cells, the nuclear envelope might act as MT-organizing center during the establishment of the interphase array of MTs. [ABSTRACT FROM AUTHOR]

The article presents a study on the concentrations of the herbicide propyzamide, chlorpropham, and its ketone metabolite in the soil of lettuce culture. The study which was conducted in Saint Kathelijine-Waver, Belgiumuses gas chromatograph equipped with a flame ionization detector and with an electron capture detector. Results show that the soil type influences the outcome of pesticides in soil and solubility in water of chlorpropham is higher than that of propyzamide.

We studied the mechanism controlling the organization of actin filaments (AFs) in Hydrocharis root hair cells, in which reverse fountain streaming occurs. The distribution of AFs and microtubules (MTs) in root hair cells were analyzed by fluorescence microscopy and electron microscopy. AFs and MTs were found running in the longitudinal direction of the cell at the cortical region. AFs were observed in the transvacuolar strand, but not MTs. Ultrastructural studies revealed that AFs and MTs were colocalized and that MTs were closer to the plasma membrane than AFs. To examine if MTs regulate the organization of AFs, we carried out a double inhibitor experiment using cytochalasin B (CB) and propyzamide, which are inhibitors of AFs and MTs, respectively. CB reversibly inhibited cytoplasmic streaming while propyzamide alone had no effect on it. However, after treatment with both CB and propyzamide, removal of CB alone did not lead to recovery of cytoplasmic streaming. In these cells, AFs showed a meshwork structure. When propyzamide was also removed, cytoplasmic streaming and the original organization of AFs were recovered. These results strongly suggest that MTs are responsible for the organization of AFs in Hydrocharis root hair cells. [ABSTRACT FROM AUTHOR]

The kinetics of the degradation in soil of propyzamide and nine analogues have been measured at two temperatures (28 and 60°C). The degradation rates of propyzamide were determined in sterilised soil and in soil perfusates. The results obtained are in agreement with a chemical degradation of propyzamide and its analogues. Relationships were established between degradation rate constants and physicochemical parameters of the compounds: log k = − aσ+ bπ + c where σ = Hammett constant, π = hydrophobic constant, a, b, c are constants. [ABSTRACT FROM AUTHOR]

Computational Toxicology tools were used to predict toxicity for three pesticides: propyzamide (PZ), carbaryl (CB) and chlorpyrifos (CPF). The tools used included: a) ToxCast/Tox21 assays (AC 50 s μM: concentration 50% maximum activity); b) in vitro-to-in vivo extrapolation (IVIVE) using ToxCast/Tox21 AC 50 s to predict administered equivalent doses (AED: mg/kg/d) to compare to known in vivo Lowest-Observed-Effect-Level (LOEL)/Benchmark Dose (BMD); c) high throughput toxicokinetics population based (HTTK-Pop) using AC 50 s for endpoints associated with the mode of action (MOA) to predict age-adjusted AED for comparison with in vivo LOEL/BMDs. ToxCast/Tox21 active-hit-calls for each chemical were predictive of targets associated with each MOA, however, assays directly relevant to the MOAs for each chemical were limited. IVIVE AEDs were predictive of in vivo LOEL/BMD 10 s for all three pesticides. HTTK-Pop was predictive of in vivo LOEL/BMD 10 s for PZ and CPF but not for CB after human age adjustments 11–15 (PZ) and 6–10 (CB) or 6–10 and 11–20 (CPF) corresponding to treated rat ages (in vivo endpoints). The predictions of computational tools are useful for risk assessment to identify targets in chemical MOAs and to support in vivo endpoints. Data can also aid is decisions about the need for further studies. Image 1 • Propyzamide (PZ), carbaryl (CB) & chlorpyrifos(CPF) ToxCast/Tox21 assay data were downloaded. • There were few in vitro selected active hit-calls for each chemical that were related to the mode of action but results were predictive. • In vivo - In vitro Extrapolation (IVIVE) & HTTK-Pop administered equivalent doses (AED) modeled ToxCast/Tox21 data. • IVIVE AEDs were predictive of in vivo LOEL/BMD 10 for PZ, CB & CPF; HTTK-Pop AEDs predictive for PZ & CPF. [ABSTRACT FROM AUTHOR]

Diffuse pollution of surface waters by herbicides remains a problem despite 25 years of research into mitigation approaches. This study adopts the grassweed herbicide propyzamide as a focus to compare the efficacy of technical, field-scale, interventions with systems-based cropping solutions in a 900 ha headwater catchment on heavy clay soils. Catchment monitoring was combined with modelling of land management options using SWAT, and semi-structured discussions with farmers. Vegetated buffers are the main mitigation in the catchment at present, and these are estimated to be halving propyzamide concentrations in the headwater stream. Increasing vegetated buffers to 20 m width around all water courses would be the most effective technical intervention. Collaboration between farmers to ensure differentiated application timings would be ineffective without precise forecasting to avoid application soon before storm events. Downstream pesticide limits could only be met by restricting the area of land treated with propyzamide, requiring a switch away from oilseed rape cultivation. This restriction was not acceptable to farmers who noted the lack of enablers for coordination between landowners and the need for pesticide targets that are specific to headwater catchments. • Headwater catchments can be subject to intense pressure from single pollutants. • Existing technical, field-scale interventions halved diffuse herbicide pollution. • Systems-based solutions are most effective in reducing diffuse pollution further. • Mechanisms are required to deliver effective coordination between landowners. • Pesticide pollution targets specific to headwaters will aid negotiation with farmers. [ABSTRACT FROM AUTHOR]