Active Ingredient In Herbicide Research Articles

Efektivitas Herbisida Berbahan Aktif Metil Metsulfuron Terhadap Gulma Pakis Kawat (Dicranopteris linearis) Pada TBM Kelapa Sawit (Elaeis guineensis Jacq) Di Desa Sukoharjo Lahat Sumatera Selatan

One of the causes of low oil palm production is the presence of weeds, so weed control efforts are needed. One of the weed control methods is chemical weed control using herbicides. Methyl metsulfuron herbicide is one of the active ingredients of herbicides. The aim of this study was to obtain the optimal dose of methyl metsulfuron to control wire fern weed (Dicranopteris linearis) in immature oil palm plantations. The method used was a randomized block design (RAK) with
 8 levels of treatment, namely A (methyl metsulfuron 15 g.b.a/ha), B (methyl metsulfuron 50 g.b.a/ha), C (methyl metsulfuron 85 g.b.a/ha), D (methyl metsulfuron 15). g.b.a/ha + adhesive), E (methyl metsulfuron 50 g.b.a/ha+ adhesive), F (methyl metsulfuron 85 g.b.a/ha+ adhesive), G (manual weeding), H (without control and herbicide). All treatments were replicated 3 times. Parameters observed were weed mortality, weed dry weight and phytotoxicity. Data analysis used linear model variance with a significance of 5%, if there was a significant difference, it was continued with the Ducan Multiple Range Test (DMRT) further test. The results showed that the mortality of Dicranopteris linearis weeds with the herbicide methyl metsulfuron 85 g.b.a/ha was significantly different from the treatment with methyl metsulfuron 15-50 g.b.a/ha. Weed dry weight with the herbicide methyl metsulfuron 15-85 g.b.a/ha and manual control was significantly different from that without control. Weed control with methyl metsulfuron herbicide does not cause phytotoxicity.

Humic and Fulvic Acids as Specific Sorbents of Herbicides in Water

AbstractThe ability of humic and fulvic acids (isolated from lignite with a simple, quick, and inexpensive method) to bind the active ingredients of herbicides contaminating drinking water is evaluated. During this study drinking water samples are contaminated with formulated herbicides (imazamox or a mixture of thifensulfuron methyl and tribenuron methyl), while humic and fulvic acids are used as reducing agents. The maximum reducing ability presented by humic and fulvic acids is 72.72% for thifensulfuron methyl and tribenuron methyl and 37.52% for imazamox. Humic acids’ binding ability is superior to that of fulvic acids.

Glyphosate Contamination at Several Concentrations And Its Impact onChanges in Goat (Capra hircus) Organ Tissue

Herbicides are generally used in the control of weeds in plants. The use of synthetic chemicals such as herbicides is known tohave a negative impact on the environment. This is because the chemicals in the herbicide can kill or poison the organismsthat eat plants that are exposed to these chemicals. Glyphosate is one of the active ingredients of herbicides which is systemic,so it may leave a residue on weeds such as grasses which are usually used as animal feed. The aim of this study is to analyzethe impact of glyphosate residues on changes in the organ tissue of goats (Capra hircus) fed with feed exposed to glyphosatecompounds. The study was conducted using an experimental method with four treatments of glyphosate concentrationincluding control. The treatment consists of four goats with age of 12 months. The results showed that glyphosate treatmentin feed influenced the development and tissue of the goats. The higher the concentration of the residue exposed to the feed,the higher the residual concentration of glyphosate in livestock blood, namely 0.2377 ppm (P1), 0.3118 ppm (P2), and 0.9377ppm (P3), respectively. The results of the observation on livestock organ tissue showed that there was severe damage to theliver and minor damage to the lung, gastric and kidney tissue. The higher the concentration of the residue exposed to thefeed, the higher the residual concentration of glyphosate in livestock blood and causing more damage

Effect of UV-A, UV-B and UV-C irradiation of glyphosate on photolysis and mitigation of aquatic toxicity

The active herbicide ingredient glyphosate [N-(phosphonomethyl)glycine] is frequently detected as a contaminant in groundwater and surface waters. This study investigated effects of UV-A (365 nm), UV-B (302 nm) and UV-C (254 nm) irradiation of glyphosate in water on photolysis and toxicity to aquatic organisms from different trophic levels. A test battery with bacteria (Bacillus subtilis, Aliivibrio fischeri), a green microalga (Raphidocelis subcapitata), and a crustacean (Daphnia magna) was used to assess biological effect of glyphosate and bioactive transformation products before and after UV irradiation (4.7–70 J/cm2). UV-C irradiation at 20 J/cm2 resulted in a 2–23-fold decrease in toxicity of glyphosate to aquatic test organisms. UV-B irradiation at 70 J/cm2 caused a twofold decrease whereas UV-A did not affect glyphosate toxicity at doses ≤ 70 J/cm2. UV-C irradiation of glyphosate in drinking water and groundwater with naturally occurring organic and inorganic constituents showed comparable or greater reduction in toxicity compared to irradiation in deionized water. High-resolution mass spectrometry analyses of samples after UV-C irradiation showed > 90% decreases in glyphosate concentrations and the presence of multiple transformation products. The study suggests that UV mediated indirect photolysis can decrease concentrations of glyphosate and generate less toxic products with decreased overall toxicity to aquatic organisms.

Identification and Characterization of a 2,2-Dichloropropionic Acid (2,2-DCP) Degrading Alkalotorelant Bacterium Strain BHS1 Isolated from Blue Lake, Turkey

An acid, 2,2-dichloropropionic acid (2,2-DCP) is an active ingredient in herbicide (Dalapon®). Using 2,2-DCP as a model substrate, an alkalotolerant bacterium was successfully isolated from the Blue Lake, Turkey. This bacterium is a potential bioremediation agent of recalcitrant xenobiotic halogenated compounds. This study aimed to prove the efficacy of the alkalotolerance Bacillus megaterium BHS1 in degrading 2,2-DCP as the sole source of carbon. Biolog GEN III system and 16S rRNA analysis were used for the identification of the bacterium. It was discovered that the strain BHS1 is Bacillus megaterium, and the bacterium that was observed to thrive in alkaline conditions (pH 7.0−14.0), supplemented with varying concentrations of 2,2-DCP (from 20 to 60 mM). Growth of strain BHS1 was exceptional in 40 mM of 2,2-DCP at pH 9, corresponding to a cell doubling time of 17.7 hour, whereas was fully inhibited at 50 mM 2,2-DCP. Since halogenated pollutants can make their way into highly alkaline environments, therefore, identifying threshold levels of strain BHS1 with respect to alkaline-tolerance and maximum level of 2,2-DCP may prove pertinent. This is to ensure that an optimal environment is created for the bacteria to degrade 2,2-DCP-contaminated water. In addition, this is the first study exploring a Bacillus species isolated from an alkaline environment adept in utilizing 2,2-DCP as a sole source of carbon. Hence, the ability of this strain to degrade other types of haloalkanoic acids constitutes a worthy future study.

The method of multicomponent determination of herbicides of various chemical classes in water

In the work there are considered results of the development of the multicomponent method of measurement of concentration of herbicides of various chemical nature under their joint presence in the water. There was justified the optimality of application of HPLC-DAD (the working wavelength of 240 nm) for the determination of levels of 10 active ingredients of herbicides of class of sulfonylurea (metsulfuron-methyl, nikosulfuron, sulfometuron-methyl, thifensulfuron-methyl, triflusulfuron-methyl), imidazolinone (imazapyr, imazethapyr), 2,6-Bis[(4,6-dimethoxy-2- pyrimidinyl)oxy]benzoic acid (bispyribac acid), triazol-pyrimidines (Penoxsulam), a benzoylpyrazole compound (Topramenzone). For the concentrating and cleaning of samples of water there were used cartridges for solid-phase extraction of Oasis HLB - the macro porous copolymer made on the basis of the balanced ratio of 2 monomers - lipophilic divinylbenzene and hydrophilic N-vinylpirrolidone. The range of the detected concentrations in water was volatile between 0.0005 and 0.005 mg/L, values of standard deviation vary in the range of 1.8-3.9%. Chlorine-containing acidic herbicides were analyzed by the method of GC-ECD and GC-MS (IE) after preliminary converting of compounds into flying derivatives with the use of diazomethane. Satisfactory extraction of substances from a water sample may be achieved by classical extraction in the system “liquid-liquid” with the application of Methyl tert-butyl ester. For cleaning of the derivatized sample there were used cartridges for solid-phase extraction on the basis of silica gel. The range of the determination of 9 active ingredients referring to classes of phenoxy-acetic acid (2,4- D, MCPA), pyridinecarboxylic (aminopyiralid, picloram, clopyralid), benzoic acids (dicamba), benzothiadiazinone (bentazone), biphenyl ester (acifluorfen) and a chloroacetamide (acetochlor) - 0.0001-0.001 mg/L, SD values vary in the range of 1.8-33%.

Adverse Metabolic Outcomes in Soil Pseudomonas Species Exposed to Polyethoxylated Tallow Amine and Glyphosate

Polyethoxylated tallow amine (POEA) is a common surfactant used in glyphosate-based herbicide formulations to enhance the bioavailability of the active herbicide ingredient. Toxic effects of POEA e...

Re-registration Challenges of Glyphosate in the European Union

One of the most controversial societal issues today, regarding pesticide registration in the European Union (EU) may be the case surrounding re-registration of the active herbicide ingredient glyphosate. Shortly before the announcement of the conflicting views regarding the carcinogenicity status of this regulated agrochemical by EU Agencies, the European Food Safety Authority (EFSA) and the European Chemicals Agency (ECHA) on the one hand, and the International Agency for Research on Cancer (IARC) on the other hand, the Cancer Assessment Review Committee of the US Environmental Protection Agency (US EPA) also published re-evaluations. The US EPA assessment classified glyphosate into Group E, “not likely to be carcinogenic to humans”. Similar positions were reached by EFSA and ECHA, assessing glyphosate as “unlikely to pose a carcinogenic hazard to humans” and “not classified as a carcinogen”, respectively. A strongly opposing evaluation has previously been reached by IARC by classifying glyphosate into Group 2A, “probably carcinogenic to humans”. IARC identified potential cancer hazards in this case, but did not estimate the level of risk it may present, which was taken into consideration by opposing agencies. Multiple effects of glyphosate have been reported, of which carcinogenic effects are only one component. Formulated glyphosate products – especially with polyethoxylated tallowamine and related compounds – have been shown to cause stronger cytotoxic or endocrine disrupting effects than the active ingredient glyphosate alone. Questions related to hazards and corresponding risks identified in relation to this active ingredient and its formulated herbicide preparations divide scientific circles and official health and environmental authorities and organizations, and touch upon fundamental aspects of risk assessment and product regulation. The decision has to consider both hazard-based (IARC) and risk-based analysis (EFSA); the former may not be suitable to calculate practical significances, and the latter being challenged if exposure estimations are uncertain in light of new data on residue levels. The results of current analytical surveys on surface water are particularly worrisome. In turn, the precautionary principle appears to be the optimal approach in this case for regulation in the EU.

Weed control efficacy and selectivity of preemergence herbicides in Sorghum vulgare Perz. cultivationOcena skuteczności chwastobójczej i selektywności herbicydów stosowanych doglebowo w uprawie Sorghum vulgare Perz.

Summary In 2010–2011 field experiments were carried out to determine the weed control and phytotoxicity effect of the selected active ingredients of herbicides in Sorghum vulgare cultivation. During crop vegetation weed control was described and S. vulgare sensivity was conducted in the base of plant density, plant height and fresh mass. Following active ingredients were assessed: acetochlor, terbuthylazine + mesotrione + s-metolachlor, s-metolachlor + mesotrione, propisochlor, propisochlor + linuron, flufenacet + isoksaflutol. Data indicated that after application of: terbuthylazine + mesotrione + s-metolachlor, s-metolachlor + mesotrione and propisochlor + linuron very good weed control effect and significant plant height and fresh mass increasing were achieved.

Studies on maize inbred lines susceptibility to herbicides

This paper presents the analysis of results obtained during long- term studies on the response of maize inbred lines to herbicides. Under the agroecological conditions of Zemun Polje the response (reaction of maize inbred lines to herbicides of different classes was investigated. Biological tests were performed and some agronomic, morphological, physiological and biochemical parameters were determined when the response of maize inbred lines to herbicides was estimated. The use of active ingredients of herbicides from triazine, acetanilide, thiocarbamate to new chemical groups (sulfonylurea etc.), have been resulted in changes in weed suppression and susceptibility of inbred lines. Obtained results show that effects of herbicides on susceptible maize genotypes can be different: they can slowdown the growth and development and affect the plant height; they can also affect the stages of the tassel and ear development and at the end they can reduced grain yield of the tested inbreds. Numerous studies confirmed the existence of differences in susceptibility level of maize genotypes in relation to herbicides. According to gained results the recommendations for growers are made on the possibility of the application of new herbicides in the hybrid seed production.

A glyphosate-based pesticide impinges on transcription

Widely spread chemicals used for human benefits may exert adverse effects on health or the environment, the identification of which are a major challenge. The early development of the sea urchin constitutes an appropriate model for the identification of undesirable cellular and molecular targets of pollutants. The widespread glyphosate-based pesticide affected sea urchin development by impeding the hatching process at millimolar range concentration of glyphosate. Glyphosate, the active herbicide ingredient of Roundup, by itself delayed hatching as judged from the comparable effect of different commercial glyphosate-based pesticides and from the effect of pure glyphosate addition to a threshold concentration of Roundup. The surfactant polyoxyethylene amine (POEA), the major component of commercial Roundup, was found to be highly toxic to the embryos when tested alone and therefore could contribute to the inhibition of hatching. Hatching, a landmark of early development, is a transcription-dependent process. Correlatively, the herbicide inhibited the global transcription, which follows fertilization at the 16-cell stage. Transcription inhibition was dose-dependent in the millimolar glyphosate range concentration. A 1257-bp fragment of the hatching enzyme transcript from Sphaerechinus granularis was cloned and sequenced; its transcription was delayed by 2 h in the pesticide-treated embryos. Because transcription is a fundamental basic biological process, the pesticide may be of health concern by inhalation near herbicide spraying at a concentration 25 times the adverse transcription concentration in the sprayed microdroplets.

The use of cytochrome P450 genes to introduce herbicide tolerance in crops: A review

Mechanisms of herbicide resistance include (1) modified target site, (2) enhanced detoxification or delayed activation, and (3) alterations in the uptake, translocation, or compartmentalization of a herbicide. The first two mechanisms have mainly been identified in plants. Herbicide resistance genes were isolated for several herbicides of different modes of action. Genes that coded for herbicide target or detoxification enzymes were transferred into crop plants. The transgenic plants expressing these genes were tolerant of the active ingredients of herbicides. Before commercialization, the transgenic plants were tested in the field for risk assessment. In the case of crops with herbicide detoxification enzymes, including cytochrome-P450-species-metabolizing xenobiotics, the substrate specificity of the enzymes as well as the toxicological properties of the herbicide metabolites and the pattern of secondary metabolites in plants must be evaluated. © 1999 Society of Chemical Industry

The use of cytochrome P450 genes to introduce herbicide tolerance in crops: a review

Mechanisms of herbicide resistance include (1) modified target site, (2) enhanced detoxification or delayed activation, and (3) alterations in the uptake, translocation, or compartmentalization of a herbicide. The first two mechanisms have mainly been identified in plants. Herbicide resistance genes were isolated for several herbicides of different modes of action. Genes that coded for herbicide target or detoxification enzymes were transferred into crop plants. The transgenic plants expressing these genes were tolerant of the active ingredients of herbicides. Before commercialization, the transgenic plants were tested in the field for risk assessment. In the case of crops with herbicide detoxification enzymes, including cytochrome-P450-species-metabolizing xenobiotics, the substrate specificity of the enzymes as well as the toxicological properties of the herbicide metabolites and the pattern of secondary metabolites in plants must be evaluated. © 1999 Society of Chemical Industry

Determination of aryloxyphenoxypropanoic acid derivatives in crops treated with herbicidal sprays

A reproducible and sensitive gas chromatographic method has been developed for the trace analysis of fluazifop-butyl, haloxyfop-ethoxyethyl and quizalofop-ethyl as well as their main metabolites (corresponding acids analysed after conversion to methyl esters) in some fruits and vegetables treated with herbicidal sprays. Comparable detection limits (0.01 mg/kg) were achieved when mass fragmentography and/or the electron capture detector were employed. However, in the latter case, bromination of fluazifop esters had to be carried out prior to GC analysis. By means of the nitrogen-phosphorus detector, determination of residues at a level of 0.05 mg/kg was possible. The residue values found in strawberries, cabbages, cauliflower and carrots were used to discuss the degree of metabolic hydrolysis of parent esters, i.e. active ingredients of herbicides.