Systemic Herbicide Research Articles

Analytical control of residues of the herbicide trifluralin in the assessment of the food safety

Introduction. Trifluralin is a systemic herbicide of the chemical class of dinitroaniline derivatives. During monitoring studies, trifluralin was detected in carrots produced in the Russian Federation. Since trifluralin-based pesticides are not approved for the use in the Russian Federation, residual amounts of the substance are not typical for this crop. To check the contamination of carrots with a pesticide not typical for this crop, confirmatory qualitative and quantitative studies were carried out. Purpose of the work. Increasing the efficiency of identification and reliability of quantitative results when monitoring food products for safety when performing confirmatory analytical studies using the example of determining trifluralin in carrots to assess the safety of food products intended for the consumer. Materials and methods. Gas chromatography coupled with tandem mass spectrometry (GC-MS/MS) was used to identify and quantify trifluralin. Samples were prepared for analysis using the QuEChERS method. Identification was carried out by multiple reaction monitoring (MRM) using a triple quadrupole mass spectrometer using two to four MRM transitions (m/z): 306,1→264,0; 264,0→206,0; 264,0→188,0; 264,0→160,1. Matrix-matched calibration was used for quantitation. Results. The effectiveness of screening studies when monitoring food products using the GC-MS/MS method can be significantly elevated by increasing the number of MRM transitions (at least 3), controlling the reference retention time of the substance, and maintaining the ratio of confirmatory ions. To obtain a reliable quantification of trifluralin content in carrots, the use of a matrix-matched calibration is recommended. Limitation. In the study, only carrots were considered as food products. Conclusion. Confirmation of test results is especially important when determining pesticide residues that are not normally found in a given matrix, or when it is suspected that the maximum permissible level may be exceeded. When conducting a screening study and detecting a food contaminant, contamination of the product can only be reported in advance. Next, a confirmatory analysis is required using a validated quantitative method, including an appropriate calibration procedure. In quantitative analysis, the presence of matrix sample components can cause problems due to sample suppression/enhancement phenomena. Matrix-aware calibration has been shown to be effective in compensating for matrix effects.

The systemic herbicide glyphosate affects the sporulation dynamics of Rhizophagus species more severely than mechanical defoliation or the contact herbicide diquat.

Arbuscular mycorrhizal fungi (AMF) are totally dependent on a suitable host plant for their carbon resources. Here, we investigated under in vitro conditions, the impact of defoliation practices, i.e., mechanical defoliation or chemical defoliation with a contact herbicide (Reglone®, containing the active ingredient diquat) or systemic herbicide (RoundUp®, containing the active ingredient glyphosate),on the dynamics of spore production of Rhizophagus irregularis and Rhizophagus intraradices associated with Solanum tuberosum and/or Medicago truncatula. Glyphosate affected the spore production rate more rapidly and severely than diquat or mechanical defoliation. We hypothesize that this effect was related to disruption of the C metabolism in the whole plant combined with a possible direct effect of glyphosate on the fungus within the roots and/or perhaps in soil via the release of this active ingredient from decaying roots. No glyphosate could be detected in the roots due to technical constraints, while its release from the roots in the medium corresponded to 0.11% of the active ingredient applied to the leaves. The three defoliation practices strongly affected root colonization, compared to the non-defoliated plants. However, the amount of glyphosate released into the medium did not affect spore germination and germ tube growth. These results suggest that the effects of defoliation on the dynamics of spore production are mainly indirect via an impact on the plant, and that the effect is faster and more marked with the glyphosate-formulation, possibly via a direct effect on the fungus in the roots and more unlikely on spore germination.

Evaluation of Herbicides Efficacy against Weeds in Coffee (<i>Coffea arabica </i>L.) at Jimma Southwest, Ethiopia

Weeds are one of the most serious causes of economic losses in agricultural production. As a result weed completions contributes 60 to 80% yield losses in coffee under Jimma condition. Currently, expensiveness of weed management has been a principle issue in economic analysis of coffee production particularly in large scale farm in Ethiopia. Hence, evaluation of systemic herbicide with different mode of action is essential to effectively control dangerous weeds in coffee production system. The study was conducted in Jimma Agricultural Research Center in 2021 cropping season at Jimma Agricultural Research Center on Station to evaluate the efficacy of newly introduced herbicides (Fascinate 280SL at 3.3l/h, Jimila 480% SL at 3.0l/h and Proper 360 SL at 3.0l/ha) against major weeds in coffee. Tested herbicides (Fascinate 280SL, Jimila 480% SL and Proper 360 SL) were effectively controlled the noxious weeds infested coffee experimental plots. These herbicides also showed significant effect on inhibiting weed density over standard check. The herbicide were effective in controlling weeds in coffee safe for crops if applied at active growth stage of weeds following the instructions on technical guide line of herbicides properly. Therefore, the herbicides were recommended used as management option against weeds in coffee with the application rate mentioned above

Fast and economic method for chlorpropham residues screening in potato peel

Chlorpropham is a selective and systemic herbicide extensively used to control sprouting, a major process affecting the quality of stored potatoes. Main concern about the usage of chlorpropham arises from the fact that chlorpropham degrades to toxic aniline-based metabolites during thermal processing of potatoes. The issue has led to chlorpropham withdrawal from the treatment practices, however, cross contamination from storage facilities requires ongoing monitoring of pesticide residues for a prolonged period. This study offers a fast and economic method suitable for chlorpropham screening in potatoes. The developed method targets the potato peel, simply prepared and analyzed by GC/MS. The method performance and cost-effectiveness were compared to that of the official method for chlorpropham analysis approved by the European Food Safety Authority. The method was used for the targeted analysis of potato samples from southeastern Serbia.

In vitro genomic damage caused by glyphosate and its metabolite AMPA

Glyphosate is the most widely used systemic herbicide. There is ample scientific literature on the effects of this compound and its metabolite aminomethylphosphonic acid (AMPA), whereas their possible combined genotoxic action has not yet been studied. With the present study, we aimed to determine the level of genomic damage caused by glyphosate and AMPA in cultured human lymphocytes and to investigate the possible genotoxic action when both compounds were present at the same concentrations in the cultures. We used a micronuclei assay to test the genotoxicity of glyphosate and AMPA at six concentrations (0.0125, 0.025, 0.050, 0.100, 0.250, 0.500 μg/mL), which are more realistic than the highest concentrations used in previous published studies. Our data showed an increase in micronuclei frequency after treatment with both glyphosate and AMPA starting from 0.050 μg/mL up to 0.500 μg/mL. Similarly, a genomic damage was observed also in the cultures treated with the same concentrations of both compounds, except for exposure to 0.0065 and 0.0125 μg/mL. No synergistic action was observed. Finally, a significant increase in apoptotic cells was observed in cultures treated with the highest concentration of tested xenobiotics, while a significant increase in necrotic cells was observed also at the concentration of 0.250 μg/mL of both glyphosate and AMPA alone and in combination (0.125 + 0.125 μg/mL). Results of our study indicate that both glyphosate and its metabolite AMPA are able to cause genomic damage in human lymphocyte cultures, both alone and when present in equal concentrations.

The ability of photochemical decomposition products of the Roundup to induce oxidative stress in bacterial cells

BACKGROUND: A common non-selective systemic herbicide Roundup (Glyphosate, active ingredient N-phosphonomethylglycine, N-PMG) is used to control perennial weeds. It is necessary to assess the hazard of the products of photochemical decomposition of N-FMG formed under the influence of solar UV and ozone. AIM: Using lux-biosensors based on Escherichia coli, studying the ability of N-FMG photochemical degradation products to induce oxidative stress in bacterial cells. MATERIALS AND METHODS: The work used the active substance of the herbicide Roundup N-phosphonomethylglycine (N-PMG), biosensors E. coli (pSoxS-lux), E. coli (pKatG-lux). UV radiation, Mass spectrometry. RESULTS: Using biosensors, it was shown that the products of photochemical decomposition of N-PMG (2-(N-hydroxymethyl-hydroxyamine) ethanoic acid) cause an increase in the concentration of superoxide anion radical and H2O2 in E. coli cells, which induces oxidative stress in the bacterial cell. CONCLUSIONS: The photochemical decomposition product of N-PMG (2-(N-hydroxymethyl-hydroxyamine) ethanoic acid) induces the formation of superoxide anion radical and H2O2 in bacterial cells.

Влияние фосфорсодержащих пестицидов на ферментативную активность и множественные формы кислой фосфатазы живородки речной (Viviparus viviparus L.)

Organophosphate pesticides are used in agriculture and for treating landscape and park areas due to their high efficiency and economic availability, and therefore they are potential toxicants in water bodies. Broad-spectrum systemic herbicide (Glyphosate) and an organophosphorus insecticide (Malathion) have been studied against the freshwater mollusks (Viviparus viviparus L.), widespread in permanent water bodies of the European part of Russia and Siberia. Changes in the activity and composition of multiple forms of acid phosphatase (AcP) were revealed in the hepatopan creas of mollusks under the influence of high doses of glyphosate and malathion in an acute toxicological experiment (96 hours). In both cases, an increase in enzyme activity is observed, but the cholinomimetic malathion is significantly more active than glyphosate, the neurotropic activity of which is unknown. It was shown that the increase in activity in the experimental groups of mollusks is associated with the appearance of new multiple forms of acid phosphatase, which persist throughout the experiment. Multiple form of AсP with low relative electrophoretic mobility revealed as an effect of glyphosate and malathion. In addition, in mollusks exposed to malathion, a multiple form of the enzyme with an average electrophoretic mobility was detected. The composition of multiple forms of acid phosphatase in mollusks of the control group did not change during the exposure. The results indicate the formation of nonspecific adaptations in response to organophosphate pesticides and confirm that acid phosphatase can be an indicator of toxic effects in environmental and biochemical monitoring of freshwater pollution.

The influence of herbicide systems and methods of basic tillage on grain productivity of peas in the conditions of the steppe zone of Kabardino-Balkaria

The influence of herbicide systems and methods of basic tillage on grain productivity of peas in the conditions of the steppe zone of Kabardino-Balkaria

Injection-based approaches for controlling Douglas-fir (Pseudotsuga menziesii) invasion in conservation efforts of the Patagonian forest

Abstract Invasion by nonnative woody species poses a major threat to the environment, biodiversity, and economies worldwide. Nahuel Huapi National Park in Argentina is a protected area for habitat conservation that harbors several invasive Pinaceae species, where Douglas-fir [Pseudotsuga menziesii (Mirb.) Franco] is one of the most aggressive and abundant conifer tree invaders. Management of invasions in protected areas must include efficient, easy to deploy, and cost-effective techniques, while reducing the impact on native ecosystems. Because the region has no control measures applied other than conventional felling, we analyzed the effectiveness of two systemic herbicides (glyphosate and aminopyralid + triclopyr) at two different concentrations, applied with the drill and fill method. We then quantified defoliation of P. menziesii trees 6, 12, and 24 mo after application and performed an economic cost analysis to determine profitability. For the application, the trees were grouped into diameter at breast height classes and randomly assigned to one of the four treatments. Herbicide doses were adjusted according to tree size. We found that glyphosate at high concentrations completely defoliated 33% of the trees after 6 mo and 87% after 12 and 24 mo. Glyphosate at low concentrations defoliated almost 30% of the trees after 24 mo, most of which were smaller trees. The aminopyralid + triclopyr treatment did not produce significant defoliation at any of the tested concentrations. When compared with conventional felling, the drill and fill method was found to reduce removal costs by 98%. We observe that differences in costs are mainly due to dead trees that remain standing, decompose slowly, and do not generate costs associated with their removal and debris management. Drill and fill is a suitable method for treating scattered trees in a native forest community, with reduced environmental consequences compared with other removal techniques currently applied within conservation areas of the Patagonian forest.

Gamma irradiation was able to degrade the glyphosate and aminomethylphosphonic acid (AMPA) from drinking water analyzed by LC-MS/MS

Glyphosate is the most widely used systemic herbicide in the world, applied post-emergence to control weeds and is non-selective. However, due to its toxicity to aquatic organisms and high persistence in water, it is necessary to conduct studies on the decontamination of water resources with glyphosate residues and its metabolite aminomethylphosphonic acid (AMPA). The objective of this study was to evaluate the degradation of glyphosate and AMPA in drinking water using gamma irradiation. First, the drinking water sample was found to be free of the herbicide and its metabolite, and then three concentrations of glyphosate and AMPA alone were added (0.5, 5.0, and 50.0 mg L−1). The samples were then exposed to different doses of gamma irradiation (0, 0.5, 1.0, 2.5, 5.0, and 10 kGy) in a cobalt-60 (60Co) source. The procedure was performed at room temperature with a dose of 0.08 kGy h−1 from the irradiator (source power: 215.95 Ci). Glyphosate and AMPA were quantified by Liquid Chromatography coupled to tandem Mass Spectrometry (LC-MS/MS). A pseudo-first order model was fitted from the kinetic study of the degradation of the chemicals. The irradiation doses required to degrade 50% of glyphosate (D0.5 = 8.97, 12.03, and 9.73 kGy) and the value for complete degradation (90%) of the herbicide (D0.9 = 29.82, 39.97, and 32.34 kGy), as the value of the dose constant (k), were 0.0772, 0.0576, and 0.0712 kGy−1 at concentrations of 0.5, 5.0, and 50.0 mg L−1, respectively. The increase in gamma irradiationgradually decreased of glyphosate and AMPA in drinking water. Thus, this study showed that the use of gamma irradiation can decontaminate drinking water with glyphosate and AMPA residues and be used in treatment plants, but it is necessary to use higher doses of radiation.

Short-term immunotoxicity induced by florpyrauxifen-benzyl herbicide exposure in the spleen of male albino mice.

Florpyrauxifen-benzyl (FPB)is a new arylpicolinate systemic herbicide that has been used to control or suppress the majority of herbicide-resistant biotype weeds in rice. To our knowledge, the impact of FPB on the immune system remains undetected thus far. Hence, this work aimed to address the toxic effects of FPB and the possible related mechanisms on the spleen of exposed mice. Initially, an acute toxicological test was performed to ascertain the median lethal dose (LD50) of FPB for 24 h which was found to be 371.54 mg/kg b.wt. For mechanistic evaluation of FPB toxicity, three sublethal doses (1/20th, 1/10th, and 1/5thLD50) were orally administered to mice for 21 consecutive days. Changes in spleen relative weight, oxidative status, apoptotic and inflammatory markers, histopathological alterations were evaluated. Following the FPB exposure, significant (p < 0.05) decline in spleen index, apoptotic features, histolopathological changes were observed. Additionally, excessive oxidative stress in spleen tissues was monitored by downregulating antioxidant enzymes and upregulating the oxidant parameters. Furthermore, exposure to FPB resulted in notable activation of the NF-қB signaling pathway, accompanied by elevated levels of pro-inflammatory cytokines (namely, IL-1βand TNF-α)as well as CD3 and CD19 levels have decreased significantly in spleen tissues. Collectively, FPB exposure exhibited apoptosis, oxidative stress, immunosuppression, and inflammatory response in a dose-dependent manner, leading to spleen tissue damage and immunotoxicity. Further studies on FPB is recommended to outstand its hazards on ecosystems.

In vitro effects of two environmental toxicants, beauvericin and glyphosate in Roundup, on cell numbers and steroidogenesis of bovine ovarian cells.

Beauvericin is an emerging Fusariotoxin naturally occurring in cereal grains throughout the world whereas glyphosate (N-phosphonomethyl-glycine) is a non-selective systemic herbicide used worldwide. The purpose of this study is to evaluate a newly developed ovarian cell culture system (that includes both granulosa and theca cells) as an in vitro model for toxicological studies. Specifically, the effects of beauvericin and glyphosate in formulation with Roundup on ovarian cell numbers and steroid production were evaluated. Ovaries collected from cattle without luteal structures were sliced into 30-70 pieces each, and granulosa and theca cells were collected. Harvested cells were cultured for 48h in 10% fetal bovine serum-containing medium followed by 48h in serum-free medium containing testosterone (500 ng/mL; as an estrogen precursor) with the following eight treatments: (1) controls, (2) FSH (30 ng/mL) alone, (3) FSH plus insulin-like growth factor-1 (IGF1; 30 ng/mL), (4) FSH plus IGF1 plus beauvericin (3 µM), (5) FSH plus IGF1 plus glyphosate in Roundup (10µg/mL), (6) FSH plus IGF1 plus fibroblast growth factor 9 (FGF9, 30 ng/mL), (7) a negative control without added testosterone, and (8) IGF1 plus LH (30 ng/mL) with basal medium without added testosterone. In the presence of FSH, IGF1 significantly increased cell numbers, estradiol and progesterone production by severalfold. Glyphosate in Roundup formulation significantly inhibited IGF1-induced cell numbers and estradiol and progesterone production by 89-94%. Beauvericin inhibited IGF1-induced cell numbers and estradiol and progesterone by 50-97% production. LH plus IGF1 significantly increased androstenedione secretion compared with controls without added testosterone indicating the presence of theca cells. In conclusion, the present study demonstrates that toxicological effects of beauvericin and glyphosate in Roundup formulation are observed in a newly developed ovarian cell model system and further confirms that both glyphosate and beauvericin may have the potential to impair reproductive function in cattle.

Ecotoxicity studies reveal that organic cations in dicamba-derived ionic liquids can pose a greater environmental risk than the herbicide itself

The following research provides novel and relevant insights into potential environmental consequences of combination of various organic cations with commercial systemic herbicide (dicamba), in accordance with a ‘herbicidal ionic liquids’ (HILs) strategy. Toxicity assays of five dicamba-based HILs comprising different hydrophobic and hydrophilic cations, namely choline [CHOL][DIC], ethyl betainate [BETC2][DIC], decyl betainate [BETC10][DIC], hexadecyl betainate [BETC16][DIC] and didecyldimethylammonium [DDA][DIC]), have been tested towards bacteria (Pseudomonas putida, Escherichia coli, Bacillus subtilis), algae (Chlorella vulgaris), fresh and marine water crustaceans (Daphnia magna, Artemia franciscana). The structure of respective substituents in the cation emerged as a decisive determinant of toxicity in the case of tested species. In consequence, small ions of natural origin ([CHOL] and [BETC2]) demonstrated toxicity numerous orders of magnitude lower compared to fully synthetic [DDA]. These results emphasize the role of cations' hydrophobicity, as well as origin, in the observed acute toxic effect. Time-dependent toxicity assays also indicated that betaine-type cations comprising an ester bond can rapidly transform into less harmful substances, which can generally result in a reduction in toxicity by even several orders of magnitude. Nonetheless, these findings challenge the concept of ionic liquids with herbicidal activity and give apparent parallels to adjuvant-dependent toxicity issues recently noted in typical herbicidal formulations.

Glyphosate- and aminomethylphosphonic acid (AMPA)-induced mortality and residues in juvenile brown trout (Salmo trutta f. fario) exposed at different temperatures

BackgroundGlyphosate is a broad-spectrum, non-selective systemic herbicide with a commonly assumed low potential for accumulation in biota. Nevertheless, glyphosate has been shown to bioaccumulate in the tissues of several organisms. To understand the bioconcentration dynamics of glyphosate in fish, brown trout (Salmo trutta forma fario) of different age were exposed to different concentrations of glyphosate, the formulation Roundup® LB Plus, and the major transformation product aminomethylphosphonic acid (AMPA) for two, three, or four weeks at different temperatures in the laboratory. Mortality rates were determined, and tissue samples were collected at the end of the experiment to ascertain concentrations of glyphosate and AMPA residues by liquid chromatography coupled to mass spectrometry (LC–MS/MS).ResultsBrown trout mortality during exposure to glyphosate or AMPA was considerably higher at 15 °C than at 7 °C. Also, a significant increase in glyphosate concentrations in samples containing muscle, head, backbone, and caudal fin tissue with increasing exposure concentrations and temperatures was observed. Six-month-old fish contained more glyphosate per kg wet weight after exposure than ten-month-old fish. The bioconcentration factors (BCFs) for glyphosate and AMPA were much higher at 15 °C than at 7 °C, but in both cases decreased with higher glyphosate concentrations. The BCF for glyphosate formulated in Roundup® was higher than the one for the parent compound. Approximately 30–42% of the organ-absorbed glyphosate and AMPA remained in the tissues even when the fish were kept in clean water lacking the test substances for three weeks after termination of exposure.ConclusionOur study demonstrated that there is an interaction between glyphosate and ambient temperature in terms of toxicity. Further it was shown that increasing concentrations of glyphosate and AMPA in the surrounding media lead to significantly increased concentrations of these substances in brown trout tissues, although neither bioconcentration nor bioaccumulation of glyphosate in animal tissues is expected due to the high water solubility of this chemical. As a consequence, the uptake of glyphosate by humans through the consumption of contaminated edible fish is very likely.

Exploration of the intermolecular isoproturon–bovine serum albumin combination: Biophysical and computational prospects

Isoproturon (IPU), a selective systemic herbicide that is frequently applied to eradicate large-leaved weeds and annual grasses in agricultural fields. However, the accumulation of IPU residues during food production might negatively affect on human and animal health. To comprehend the impact of IPU on the mankind and environment, the interaction analysis of IPU with plasma protein is crucial. This work used a variety of techniques, including fluorescence, UV–vis absorption, computational docking and dynamics simulation to extensively examine the combination of IPU with bovine serum albumin (BSA) under typical physiological settings. IPU quenched the BSA fluorescence and form the IPU–BSA complex through a static process. A weak binding affinity was anticipated (binding constant = 4.68–2.48 × 103 M−1) for IPU–BSA interaction. Thermodynamic results revealed that the IPU–BSA binding reaction was a spontaneous process, predominantly governed by hydrogen bonds, van der Waals and hydrophobic forces, which was well supported by molecular docking analysis. Synchronous and three-dimensional fluorescence spectral results exhibited microenvironmental fluctuations near the protein’s Trp and Tyr residues with added IPU, but inclusion of IPU to BSA was observed to enhance the protein’s thermal constancy. Site marker displacement results demonstrated that IPU desirably binds to BSA at site II. An in silico findings also unveiled the primary binding arrangement of IPU was placed at site II of BSA and surrounded by hydrophobic and polar residues. Molecular dynamics simulation results suggested the IPU–BSA complex persisted compact and stable.

Gestational glyphosate exposure and early childhood neurodevelopment in a Puerto Rico birth cohort

IntroductionN-(phosphonomethyl)glycine, or glyphosate, is a non-selective systemic herbicide widely used in agricultural, industrial, and residential settings since 1974. Glyphosate exposure has been inconsistently linked to neurotoxicity in animals, and studies of effects of gestational exposure among humans are scarce. In this study we investigated relationships between prenatal urinary glyphosate analytes and early childhood neurodevelopment. MethodsMother-child pairs from the PROTECT-CRECE birth cohort in Puerto Rico with measures for both maternal urinary glyphosate analytes and child neurodevelopment were included for analysis (n = 143). Spot urine samples were collected 1–3 times throughout pregnancy and analyzed for glyphosate and aminomethylphosphonic acid (AMPA), an environmental degradant of glyphosate. Child neurodevelopment was assessed at 6, 12, and 24 months using the Battelle Developmental Inventory, 2nd edition Spanish (BDI-2), which provides scores for adaptive, personal-social, communication, motor, and cognitive domains. We used multivariable linear regression to examine associations between the geometric mean of maternal urinary glyphosate analytes across pregnancy and BDI-2 scores at each follow-up. Results were expressed as percent change in BDI-2 score per interquartile range increase in exposure. ResultsPrenatal AMPA concentrations were negatively associated with communication domain at 12 months (%change = −5.32; 95%CI: 9.04, −1.61; p = 0.007), and communication subdomain scores at 12 and 24 months. At 24 months, four BDI-2 domains were associated with AMPA: adaptive (%change = −3.15; 95%CI: 6.05, −0.25; p = 0.038), personal-social (%change = −4.37; 95%CI: 7.48, −1.26; p = 0.008), communication (%change = −7.00; 95%CI: 11.75, −2.26; p = 0.005), and cognitive (%change = −4.02; 95%CI: 6.72, −1.32; p = 0.005). Similar trends were observed with GLY concentrations, but most confidence intervals include zero. We found no significant associations at 6 months. ConclusionsOur results suggest that gestational exposure to glyphosate is associated with adverse early neurodevelopment, with more pronounced delays at 24 months. Given glyphosate's wide usage, further investigation into the impact of gestational glyphosate exposure on neurodevelopment is warranted.

Effectiveness of herbicides against the volunteer plants of imidazolinone-resistant sunflower in oil flax sowings

In 2020-2021, we conducted research on the effect of herbicides on oil flax productivity and volunteer plants of imidazolinone-resistant sunflower in oil flax sowings. We used the contact herbicide Basagran, AS (a.i. bentazon, 480 g/l) and the systemic herbicides Tifi, WDG (a.i. thifensulfuron-methyl, 750 g/kg), Cleo, WDG (a.i. clopyralid, 750 g/kg), Magnum, WDG (a.i. metsulfuron-methyl, 600 g/kg), Zellek-super, EC (a.i. haloxyfop-P-methyl,104 g/l), Miura, EC (a.i. quizalofop-P-ethyl,125 g/l), Sekator Turbo, OD (a.i. amidosulfuron, 100 g/l + iodosulfuron-methyl-sodium, 25 g/l + mefenpyr-diethyl, 250 g/l). We evaluated the phytotoxicity of the herbicides on the volunteer plants using a 9-point EWRC scale. We found that the of Basagran, AS (4.0 l/ha) + Zellek-super, EC (1.0 l/ha) + Cleo, WDG (0.12 kg/ha) provides the effective control of the volunteer plants and contributes to the stable high indicators of oil flax productivity.

Integrating cover crops and herbicides for weed control in soybean

Abstract In mid-southern, southeastern, and northeastern U.S. soybean production regions, the evolution of herbicide-resistant weeds has become a significant management challenge for growers. The rising herbicide costs for managing herbicide-resistant weeds are also a growing concern, leading to the utilization of cover crops as an integrated weed management strategy for addressing these challenges. Field experiments were conducted at two locations in Alabama in 2022 to evaluate winter cereal cover crops, including a mixture and herbicide system integration in soybean. Treatments included five cover crops: oats, cereal rye, crimson clover, radish, and a cover crop mixture. Cover crops were evaluated for their weed-suppressive characteristics compared to a winter fallow treatment. Additionally, four herbicide treatments were applied: a preemergence (PRE) herbicide, a postemergence (POST) herbicide, PRE plus POST herbicides, and a nontreated (NT) check. The PRE herbicide was S-metolachlor; the POST treatment contained a mixture of dicamba and glyphosate. The PRE plus POST system contained the PRE application followed by POST application. Results show that cereal rye and the cover crop mixture provided weed biomass reduction compared to all cover crop treatments across both locations. Furthermore, we observed greater soybean yield following the cereal rye cover crop than following the winter fallow treatment at one location. POST and PRE plus POST herbicide treatment resulted in greater weed biomass reduction and improved soybean yield than the PRE herbicide treatment alone and the NT check at both locations.

Herbicides weed management in changing environmental conditions

Elevate CO2 levels in the atmosphere might have prominent effects on weed phenology, consequently changing herbicide performance on weeds. Increased atmospheric CO2 concentration increase leaf thickness and reduce stomatal number and conductance potentially reducing the absorption of POST–emergence applied herbicides. From the other side, higher temperature stimulates stomata conductance, reduce the viscosity of epicuticle waxes, thus increasing the penetration and diffusion of herbicides as a result of changes in the composition and the permeability of the cuticle. However, in some circumstances higher temperatures might cause hastened metabolism, which consequently decreases herbicide activity on target plants. In conditions of higher RH, cuticle hydration and stomatal conductance increases, consequently increases the permeability and translocation particularly of hydrophilic herbicides into the leaves. Similar, under higher irradiance, stomata stay open, photosynthetic rate increases consequently increasing absorption, penetration and subsequent phloem translocation of POST–em systemic herbicides in weed tissue. Drought might cause increased cuticle thickness and increased leaf pubescence, with consequent reductions in herbicide absorption into the leaves. Rainfall after POST–emergence herbicides application might reduce their efficiency through washing out. Increased frequency and intensity of precipitation will have a negative effect on absorption, translocation, and activity of PRE–emergence herbicides.

Determination of the efficiency and intensity of the phytotoxic effect of herbicides in winter cereal crops

Research on the study of the effective use of herbicides, and subsequently their effect directly on the plants of agricultural crops, is an urgent task in both agroecology and agronomy. Ago, the study was conducted to determine the effectiveness and intensity of the phytotoxic effect of one- and twocomponent systemic herbicides in winter wheat crops in the field conditions, on the Skvyra Experimental Station of Organic Production (SESOP) in the city of Skvyra, during October — December 2022, in the phase of VVSN 13–20 (before the tillering phase). The effectiveness of herbicides was determined on the 23rd day after spraying of the crops. Therefore, the preparation with the active ingredient 2,4-d, 2-ethyl hexyl ester 300 g/l + iodosulfuron methyl sodium 15 g/kg, in the consumption rate of 0.7 l/ha for 21 days after spraying wheat had an efficiency of 65.8 — 83,0 which was the highest among the studied variants. After spraying the crops and studying the effectiveness of of herbicides, the intensity of phytotoxic effects of the preparations on winter wheat was determined. The herbicide variant with the highest phytotoxicity on plants was tribenuron-methyl, 102.5 g/kg + dicamba, 659 g/kg at a consumption rate of 20.0 g/ha. It was showed that on the 7th day after application, the intensity of phytotoxicity was 12.02%, and on 21st day after application — 7.14%. The phytotoxic effect of the herbicide with the active substance aclonifen 520 g/kg at a consumption rate of 2.0 l/ha, on wheat plants, which was 9.16% on 7th day after application and 4.80% — on the 21st day after application. In the variants where the abovementioned preparations were applied, yellowing of the leaves, curling of the leaf edges (single), and minor necrosis on the tops of the leaves were observed. It has been proved that on the scale of phytotoxicity, all the studied herbicides had a barely noticeable degree of phytotoxicity — 10%, which corresponded to 1 point.