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Phytotoxicity refers to the capacity of chemical substances or environmental factors to have a negative impact on plants. This is a crucial issue in both the context of crop cultivation and environmental protection. The research results were based on a 3-year field experiment conducted at an experimental station in Jadwisin (52°28′ N, 21°02′ E) on loamy soil. The experiment was set up using a randomized sub-block design in a split–split–plot arrangement with three replications. The first-order factor consisted of potato cultivars, while the second-order factors were weed control methods: (1) without protection; (2) mechanical weed control, extensive mechanical treatments to close rows; (3) Sencor 70 WG—pre-emergence (PRE) of potatoes; (4) Sencor 70 WG + Titus 25 WG + Trend 90 EC—PRE of potatoes; (5) Sencor 70 WG—post-emergence (POST) of potatoes; (6) Sencor 70 WG + Titus 25 WG + Trend 90 EC—POST of potatoes; (7) Sencor 70 WG + Fusilade Forte 150 EC—POST of potatoes; and (8) Sencor 70 WG + Apyros 75 WG + Atpolan 80 SC—POST of potatoes. The phytotoxic effects of herbicides on potato plants and weeds were assessed every 7 days, starting from the date when the first signs of damage appeared until they stabilized or disappeared. Phytotoxic damage to potato and weed plants was caused by the chemical weed control methods used. The response of potato plants to herbicides was significantly related to the genetic traits of the cultivars and meteorological conditions in the years of research. Phytotoxicity is an important aspect in both agriculture and environmental protection. Research on its mechanisms and impact will enable the development of effective plant protection strategies and the preservation of ecosystem balance. [ABSTRACT FROM AUTHOR]

We characterized the chemical compounds present in the extract of dry leaves from Duranta erecta L. using ESI-MSn mass spectrometry and assessed their phytotoxic potential on Lactuca sativa L.. The extraction process involved exhaustive extraction with 50% ethanol, and the resulting extracts were subsequently dried through lyophilization. Solutions of 2.5, 5, 10, 20, and 40 mg/mL concentrations were prepared from the dried extracts to investigate their allelopathic effects on L. sativa, focusing on germination, germination speed, root elongation, shoot length, and fresh biomass. Statistical analysis was performed using Analysis of Variance, and means were compared using the Scott-Knott test (p < 0.05). The ESI-MSn analysis identified a total of 20 compounds in the extract, with 12 of them being reported for the first time in Duranta sp. Our findings suggest that D. erecta possesses allelopathic potential, as evidenced by its cytotoxicity, mitodepressive effects, and phytotoxicity on germination and morphological parameters in the bioassay conducted with L. sativa. [ABSTRACT FROM AUTHOR]

Wildflowers attract wildlife, increase pollinator habitat, and enhance the aesthetic value of the landscape. Wildflower establishment is increasingly part of an effort to reduce maintained turfgrass on golf courses, lawns, and other maintained environments. Weed competition decreases wildflower establishment and results in poor long-term stands. Research was conducted in a controlled environment to investigate the tolerance of wildflower species to common postemergence herbicides. Wildflower species included California poppy (Eschscholzia californica Cham.), common sunflower (Helianthus annuus L.), cornflower (Centaurea cyanus L.), garden coreopsis (Coreopsis lanceolata L.), partridge pea [Chamaecrista fasciculata (Michx.) Greene], plains coreopsis (Coreopsis tinctoria Nutt.), purple coneflower [Echinacea purpurea (L.) Moench], rosering gaillardia (Gaillardia pulchella Foug.), and violet prairie clover (Dalea purpurea Vent.). Herbicides evaluated were fluazifop at 0.28 kgha-1 a.i., mesotrione at 0.14 kgha-1 a.i., clopyralid at 0.29 kgha-1 a.i., bentazon at 0.56 kgha-1 a.i., halosulfuron at 0.053 kgha-1 a.i., and imazaquin at 0.42 kgha-1 a.i. An untreated check was included for comparison. Excessive damage ($ 53% phytotoxicity) was observed on all wildflower species in response to clopyralid, except for California poppy. Fluazifop and bentazon were relatively safe (# 19% phytotoxicity, regardless of herbicide) on all wildflower species; however, bentazon resulted in $ 40% aboveground biomass reduction in several species. Common sunflower and garden coreopsis were susceptible to halosulfuron (37% and 73% phytotoxicity, respectively) and imazaquin (37% and 87% phytotoxicity, respectively), but on all other wildflower species, phytotoxicity was # 18%. Although both halosulfuron and imazaquin only resulted in # 18% phytotoxicity to purple coneflower, a 43% to 44% aboveground biomass reduction was recorded. Mesotrione was only safe on California poppy and cornflower (# 11% phytotoxicity and # 24% aboveground biomass reduction). Results suggest high tolerance variability across herbicides and species considered, but may prompt new investigation of safety and utility within field and production scenarios. [ABSTRACT FROM AUTHOR]

Ammonium sensitivity is considered a globally stressful condition that affects overall crop productivity. The major toxic symptom associated with ammonium nutrition is growth retardation, which has been associated with a high energy cost for maintaining ion, pH, and hormone homeostasis and, eventually, the NH3/NH4+ level in plant tissues. While certain species/genotypes exhibit extreme sensitivity to ammonium, other species/genotypes prefer ammonium to nitrate as a form of nitrogen. Some of the key tolerance mechanisms used by the plant to deal with NH4+ toxicity include an enhanced activity of an alternative oxidase pathway in mitochondria, greater NH4+ assimilation plus the retention of the minimum level of NH4+ in leaves, and/or poor response to extrinsic acidification or pH drop. Except for toxicity, ammonium can be considered as an energy-efficient nutrition in comparison to nitrate since it is already in a reduced form for use in amino acid metabolism. Through effective manipulation of the NH4+/NO3 − ratio, ammonium nutrition can be used to increase productivity, quality, and resistance to various biotic and abiotic stresses of crops. This review highlights recent advancements in ammonium toxicity and tolerance mechanisms, possible strategies to improve ammonium tolerance, and omics-based understanding of nitrogen use efficiency (NUE) in plants. [ABSTRACT FROM AUTHOR]

Silver nanoparticles (AgNPs) are noteworthy used nanomaterials in a wide array of fields, particularly in the agricultural sector. Plants play a multifarious role in the ecosystem and provide a source of food for mankind. The responsibility of the scientific community is to recognize the deleterious impact of AgNPs (1–100 nm in size) on critical crop growth and development of plants, which is required for the assessment of environmental threats to plant, human, and animal health. The continued use of AgNPs in agriculture areas may have negative effects on plant biochemical and physiological responses. The current context focused mainly on AgNPs uptake, transport, and accumulation on crop plants and summarizes different levels of phytotoxicity of AgNPs on plant functions and focused on mechanisms of phytotoxicity employed by AgNPs. Moreover, some tolerance mechanisms and various survival strategies developed by plants under AgNPs toxicity are discussed. This background provides comprehensive information necessary to facilitate profound understanding of the toxic impacts of AgNPs on crop plants. [ABSTRACT FROM AUTHOR]

• The effects of PS on HTAP characteristics and phytotoxicity were studied. • PS can significantly improve the humification index of HTAP. • PS reduced the proportions of aldehydes, ketones, and N-heterocyclic compounds in HTAP. • PS can reduce the phytotoxicity of HTAP. Hydrothermal technology (HT) has received much attention in recent years as a process to convert wet organic waste into hydrochar. The aqueous phase (HTAP) produced by this process is still a burden and has become a bottleneck issue for HT process development. In this study, we provide the first investigation of the HTAP characteristics, phytotoxicity, and their correlation with persulfate (PS) (PS, 2.0 mmol/g TS)-assisted municipal sludge HT. The results showed that PS accelerated the hydrolysis of protein substances and increased the concentration of NH 4 + by 13.4% to 190.5% and that of PO 4 3− by 24.2% to 1103.7% in HTAP at hydrothermal temperatures of 120 to 240 °C. PS can reduce the phytotoxicity of HTAP by reducing aldehydes, ketones, N heterocyclic compounds, and particle size and by increasing its humification index. The maximum values of the root length and biomass of pakchoi (Brassica chinensis L.) seedlings occurred when electrical conductivity was 0.2 mS/cm of HTAP. This work provided a new strategy for the selection and design of HTAP management strategies. [Display omitted] [ABSTRACT FROM AUTHOR]

Herbicides based formulations are conventionally used as wettable powder or as Emulsifiable concentrate. The Emulsifiable Concentrates (EC) are prepared by mixing the active content with solvents and surfactants. However, these formulations have undesirable phytotoxic effects due to hazardous solvent and are unsafe to operators during application. Thus, capsule suspension (CS) formulation is considered as an alternative to EC formulations. In this study, we report the preparation of CS formulation of herbicide oxyfluorfen by polymerizing Methylene diphenyldiisocyanate (MDI) and Ethylenediamine (EDA). Water suspensions of the oxyfluorfen microcapsules were prepared by adding anionic, nonionic, polymeric surfactants and formulation auxiliaries. The study also aimed to determine the effect of surfactant on the stability of the microcapsule suspension. It was found that the nature of surfactant influenced the properties of the formulation. The synthesized microcapsules were characterized by Scanning electron microscope (SEM), Fourier Transform Infrared (FTIR) spectroscopy and thermogravimetric analysis (TGA). The microcapsule suspensions were applied on rice crop to establish the safety and its future use instead of oxyfluorfen EC. [ABSTRACT FROM AUTHOR]

Sugarcane expansion has been associated with soil contamination by agrochemicals. Pesticides can affect plant growth, and their mixture might have potentiated effects on exposed species. This research aimed to evaluate the influence of fipronil on the phytotoxicity of 2,4-D on three green manure plant species: Canavalia ensiformis, Dolichos lablab, and Lupinus albus. Plants were exposed (for 21 days, at 25 °C) to a control soil and five concentrations of each pesticide and their combinations (36 treatments, considering a full-factorial approach). Effect concentrations of 50% growth inhibition (EC50) were estimated. No phytotoxicity effects were identified when plants were exposed to different fipronil concentrations (up to 0.12 mg kg−1). All species exposed to 2,4-D showed a decrease in shoot and root length and fresh/dry biomass. L. albus and D. lablab roots showed the highest sensitivity when exposed to 2,4-D among the endpoints (EC50 = 0.02 and 0.05 mg kg−1, respectively), while C. ensiformis roots were the most tolerant (EC50 = 0.98 mg kg−1). However, the interference of fipronil on the toxicity of 2,4-D was not detected in different mixture proportions, indicating no interaction between pesticides. Residues of 2,4-D might also impair other crops' growth, compromise productivity, and limit phytotechnologies for soil recovery. [ABSTRACT FROM AUTHOR]

Photooxidative removal of pharmaceuticals and organic dyes is an effective way to eliminate growing micropollutants. However, photooxidation often results in byproducts as secondary hazardous substances such as phytotoxins. Herein, we found that photooxidation of common antibiotic tetracycline hydrochloride (TCH) over a metal-free 8-hydroxyquinoline (8-HQ) functionalized carbon nitride (CN) photocatalyst significantly reduces the TCH phytotoxic effect. The phytotoxicity test of photocatalytic treated TCH-solution evaluated towards seed growth of Cicer arietinum plant model endowed natural root and shoot growth. This study highlights the conceptual insights in designing of metal-free photocatalyst for environmental remediation. [Display omitted]. [ABSTRACT FROM AUTHOR]

Unexpected bioaccumulation and biomagnification of heavy metal(loid)s (HMs) in the environment have become a predicament for all living organisms, including plants. The presence of these HMs in the plant system raised the level of reactive oxygen species (ROS) and remodeled several vital cellular biomolecules. These lead to several morphological, physiological, metabolic, and molecular aberrations in plants ranging from chlorosis of leaves to the lipid peroxidation of membranes, and degradation of proteins and nucleic acid including the modulation of the enzymatic system, which ultimately affects the plant growth and productivity. Plants are equipped with several mechanisms to counteract the HMs toxicity. Among them, seed priming (SP) technology has been widely tested with the use of several inorganic chemicals, plant growth regulators (PGRs), gasotransmitters, nanoparticles, living organisms, and plant leaf extracts. The use of these compounds has the potential to alleviate the HMs toxicity through the strengthening of the antioxidant defense system, generation of low molecular weight metallothionein's (MTs), and phytochelatins (PCs), and improving seedling vigor during early growth stages. This review presents an account of the sources, uptake and transport, and phytotoxic effects of HMs with special attention to different mechanism/s, occurring to mitigate the HMs toxicity in plants employing SP technology. Novelty statement: To the best of our knowledge, this review has delineated the consequences of HMs on the crucial plant processes, which ultimately affect plant growth and development. This review also compiled the up to dated information on phytotoxicity of HMs through the use of SP technology, this review discussed how different types of SP approaches help in diminishing the concentration HMs in plant systems. Also, we depicted mechanisms, represent how HMs transport and their actions on cellular levels, and emphasized, how diverse SP technology effectiveness in the mitigation of plants' phytotoxicity in unique ways. [ABSTRACT FROM AUTHOR]

Polyvinyl chloride microplastics (PVC-MPs) are toxic to crops, resulting in economic losses during agricultural production. Owing to its strong adsorption capacity, biochar can effectively remove MPs from water. It is presumed that biochar can alleviate the phytotoxicity of PVC-MPs. To verify this hypothesis, the effects of different concentrations of corncob biochar (CCBC) on the phytotoxicity of PVC-MPs were investigated using hydroponic experiments. The results showed that PVC-MPs attached to lettuce roots substantially inhibited the growth and quality of lettuce. The tested CCBC adsorbed the PVC-MPs. At appropriate concentrations, CCBC alleviated the inhibitory effect of PVC-MPs on lettuce yield; however, it decreased some quality indicators. The single PVC-MPs induced oxidative damage to lettuce, as demonstrated by the increased hydrogen peroxide (H 2 O 2) and malondialdehyde (MDA) content. Addition of CCBC considerably decreased the contents of H 2 O 2 and MDA in the lettuce shoots but increased the H 2 O 2 content in the roots. These findings indicate that CCBC may alleviate the adverse effects caused by PVC-MPs to the lettuce shoots but aggravate the toxic effects on the lettuce roots. This study provides a basis for understanding the removal of the phytotoxicity of MPs. [Display omitted] • CCBC can adsorb PVC-MPs. • CCBC alleviated the adverse effect of PVC on lettuce yield but reduced its quality. • In the co-exposed treatments, CCBC reduced ROS and MDA content in the shoots. • CCBC aggravated the toxic effect of PVC on lettuce roots. [ABSTRACT FROM AUTHOR]

• Phytotoxicity of BDE-28, BDE-47 and BDE-99 to maize (Zea mays L.) during germination and early growth was studied. • PBDEs inhibited seed germination, root and shoot elongation and seedling biomass of maize in a dose-dependent manner. • PBDEs induced overproduction of ROS, which led to lipid peroxidation and DNA damage in maize roots. • BDE-99 caused more severe damage and ROS generation in maize roots than BDE-28 and BDE-47. Although research on the toxic effects of polybrominated diphenyl ethers (PBDEs) on animals has made significant progress, the phytotoxicity of low and medium brominated PBDE congeners to plants has received little attention. A hydroponic experiment was conducted to investigate the toxic effects of 2,4,4′-tribromodiphenyl ether (BDE-28), 2,2′,4,4′-tetrabromodiphenyl ether (BDE-47) and 2,2′,4,4′,5-pentabromodiphenyl ether (BDE-99) on maize. Seed germination, root and shoot elongation and seedling biomass of maize were inhibited by PBDEs in a dose-dependent manner, and the maximum inhibition rate was achieved at 15 μg L−1. BDE-47 and BDE-99 treatments increased levels of malondialdehyde (MDA) in maize roots in a dose-dependent manner, whereas BDE-28 had no effect on MDA content. The phosphorylated histone H2AX (γ-H2AX) contents in maize roots first increased and then slightly decreased as the exposure concentration of PBDEs increased. These results suggested that PBDEs could induce lipid peroxidation and DNA damage in maize. BDE-28, BDE-47, and BDE-99 exposure increased the production of H 2 O 2 , O 2 •, and •OH, as well as the activity of antioxidant enzymes in the roots. In comparison, BDE-99 caused more severe damage and reactive oxygen species (ROS) generation in maize roots than BDE-28 and BDE-47. These findings show that PBDEs cause oxidative damage to maize and contribute to a better understanding of PBDE safety in terrestrial ecosystems. [ABSTRACT FROM AUTHOR]

Pendimethalin herbicide toxicity to rice plants and barnyard grass invasion have increasingly affected the productivity of direct-seeded rice (DSR) in the fields. Whether and how to promote DSR productivity and sustain weed management depend on the appropriate pre-emergence herbicide application rate to minimise its toxicity in the rice ecosystem. Pot experiments were conducted to determine the effects of pendimethalin rates (1.5, 1.75, 2.0 kg a.i. ha−1, two control treatments include the untreated control and the treated control with 1.5 kg a.i. ha−1 S-metolachlor) on barnyard grass (Echinochloa crus-galli (L.) Beaux) and their potential toxicity risk to photosynthetic performances of rice (Topaz and Sen pidao). All the pendimethalin treatments provided excellent control of barnyard grass. Among the treatments, 1.5, 1.75, 2.0 kg a.i. ha−1 pendimethalin and 1.5 kg a.i. ha−1 S-metolachlor (treated control) decreased leaf area of barnyard grass significantly by 38.9, 49.6, 49.6 and 46.2%, respectively, compared with the untreated control at 40 days after sowing (DAS). The above-ground biomass of barnyard grass significantly decreased by 40% (1.48 g plant−1) with 2.0 kg a.i. ha−1 pendimethalin and by 46.2% (1.33 g plant−1) when 1.5 kg a.i. ha−1S-metolachlor was applied at 40 DAS compared with the untreated pots. Higher pendimethalin rates increased toxicity in Topaz and Sen pidao varieties, and 2.0 kg a.i. ha−1 pendimethalin significantly reduced effective quantum yield (light-adapted) of photosystem (PS) II by 18% (0.58) and 19% (0.52), respectively, compared with the untreated control. Application of 2.0 kg a.i. ha−1 pendimethalin rate significantly decreased the maximum quantum yield (dark-adapted) of Sen pidao (0.66) compared with 1.5 kg a.i. ha−1 pendimethalin (0.68) including the untreated control. All pendimethalin treatments suppressed above-ground biomass at 55 DAS, but above-ground biomass of barnyard grass significantly decreased by 59.9% when 2.0 kg a.i. ha−1 pendimethalin was applied compared with the untreated control. Although application of 1.5 kg a.i. ha−1 pendimethalin rates reduced the effective quantum yield (light-adapted) of photosystem II of Sen pidao (0.55) by a small percentage (8%) than Topaz (0.65), it was non-toxic for both varieties compared with 2.0 kg a.i. ha−1 pendimethalin. Therefore, the use of 1.5 kg a.i. ha−1 pendimethalin can be used for effective weed management in the direct seeding of rice at an early growth stage. [ABSTRACT FROM AUTHOR]

Natural products have been postulated as an alternative to the use of synthetic herbicides in pest control. The latter compounds have caused numerous problems and these include the appearance of resistance to such herbicides. Aminophenoxazinones are natural products that have shown multiple biological activities, such as pharmacological or phytotoxic effects. In the case of phytotoxicity, the mode of action of aminophenoxazinones has not been widely exploited in agriculture and resistant weeds have not been reported to date. This fact makes aminophenoxazinones promising candidates in the development of herbicides. In the study reported here, seven aminophenoxazinone derivatives have been synthesized and their phytotoxicity has been evaluated on wheat coleoptiles and two important agricultural weeds (Lolium rigidum and Portulaca oleracea). Several derivatives have shown phytotoxic activity, which is similar to the positive control pendimethalin, and even higher in some cases at the highest concentrations tested. The most affected parameter in weeds was root length and the most susceptible weed was P. oleracea. Compound 2, in which nitrogen atoms are present in the heterocycles, was the most active and this was followed by compound 1. Modifications at C-8 led to a reduced activity, with the exception of the nitro compound on the root length of P. oleracea. However, the phytotoxicity also increased on introducing an iodo-substituent at C-4. The results highlight aminophenoxazinones as promising candidates in the development of natural herbicides. [ABSTRACT FROM AUTHOR]

Despite their advantages, biotechnological and omic techniques have not been applied often to characterize phytotoxicity in depth. Here, we show the distribution of phytotoxicity and glycoalkaloid content in a diploid potato population and try to clarify the source of variability of phytotoxicity among plants whose leaf extracts have a high glycoalkaloid content against the test plant species, mustard. Six glycoalkaloids were recognized in the potato leaf extracts: solasonine, solamargine, α-solanine, α-chaconine, leptinine I, and leptine II. The glycoalkaloid profiles of the progeny of the group with high phytotoxicity differed from those of the progeny of the group with low phytotoxicity, which stimulated mustard growth. RNA sequencing analysis revealed that the upregulated flavonol synthase/flavonone 3-hydroxylase-like gene was expressed in the progeny of the low phytotoxicity group, stimulating plant growth. We concluded that the metabolic shift among potato progeny may be a source of different physiological responses in mustard. The composition of glycoalkaloids, rather than the total glycoalkaloid content itself, in potato leaf extracts, may be a driving force of phytotoxicity. We suggest that, in addition to glycoalkaloids, other metabolites may shape phytotoxicity, and we assume that these metabolites may be flavonoids. [ABSTRACT FROM AUTHOR]

The production and use of common vetch has great potential, but the lack of approved pesticides makes the success of cultivation difficult and unpredictable. The research was carried out on sandy soil at the Nyíregyháza Research Institute of the University of Debrecen in Hungary in April 2022. Five different herbicides, pendimethalin, metolachlor, flumioxazin, bentazon in doses 5 L ha-1, 1.4 L ha-1, 0.06 kg ha-1, 2 L ha-1, respectively, and imazamox in four different doses (0.6, 0.8, 1.0, 1.2 L ha-1) were applied with the consideration of the ranges specified in the Hungarian legislation. The results showed that the highest NDVI (Normalized Difference Vegetation Index) values were obtained with flumioxazin compared to the other treatments. The maximum harvested seed yield (194.1 kg ha-1) was obtained with the application of flumioxazin compared to the control treatment (132.5 kg ha-1). Flumioxazin was also the best as it had the fewest weeds per plot and the lowest phytotoxicity score. Although pendimethalin approached the cleaned and harvested average seed yield of the control plots with 121.3 kg ha-1, it did not feature prominently in the other indicators. With regard to plant trash after cleaning of vetch seed, the highest plant trash (179.4 kg ha-1) was obtained with bentazon. Pendimethalin had the highest percentage ratio between seed yield ha-1 and plant trash ha-1 (61.8%), followed by flumioxazin (60.7%). The results also showed that there was a positive correlation between NDVI values and seed yield and a positive correlation between NDVI values and plant trash, while there was a negative correlation at the 0.01 level between NDVI values and phytotoxicity. [ABSTRACT FROM AUTHOR]

Weeds result in a significant yield loss in mungbean (Vigna radiata [L.] R. Wilczek). However, post‐emergence (POST) herbicides are limited in mungbean for broad‐spectrum weed control. Therefore, we evaluated the efficacies of different herbicides in mungbean to find a suitable broad‐spectrum POST herbicide. Nine herbicides, weed‐free check, and unweeded control treatments were tested in a randomised block design with three replications for two consecutive years. Among the tested herbicides, clodinafop‐propargyl + sodium‐acifluorfen 122.5 g a.i. ha−1 applied at 15 days after sowing (DAS) reduced the broad‐leaved weed dry weight at 35 DAS and harvest by 55.8% and by 58.6% (p < 0.05) compared with the unweeded control respectively. Notably, it minimised the total weed dry weight by 23.1%–30.3% compared with the recommended herbicide pendimethalin 1 kg a.i. ha−1 – quizalopfop‐p‐ethyl 100 g a.i. ha−1 (p ≤ 0.05). Clodinafop‐propargyl + sodium‐acifluorfen had higher weed control index (58.2% at 35 DAS and 62.1% at harvest) over the remaining tested herbicides. Unweeded controls resulted in 51% yield loss compared with the clodinafop‐propargyl + sodium‐acifluorfen that did not differ from pendimethalin − quizalofop‐p‐ethyl for seed yield of mungbean. Decreasing order of treatment efficacy on mean grain yield across two years comprised the weed‐free check, clodinafop‐propargyl + sodium‐acifluorfen and pendimethalin − quiza‐lofop‐p‐ethyl, imazethapyr + imazamox, tembotrione, and topramezone. [Correction added on 10 November 2022, after first online publication: In the preceding sentence, changes have been made to the article content to improve clarity in this version.] Application of clodinafop‐propargyl + sodium‐acifluorfen led to the greatest increase in soil microbial biomass carbon, indicating higher levels of soil biological and rhizospheric activity. We suggest that clodinafop‐propargyl + sodium acifluorfen is a suitable broad‐spectrum option for weed management of mungbean. [ABSTRACT FROM AUTHOR]

The use of biocompatible and low-cost polymeric matrices to produce non-phytotoxic nanoparticles for delivery systems is a promising alternative for good practices in agriculture management and biotechnological applications. In this context, there is still a lack of studies devoted to producing low-cost polymeric nanoparticles that exhibit non-phytotoxic properties. Among the different polymeric matrices that can be used to produce low-cost nanoparticles, we can highlight the potential application of cellulose acetate, a natural biopolymer with biocompatible and biodegradable properties, which has already been used as fibers, membranes, and films in different agricultural and biotechnological applications. Here, we provided a simple and low-cost route to produce cellulose acetate nanoparticles (CA-NPs), by modified emulsification solvent evaporation technique, with a main diameter of around 200 nm and a spherical and smooth morphology for potential use as agrochemical nanocarriers. The non-phytotoxic properties of the produced cellulose acetate nanoparticles were proved by performing a plant toxic test by Allium cepa assay. The cytotoxicity and genotoxicity tests allowed us to evaluate the mitotic process, chromosomal abnormalities, inhibition/delay in root growth, and micronucleus induction. In summary, the results demonstrated that CA-NPs did not induce phytotoxic, cytotoxic, or genotoxic effects, and they did not promote changes in the root elongation, germination or in the mitotic, chromosomal aberration, and micronucleus indices. Consequently, the present findings indicated that CA-NPs can be potentially used as environmentally friendly nanoparticles. [ABSTRACT FROM AUTHOR]

Plants are rich in active compounds, which can have an effect on the growth of other plants. In this context, the present work aimed to evaluate the effect of dichloromethanolic extracts from fresh and dried plants of Dionaea muscipula and compare it with its major compound in Lactuca sativa and Allium cepa. For this end, we conducted biological assays, determining the effects on germination, early development and cell cycle in plantlets and meristematic cells of L. sativa and A. cepa. The major compound identified by GC-EM was plumbagin with 89.71% in fresh plants and 53.13% in dry plants. The growth curves revealed the concentrations of 305,5; 538,4 and 32,08 μg mL−1 for fresh, dried and plumbagin, respectively, as those reducing 50% of germination %. And A. cepa with IC50: 279,3; 552,7 and 11,68 μg mL−1, respectively. Treatment with both extracts affected seedling growth (root and shoot) similarly to glyphosate, but only in L. sativa. Glyphosate did not affect the growth of A. cepa, which was observed in the extracts and plumbagin. Extracts at 1600, 800, and 400 μg mL−1 proved to be good options for pre-emergence control, while concentrations of 800, 400, and 200 μg mL−1 caused cell-cycle changes that compromised seedling viability in late development. Chromosome stickiness was the most frequent and did not indicate the mechanism of genotoxicity of the extracts, but the high prevalence of condensed nuclei suggests that cytotoxicity occurred with the activation of apoptotic pathways, common to naphthoquinones. This suggests that D. muscipula extracts are toxic to plants due to the availability of plumbagin, and they have the potential of use, affecting from seed germination to the early development of L. sativa and A. cepa. [ABSTRACT FROM AUTHOR]

As a result of military operations on the territory of Ukraine, sown areas are reduced, the cost of plant protection products and fertilizers increases which emphasizes the problem of obtaining maximum yields from a smaller area of farmland. Given that a shortage of food grains can cause a global food crisis, research on the use of MSW as an environmentally friendly substitute for agrochemicals is relevant today. The aim of the research was to assess the ecotoxicological properties of MSW as an environmentally friendly substitute for synthetic agrochemicals. The impact of MSW as a fertilizer on soil chemical properties and assessment of MSW phytotoxicity as an herbicide for weeds and productivity of winter wheat were studied under field conditions. Toxicological assessment of MSW under laboratory conditions was carried out according to the following parameters: acute oral toxicity and resorptive-toxic effect of MSW. As a result of the assessment of MSW impact on soil chemical properties, it was found that significant soil acidification occurs only when MSW dose of more than 2,400 L ha-1 is used. The content of nitrates and oil products did not increase and there was no soil salinity when the MSW was used in doses of 300-1,200 L ha-1. It was determined that the greatest decrease in weed plant biomass (85.5%) was observed when 100% concentration of MSW was used in a dose of 350 L ha-1. As a consequence, with reduced weed infestation, there was a 21.5% increase in winter wheat yield if 100% MSW was used and a 19.1% increase if 75% MSW was used. As a result of the toxicological assessment of MSW, it was found that it belongs to low-toxic compounds. These results of ecotoxicological investigation of MSW make it possible to assert that its use is safe in agriculture, in particular as an environmentally safe organomineral fertilizer and herbicide. [ABSTRACT FROM AUTHOR]

Given the country's financial deficit for the acquisition of pre-emergent herbicides, the Cuban chemical industry is developing new agrochemicals for the control of weeds in sugarcane. Of them, the effectiveness and toxic effect on the crop is unknown, among which is Hexazinone LS 25. An investigation was developed in commercial production areas of the production unit "Romana VII", Sugar Enterprise "America Libre" of Santiago de Cuba province with the objective of evaluating the effectiveness of Hexazinone LS 25 of national production and crop tolerance, compared with different pre-emergent herbicides for the control of weeds in sugarcane. An experiment was established in the period from September to December 2020 for the cold cycle and cultivar 'B7274', on a typical Brown soil with carbonates. A randomized block experimental design with eight treatments and five replications was used. The products evaluated were Isoxaflutole, Imazapic, Merlin Total, Hexazinone LS 25, as well as the combination Isoxaflutole + Hexazinone LS 25. The results were processed with the statistical package Statistica v. 8. It was demonstrated that the application of the national formulation of Hexazinone LS 25 at doses of 3.0 and 3.5 L ha-1 achieved the best control of weeds without causing phytotoxic damage to the crop. [ABSTRACT FROM AUTHOR]

The objective of this research was to evaluate the sensitivity of 3 potato cultivars (different ripening periods) to fomesafen (300 g/ha a.i.) and metribuzin (980 g/ha a.i.) herbicides applied preemergence (PRE). The experiments were conducted during 2020 and 2021 in the Leningrad region of the Russian Federation. The application of herbicides at all three potato cultivars caused slight yellowing of tips of the leaves (less than 5%). This symptom of phytotoxicity was more noticeable in the early season cultivars Udacha (ripening time from 65 days) and Nevsky (ripening time from 75 days). The negative effect of herbicides on plant height was demonstrated in arid conditions (in 2021), when after applying fomesafen and metribuzin there was a significant delay in plant growth in two cultivars (Udacha and Avrora) at 7 and 14 days after emergence (DAE). By 28 DAE, the plant height of all three cultivars after herbicide treatments and in the nontreated check were equalized (differences did not exceed 10%). Despite the observed symptoms of phytotoxicity, none of the herbicide treatments in both years didn't show a statistically significant negative effect of herbicides on potato yield, indicating the high regenerative capacity of potatoes. [ABSTRACT FROM AUTHOR]

Pseudomonas brassicacearum Q8r1-96 and other 2,4-diacetylphloroglucinol (DAPG)-producing pseudomonads of the P. fluorescens complex possess both biocontrol and growth-promoting properties and play an important role in suppression of take-all of wheat in the Pacific Northwest (PNW) of the United States. However, P. brassicacearum can also reduce seed germination and cause root necrosis on some wheat cultivars. We evaluated the effect of Q8r1-96 and DAPG on the germination of 69 wheat cultivars that have been or currently are grown in the PNW. Cultivars varied widely in their ability to tolerate P. brassicacearum or DAPG. The frequency of germination of the cultivars ranged from 0 to 0.87 and 0.47 to 0.90 when treated with Q8r1-96 and DAPG, respectively. There was a significant positive correlation between the frequency of germination of cultivars treated with Q8r1-96 in assays conducted in vitro and in the greenhouse. The correlation was greater for spring than for winter cultivars. In contrast, the effect of Q8r1-96 on seed germination was not correlated with that of DAPG alone, suggesting that DAPG is not the only factor responsible for the phytotoxicity of Q8r1-96. Three wheat cultivars with the greatest tolerance and three cultivars with the least tolerance to Q8r1-96 were tested for their ability to support root colonization by strain Q8r1-96. Cultivars with the greatest tolerance supported significantly greater populations of strain Q8r1-96 than those with the least tolerance to the bacteria. Our results show that wheat cultivars differ widely in their interaction with P. brassicacearum and the biocontrol antibiotic DAPG. [ABSTRACT FROM AUTHOR]

Herbicides are powerful means for weed control in modern agriculture. However, in some cases they can negatively affect the crops, for example after herbicide drift. One suitable approach, aimed to improve recovery of herbicide-damaged crops, is the therapeutic biostimulant application. The aim of our study was to evaluate the potential of the plant biostimulant Amino Expert® to ameliorate recovering of florasulam + aminopyralid-potassium (Derby® Super) - damaged oilseed rape plants. The experiment included five treatments: 1. Untreated plot, accepted as a control. Treatments 2 and 3 represented Derby® Super 100% (of the registered rate) and Derby® Super 20% respectively. The treatments 4 and 5 included two applications - first by the herbicide and second - by the biostimulant four days later. The observations showed that the herbicide drift caused negative effect on oilseed rape plants distinguished by yellowing and growth retardation, which was visible to the beginning of flowering. On the contrary, the plants received an additional therapeutic application by Amino Expert® Impuls recovered faster and finally developed a higher silique number plant-1 as well as biological yield. The physiological parameters such as photosynthetic rate and pigments content also confirmed the ameliorative effect of the plant biostimulant application. [ABSTRACT FROM AUTHOR]

Asteraceae family is as an interesting target for researching natural alternatives for crop protection. Many species from this family grow as weeds, and some of them can influence the development of other species by the allelopathy phenomenon. This paper aimed to review the literature for the main genera and species of the Asteraceae family with allelopathic or phytotoxic potential, as well as the classes of secondary metabolites present in this family and responsible for such activity. Artemisia, Ambrosia, Bellis, Bidens, Helianthus and Tagetes were identified as the main genera with phytotoxic or allelopathic activity. Among the secondary metabolites from this family, terpenes, polyacetylenes, saponins, sesquiterpene lactones, phenolic acids and flavonoids were described as responsible for inhibiting the development of other species. In addition, the phytotoxic potential of Acmella oleracea and Sphagneticola trilobata against the weeds Calopogonium mucunoides. and Ipomoea purpurea was described for the first time. At 0.2 mg/mL, crude extract and fractions of A. oleracea inhibited above 60% of C. mucunoides root growth. Hydroalcoholic extract and fractions of S. trilobata, except hexane, significantly affected I. purpurea root growth, ranging from 38 ± 14% to 59 ± 8% of inhibitory effect at different concentrations (0.19 mg/mL to 1.13 mg/mL). [ABSTRACT FROM AUTHOR]

Field experiments were conducted to evaluate the efficacy, selectivity and health harmlessness of four application rates of two pre-emergent herbicides (pethoxamid and dimethachlor) in the rocket [Eruca vesicaria (L.) Cavanilles)]. Pethoxamid was found to be less efficient on the total weed density (efficacy 86.0-93.3%) in comparison with the effect of dimethachlor (94.9-95.8%). Dimethachlor expressed an excellent efficacy on Echinochloa crus-galli (L.) P. Beauvois, Portulaca oleracea Linnaeus, Amaranthus retroflexus Linnaeus, Lamium purpureum Linnaeus, and Veronica persica Poiret from the lowest tested application rate (800 g/ha). Pethoxamid showed an excellent efficacy on E. crus-galli, Lamium purpureum, Lamium amplexicaule Linnaeus, V. persica, and P. oleracea. In higher application rates, pethoxamid controlled Chenopodium polyspermum Linnaeus and Chenopodium album Linnaeus. In contrast to mostly negative effects of dimethachlor, pethoxamid showed either no effects or positive ones on the rocket yield. Residues of both herbicides in the harvested product were always below a 'default limit', which is the baseline maximum residue level for food. The selectivity of pethoxamid at an application rate of 960 g/ha was good, herbicide residues in the rocket were not detected and the yield of the rocket increased. [ABSTRACT FROM AUTHOR]

Weeds have been a major threat in agriculture for several generations as they lead to decreases in productivity and cause significant economic losses. Parasitic plants are a specific type of weed causing losses in crops of great relevance. A new strategy has emerged in the fight against parasitic plants, which is called 'suicidal germination' or the 'honey-pot strategy'. Regarding the problem of weed control from an ecological point of view, it is interesting to investigate new natural compounds with allelopathic activity with the aim of developing new natural herbicides that can inhibit the growth of weeds without damaging the environment. Safflower crops have been affected by parasitic plants and weeds and, as a consequence, the secondary metabolites exuded by safflower roots have been studied. The sesquiterpene lactone dehydrocostuslactone was isolated and characterised, and the structurally related costunolide was identified by UHPLC-MS/MS in safflower root exudates. These sesquiterpene lactones have been shown to stimulate germination of Phelipanche ramosa and Orobanche cumana seeds. In addition, these compounds were phytotoxic on three important weeds in agriculture, namely Lolium perenne, Lolium rigidum and Echinochloa crus-galli. The exudation of the strigolactones solanacol and fabacyl acetate have also been confirmed by UHPLC-MS/MS. The study reported here contributes to our knowledge of the ecological role played by some secondary metabolites. Moreover, this knowledge could help identify new models for the development of future agrochemicals based on natural products. [ABSTRACT FROM AUTHOR]

The persistence of pesticides in soil is a summation of all the reactions, movements, and degradations affecting these chemicals. Marked differences in persistence are the rule. For example, organophosphate insecticides may last only a few days in soil; the most widely used herbicide, 2,4-D, persists in soil for only two to four weeks; chlorinated hydrocarbons may persist from three to fifteen years or longer. The persistence time of hundreds of other pesticides, are between the extremes cited. The majority of pesticides degrade rapidly enough to prevent buildup in soil. Those that do not do so have potential for environmental damage. In the article authors have studied and discussed the pesticide persistence being directly affected by physical characteristics of soil. [ABSTRACT FROM AUTHOR]

Field experiments were conducted to evaluate the efficacy, selectivity and health harmlessness of four application rates of two pre-emergent herbicides (pethoxamid and dimethachlor) in the rocket [Eruca vesicaria (L.) Cavanilles)]. Pethoxamid was found to be less efficient on the total weed density (efficacy 86.0-93.3%) in comparison with the effect of dimethachlor (94.9-95.8%). Dimethachlor expressed an excellent efficacy on Echinochloa crus-galli (L.) P. Beauvois, Portulaca oleracea Linnaeus, Amaranthus retroflexus Linnaeus, Lamium purpureum Linnaeus, and Veronica persica Poiret from the lowest tested application rate (800 g/ha). Pethoxamid showed an excellent efficacy on E. crus-galli, Lamium purpureum, Lamium amplexicaule Linnaeus, V. persica, and P. oleracea. In higher application rates, pethoxamid controlled Chenopodium polyspermum Linnaeus and Chenopodium album Linnaeus. In contrast to mostly negative effects of dimethachlor, pethoxamid showed either no effects or positive ones on the rocket yield. Residues of both herbicides in the harvested product were always below a 'default limit', which is the baseline maximum residue level for food. The selectivity of pethoxamid at an application rate of 960 g/ha was good, herbicide residues in the rocket were not detected and the yield of the rocket increased. [ABSTRACT FROM AUTHOR]

The need to reduce the use of chemical pesticides currently fosters great interest in eco-friendly biological control agents. In addition, the isolation of plant allelopathic substances and the evaluation of their phytotoxic effects can lead to the discovery of new natural herbicides. In this context, our study aimed to assess the herbicidal activity of ten crude extracts obtained from aerial parts of Tunisian spontaneous plants against Trifolium incarnatum, Silybum marianum and Phalaris minor. It confirmed that the Cynara cardunculus methanolic extract best inhibited weed germination and seedling growth, and caused necrosis or chlorosis. Following a bioassay-guided fractionation, five main phenolic compounds, (1) syringic acid, (2) p -coumaric acid, (3) myricitrin, (4) quercetin and (5) naringenin were identified in the most active crude methanolic extract. Then, only 3 of the flavonoids contained in the most active fraction were tested on Trifolium incarnatum. The 3 compounds had a significant phytotoxic effect and therefore could be employed in a new composition of botanical herbicides to control crop weeds. Besides, a novel herbicide composition was designed to improve the post-emergence activity of the methanolic extract. The formulation containing the C. cardunculus crude methanolic extract showed the same herbicidal activity as the standard industrial bioherbicide containing pelargonic acid. These results make C. cardunculus a suitable source of natural compounds potentially usable as natural herbicides. Image, graphical abstract • C. cardunculus extract had the best herbicidal activity among 10 plant extracts. • Five phenolic compounds were identified in C. cardunculus. • Myricitrin, naringenin and quercetin were the main active compounds in C. cardunculus. • Fraction 2 of C. cardunculus had the same herbicidal effect as biological herbicide. [ABSTRACT FROM AUTHOR]

The objective of this study was to evaluate the selectivity of the post emergent sulfentrazone molecule in sunflower crop. The experiment was conducted in 2014 in Campo Novo do Parecis. The design was in randomized blocks with nine treatments and four replications. Treatments consisted of seven doses of sulfentrazone (50, 62.5, 75, 87.5, 100, 112.5 and 125 g i.a ha-1) and a control with weeding. The herbicide application was carried out with a CO2 pressurized costal sprayer and equipped with an application bar containing five TeeJet XR 110 02 VS tips, with an application volume of 200 L ha-1. Phytotoxicity (%), chapter height, stem diameter, chapter mass, achenes mass per chapter, yield and thousand achenes mass were evaluated. There was a reduction in chapter height at 112.5 and 125 g i.a ha-1, while no significant differences were observed in the other variables. Up to 14 days after application (DAA) some injuries were observed. Yield was not affected by sulfentrazone doses. Which proved selective to sunflower crop. [ABSTRACT FROM AUTHOR]

The objective of this work is to evaluate the performance of soybean submitted to glyphosate doses in association with foliar fertilizers and plant growth regulator, aiming the reversal of phytotoxic effect in RR2 soybean. The experiment was conducted between November 2015 and January 2016, in a greenhouse located at the Federal University of Paraná - Setor Palotina. Monsoy 6210 IPRO® was used. The plants were submitted to glyphosate application at 0, 720, 1440, 2160 and 2880 g a. e ha-1 and glyphosate in association with the products: plant growth regulator (kinetin 0.09 g L-1, gibberellic acid). 0.05 g L-1 and 4-indol-3-butyl acid 0.05 g L-1) at the dose 250 ml ha-1, manganese (Mn as an aminoacid chelate, 62.5 g L-1) at a dose of 1L, and the aminoacid compound (protein hydrolysate, phosphoric acid, potassium hydroxide and water, 1L ha- 1). The application was performed at stage V4. Chlorophyll index shoot and root dry matter, and phytointoxication symptoms in the crop were evaluated. Data were subjected to analysis of variance, Tukey test (p=0.05) and regression analysis for the dose factor. No differences were observed between fertilizer and plant regulator treatments and herbicide. Symptoms of crop phytointoxication and chlorophyll levels were proportional to herbicide dose increase, but there was a recovery of culture after 35 DAA. For root and shoot dry matter, no difference was observed between the phytointoxication reversal management. Field work is necessary to verify the effects of products on plant physiology aiming at a possible increase of productivity. [ABSTRACT FROM AUTHOR]

The aim of this paper was quantify the effect of the herbicides clethodim and paraquat associated with different adjuvants class on phytotoxicity of Digitaria insularis at flowering stage. The herbicides were applied at 0, 6.25, 12.5, 25, 50, 75 and 100% of recommended label isolated or associated with the adjuvants: nonylphenoxy polyethoxy ethanol at 0.05%; silicone polyether copolymer at 0.1%; lecithin-based adjuvant and acid propionic at 0.5% and mineral oil at 0.5%. The experimental design was completely randomized with five replications in factorial scheme (herbicides rates x adjuvants). The phytotoxicity effect was visually assessed for paraquat at 12 days after treatment (DAT) and at 21 DAT for clethodim. The treatments applied clethodim with the adjuvants nonylphenoxy polyethoxy ethanol, lecithin-based adjuvant and acid propionic and mineral oil significantly increased the phytotoxicity of D. insularis plants. For the paraquat the increase phytotoxicity of D. insularis plants was provided by the treatment with the lecithin-based and acid propionic adjuvant. [ABSTRACT FROM AUTHOR]

The physicochemical attributes of textile effluents collected from secondary treatment stage was investigated in this study and also assess the biosorption potential of membrane immobilized Bacillus cereus and free form of Bacillus cereus on textile effluent through bioreactor model study to find a sustainable solution to manage the textile effluent as vital need. Furthermore, the phytotoxicity and cytotoxicity nature of treated and untreated textile effluents on Vigna mungo and Artemia franciscana larvae under laboratory conditions as a novel approach. The textile effluent physicochemical parameter analysis results showed that the properties such as colour (Hazen unit), pH, turbidity, As, Biological Oxygen Demand (BOD), Chemical Oxygen Demand (COD), Cd, Cl, Cr, Cu, Hg, Ni, Pb, SO 4 2−, and Zn were beyond the acceptable limits. Bacillus cereus immobilized on a polyethylene membrane eliminated greater amounts of dye (25.0 ± 1.3, 56.5 ± 1.8, 57.18 ± 1.5, and 54.34 ± 1.7 Hazen unit from An1, Ae2, Ve3, and So4 respectively) and pollutants (As: 0.9–2.0, Cd: 6–8, Cr: 300–450, Cu: 5–7, Hg: 0.1–0.7, Ni: 8–14, Pb: 4–5, and Zn: 4–8 mg L−1) from textile effluent in a week of biosorption investigation using a bioreactor model (batch type) compared to a free form of B. cereus on textile effluent. The phytotoxicity and cytotoxicity study results revealed that the membrane immobilized B. cereus treated textile effluent exposure showed reduced phytotoxicity and minimal cytotoxicity (including mortality) percentage compared with free form B. cereus treated and untreated textile effluents. These entire results conclude that the membrane immobilized B. cereus may considerably minimize/detoxify the harmful pollutants from the textile effluents. A large scale level biosorption approach need to be performed to validate the maximum pollutants removing potential of this membrane immobilized bacteria species and optimal conditions for effective remediation. • Textile effluents from secondary treatment phase also have more harmful dyes & metals. • The DO levels in immobilized B.cereus treated effluent was considerably increased. • Immobilized B.cereus treated effluent has minimal phytotoxicity on V.mungo. • BOD & COD levels were considerably decreased in immobilized B.cereus treated effluent. • Immobilized B.cereus treated effluent has lowest cytotoxicity on A. franciscana. [ABSTRACT FROM AUTHOR]

Arsenic (As) causes phytotoxicity to rice plants, decreases rice production and causes serious human health concerns due to rice consumption. Additional stresses may be posed to rice plants due to the increasing release into the environment by the expanding production and application of copper oxide nanoparticles (nCuO). The influence of nCuO on As uptake in and effects on rice ( Oryza sativa japonica ) are explored here for the first time. An 18-d factorial experiment was conducted to determine main effects of nCuO (0, 0.1, 1.0, 10, 50, and 100 mg/L) and As (0 and 10 mg/kg), and the interaction between nCuO and As on rice seed germination and seedling growth. Arsenic alone decreased the germination percentage. Both As and nCuO reduced seedling shoot and root length, and exhibited interactive effects. nCuO and As also produced an interaction effect on the number of root branches (NRB) of rice seedlings. Notably, high nCuO concentrations (50 and 100 mg/L) mitigated the negative effect of As on the NRB. Copper uptake in shoots and roots was linearly correlated with Cu concentration in the sand without As addition (R 2  > 0.756). Whereas, As addition to the sand produced non-monotonic changes in Cu concentrations in shoots and roots versus Cu concentration in the sand (R 2  > 0.890). Arsenic concentration in shoots had a slightly negative linear correlation with Cu concentration in the sand (R 2  = 0.275). [ABSTRACT FROM AUTHOR]

Herbicide safeners protect crop plants from herbicide phytotoxicity, but an understanding of their molecular mechanisms is still lacking. We investigated the effects of the safener isoxadifen-ethyl and/or nicosulfuron on the expression of 10 genes, 8 glutathione transferases (GSTs), 1 glutathione transporter and 1 multidrug resistance protein gene in two maize cultivars. Nicosulfuron and isoxadifen-ethyl induce different detoxification enzyme genes. The expression analyses of the 10 genes revealed that most were expressed much higher in ‘Zhengdan958’ than those in ‘Zhenghuangnuo No.2’, both in control and in isoxadifen-ethyl- and/or nicosulfuron-treated plants. The expression levels of ZmGSTIV , ZmGST6 , ZmGST31 and ZmMRP1 in two maize cultivars were up-regulated by isoxadifen-ethyl only, or in combination with nicosulfuron, whereas nicosulfuron down-regulated the expression of eight genes. Thus, ZmGSTIV , ZmGST6 , ZmGST31 and ZmMRP1 could be considered safener-responsive and may be the core genes responsible for isoxadifen-ethyl increasing the tolerance of maize to nicosulfuron. [ABSTRACT FROM AUTHOR]

The effects of four phytotoxins usnic acid (UA), salicylic acid (SA), cinnamic acid (CA) and benzoic acid (BA) on photosynthesis of Chlamydomonas reinhardtii were studied in vivo to identify and localise their initial action sites on two photosystems. Our experimental evidence shows that the four phytotoxins have multiple targets in chloroplasts, which mainly lie in photosystem II (PSII), not photosystem I (PSI). They share an original action site by blocking electron transport beyond Q A (primary plastoquinone acceptor) at PSII acceptor side since a fast increase of the J-step level is the greatest change in chlorophyll a fluorescence induction kinetics OJIP in C. reinhardtii cells treated with the phytotoxins. UA decreases photosynthetic activity by reducing O 2 evolution rate, interrupting PSII electron transport at both the donor and acceptor sides, inactivating the PSII reaction centers (RCs), reducing the content of chlorophylls and carotenoids, destroying the conformation of antenna pigment assemblies, and casuing the degradation of D1/D2 proteins. SA damage to photosynthetic machinery is mainly attributed to inhibition of PSII electron transport beyond Q A at the acceptor side, inactivation of the PSII RCs, reduction of chlorophyll content, digestion of thylakoid ploypeptides and destabilization of thylakoid membranes. Both CA and BA affect the photosynthetic process by decreasing PSII electron transport efficiency at the acceptor side and the amount of active PSII RCs. Besides, the initial cause of BA-inhibiting photosynthesis is also assocaited with the O 2 evolution rate and the disconnection of some antenna molecules from PSII RCs. [ABSTRACT FROM AUTHOR]

Herbicides may damage soybean in conventional production systems. Chlorophyll fluorescence imaging technology has been applied to identify herbicide stress in weed species a few days after application. In this study, greenhouse experiments followed by field experiments at five sites were conducted to investigate if the chlorophyll fluorescence imaging is capable of identifying herbicide stress in soybean shortly after application. Measurements were carried out from emergence until the three-to-four-leaf stage of the soybean plants. Results showed that maximal photosystem II (PS II) quantum yield and shoot dry biomass was significantly reduced in soybean by herbicides compared to the untreated control plants. The stress of PS II inhibiting herbicides occurred on the cotyledons of soybean and plants recovered after one week. The stress induced by DOXP synthase-, microtubule assembly-, or cell division-inhibitors was measured from the two-leaf stage until four-leaf stage of soybean. We could demonstrate that the chlorophyll fluorescence imaging technology is capable for detecting herbicide stress in soybean. The system can be applied under both greenhouse and field conditions. This helps farmers to select weed control strategies with less phytotoxicity in soybean and avoid yield losses due to herbicide stress. [ABSTRACT FROM AUTHOR]

The present investigation was carried out at Institute ResearchFarmofICAR-NRRI, Cuttack (Odisha) during wet season of 2016 to study the phytotoxicity of a new herbicide molecule XR-848 Benzyl Ester along with its mixture with Cyhalofop Butyl in different doses and its effect on yield of direct-sown rice. The experiment was laid out in Randomized Block Design (RBD) with three replications and nine treatments viz. four herbicide mixtures(T1-XR-848 Benzyl Ester+Cyhalofop Butyl 12% EC (w/v) @ 120(20+100)g ha-1, T2-XR-848 Benzyl Ester+Cyhalofop Butyl 12% EC (w/v) @ 150(25+125)g ha-1, T3-XR-848 Benzyl Ester+Cyhalofop Butyl 12% EC (w/v) @ 180(30+150)g ha-1 andT4-XR-848 Benzyl Ester+Cyhalofop Butyl 12% EC (w/v) @ 360(60+300)g ha-1), three alone herbicides(T5-XR-848 Benzyl Ester 2.5% EC (w/v) @ 25g ha-1, T6- XR-848 Benzyl Ester 2.5% EC (w/v) @ 30g ha-1 andT7-Bispyribac-Na 10% SC @ 30g ha-1), one weed free (T8)and an untreated weedy check (T9).Under phytotoxicity analysis, visual observations (Phyotoxic score), chlorophyll content and SPAD meter readings at 10, 20 and 30 days after treatment (DAT) of herbicides were taken, in which the T4proved to be the most phytotoxic causing a reduction of 29.41% in grain yield which was at par with the untreated weedy check. Whereas T2 showed a minimal phyotoxicity at initial stage with a quick recovery within 30 DAT of herbicide and was proved to be the best herbicide mixture yielding at par with the weed free (T8). [ABSTRACT FROM AUTHOR]

Nature of exposure is a fundamental driver in nontarget terrestrial plant risk assessment for pesticides; consequently a novel study was designed to generate field-based drift exposure and evaluate corresponding biological effects of the herbicide mesotrione. The approach used a combination of US guideline drift reduction technology and vegetative vigor approaches. In each of 3 independent replicate spray application trials, 10 pots each of lettuce and tomato were placed at distances of 10, 20, 30, 40, and 50 ft (∼3, 6, 9, 12, and 15 m) from the downwind edge of the spray boom. Each application was conducted using a commercial 60-ft (18-m) boom sprayer fitted with TeeJet® Technologies TTI110025 nozzles, with a nominal application rate of 0.2 lb a.i./A (224 g a.i./ha). The environmental conditions required by the protocol (air temperature 10-30 °C and wind perpendicular to the swath (±30°) blowing toward the plants at a mean wind speed of ≥10 mph [≥4.5 m/s] measured at 2.0 m above the ground) were met for each application. Following exposure, plants were transferred to a greenhouse for the 21-d vegetative vigor phase of the study. Symptoms of phytotoxicity and plant height were assessed at 7, 14, and 21 d after treatment. On completion of the 21-d after treatment assessment, all plants were harvested and dried in an oven to determine shoot dry weight. The biological data indicated that no statistically significant effects were observed at a distance of 30 ft (∼9 m) from mesotrione drift at wind speeds of ≥10 mph (10.9-12.4 mph); this endpoint (30 ft) is defined as the no observed effects distance (NOED). Environ Toxicol Chem 2017;36:2465-2475. © 2017 SETAC [ABSTRACT FROM AUTHOR]

The grapevine is a key crop for Mediterranean environments and is both sensitive to climate warming and air pollutants, of which ozone is the most damaging to crop yield and quality. Ambient ozone effects on the grapevine have been noticed since the late fifties but risk assessments are still impaired by the lack of information concerning differences in cultivar sensitivity, and adaptation capacity to environmental factors including drought conditions. This study develops a specific parametrization for autochthonous grape cultivars within a leaf-level stomatal flux model, the DO3SE model, coupled with a meteorological and atmospheric chemical transport modelling system, the WRF-CHIMERE, by using a renowned wine producing area, the Douro wine region of Portugal, as case study. The DO3SE model parametrization introduced in this study included phenology, photosynthetic active radiation, air temperature, air vapour pressure deficit, and leaf water potential as a proxy of soil water content. The modelling experiments, which included simulations with the current default Convention on Long-Range Transboundary Air Pollution DO3SE parametrization and with the proposed parametrization, covered a reference grapevine growing season (from April to September 2017), during which a measuring campaign was carried out. Simulation results show that the proposed parametrization succeeded to replicate the observed grapevine leaf-level stomatal flux gradient in the region. Both field and modified DO3SE model values indicate that considerable areas in the Douro wine region of Portugal can exceed critical phytotoxic ozone dose (POD) values, although with a lower and different spatial extent when compared to the default DO3SE parametrization for the grapevine. However, under irrigated conditions, the POD values increase, and the values are close to those obtained with the default parametrization. Overall, the research results indicate that air quality management, in particular the reduction of ozone levels in the ambient air, must also be considered to define sustainable grape and wine production strategies in the context of climate and wine production management change. [Display omitted] • DO3SE parametrization for key autochthonous grape cultivars was developed. • The grapevine stomatal flux gradient in the region was successfully replicated. • Adjusted DO3SE PODs were lower and with different spatial extent than CLRTAP ones. • Under irrigated conditions, POD values increase being closer to default CLRTAP PODs. • Air quality management must also be considered for sustainable grape production. [ABSTRACT FROM AUTHOR]

Glyphosate-based herbicides are the most commonly used worldwide because they are effective and relatively nontoxic to nontarget species. Unlimited and uncontrolled use of such pesticides can have serious consequences for human health and ecological balance. The present study evaluated the acute toxicity and genotoxicity of 2 glyphosate-based formulations, Roundup Original (Roundup) and Glyphosate AKB 480 (AKB), on different organisms: cucumber ( Cucumis sativus), lettuce ( Lactuca sativa), and tomato ( Lycopersicon esculentum) seeds, and microcrustacean Artemia salina and zebrafish ( Danio rerio) early life stages. For the germination endpoint, only L. esculentum presented significant sensitivity to AKB and L. sativa to Roundup, whereas both formulations significantly inhibited the root growth of all species tested. Both AKB and Roundup induced significant toxicity to A. salina; both are classified as category 3, which indicates a hazard for the aquatic environment, according to criteria of the Globally Harmonized Classification System. However, Roundup was more toxic than AKB, with 48-h median lethal concentration (LC50) values of 14.19 mg/L and 37.53 mg/L, respectively. For the embryo-larval toxicity test, Roundup proved more toxic than AKB for the mortality endpoint (96-h LC50 values of 10.17 mg/L and 27.13 mg/L, respectively), whereas for the hatching parameter, AKB was more toxic than Roundup. No significant genotoxicity to zebrafish larvae was found. We concluded that AKB and Roundup glyphosate-based formulations are phytotoxic and induce toxic effects in nontarget organisms such as A. salina and zebrafish early life stages. Environ Toxicol Chem 2017;36:1755-1763. © 2016 SETAC [ABSTRACT FROM AUTHOR]

A field experiment was conducted during rabi season of 2011-2012 at College of Agriculture, Vellayani, Kerala, India to evaluate three promising new generation herbicides for managing water cabbage. The experiment was laid out in randomized block design with eight treatments replicated thrice. The treatments comprised of Azimsulfuron @ 20 and 30 g/ha, bispyribacsodium @ 20 and 30 g/ha, (metsulfuron-methyl + chlorimuron-ethyl) @ 4 and 6 g/ha, 2-4 -D @ 1 kg/ha and a weedy check. The results of the field study on weed control efficiency of the different herbicides indicated that 2, 4-D @1 kg a.i. ha-1 was most effective for controlling water cabbage. Among the new generation herbicides (metsulfuron methyl + chlorimuron ethyl) @ 6 g a.i. ha-1 and bispyribac sodium @ 30 g a.i. ha-1 were equally effective for controlling water cabbage. Azimsulfuron at both doses were found to be least effective in controlling water cabbage. [ABSTRACT FROM AUTHOR]

Sunflower (Helianthus annuus L.) is one of the most economically important field crops grown in Bulgaria. In some cases sunflowers from different systems (IMI-SUN or ExpressSUN) are sprayed by mistake with the unappropriated herbicidal product for the growing system – IMI- or Express SUN and reverse. Then, acute or chronic phytotoxic effects (even death of the plants) may occur. In some situations, the plants mistakenly treated with the wrong herbicidal product may recover completely, or to different extents after ameliorative treatment with plant biostimulants. For this reason, two field trials in three consecutive growing seasons in 2017, 2018, and 2019 were conducted. The experiments were performed in the experimental field of the Department of Agriculture and Herbology at the Agricultural University of Plovdiv, Bulgaria. The experiments aimed to evaluate the ameliorative effect of the plant biostimulant Amino Expert® Impuls after imitation of "mistaken" herbicide application. In the first experiment the ExpressSUN sunflower hybrid "P 64 LE 25″ was treated with imazamox, and in the second, the IMI-SUN sunflower hybrid "Bacardi" CLP (Clearfield Plus) was sprayed with tribenuron-methyl. The treatments included untreated control plots, application of imazamox (Pulsar Plus – 2.00 l ha−1), or tribenuron-methyl (Express 50 WG (water-soluble granules) - 0.04 kg ha−1 + Trend 90–0.1%) alone and variants with the ameliorative supplication of plant biostimulant four days after the herbicidal intervention. After the application of the plant biostimulant Amino Expert Impuls for ameliorative treatment, the plants from both cropping systems overcome the herbicide stress to different extents. The Chlorophylls (a and b) and carotenoids as well as net photosynthetic rate were higher for the untreated plants from both technologies. For the treatments where plant biostimulant application was used, an increase of the parameters sunflower head diameter, plant height, seed yield, absolute seed mass, as well as seed oil content were recorded. The obtained results showed that the significant results are in favor of ExpressSun technology. In the event of errors in the application of herbicides in these two cropping systems, the consequences are much more corrective in cases where tribenuron-methyl-tolerant sunflower is treated with Pulsar Plus than if IMI-SUN sunflower is treated with the herbicide Express 50 WG + Trend 90. • Herbicide damage levels in sunflower are hybrid dependable. • Stress caused by "mistaken" herbicidal treatment may be reduced by ameliorative biostimulant application. • Growth and yield performance of herbicide-damaged sunflowers are enhanced after additional treatment with amino acid-containing biostimulant. [ABSTRACT FROM AUTHOR]

Ten species of terrestrial plants, including 6 dicotyledonous and 4 monocotyledonous species, were exposed to a direct overspray of atrazine according to US Environmental Protection Agency seedling emergence and vegetative vigor study guidelines and subsequently evaluated for potential recovery. For each species, no-observed-effect rate (NOER), 10% effect rate, 25% effect rate, and 50% effect rate values were calculated (where possible) for a variety of guideline-required endpoints (but focusing on growth rate) for both the standard experimental phase and a recovery phase; and the rates subsequently were compared. For the seedling emergence study, the standard experimental (designated test 1) and recovery (designated test 2) phases encompassed days 0 to 14 and days 14 to 28, respectively. Similarly, for the vegetative vigor study, test 1 and test 2 encompassed days 0 to 21 and days 21 to 42, respectively. Plants were exposed to atrazine at nominal application rates ranging from 1.1 g active ingredient (a.i.)/ha (0.0010 lb a.i./A) to 28 000 g a.i./ha (25 lb a.i./A), depending on the species; the 28 000 g a.i./ha rate is greater than 12 times the maximum application rate of 2250 g a.i./ha (2 lb a.i./A) registered on corn. For seedling emergence, only 2 of 10 species tested, cabbage and tomato, provided clear rate responses in the initial 14 d of exposure (test 1). Based on a comparison of x% effect rate (ER x) and NOER values for growth rates of shoot length and shoot dry weight for days 0 to 14 relative to days 14 to 28, recovery was apparent for cabbage shoot length growth rate and tomato shoot length and shoot dry weight growth rates. Test application rates selected for the remaining 8 species showed either a weak response that did not allow a clear assessment of recovery or no response at all. For the vegetative vigor study, 9 of the 10 species tested provided clear rate responses in test 1 (days 0-21); corn did not demonstrate any herbicidal response up to the highest rate tested, 28 000 g a.i./ha. Based on comparison of day 0 to 21 (test 1) relative to day 21 to 42 (test 2) ER x and NOER values for shoot length, average growth rates indicated that 8 of 9 species clearly demonstrated an increase in 2 or more metrics (cabbage did not demonstrate a response based on shoot length). Clear recovery was also indicated by an increase in ER x and/or NOER values from test 1 to test 2 for shoot dry weight average growth rates for 7 of the 9 species (corn did not show a response, and oat and soybean showed variable responses). Thus, in most species, where initial herbicidal effects were observed, the effects are largely ameliorated over time. Environ Toxicol Chem 2016;35:1284-1296. © 2015 SETAC [ABSTRACT FROM AUTHOR]

Specific scope: This Standard describes the conduct of trials for the efficacy evaluation of fungicides against Fusarium spp. (FUSASP) causing ear fusariosis of maize. Specific approval and amendment: First approved in 2015‐09. [ABSTRACT FROM AUTHOR]

Specific scope: This Standard describes the conduct of trials for the efficacy evaluation of herbicides in asparagus. Specific approval and amendment: First approved in 2015–09. [ABSTRACT FROM AUTHOR]

Enantioselectivity of chiral pesticide enantiomers should be taken into consideration in pesticide application and environmental risk assessment. The phytotoxicity of the enantiomers of napropamide to cucumber, soybean, and the bioactivity to the target weeds Poa annua and Festuca arundinacea have been studied in this work. To the nontarget crops, the influences of napropamide on the root, shoot, fresh weight, chlorophyll, superoxide dismutase (SOD) and catalase (CAT) activities and membrane lipid peroxides have been studied. (−)-Napropamide was more toxic than the racemate and (+)-napropamide to soybean and cucumber in terms of root, shoot and fresh weight. The content of chlorophyll was not affected by napropamide. The impacts on the activities of SOD, CAT and membrane lipid peroxides showed that napropamide could induce the oxidative stress and rac-napropamide caused a stronger oxidative damage to cucumber and soybean than (−)-napropamide and (+)-napropamide. For the target weeds, the influences of napropamide on root, shoot and fresh weight have been studied. (−)-Napropamid was more active to P. annua , while rac-napropamide was more active to F. arundinacea . To reduce environmental pollution and improve the effectiveness of chiral pesticide, single enantiomer should be developed and produced. This work may provide evidence for developing optical pure product. [ABSTRACT FROM AUTHOR]

The present study compares the practicability, reproducibility, power, and sensitivity of a Myriophyllum aquaticum growth inhibition test in a water-sediment system with the recently accepted Myriophyllum spicatum test in an equivalent testing system and the standard Lemna sp. test. Special consideration was given to endpoints based on M. aquaticum control plant growth and variability of relative growth rate and yield: shoot length, fresh weight, dry weight, and root weight. Sensitivity analysis was based on tests performed with 3,5-dichlorophenol, atrazine, isoproturon, trifluralin, 2,4-dichlorophenoloxyacetic acid, and dicamba. Growth rates for average M. aquaticum control plants were 0.119 d-1 and 0.112 d-1, with average estimated doubling time 6.33 d and 6.74 d for relative growth rate fresh weight and shoot length, respectively. Intrinsic variability of M. aquaticum endpoints was low: 12.9%, 12.5%, and 17.8% for relative growth rate shoot length, relative growth rate fresh weight and yield fresh weight, respectively. The power of the test was fairly high. When the most sensitive endpoints were used for comparison, the 2 Myriophyllum species were similarly sensitive, more sensitive (in the case of auxin simulators), or at least equally sensitive as Lemna minor to other tested herbicides. The M. aquaticum 10-d test with a 7-d exposure period in a water-sediment system has acceptable sensitivity and can provide repeatable, reliable, and reproducible results; therefore, it should not be disregarded as a good and representative additional test in environmental risk assessment. Environ Toxicol Chem 2015;34:2104-2115. © 2015 SETAC [ABSTRACT FROM AUTHOR]