Ahybrid molecularly imprinted ratiometric fluorescence probe was constructed based on the characteristic that dicamba (DIC) can brighten the blue fluorescence of Eu-MOFs. According to the change of the fluorescence color of the probe solution from yellow to blue, a smartphone-assisted detection platform was established to realize the visual detection of DIC. The detection limits of fluorescence and smartphone analysis are 0.08μM and 0.27μM, respectively. The sensing mechanism study shows that the reaction belongs to the cross-linking fluorescence enhancement effect. Eu-MOFs form hydrogen bonds with the carboxyl groups of DIC and form a dendritic network structure, which inhibits the non-radiative transition of the luminescent center and improves the charge transfer efficiency to achieve enhanced fluorescence. So, this work provides a method for the fluorescence quantitative detection and on-site visual detection of DIC by smartphone in Hordeum vulgare and Setaria italica.

Although fluorescence analysis methods are widely used in pesticide residue detection, improving their sensitivity and selectivity remains a challenge. This paper presents a novel ratio fluorescence sensor based on the molecular imprinting polymers (MIPs) and metal-enhanced fluorescence for visual detection of dicamba (DIC). Calcium fluoride (CaF2) quantum dots (QDs) were immobilized on the surface of Ag@MIPs, resulting in a blue fluorescence response signal (Ag@MIPs-CaF2). The MIPs shell, which possesses a specific recognition capability, serves as an isolation layer to adjust the distance between Ag nanoparticles and CaF2 QDs for enhancing the fluorescence of CaF2 QDs by up to 7.1 times under optimal conditions. In the presence of DIC, the blue fluorescence was selectively quenched, while the reference signal red fluorescence from cadmium telluride QDs coated with silicon dioxide (CdTe@SiO2) remained relatively stable, resulting in a color change from blue to red. The sensor had a detection limit of 0.16μM for DIC in the range of 1.0 to 50.0μM, recovery rates of 85.4 to 103.5% for actual samples, and an imprinting factor of 3.28. The 3D finite-difference time-domain simulation revealed that the fluorescence enhancement was due to the local electric field amplification. Therefore, the developed sensing system in this work offers a broad application prospect for visual detection of DIC in food samples.

This study investigated the effects of dicamba (DIC), a widely used auxinic pesticide in agriculture, on carp fish as an experimental model, especially examining serum adrenocorticotropic hormone (ACTH), cortisol (CORT), growth hormone (GH), and insulin-like growth factor-1 (IGF-1) levels. Additionally, it analyzed serum tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and interleukin-6 (IL-6) levels, as well as histopathological changes in gill and liver tissues. Fish were exposed to varying doses (1.35 and 13.5ppm) and durations (4 and 30days). Sixty fish were randomly assigned to six groups (10 fish/group) and exposed to the specified DIC concentrations and durations. Following exposure, stress, growth, and immune parameters were assessed, along with pathological changes. Analyses revealed dose-dependent increases in ACTH, CORT, and TNF-α levels in both exposure periods compared to controls. Conversely, decreases in GH, IGF-1, IL-1β, and IL-6 levels were observed. A significant difference (p < 0.05) was noted in the changes of ACTH, CORT, TNF-α, GH, IGF-1, IL-1β, and IL-6 levels between the exposure periods in the subchronic phase for both dose groups. Histopathological examination identified significant alterations in gill and liver tissues across all dose groups. Gill pathology included epithelial separation (aneurysm), shortening and fusion of secondary lamellae, clubbing, reduced interlamellar space, and cartilage tissue damage. Liver histopathology showed hepatocellular degeneration, passive hyperemia, mononuclear cell infiltration, and hepatocyte vacuolization. In conclusion, dicamba exposure induced significant stress, growth, immune, and histopathological changes in carp, highlighting its potential harmful effects on aquatic organisms, especially at higher concentrations and prolonged exposure durations.

A detailed study on the selection of borderline features for accurate mechanism description of the adsorption of different pesticide molecules under different temperature ranges

Dicamba (DIC) is one of the most applied auxin herbicides worldwide. Sublethal effects in the South American native fish Jenynsia lineata exposed to DIC concentrations close to environmental concentrations (0.03-30µg/L) during 48h were analysed thorough the evaluation of catalase (CAT), glutathione S-transferase (GST), superoxide dismutase (SOD) activities and malondialdehyde (MDA) and H2O2 levels for detecting potential oxidative stress. In gills MDA increased showing oxidative damage probably because of an inefficient antioxidant defense. This response evidenced the important role of gills as an organ of direct contact with waterborne contaminants. In addition, other changes in the biomarkers of oxidative stress were observed such as the inhibition of SOD activities in brain and the inhibition of GST in liver. These results show that short- term exposures to environmentally relevant concentrations of DIC could induce sublethal effects in native fish.

Highly efficient catalytic degradation of dicamba using Fe3O4/montmorillonite composite: Mechanism and toxicity assessment

Single and combined toxicity assessment of primary or UV-aged microplastics and adsorbed organic pollutants on microalga Chlorella pyrenoidosa

Environmental-friendly hydrochar-montmorillonite composite for efficient catalytic degradation of dicamba and alleviating its damage to crops

Trump appointees swayed dicamba approval, watchdog reports

The effects of exposure to the herbicide Dicamba (DIC) on tadpoles of two amphibian species, Scinax nasicus and Elachistocleis bicolor, were assessed. Mortality and biochemical sublethal effects were evaluated using acetylcholinesterase (AChE), glutathione S-transferase (GST), glutathione reductase (GR), aspartate aminotransferase (AST), and alanine aminotransferase (ALT) activities and thyroid hormone (T4) levels. The LC50 value at 48h was 0.859 mg L-1 for S. nasicus and 0.221 mg L-1 for E. bicolor tadpoles. After exposure to sublethal DIC concentrations for 48 h, GST activity increased in S. nasicus but significantly decreased in E. bicolor with respect to controls. GR activity decreased only in S. nasicus at all the tested DIC concentrations. AChE activity was significantly inhibited in both S. nasicus and E. bicolor tadpoles at 48 h. DIC also caused significant changes in transamination, as evidenced by an increase in AST and ALT activities in both amphibian species. T4 levels were higher in DIC-treated tadpoles of both species than in controls. The DIC-induced biochemical alterations in glutathione system enzymes and transaminases indicate lesions in liver tissues and cellular function. Moreover, the observed AChE inhibition could lead to the accumulation of acetylcholine, excessively stimulating postsynaptic receptors, and the increase in T4 levels in both species may indicate an overactive thyroid. The commercial DIC formulation showed a high biotoxicity in the two amphibian native species after short-term exposure, controversially differing from the toxicity level indicated in the official fact sheet data. This fact highlights the need for an urgent re-categorization and reevaluation of DIC toxicity in native species.

Toxicity to Rhinella arenarum tadpoles (Anura, Bufonidae) of herbicide mixtures commonly used to treat fallow containing resistant weeds: glyphosate-dicamba and glyphosate-flurochloridone.

Pesticides might increase the production of reactive oxygen species (ROS). Dicamba (DIC) and 2,4-dichlorophenoxyacetic acid (2,4-D) are auxinic herbicides commonly applied in agroecosystems to control unwanted weeds. We analysed the oxidative damage exerted on the fish Cnesterodon decemmaculatus by an acute exposure to DIC- and 2,4-D-based herbicides formulations Banvel® and DMA®, respectively. The Endo III- and Fpg-modified alkaline comet assay was employed for detecting DNA damage caused by oxidative stress, whereas enzymatic and non-enzymatic biomarkers such as the activities of catalase (CAT), glutathione-S-transferase (GST), acetylcholinesterase (AChE), and glutathione content (GSH) were used to assess antioxidant response to these two herbicides. At the DNA level, results demonstrate that both auxinic herbicides induce oxidative damage at purines level. An increase on CAT and GST activities were detected in 48h- and 96h-treated specimens with both auxinics. GSH content decreased in fish exposed to DIC during 48h and to 2,4-D after 96h of exposure. Additionally, a diminished AChE activity in specimens treated with DIC and 2,4-D was observed only after 96h. Total protein content decreased in fish exposed to both auxinics during 96h. These results represent the first evaluation of oxidative damage related to DIC and 2,4-D exposure on a fish species as the Neotropical freshwater teleost C. decemmaculatus.

Genotoxicity by long-term exposure to the auxinic herbicides 2,4-dichlorophenoxyacetic acid and dicamba on Cnesterodon decemmaculatus (Pisces: Poeciliidae)

Opposite effects of mixtures of commercial formulations of glyphosate with auxinic herbicides on the ten spotted live-bearer fish Cnesterodon decemmaculatus (Pisces, Poeciliidae)

Synergism of mixtures of dicamba and 2,4-dichlorophenoxyacetic acid herbicide formulations on the neotropical fish Cnesterodon decemmaculatus (Pisces, Poeciliidae).

In pesticide applications, the buffer zone helps to protect water sources against pesticide contamination. In 2014, in the Adana province, the percentage of herbicides used was approximately 12% in corn, sunflower, soybean and cotton. To control the weeds, fifteen active ingredients (a.i.) were used in these crops in 2014. These a.i. were acetochlor, aclonifen, benfluralin, bromoxynil, clethodim, dicamba, fluazifop-p-butyl, foramsulfuron, linuron, mesotrione, nicosulfuron, oxyfluorfen, prometryn, trifluralin and tritosulfuron. The aim of this study was to assess the risk of these herbicides on aquatic organisms and estimate buffer zone distances for the above agricultural crops in herbicide application. Risk index (RI) values were calculated according to German Drift Model (GDM) and Dutch Drift Model (DDM). Consequently, buffer zone needs for herbicide application of five a.i., namely acetochlor, benfluralin, linuron, prometryn, and trifluralin, were determined in this study. Results showed that acetochlor a.i. has the highest risk to aquatic organisms and needs a buffer zone distance of more than 57 meters in sunflower cultivation. It was assessed that buffer zone distances should be more than 1.32 m for linuron in soybean, 3.5 m for benfluralin in sunflower, 4.13 m for prometryn (1.5 kg a.i./hm2) in sunflower and 4.19 m for trifluralin in cotton and soybean, and 5.54 m for prometryn (2.0kg a.i./hm2) in cotton. There was no need for a buffer zone in corn. Keywords: buffer zone, pesticide, herbicide, risk index, cotton, sunflower, corn, soybean DOI: 10.3965/j.ijabe.20160905.2364 Citation: Yarpuz-Bozdogan N. Assessment of buffer zone for aquatic organisms in pesticide application. Int J Agric & Biol Eng, 2016; 9(5): 227－234.

The acute toxicity of two herbicide formulations, namely, the 57.71% dicamba (DIC)-based Banvel(®) and the 48% glyphosate (GLY)-based Credit(®), alone as well as the binary mixture of these herbicides was evaluated on late-stage Rhinella arenarum larvae (stage 36) exposed under laboratory conditions. Mortality was used as an endpoint for determining acute lethal effects, whereas the single-cell gel electrophoresis (SCGE) assay was employed as genotoxic endpoint to study sublethal effects. Lethality studies revealed LC5096h values of 358.44 and 78.18mgL(-1) DIC and GLY for Banvel(®) and Credit(®), respectively. SCGE assay revealed, after exposure for 96h to either 5 and 10% of the Banvel(®) LC5096h concentration or 5 and 10% of the Credit(®) LC5096h concentration, an equal significant increase of the genetic damage index (GDI) regardless of the concentration of the herbicide assayed. The binary mixtures of 5% Banvel(®) plus 5% Credit(®) LC5096h concentrations and 10% Banvel(®) plus 10% Credit(®) LC5096h concentrations induced equivalent significant increases in the GDI in regard to GDI values from late-stage larvae exposed only to Banvel(®) or Credit(®). This study represents the first experimental evidence of acute lethal and sublethal effects exerted by DIC on the species, as well as the induction of primary DNA breaks by this herbicide in amphibians. Finally, a synergistic effect of the mixture of GLY and DIC on the induction of primary DNA breaks on circulating blood cells of R. arenarum late-stage larvae could be demonstrated.

Agricultural remote sensing has been developed and applied in monitoring soil, crop growth, weed infestation, insects, diseases and water status in farm fields to provide data and information to guide agricultural management practices. Precision agriculture has been implemented through prescription mapping of crop fields at different scales with the data remotely sensed from space-borne, airborne and ground-based platforms. Ground-based remote sensing techniques offer portability, flexibility and controllability in applications for precision agriculture. In weed management, crop injury from off-target herbicide spray drift and herbicide resistance in weeds are two important issues. For precision weed management, ground-based hyperspectral remote sensing techniques were developed for detection of crop injury from dicamba and differentiation between glyphosate resistant and sensitive weeds. This research presents the techniques for ground-based hyperspectral remote sensing for these two applications. Results illustrate the advantages of ground-based hyperspectral remote sensing for precision weed management. Keywords: ground-based remote sensing, hyperspectral, crop injury, herbicide resistance, precision agriculture DOI: 10.3965/j.ijabe.20160902.2137 Citation: Huang Y, Lee M A, Thomson S J, Reddy K N. Ground-based hyperspectral remote sensing for weed management in crop production. Int J Agric & Biol Eng, 2016; 9(2): 98－109.

Noogoora bur (Xanthium strumarium) is a large herbaceous highly competitive annual weed of arable and horticultural crops which is subject to Regional Pest Management Plans in the Waikato and Bay of Plenty regions New Zealand A study with scarified burs showed that most plants emerged from 040 mm and none from 100 mm depth Plants emerged after 8 days from 030 mm after 14 days from 90 mm and continued to emerge over summer with some also germinating in the second year after initiation Cultivated fallow resulted in germination of similar numbers of seeds over two growing seasons with no new seed input Results from a field trial showed that dicamba and atrazine alone or in combination with other products as well as topramezone provided good control of this weed in maize crop

Obtaining oat DH lines is only effective via wide crossing with maize. Seven hundred haploid embryos from 21 single F1 progeny obtained from wide crosses with maize were isolated, divided into four groups according to their size (<0.5 mm, 0.5–0.9 mm, 1.0–1.4 mm, and ≥1.5 mm), and transferred into 190–2 regeneration medium with different growth regulators: 0.5 mg L−1 kinetin (KIN) and 0.5 mg L−1 1-naphthaleneacetic acid (NAA); 1 mg L−1 zeatin (ZEA) and 0.5 mg L−1 NAA; or 1 mg L−1 dicamba (DIC), 1 mg L−1 picloram (PIC), and 0.5 mg L−1 kinetin (KIN). Among all isolated embryos, approximately 46.1% were between 1.0–1.4 mm, while the smallest group of embryos (7.1%) were those <0.5 mm. The ability of haploid embryos to germinate varied depending on oat genotypes and the size of embryos. Haploid embryos <0.5 mm were globular and did not germinate, whereas embryos ≥1.5 mm had clearly visible coleoptiles, radicles, and scutella, and were able to germinate. Germination of oat haploid embryos varied depending on growth regulators in the regeneration medium. Most haploid embryos germinated on medium with 0.5 mg L−1 NAA and 0.5 mg L−1 KIN, while the fewest germinated on medium with 1 mg L−1 DIC, 1 mg L−1 PIC, and 0.5 mg L−1 KIN. One hundred thirty germinated haploid embryos converted into haploid plants. Fifty oat DH lines were obtained after colchicine treatment.Electronic supplementary materialThe online version of this article (doi:10.1007/s11627-016-9788-z) contains supplementary material, which is available to authorized users.