Roundup WG Research Articles

Assessing testicular morphofunctionality under Roundup WG® herbicide exposure in zebrafish.

Glyphosate-based herbicides, like Roundup WG® (RWG) used for a range of crops, such as corn, soybean, coffee, sugarcane, rice, apple, and citrus, can reach aquatic ecosystems and impact non-target organisms like fish. Thus, the fish were exposed to three RWG concentrations plus one negative control, which represents the concentration allowed for inland Brazilian waters and concentrations found in surface water worldwide (0.0, 0.065, 0.65, and 6.5mg a.i./L) for 7 and 15days. Morphological analysis revealed significant alterations in the testicular structure, particularly in Sertoli cell extensions and cytoplasmic bridges between germ cells. Subcellular compartments also displayed alterations, including dilated mitochondria and the loss of electron density and autophagic vesicles. Gene transcript levels related to autophagy and steroidogenic regulation were upregulated in exposed fish. Germ cell quality was also affected, increasing ROS (reactive oxygen species) production and DNA fragmentation. The study highlighted the RWG reproductive toxicity, providing valuable insights into understanding the morphofunctional alterations in somatic and germ cells of Danio rerio. In conclusion, the environmental relevant concentrations used in this study were toxic to male somatic and germ cells, which raises a concern about the concentrations considered safe for human and animal use.

Bioherbicide effects of Trichoderma koningiopsis associated with commercial formulations of glyphosate in weeds and soybean plants

Given the environmental impacts and the need to control resistant weeds, there is a growing demand for alternative products that are less harmful to human health and the environment. In this sense, this work evaluated the effect of the bioherbicide produced based on Trichoderma koningiopsis as alternative weed control, which was associated with different doses of three formulations of the commercial herbicide glyphosate (isopropylamine salt, ammonium salt, and potassium salt), on the morpho-physiological characteristics of weeds of Euphorbia heterophylla L. and Brachiaria plantaginea (Link) Hitch.; and in the soybean crop (Glycine max L.). The experiment was carried out in vases with a completely randomized design, with five replications. The treatments consisted of keeping the plants in the presence and absence of the bioproduct (Trichoderma koningiopsis) in isolation and associated with 10, 20, 50, 70, 90, and 100% (m/v) of the herbicide dose recommended by the manufacturer. Plant performance was evaluated by morphological characteristics of height and weight of plants, length, and diameter of roots and stem, and visual phytotoxic effects. The herbicides Zapp Qi®, Roundup Original®, and Roundup WG® associated with T. koningiopsis controlled the E. heterophylla plant from the lowest concentration (10% m/v) that caused 80%–90% of plant control. In the control of B. plantaginea, the treatments were efficient (100%) from half the recommended dose concentration of the commercial products. In the soybean crop, no significant phytotoxic visual damage or interference in the morphological characteristics of plants was observed. The association of synthetic herbicides with the bioherbicide proved efficient in controlling weeds and promising for reducing doses of synthetic herbicides.

Histo Hepatic Alterations in Commercially Important Fish (Pseudoplatystoma corruscans Spix & Agassiz, 1829) Exposed to a Glyphosate-Based Herbicide

The presence of herbicides in the aquatic environment can cause different effects at all levels of biological organization. This study aimed to evaluate the hepatic alterations of the herbicide Roundup WG® on juvenile Pseudoplatystoma corruscans exposed to three different concentrations of this chemical compound: 0.25g/1000L, 0.50g/1000L, and 0.75g/1000L, plus control treatment (0.00g/1000L). The experiment lasted sixty days and, in the end, liver fragments were collected for further histological processing, using the hematoxylin-eosin (HE) technique. Only the control group showed a statistically significant increase in body mass and total length during the experiment. Blood glucose also showed no difference among the sample groups. The lesions found in the liver considered severe were hemorrhage, vacuolization, and hypertrophy of hepatocytes and the presence of free melanomacrophages, recorded in the groups exposed to 0.50 and 0.75g/1000L. The results obtained in the present study indicate that the herbicide Roundup WG® can promote liver alterations in Pseudoplatystoma corruscans.

Glyphosate-based herbicides affect behavioural patterns of the livebearer Jenynsia multidentata.

Roundup® is one of the most widely marketed glyphosate-based herbicides in the world. There are many different formulations of this brand that differ from each other in glyphosate concentration, salts and adjuvants, including surfactants, which are labelled as "inert" compounds. Several studies have shown that these formulations are highly toxic to fish, even compared with pure glyphosate. However, mechanisms underlying this toxicity are not fully understood. In this context, this study evaluated the effects of exposure to Roundup Original® (RO), Roundup Transorb® (RT), and Roundup WG® (RWG) on the behavioural patterns of the livebearer Jenynsia multidentata. This fish naturally inhabits agricultural areas in southern Brazil and Argentina where glyphosate is used extensively. In the experiment, animals were exposed to the herbicides for 96 h, at the environmentally relevant concentration of 0.5 mg/L of glyphosate. Swimming performance, anxiety, aggressiveness, long-term memory and male sexual activity were recorded. The formulation RWG negatively affected swimming performance, thigmotaxia and long-term memory consolidation. Conversely, RT reduced the sexual performance of males. These results confirm that Roundup® formulations are extremely harmful and also that they have different targets of toxicity, affecting behaviours that are essential for fish survival.

Reproductive toxicity of Roundup WG® herbicide: impairments in ovarian follicles of model organism Danio rerio.

Glyphosate-based herbicides are widely used in global agriculture, and their effects on different non-target animal organisms have been the focus of many toxicological studies. Regarding the potential role of glyphosate-based herbicides as an endocrine disruptor, the present study aims to investigate the effects of the herbicide Roundup WG® (RWG) on female reproduction, specifically on the ovarian maturation of Danio rerio. Adult females were exposed to low concentrations of RWG (0.065, 0.65, and 6.5 mg L-1) for 15 days, and then the ovaries were submitted to structural and morphometric procedures, accompanied by analysis of the vitellin protein content. Our results showed an increase of initial ovarian follicle numbers, decrease of late ovarian follicles, and smaller diameter of ovarian follicles in fish exposed to 0.065 and 6.5 mg L-1. The thickness of vitelline envelope was reduced, and the vitellin protein content was increased in the ovarian follicle in the two highest concentrations. Ultrastructural changes in the ovarian follicular component were evident and expressed by the cell index; vacuolization in follicular cells, increase of perivitelline space, and impaired mitochondria in oocytes were observed. Therefore, RWG adversely affects the ovarian maturation in D. rerio, and these changes can lead to reproductive toxicity, compromising population dynamics.

Glyphosate-resistant soybeans yield in function of glyphosate salts, doses and stadium phenological

Given the importance of soybean to the global economy and as a food source, improving crop management techniques is integral to obtaining higher yields. As such, this study aimed to assess the yield of soybean cultivars as a function of different glyphosate salt formulations, doses and application times. Two field experiments were conducted simultaneously using a randomized block design and 3x4x2 factorial scheme, with three repetitions. Factor A consisted of three glyphosate formulations: isopropylamine salt (Roundup Original®), ammonium salt (Roundup WG®), and potassium salt (Zapp Qi®), factor B four application times: 0, 14, 28, 42 days after planting (DAP), and factor C two doses: the recommended dose of 720 grams of acid equivalent per hectare and twice that (1440 grams of acid equivalent per hectare). There was no difference between the glyphosate salts for the BMX Ativa RR® cultivar, but yields of BMX Apolo RR® submitted to ammonium salt were 28% higher than those recorded for the other salts studied. Glyphosate potassium salt resulted in lower soybean yields. Potassium salt application between 14 and 28 DAP caused greater toxicity in both the soybean cultivars analyzed.

PERFORMANCE OF SOYBEANS WITH THE APPLICATION OF GLYPHOSATE FORMULATIONS IN BIOSTIMULANT ASSOCIATION

ABSTRACT Glyphosate is the main herbicide used in the Roundup Ready® (RR®) soybean crop. However, the different salt and herbicide formulations available on the market can lead to crop intoxication. In this scenario, biostimulants appear as a promising alternative to mitigate the possible phytotoxic effects of glyphosate. Thus, the objective of this work was to evaluate the effects of different MC Extra® biostimulant doses associated with glyphosate formulations on the agronomic characteristics of a herbicide-tolerant soybean cultivar. Two experiments were conducted in the 2015/16 and 2016/17 seasons with three doses of MC Extra® (0.35, 0.70, and 1.00 kg ha-1) associated with six formulations of glyphosate: Glyphotal®, Roundup Original®, Roundup Ready®, Roundup WG®, Roundup Transorb®, and Zapp QI®, plus additional treatment without the use of the herbicide. In both experiments, we used 900 g e.a. ha-1 of glyphosate. The results showed that the highest dose of MC Extra®, in combination with the Roundup Original®, Roundup Ready®, and Roundup Transorb® formulations and 0,70 kg ha-1 of MC Extra® with Glyphotal® provided the highest grain yields. When used in conjunction with the herbicide, there is a need to increase the dose of MC Extra® to obtain higher soybean yields.

Modulation of antioxidant gene expressions by Roundup® exposure in the decapod Macrobrachium potiuna.

Glyphosate-based herbicides (GBH), including Roundup®, are the most used herbicides in agricultural and non-agricultural areas, which can reach aquatic environments through drift during application or surface runoff. Some studies, mostly in fish, demonstrated that GBH caused oxidative stress in non-target animals. However, only few information is available on the GBH effects in the antioxidant and stress proteins of many other organisms, such as freshwater crustaceans. Thus, we aimed to investigate the effects of environmentally relevant GBH concentrations on the relative transcript expression (RTE) of the superoxide dismutase (sod1), catalase (cat), selenium-dependent glutathione peroxidase (gpx), glutathione-S-transferase (gst), thioredoxin (txn), heat shock protein (hsp70 and hsp90) in the hepatopancreas of the ecologically important freshwater prawn Macrobrachium potiuna. Moreover, this study aimed to assess the gender-differences responses to GBH exposure. Male and female prawns were exposed to three Roundup WG® concentrations (0.0065, 0.065 and 0.28mg of glyphosate/L) and a control group (0.0mg/L) for 7 and 14 days. In general, males had an under-expression of the studied genes, indicating an oxidative stress and possible accumulation of ROS in the hepatopancreas. In the opposite, females had an overexpression of the same genes, indicating a more robust antioxidant system, in order to cope with the possible ROS increase after Roundup WG® exposure. Therefore, results confirmed that gender could be a confounding factor in ecotoxicological assessment of GBH effects. Additionally, this work highlights that sod1, cat, gpx, gst, txn, hsp70 and hsp90 gene expressions seem to be useful biomarkers to investigate the oxidative stress caused by Roundup WG® in Macrobrachium sp.

Effects of low glyphosate-based herbicide concentrations on endocrine-related gene expression in the decapoda Macrobrachium potiuna.

Glyphosate-based herbicides (GBH) are the most used herbicides worldwide and are considered as endocrine-disrupting compounds (EDC) for non-target organisms. However, effects of GBH on their endocrine systems remain poorly understood. Thus, the aim of this study was to assess the effects of low concentrations of Roundup WG® on growth and reproduction process molecules in both males and females of the decapod crustacean Macrobrachium potiuna, by the relative transcript expression levels of the ecdysteroid receptor (EcR), the molt-inhibiting hormone (MIH), and the vitellogenin (Vg) genes. Prawns were exposed to three concentrations of GBH (0.0065, 0.065, and 0.28mgL-1) for 7 and 14days. The results revealed that only in males the three genes transcript levels were influenced by the GBH concentration, time of exposure, and the interaction between the concentrations and time of exposure, suggesting that males were more sensitive to GBH than females. For males, after 7days of exposure at 0.065mgL-1, EcR and MIH were over-expressed, while the Vg expression was only over-expressed after 14days. The present study highlighted that GBH impacted endocrine systems of M. potiuna. Moreover, EcR and MIH gene expressions could be promising EDC biomarkers of exposure in crustaceans. These results also indicate that GBH concentrations, considered secure by regulatory agencies, should be reviewed to minimize the effects on non-target organisms. Potential effects of glyphosate-based herbicides on the endocrine system of decapods Macrobrachium sp.

Histological evaluation of vital organs of the livebearer Jenynsia multidentata (Jenyns, 1842) exposed to glyphosate: A comparative analysis of Roundup® formulations

Roundup formulations are herbicides whose active principle is glyphosate. However, these formulations are potentially more toxic to non-target organisms than pure glyphosate. This study aimed to evaluate and compare the toxic potential of the Roundup formulations through histological alterations in fish. Thus, males and females of the neotropical fish species Jenynsia multidentata (Jenyns, 1842) were exposed for 24 or 96 h to the Roundup Original® (RO), Roundup Transorb® (RT) or Roundup WG® (RWG) formulations, at a fixed concentration of 0.5 mg/L of glyphosate. This concentration is close to the maximum glyphosate limits found in the environment and is non-lethal to J. multidentata. The three formulations caused histological damage to the liver, gills and brain of J. multidentata, which increased over the exposure time. Differences in the histological alterations between females and males were observed in the liver and brain. Females were more tolerant to RO and RT than RWG. Males did not exhibit these differences in sensitiveness with formulations. The RWG caused more damage in the liver and gills and RT in the brain. Overall, there were differences in the toxicity of RO, RT and RWG and the toxic effect was presented through histological damage, reinforcing the usefulness of histological biomarkers for Roundup® toxicity. The comparison of the toxic potential of glyphosate-based herbicides is important because it could give support to the governmental organizations to set protective rules for the water ecosystems and human health, as well as to reduce the use of highly toxic formulations in agriculture.

EFFICIENCY OF GLYPHOSATE COMPLEXED WITH COPPER COMPARED TO THE COMMERCIAL PRODUCT IN Brachiaria decumbens Stapf

<p><span style="font-size: medium;">Glyphosate, a non-selective herbicide with systemic action, is one of the most widely used substances in modern agriculture. With the objective of comparing the efficiency of glyphosate previously complexed with copper (Cu421) with that of the commercial product (Roundup WG®) and the purified substance (purified glyphosate) in controlling <em>Brachiaria decumbens </em>Stapf (signal grass), tests were conducted of the <em>in vitro </em>and <em>in vivo </em>activity of the enzymes 5-enolpyruvylshikimate-3-phosphate synthase (EPSPs) and phenylalanine ammonia lyase (PAL). The Cu421 complex significantly inhibited the EPSPs activity, as did the commercial product. <em>In vivo </em>test showed that treatments increased PAL activity more than double. The Cu421 complexed caused a substantial decline in the Falker chlorophyll index, as well as, the greatest reduction in the fresh mass yield and total protein concentration. In addition, the Cu 421 complexed application resulted in an increase in N-NO3- content in <em>B. decumbens</em>. The Cu421 complex had similar action as Roundup WG® and the purified glyphosate, indicating the possibility of using this complex to control weeds.</span></p>

Action of rain on formulations of glyphosate mixed with saflufenacil for the control of Brachiaria decumbens

ABSTRACT: This study aimed to evaluate the effects of rain on the efficiency of different formulations of glyphosate applied in isolation and in combination with saflufenacil on the control of Brachiaria decumbens. This study was conducted during the first half of 2013. The treatments consisted of an isolated application of three formulations of glyphosate (Roundup Original, Roundup Transorb R, and Roundup WG) at 1,080 g a.e. ha-1 and mixed with saflufenacil at 24.5 g a.e. ha-1 + Dash at 0.5% v/v at six time intervals of simulated rain: 15, 30, 60, 120, 240 and 360 minutes after application of herbicides and a control treatment without rain. We performed visual evaluations of plant control at 4, 7, 14, 21 and 28 days after application of herbicides. The mixture of saflufenacil + Dash with the original Roundup formulations, Roundup Transorb R and Roundup WG increased the control speed of B. decumbens plants regardless of the rain interval studied. The formulations of glyphosate (Roundup Transorb R and Roundup WG) applied in isolation were affected by rains that occurred shortly after spraying. In combination with saflufenacil + Dash, there was a synergistic effect on weed control.

Evaluation of reference genes for reverse transcription-quantitative PCR assays in organs of zebrafish exposed to glyphosate-based herbicide, Roundup

Roundup is a glyphosate-based herbicide (GBH) widely used in agriculture and may cause toxic effects in non-target organisms. Model organisms, as zebrafish, and analysis of gene expression by reverse transcription-quantitative PCR (RT-qPCR) could be used to better understand the Roundup toxicity. A prerequisite for RT-qPCR is the availability of appropriate reference genes; however, they have not been described for Roundup-exposed fish. The aim of this study was to evaluate the expression stability of six reference genes (rpl8, β-act, gapdh, b2m, ef1α, hprt1) and one expressed repetitive element (hatn10) in organs of males (brain, gill, testis) and females (ovary) of zebrafish exposed to Roundup WG at three concentrations (0.065, 0.65 and 6.5 mg N-(phosphonomethyl) glycine/l) for 7 days. Genes were ranked by geNorm, NormFinder, BestKeeper, Delta Ct and RefFinder, and their best combinations were determined by geNorm and NormFinder programs. The two most stable ranked genes were specific to each organ: gill (β-act; rpl8); brain (rpl8; β-act); testis (ef1α; gapdh); and ovary (rpl8; hprt1). The cat transcript level was used to evaluate the effect of normalization with these reference genes. These are the first suitable reference genes described for the analysis of gene expression in organs of Roundup-exposed zebrafish, and will allow investigations of the molecular mechanisms of Roundup toxicity.

Glyphosate Formulations on Nutritional Condition and Productivity of Roundup Ready Soybean

ABSTRACTWe evaluate the effect of different commercial formulations of glyphosate on the nutritional status of Roundup Ready soybeans (TMG 125). The experiment was conducted under field conditions for two agricultural years. The experimental design used was randomized blocks with four repetitions. The treatments were the implementation of Roundup Original, Trop, Roundup Ultra, Roundup WG, Roundup Transorb R and Zapp QI formulations, all at a dose of 720 g e.a. ha−1 of glyphosate and two controls (weeding and no weeding). There was no difference in the accumulation of macronutrients. In the second year of evaluation (2011/2012), manganese (Mn) accumulation was affected by the Trop formulations, Roundup Transorb, Zapp QI, Roundup Ultra, Roundup WG. To the accumulation of zinc (Zn), there was a reduction in the application of Trop formulations and Zapp QI. However, this reduction observed did not influence the response of plants in relation to the productive yield.

Effects of Roundup formulations on biochemical biomarkers and male sperm quality of the livebearing Jenynsia multidentata

Roundup® formulations are the most consumed glyphosate-based herbicides in the world. When applied, they may reach water bodies and exert toxicity toward non-target species. This study evaluated and compared the effects of different variations of Roundup on biochemical biomarkers as oxidative parameters and Acethylchorinesterase (AChE) activity, and sperm quality of the livebearing Jenynsia multidentata. Fish were acutely (96 h) exposed to Roundup Original® (RO), Roundup Transorb® (RT) and Roundup WG® (RWG) at 0.0, 0.5, 1 and 5 mg L−1 of nominal glyphosate. The highest mortality (60%) was observed for fish exposed to RT at the highest concentration tested and at 0.5 mg L−1 non-mortality was observed, so this concentration was chosen for the experiments. Fish exposed to RO and RT (24 and 96 h) presented a state of oxidative imbalance, which caused lipid peroxidation (LPO) in their livers. Oxidative stress was more severe in RO treatment, which may be resulted in the highest hepathosomatic index at 96 h. However, fish exposed to RT presented a marked inhibition of AChE activity from membrane cells of muscle and brain tissues. Sperm quality was investigated in livebearing exposed (24 and 96 h) to the three formulations. Spermatozoa motility and concentration were affected by all formulations. Overall, Roundup formulations are harmful to the fish J. multidentata at 0.5 mg L−1 of glyphosate; however, mechanisms and potential of toxicity are different between formulations. The J. multidentata also represents a sensitive species and a good regional bio-monitor.

Side-Effects of Glyphosate to the Parasitoid Telenomus remus Nixon (Hymenoptera: Platygastridae).

The aim of this study was to compare the side-effects of glyphosate to the parasitoid Telenomus remus Nixon (Hymenoptera: Platygastridae) when parasitoids were exposed to this chemical at the pupal (inside host eggs) and adult stages. Bioassays were conducted under laboratory conditions according to the International Organization for Biological Control (IOBC) standard methods for testing side-effects of pesticides to egg parasitoids. Different glyphosate-based pesticides (Roundup Original®, Roundup Ready®, Roundup Transorb®, Roundup WG®, and Zapp Qi®) were tested at the same acid equivalent concentration. Treatments were classified following the IOBC toxicity categories as (1) harmless, (2) slightly harmful, (3) moderately harmful, and (4) harmful. When tested against T. remus adults, Roundup Original®, Roundup Ready®, Roundup Transorb®, and Roundup WG® reduced parasitism 2days after parasitoid emergence, being classified as slightly harmful. Differently, when tested against T. remus pupae, all tested glyphosate-based products did not differ in their lethal effect and therefore did not reduce T. remus adult emergence or parasitism capacity, being classified as harmless. However, differences on sublethal toxicity were found. Parasitism of individuals emerging from parasitized eggs sprayed at the pupal stage of T. remus with Zapp Qi® was lower compared to control, but parasitism was still higher than 66%, and therefore, Zapp Qi® was still classified as harmless. In conclusion, all tested glyphosate-based products can be used in agriculture without negative impact to T. remus as none was classified as harmful or moderately harmful to this parasitoid when exposure occurred at the pupal or adult stages.

The impact of glyphosate herbicides on soil microbial activity from the Carajás National Forest

The objective of this study was to evaluate the impact of different glyphosate‑based herbicide formulations on microbial activity of soils from Carajas National Forest. We tested three formulations of glyphosate, i.e., Roundup Original®, Roundup Ultra® and Roundup WG® that were applied in five doses: 0; 240; 480; 720 and 1440 g of active ingredient in acid equivalent ha-1, with four replications. Herbicides were sprayed on pots containing 500 g of soil derived from the 0-10 cm layer of the study site. We determined the carbon from microbial biomass (C-MB), microbial respiration rate (MR) and metabolic quotient (qCO2) at one and 28 days after herbicide application. No treatment affected the C-MB and MR at one and 28 days of incubation. There was no difference for qCO2 at any dose of Roundup Ultra® and WG® formulations at one and 28 days of incubation. However, the qCO2 was inhibited by the Roundup Original® at one day post treatment. This parameter was normalized at 28 days after herbicide application. The data indicate that no one of the treatments tested cause significant impact on soil microorganisms of the Carajas National Forest, suggesting that herbicide-based invasive weed control could be used.

Action of rain on the efficiency of herbicides applied post-emergence in the control of Senna obtusifolia

The objective of this study was to evaluate the effect of rainfall on the effectiveness of herbicides applied post-emergence on plants of Senna obtusifolia. The experiment was carried out under green-house conditions and the experimental design was completely randomized design with four replications, with treatments in a 7x8 factorial arrangement (seven herbicides treatments and eight rain intervals). The herbicides used were five formulations of glyphosate (Roundup Original, Roundup WG, Roundup Transorb, Roundup Transorb R and Roundup Ultra) applied at a rate of to 1,080 g a.e. ha-1, glufosinate-ammonium (Finale) at 400 g a.i. ha-1 and 2,4-D (DMA 806) at 1,000 g a.e. ha-1. The rain simulation occurred at intervals of 15; 30; 60; 120; 240, 360, and 480 minutes after the herbicides application. A control treatment without herbicide application was added. Visual evaluations of control plants were taken at 7; 14; 21 and 28 days after application and at the end the dry mass of plants was determined. The rain occurrence after 15 minutes of application of glyphosate formulations Roundup Transorb, Roundup Transorb R and Roundup Ultra did not affect the control efficiency on plants of S. obtusifolia. For formulations of Roundup Original and Roundup WG and, 2,4-D it was necessary a 30 minutes period without rain for an efficient control of weed.

Micorrização, nodulação e produção da soja roundup ready após a aplicação de diferentes formulações de glyphosate

Objetivou-se neste trabalho avaliar o efeito de diferentes formulações à base de glyphosate sobre a colonização micorrízica e nodulação no cultivar de soja RR TMG 125. Os experimentos foram desenvolvidos em condições de campo, em Latossolo Vermelho-Amarelo, durante os anos agrícolas 2010/2011 e 2011/2012. Os tratamentos constaram da aplicação da dose de 720 g e.a. ha-1 das seguintes formulações de glyphosate: Trop®, Roundup Original®, Roundup Ultra®, Roundup WG®, Roundup Transorb R® e Zapp Qi®, além de duas testemunhas (capinada e não capinada). Utilizou-se o delineamento em blocos casualizados com quatro repetições. A matéria seca da parte aérea, nodulação e produtividade de soja não foram influenciadas pelas diferentes formulações de glyphosate. Para a colonização micorrízica, observou-se efeito positivo da formulação Roundup Original®, em relação à testemunha capinada; no entanto, esse efeito não foi contínuo nos dois anos de experimento. A variável número de nódulos foi mais afetada pelas formulações de glyphosate testadas.

Mitigation of glyphosate side effects on non-target plants: use of different agrochemicals as protectants in common bean plants

Objetivou-se avaliar o efeito de diferentes agroquímicos na reversão da fitotoxidez do glyphosate (Roundup WG 0,06 kg ha -1 ) em feijoeiro (Phaseolus vulgaris cv. Carioca), a aplicação do herbicida foi realizada em todas as plantas exceto na testemunha absoluta, aos 31 dias após o plantio (DAP), no estádio de 3° trifólio. Aos 36 DAP, as plantas foram tratadas com: ácido fúlvico 25% (1000 ml ha -1 e 2000 ml ha -1 ), aminoácido (500 ml ha -1 e 1000 ml ha -1 ), fosfito (2000 ml ha -1 e 4000 ml ha -1 ), além de bioestimulante (250 ml ha -1 e 500 ml ha -1 ). Aos 36, 40, 46 e 54 DAP foram conferidas notas às plantas e aos 54 DAP as plantas foram coletadas e determinou-se a área foliar e a massa seca de três plantas. Pelas notas conferidas verificou-se que somente a testemunha absoluta e o aminoácido 500 ml ha -1 apresentaram menores danos do que o tratamento com glyphosate. A área foliar somente mostrou-se maior na testemunha absoluta, sendo que a massa seca revelou-se superior na testemunha absoluta e nos tratamentos com aminoácido 500 e 1000 ml ha -1 . Abstract Glyphosate is an herbicide widely used in agriculture. However, it may causes phytotoxic effects on non-target plants (crops), generating productivity losses. Currently there are evidences about agrochemicals as potential mitigators of glyphosate side effects. Therefore, the objective of this study was to evaluate the effects of distinct doses of fulvic acid 25% (k tionic® 1000 and 2000 mL ha-1), amino acids (Codamin BR® 500 and 1000 mL ha-1), phosphite (Nutex0-30-20®, 2000 and 4000 mL ha-1) and biostimulant (Byozime TF® 250 and 500 mL ha -1) in reversion of fitotoxicity caused by glyphosate on ‘Carioca’ common bean plants. For comparison, plants treated only with glyphosate, and untreated plants (control) were also evaluated. Glyphosate spray (Roundup WG 0.06 kg ha -1) was performed at 31 days after planting (DAP), and agrochemicals were applied at 36 DAP. Phytotoxicity symptoms, as well as leaf area, dry mass of leaves and stems, and physiological indexes were evaluated at 54 DAP. Application of amino acid-based product (500 mL ha-1) significantly reduced (29.90%) phytotoxicity symptoms. Both doses of amino acid-based product increased dry mass of leaves; therefore, they were able to maintain the leaf weight ratio similar to the control plants. However, there was a decrease in leaf area, which was not reverted by any of the agrochemicals. It is concluded that application of amino acid-based product Codamin BR 500 mL ha-1) reduces, even partially, glyphosate phytotoxicity in ‘Carioca’ common bean plants.