Glyphosate Solution Research Articles

Combined effect of glyphosphate, saccharin and sodium benzoate on rats

Herbicides and food additives are included in many food products for humans. Non-used products or products beyond their expiry date are deposited in places of utilizatioin of solid municipal wastes, where they can take effects on the organisms of mouse-like rodents. Among the herbicides, glyphosphate takes first place in the world for volume of production, and is the most intensely used in agricultural farming. The discussion about negative impact on the organisms of mammals, especially against the background of using various substances and environmental factors, continues. In this study, we determined the combined effect of glyphosphate and food additives on the organism of laboratory animals, which manifested in changes in body weight, condition and indices of mass of the internal organs and blood parameters. Four groups of laboratory male rats were formed, which over 42 days received: unlimited access to clean water; 1% aqueous solution of glyphosate; 1% solution of glyphosphate and 1% solution sodium benzoate; 1% solution of glyphosphate with 1% solution of saccharin. Glyphosphate and glyphosphate with sodium benzoate and saccharin significantly reduced the daily increases in body weight of animals compared to the control group. The studied substances have notable suppressive effect on the immune system and haematopoiesis in general, which is manifested in reduce of relative mass of the thymus and spleen against the background of increase in the amount of lymphocytes in the peripheral blood. The inhibition of haematopoiesis is indicated by decrease in the amount of erythrocytes, neurophils and hemoglobin of blood of animals from the experimental groups. The impact on the digestive system of glyphosphate and food additives is indicated by occurance of the effect of “irritation” of mucous membranes, and, as a result, disorders in absorption followed by the disorder in metabolic processes. A dysbalance occurs in enzymic systems of the organism, which is manifested in distrophic processes, especially in the liver parenchyma, indicated by the activity of blood enzymes (ALT, AST, alkaline phosphatase), total number and ratio of proteins of blood plasma. We determined the impact of glyphosphate and its mixes with benzoate and saccharin on the pancreas, which manifests in severe pancreatitis with steep increase in the level of glucose of blood. The results of the study allow us to state that mixture of glyphosphate and food additives can cause toxic effect in animals and humans, which often contact with herbicides.

The Teratogenic Effects of Glyphosate Based Herbicide (GBH) on the Development of Chick Embryos

Objective: This study was conducted to investigate the teratogenic effects of GBH by using chick embryo as an animal model. Methods: The equal volume of 0.1 ml of 0.01%, 0.05%, 0.3%, and 0.5% w/v glyphosate solution were injected into yolk sacs of fertilized White Leghorn eggs at 21 h of incubation and repeated at the volume of 0.05 ml on the 3rd day of incubation. The embryos were observed for abnormalities on day 3, 6 and 10 of incubation. Results: The results showed that the mortality percentages increased as the concentration of glyphosate increased. Day 3 chick embryos showed retardation of development and several abnormalities, for instance, the irregular shape of the brain vesicles with an opening of anterior neuropore, small eye primordia with the optic cup and lens vesicle retardation, looser of the heart looping with dilated lumen, lesser number of branchial arches, absent of limb bud or tail fold. Day 6 chick embryos showed severe retardation of several organs. Microphthalmia, anophthalmia, ectopia cordis and ectopic viscerae were observed in day 6 chick embryos. On day 10, most embryos died earlier and living embryos showed normal external features but delayed ossifications which were significantly different from the control (P<0.05). Conclusion: Glyphosate was toxic to chick embryos which directly caused mortality and was also a powerful teratogen which caused growth retardation and malformations on day 3 and day 6 and skeletal alteration on day. The effects were predicted to occur in other embryos including humans. Pregnant women should avoid contamination with GBH especially in the first trimester of pregnancy.

Identifying glyphosate-tolerant maize by soaking seeds in glyphosate solution

The identification of glyphosate-tolerant maize genotypes by field spraying with glyphosate is time-consuming, costly and requires treatment of a large area. We report a potentially better technique of seed-soaking to identify glyphosate-tolerant maize genotypes. The effects of soaking maize seeds in glyphosate solution under controlled conditions were studied on seed germination rate, seedling morphological indices, seedling growth and leaf chlorophyll content. These responses were compared among a glyphosate-tolerant transgenic maize cultivar CC-2, glyphosate-susceptible inbred line Zheng 58 (the recurrent parent of CC-2) and hybrid cultivar Zhengdan 1002. The results showed that the germination rate, seedling morphological indices and leaf chlorophyll content of glyphosate-tolerant CC-2 seeds did not change significantly among five different concentrations of glyphosate treatment (0 to 2%). In contrast, germination rates, seedling morphological indices and leaf chlorophyll contents of Zheng 58 and Zhengdan 1002 seeds were significantly negatively affected by exposure to increasing concentrations of glyphosate. The glyphosate-tolerant inbred line CC-2 displayed a strong tolerance to glyphosate after soaking in 0.1 to 2.0% glyphosate solutions, while both the inbred line Zheng 58 and hybrid Zhengdan 1002 were susceptible to glyphosate. The accuracy of the glyphosate-soaking method for screening glyphosate-tolerant maize was confirmed using a field spraying trial.

Effects of glyphosate on the ovarian function of pregnant mice, the secretion of hormones and the sex ratio of their fetuses

Glyphosate is the active ingredient of the commercial formulation Roundup®, which is used worldwide. This study aimed to investigate the toxic effects of pure glyphosate or Roundup® on pregnant mice and their fetuses during pregnancy. From gestation days (GDs) 1–19, ICR mice were orally administered distilled water, 0.5% glyphosate solution or 0.5%-glyphosate Roundup® solution. The ovaries and serum were collected at GD19. The results showed decreases in body weight gain and, ovary and liver weight in glyphosate-treated mice. Additionally, histopathological alterations in the ovary including increased atretic follicles, interstitial fibrosis and decreased mature follicles were observed in the groups treated with glyphosate. The serum concentrations of both progesterone and estrogen were markedly altered after glyphosate exposure, and there were also changes in the expression of GnRH, LHR, FSHR, 3β-HSD and Cyp19a1 genes at the hypothalamic-pituitary-ovarian axis. Furthermore, oxidative stress was observed in the treated mice, increasing the activity of T-AOC, CAT and GSH-Px, as well as the MDA content in both the serum and ovary. With regard to litters, the sex ratio was significantly altered by pure glyphosate. These results show that glyphosate is able to cause several effects on pregnant mice, such as ovarian failure, interference with hormone secretion by affecting the steroidogenesis-related gene expression, and oxidative stress. The sex ratio of litters was also influenced by prenatal exposure to pure glyphosate.

Horseradish Peroxidase Immobilized on Polyaniline onto Monocrystalline Silicon for Glyphosate Herbicide Detection

In this work a special electrode configuration with potential application in enzymatic biosensors for the detection of glyphosate was studied. The enzyme used was Horseradish Peroxidase (HRP), which was immobilized on a polyaniline film (PAni), electrodeposited on the surface of the n-type monocrystalline silicon electrode. PAni has the ability to bind to biomolecules and thereby potentiate their biocatalytic properties by favoring the transfer of electrons between enzyme and substrate. Monocrystalline silicon is one of the most used materials in electronic technology due to its semiconductor character. In this work, different parameters were investigated in the electrode preparation, including concentration of polyaniline in the electrodeposition solutions, as well as the electrodeposition times and potentials. The response of the electrode as biosensor was evaluated by the electric current density characteristic of hydroquinone oxidation in the presence of standardized glyphosate solutions. The peroxidase enzyme catalyzes the oxidation of hydroquinone to the o-quinone form in the presence of hydrogen peroxide. In turn, glyphosate inhibits the activity of HRP and causes a reduction of the electric current density in the biosensor electrode. The results obtained with glyphosate using the proposed method are in agreement with the literature and show that the n-Si/PAni/HRP biosensor maintains the catalytic activity and is of considerable interest due to the simple procedure in practical applications and a promising platform for the lack of environmental monitoring for these contaminants.

Influence of Airspeed and Adjuvants on Droplet Size Distribution in Aerial Applications of Glyphosate

Abstract. Drift is one of the most hazardous consequences of an improper aerial application of glyphosate. Wind, droplet size, application height, and distance to sensitive areas are the most important factors for drift. Droplet size is affected by nozzle, operating pressure, flight speed, deflection angle, and physicochemical properties of the spray solution. The objective of this study was to evaluate the effect of flight speed and the use of adjuvants on droplet size spectra in aerial applications of glyphosate. The study was conducted in a high-speed wind tunnel at the Pesticide Application Technology Laboratory (University of Nebraska-Lincoln, West Central Research and Extension Center, North Platte, Neb.). Aerial applications were simulated with four different airspeeds (44.4, 52.8, 61.1, and 69.4 m/s) and glyphosate combined with adjuvants (high surfactant oil concentrate, microemulsion drift reduction agent, nonionic and acidifier surfactant, polyvinyl polymer, and glyphosate alone). Droplet size spectra were evaluated using a Sympatec Helos laser diffraction instrument measuring 90 cm from the nozzle tip (CP11-4015). The volumetric droplet size distribution parameters (VMD, DV0.1, and DV0.9) and the percentage of droplets smaller than 100 µm were reported. The relative span was calculated to indicate the droplet size homogeneity [(DV0.9 - DV0.1) / DV0.5]. Glyphosate solutions with adjuvants had a larger VMD than the glyphosate alone solution at 44.4 m/s wind speed. At 69.4 m/s only the glyphosate solution with polymer had a larger VMD. Conversely, the glyphosate with polymer had the smallest DV0.1, and the greatest relative span and percentage of droplets smaller than 100 µm. Generally, adjuvants influence on droplet size was diminished or muted as the airspeed was increased. The polymer tested in this study failed as a drift agent reduction agent, especially at higher airspeeds. While not all polymers were tested, cautions should be taken if using these types of adjuvants in aerial applications. The interaction of airspeed and adjuvants influencing droplet size distribution in aerial applications of glyphosate should be considered by applicators in order to mitigate glyphosate drift to the surrounding environment. Further studies are necessary to better understand the interaction between solution viscosity and air shear effect on the atomization process and droplet size distribution, as well as confirm that trends hold true for other adjuvants in the polymer class. Although applicators tend to operate aircrafts with increased flight speeds in order to optimize the application time efficiency, this practice can reduce or mute adjuvants effects, decrease the droplet size distribution, and increase drift potential in aerial applications of glyphosate. Keywords: Drift reduction technologies, Flight speed, High-speed wind tunnel, Laser diffraction.

Glyphosate impairs learning in Aedes aegypti mosquito larvae at field-realistic doses.

Glyphosate is the most widely used herbicide in the world. Over the past few years, the number of studies revealing deleterious effects of glyphosate on non-target species has been increasing. Here, we studied the impact of glyphosate at field-realistic doses on learning in mosquito larvae (Aedes aegypti). Larvae of A. aegypti live in small bodies of water and perform a stereotyped escape response when a moving object projects its shadow on the water surface. Repeated presentations of an innocuous visual stimulus induce a decrease in response due to habituation, a non-associative form of learning. In this study, different groups of larvae were reared in water containing different concentrations of glyphosate that are commonly found in the field (50 µgl-1, 100 µgl-1, 210 µgl-1 and 2 mg l-1). Larvae reared in a glyphosate solution of 2 mg l-1 (application dose) could complete their development. However, glyphosate at a concentration of 100 µg l-1 impaired habituation. A dose-dependent deleterious effect on learning ability was observed. This protocol opens new avenues to further studies aimed at understanding how glyphosate affects non-target organisms, such as insects. Habituation in mosquito larvae could serve as a parameter for testing the impact of pollutants in the water.

Impact of Glyphosate on the Rhizosphere Microbial Communities of An EPSPS-Transgenic Soybean Line ZUTS31 by Metagenome Sequencing.

Background:The worldwide use of glyphosate has dramatically increased, but also has been raising concern over its impact on mineral nutrition, plant pathogen, and soil microbiota. To date, the bulk of previous studies still have shown different results on the effect of glyphosate application on soil rhizosphere microbial communities.Objective:This study aimed to clarify whether glyphosate has impact on nitrogen-fixation, pathogen or disease suppression, and rhizosphere microbial community of a soybean EPSPS-transgenic line ZUTS31 in one growth season.Method:Comparative analysis of the soil rhizosphere microbial communities was performed by 16S rRNA gene amplicons sequencing and shotgun metagenome sequencing analysis between the soybean line ZUTS31 foliar sprayed with diluted glyphosate solution and those sprayed with water only in seed-filling stage.Results:There were no significant differences of alpha diversity but with small and insignificant difference of beta diversity of soybean rhizosphere bacteria after glyphosate treatment. The significantly enriched Gene Ontology (GO) terms were cellular, metabolic, and single-organism of biological process together with binding, catalytic activity of molecular function. The hits and gene abundances of some functional genes being involved in Plant Growth-Promoting Traits (PGPT), especially most of nitrogen fixation genes, significantly decreased in the rhizosphere after glyphosate treatment.Conclusion:Our present study indicated that the formulation of glyphosate-isopropylamine salt did not significantly affect the alpha and beta diversity of the rhizobacterial community of the soybean line ZUTS31, whereas it significantly influenced some functional genes involved in PGPT in the rhizosphere during the single growth season.

Determination of phenolic compounds and assessment of the genotoxic and proliferative potential ofPsidium cattleianumSabine (Myrtaceae) fruits

AbstractThe purpose of this paper was to investigate the proliferative and genotoxic activity of juices from fruits of Psidium cattleianum, also known as strawberry guava, using the Allium cepa test. Fruits were collected and frozen for subsequent juice preparation at a concentration of 125 g l−1. The treatments consisted of T1: distilled water (negative control), T2: juice of yellow strawberry guava collected in Arroio Grande, T3: juice of yellow strawberry guava collected in Palma, T4: juice of red strawberry guava collected at UFSM, and T5: 1% glyphosate solution (positive control). Eight thousand cells per treatment were analysed and the mitotic indices (MI) were calculated. The juice samples were analysed by high-performance liquid chromatography (HPLC). Statistical analyses were performed using the chi-square and Tukey tests (p < 0.05). The results show irregularities in the cell division, mainly during metaphase, and an antimitotic effect in addition to an increase in the MI in treatments containin...

Sweetpotato Response to Simulated Glyphosate Wick Drip

Field studies were conducted in 2009 at Clinton, NC and 2014 at Pontotoc, MS to determine the influence of simulated glyphosate drip on sweetpotato yield and quality. Treatments consisted of three glyphosate solution (140 g ae L–1) drip volumes (0.16, 0.32 and 0.48 ml) by four application timings [(4 wk after transplanting (WAP); 6 WAP; 8 WAP; and 4 WAP followed by (fb) 6 WAP fb 8 WAP]. A non-treated check was included for comparison. Visual sweetpotato injury consisted of chlorosis at the shoot tips approximately 1 wk after treatment fb necrosis and stunting. At 6 WAP and 8 WAP, sweetpotato injury following glyphosate applied 4 WAP was 71 and 65%, respectively. Injury from glyphosate applied 4 WAP fb 6 WAP was 78%. Injury from glyphosate applied 6 WAP was 26% at 8 WAP. In 2009, jumbo, no. 1, canner, and marketable yield of the non-treated check were two to three times greater than glyphosate treatments (0.16, 0.32, 0.48 ml). Likewise, yield of the non-treated check was substantially greater than those treated with 0.16 to 0.48 ml glyphosate solution in 2014. In 2009 and 2014, sweetpotato yield of all grades increased as glyphosate application timing was delayed. In 2009, no. 1 yield from glyphosate 8 WAP (8,210 kg ha–1) was similar to the non-treated check. In 2009, there were no cracked storage roots in the non-treated check. However, sweetpotatoes receiving 0.16 to 0.48 ml glyphosate solution displayed 8 to 17%, 11 to 18%, 5 to 13%, and 11 to 16% cracking (by weight) in jumbo, no. 1, canner, and marketable storage roots, respectively. Compared to the non-treated check, glyphosate applied 4 WAP, 6 WAP, or 4 WAP fb 6 WAP fb 8 WAP had a greater percentage of cracked marketable sweetpotato storage roots.

Glyphosate hormesis in broad-leaved weeds: a challenge for weed management

ABSTRACTLittle is known of glyphosate-induced hormesis in weeds and how this might influence weed management. To test the hormetic effect of low doses of glyphosate on broad-leaved weeds, two experiments were conducted, in the laboratory and the screenhouse. The hormetic effects of glyphosate solution in growth media (0, 65, 130, 250, and 500 g acid equivalent (a.e) ha−1) and foliar spray (0, 4, 8, 16, 32, and 64 g a.e. ha−1) were tested on four broad-leaved weeds (Coronopus didymus, Chenopodium album, Rumex dentatus, and Lathyrus aphaca). Glyphosate solution in the range 65–250 g a.e. ha−1 stimulated the germination and seedling growth of all tested weeds. However, at 500 g a.e. ha−1 inhibition of germination and growth was observed. Foliarly applied glyphosate in the range 4–32 g a.e. ha−1 increased root and shoot length, dry biomass, and seed production ability of all four weeds species; however, the stimulatory response was species dependent. These results indicate that glyphosate hormesis could play a significant role in altering crop/weed competition and might influence weed management.

Efficient electrochemical treatment based on electrodeposited thin films of birnessite for mineralisation of AMPA (aminomethylphosphonic acid) in very soft conditions

The presence of AMPA in environment becomes today a real problem due to its persistence, its toxicity, and its multiple origins (main metabolite of glyphosate, the pesticide the most used in the world; degradation product of personal care and industrial products). This paper reports the development of a simple, effective, cheap and easy electrochemical treatment, for mineralising AMPA under very soft conditions: at room temperature, at free pH, and in a classical open electrochemical cell. The electrode material used is an electrodeposited thin film of birnessite, a non-toxic material, synthesised in very soft conditions. The original idea is to couple the spontaneous oxidative properties of birnessite to an electrochemical oxidation treatment in the aim to increase its reactivity towards this pollutant. Very good mineralisation rates and capacity (≈0.115g AMPA mineralized by gramme of birnessite) were obtained with very low energy supplies (Q≈3C). Some tests performed with concentrated glyphosate solutions, one of its main parents, give also good results allowing us to envisage the development of an easy method of wastewater treatments at very low costs in complement of classical methods and/or directly at the source of pollution.

Effects of soil treated glyphosate on growth parameters and chlorophyll content of maize Zea mays L. and bean Phaseolus vulgaris L. plants

Extended use of glyphosate poses the problem of its accumulation into soil and further on crops. The objective of this study was to evaluate the effects of different doses of soil glyphosate on growth parameters and chlorophyll content of maize Zea mays L. and bean Phaseolus vulgaris L. plants. An experiment was arranged in randomized complete blocks design with ten replications. Glyphosate solutions were applied to the soil in six concentrations, two subdoses of 0.1 and 0.2 g, the recommended dose of 0.4 g and three overdoses of 0.6, 0.8 and 1.0 g kg-1 of soil. An uncontaminated soil control was used. At 21, 28, 35 and 42 days after sowing (DAS), evaluations of plant height, number of leaves, stem diameter, leaf surface and plant injury were conducted. At 42 DAS, nodulation (in bean), root length, chlorophyll and dry matter yield were assessed. Already at the recommended dose and beyond, glyphosate caused significant damage to growth characteristics, nodulation and chlorophyll content in both plants. Some similar effects of the product were observed on the both plants at each time period. Therefore, there was an evidence that soil glyphosate already at the recommended dose had an inhibitory and even a phytocide effects on non-target plants.

Clinical and Hematological Effects of Glyphosate Herbicide on Clarias gariepinus Juvenilles

Juveniles of Clarias gariepinus were exposed to 0.00mg/l (control) 20mg/l, 40mg/l and 60mg/l of glyphosate solution for 96 hours. Clinical signs were observed and blood was analyzed for hematological parameters such as haemoglobin (Hb), packed cell volume (PCV), white blood cell (WBC), red blood cell (RBC) and its indices: mean corpuscular haemoglobin concentration (MCHC), mean corpuscular haemoglobin (MCH) and mean corpuscular volume (MCV). The results from the study indicated a significant (P

Morphological Differences in Response to Physiological Integration and Spatial Heterogeneity of Root Zone Glyphosate Exposure in Connected Ramets of Ludwigia peploides (Creeping Water Primrose)

The effects of applying glyphosate to the root zone of one of a pair of connected ramets were investigated. In the low root density (LRD) treatment, daughter ramet roots were exposed to 100 mL of 10 mg L−1 glyphosate, while in the high root density (HRD) treatment, mother ramet roots were exposed to the same glyphosate solution. These treatments were compared to unexposed controls. The morphologies (leaf and shoot numbers) of control and HRD treatments were identical. In these treatments, daughter ramets had greater numbers of leaves and shoots than mother ramets. The morphology of the LRD treatment was opposite: mother ramets had more leaves and shoots than daughter ramets. Growth parameters were unaffected by glyphosate exposure except for relative growth rate, which was significantly greater for the HRD treatment. This study provides insights about the responses of clonal plants to physiological integration and spatially heterogeneous environmental stressors.

Developing an effective glyphosate application technique to control Bischofia javanica Blume, an invasive alien tree species in the Ogasawara Islands

Bischofia javanica is a non-native tree species in Japan's Ogasawara Islands, where it threatens native tree species due to its rapid propagation and growth. An effective method is needed to limit the expansion of B. javanica populations and to conserve the natural forest ecosystem of the islands. For this purpose, we examined the effectiveness of a new application technique for the herbicide glyphosate on B. javanica. In this method, glyphosate solution is directly injected into holes drilled in the stem, and each hole is then plugged with a cork stopper to prevent loss of the solution, namely the drill-and-plug method. We also developed an allometric regression model linking stem diameter with total aboveground biomass (AGB) to estimate the necessary herbicide dosage. Our results suggest that between 0.1 and 0.5 g kg−1 (active ingredient per unit AGB) is required to control most B. javanica trees. Verification of the drill-and-plug method using the minimum dosage (0.1 g kg−1) showed that most of the herbicide-treated trees were killed. These results suggest that the drill-and-plug method can help control the B. javanica invasion of the Ogasawara Islands.

Detection of the onset of glyphosate-induced soybean plant injury through chlorophyll fluorescence signal extraction and measurement

In this study, chlorophyll fluorescence (ChlF) was used to detect the onset of soybean plant injury from treatment of glyphosate, the most widely used herbicide. Thirty-six pots of nonglyphosate-resistant soybean were randomly divided into three groups and treated with different doses of glyphosate solutions. The three treatment groups were control (CTRL) group (with no glyphosate treatment), 0.25X group (treated with 0.217 kg·ae/ha solution of glyphosate), and 0.5X group (treated with 0.433 kg·ae/ha solution of glyphosate). Three kinds of fluorescence measurements, steady-state fluorescence spectra, Kautsky effect parameters, and ChlF-related spectral indices were extracted and generated from the measurements in the glyphosate treatment experiment. The mean values of these fluorescence measurements for each of the CTRL group, the 0.25X group, and the 0.5X group were calculated. Glyphosate-induced leaf injury was then analyzed by examining the separability of these mean values at 6, 24, 48, and 72 hours after the treatment (HAT). Results indicate that the peak position of far-red ChlF shows an obvious blue shift for glyphosate-treated soybean, and peak values of steady-state fluorescence spectra for the three groups can be significantly distinguished from each other at 48 HAT and later. Four Kautsky effect parameters, Fv, Fv/Fm, Area, and PI, are parameters sensitive to glyphosate treatment, showing some differences between the CTRL group and treated groups at 24 HAT, and significant differences among the three groups at and beyond 48 HAT. Moreover, ChlF-related spectral indices, R6832/(R675·R690) and R690/R655, are also shown to be useful in detection of the glyphosate injury, though they are less effective than the steady-state fluorescence spectra and the Kautsky effect parameters. Based on the presented results, it can be concluded that glyphosate-induced soybean injury can be detected in a timely manner by the ChlF measurements, and this method has the potential to be further developed into practical use.

Quick tests for detecting glyphosate-resistant Italian and perennial ryegrass

Three quick tests were evaluated for detecting glyphosate-resistant biotypes of Italian ryegrass and perennial ryegrass. Biotypes of these two species were used that were 13.4 and 7.3 times more resistant to glyphosate, respectively, than susceptible biotypes when assessed using a sprayed pot study. One assay exposed germinating seeds of resistant and susceptible populations for 8 days to different concentrations of glyphosate. Measurements of reduction in seedling root growth gave an estimate of resistance magnitude of 10.8 and 8.9 for Italian ryegrass and perennial ryegrass, respectively, similar to that from the sprayed pot study. Two other assays were tested and were able to differentiate resistant and susceptible biotypes. One measured the relative levels of shikimic acid in leaves following exposure to glyphosate; four to seven times more shikimic acid accumulated in glyphosate-susceptible populations of Italian and perennial ryegrass than in resistant populations. The other assay involved growing tillers of the plants in glyphosate solutions and the results showed that at glyphosate concentrations of 10 and 40 mg/L, the plantlets of resistant plants showed negligible visual injury and growth reduction compared with susceptible ones. Results obtained from these assays were not affected by whether the glyphosate formulation used was an isopropylamine salt or potassium salt.

Glyphosate affects the spontaneous motoric activity of intestine at very low doses – In vitro study

Glyphosate is an active substance of the most popular herbicides worldwide. Its common use results from the belief that it affects exclusively plants. However, studies on glyphosate and its trade formulations reveal that it causes numerous morphological, physiological and biochemical disturbances in cells and organisms of animals, including mammals. Due to the fact that shortly after oral exposure glyphosate is detected in the highest amount in small intestine, the aim of this study was to evaluate the effect of this compound on the spontaneous motoric activity of intestine under in vitro conditions. The experiments were conducted on rat jejunum strips under isotonic conditions. The strips were incubated in buffered (pH 7.35) and non-buffered (pH 5.2) glyphosate solutions ranged from 0.003 to 1.7g/L. The results indicate that glyphosate applied in buffered solution affects significantly the spontaneous motoric activity of rat isolated jejunum strips. The muscle response is biphasic (miorelaxation accompanied by contraction). The contraction is observed already at a dose of 0.003g/L and the first significant biphasic reaction at a dose of 0.014g/L. The incubation of jejunum strips with glyphosate in non-buffered solution (pH 5.2) results in a different reaction. The smooth muscle undergoes only persistent relaxation, which is stronger than the response to glyphosate solution in pH 7.35. Motility disturbances are also observed after glyphosate removal from the incubation solution. The gathered data suggests that glyphosate impairs gastrointestinal strips’ motility at concentration that are noticed in human exposed to non-toxic doses of glyphosate.

Early Detection of Crop Injury from Glyphosate on Soybean and Cotton Using Plant Leaf Hyperspectral Data

In this paper, we aim to detect crop injury from glyphosate, a herbicide, by both traditionally used spectral indices and newly extracted features with leaf hyperspectral reflectance data for non-Glyphosate-Resistant (non-GR) soybean and non-GR cotton. The new features were extracted by canonical analysis technique, which could provide the largest separability to distinguish the injured leaves from the healthy ones. Spectral bands used for constructing these new features were selected based on the sensitivity analysis results of a physically-based leaf radiation transfer model (leaf optical PROperty SPECTra model, PROSPECT), which could help extend the effectiveness of these features to a wide range of leaf structures and growing conditions. This approach has been validated with greenhouse measured data acquired in glyphosate treatment experiments. Results indicated that glyphosate injury could be detected by NDVI (Normalized Difference Vegetation Index), RVI (Ratio Vegetation Index), SAVI (Soil Adjusted Vegetation Index), and DVI (Difference Vegetation Index) in 48 h After the Treatment (HAT) for soybean and in 72 HAT for cotton, but the other spectral indices either showed little use for separation, or did not show consistent separation for healthy and injured soybean and cotton. Compared with the traditional spectral indices, the new features were more feasible for the early detection of glyphosate injury, with leaves sprayed with a higher rate of glyphosate solution having larger feature values. This trend became more and more pronounced with time. Leaves sprayed with different glyphosate rates showed some separability 24 HAT using the new features and could be totally distinguished at and beyond 48 HAT for both soybean and cotton. These findings demonstrated the feasibility of applying leaf hyperspectral reflectance measurements for the early detection of glyphosate injury using these newly proposed features.