Herbicide Mixtures Research Articles

Glyphosate-resistant downy brome (Bromus tectorum) control using alternative herbicides applied postemergence

AbstractDowny brome is a troublesome facultative winter-annual grass weed that invades agricultural and nonagricultural lands in western North America and can cause substantial crop yield losses particularly in no-till winter wheat. Glyphosate-resistant (GR) downy brome was identified in southern Alberta in 2021, representing the first confirmation of a GR grass weed in Canada. This study was designed to evaluate alternative herbicides and herbicide mixtures applied postemergence (POST) for control of GR and glyphosate-susceptible (GS) downy brome populations at the seedling stage under a controlled environment. The GR downy brome did not exhibit cross-resistance to other herbicides applied POST. Quizalofop alone or in combination with imazamox, imazamox + bentazon, or imazamox/imazethapyr, and glufosinate mixed with either clethodim or tiafenacil resulted in ≥80% visible control, plant mortality, and reduction in biomass of both GR and GS downy brome populations 21 d after treatment. Diligent stewardship of these remaining herbicide options is warranted since downy brome populations with resistance to herbicides that inhibit acetyl-CoA carboxylase or acetolactate synthase have been reported in neighboring states.

Leaching of herbicides mixtures from pre-exposed agricultural plastics severely impact microalgae

Farmlands represent a source of aged plastics and pesticides to the surrounding environments. It has been shown that chemicals can be sorbed and desorbed from plastics, but the interaction between plastic and mixtures of pesticides and their effects on freshwater biota has not been assessed yet. The aim of the work was to assess the potential role of agricultural plastics as vectors for a mixture of two herbicides and the impact of the herbicide mixture lixiviated from them towards the freshwater microalga Chlamydomonas reinhardtii. Pristine and aged polyethylene plastics collected from agricultural areas were exposed to the herbicides, bifenox, oxyfluorfen and their mixtures. The microalgae were exposed for 72 h to the leachates desorbed from plastics and the effect was quantified in terms of total chlorophyll content and several physiological parameters assessed by flow cytometry. Our results showed that changes in physicochemical properties (hydroxyl and carbonyl index, hydrophobicity, texture) in aged plastics increased their capacity to retain and to desorb the herbicides. Microalgae exposed to leachates containing bifenox, oxyfluorfen, or their mixture showed reactive oxygen species overproduction, lipid peroxidation, membrane potential hyperpolarization, intracellular pH acidification, and a loss of metabolic activity. The toxicological interactions of the leachate mixture were assessed using the Combination Index (CI)-isobologram method showing antagonism at low effect levels turning to synergism when the effect increased. In this work, we proved the hypothesis that ageing increases the capacity of agricultural plastics to behave as vector for toxic chemicals to the biota.

Synergistic and Antagonistic Herbicide Interactions for Control of Volunteer Corn in Glyphosate/Glufosinate/2,4-D-Resistant Soybean

Weed interference from glyphosate/glufosinate-resistant (GGR) volunteer corn can reduce soybean yield and quality. The recent release of glyphosate/glufosinate/2,4-D choline (GG2)-resistant soybean will allow for expanded POST herbicide mixture options for broad-spectrum weed control. Herbicide antagonism between ACCase-inhibiting graminicides and synthetic auxin herbicides has been confirmed for various grass weed species, including volunteer corn. Field experiments (total of 4) were carried out in 2021 and 2022 in southwestern Ontario to assess volunteer corn control with combinations of glufosinate, 2,4-D choline, or dicamba plus clethodim or quizalofop-p-ethyl applied POST to GG2-resistant soybean. Quizalofop-p-ethyl and quizalofop-p-ethyl + glufosinate controlled GGR volunteer corn 95 and 98%, respectively, 6 weeks after application (WAA); adding 2,4-D choline or dicamba to quizalofop-p-ethyl reduced control to ≤ 15%. Clethodim controlled GGR volunteer corn 81%, and the addition of glufosinate increased control to 97%; the co-application of 2,4-D choline or dicamba with clethodim reduced GGR volunteer corn control to 58 and 45%, respectively at 6 WAA. ACCase-inhibiting herbicides co-applied with glufosinate resulted in a synergistic improvement in GGR volunteer corn control while co-applications with synthetic auxin herbicides resulted in an antagonistic decrease in GGR volunteer corn control. Greater antagonism occurred when the synthetic auxin herbicides were co-applied with quizalofop-p-ethyl than clethodim. All mixtures of quizalofop-p-ethyl or clethodim with 2,4-D or dicamba resulted in unacceptable control of GGR volunteer corn.

Allelochemical of Archidendron jiringa Pods and Sorghum bicolor Biomass Extracts Combined with a Premixed Formulation of Atrazine and Mesotrione

The aim of this research was to evaluate the allelochemicals in jering pods and sorghum biomass extracts combined with premixed formulations of the herbicides, atrazine and mesotrione. The research was conducted in the laboratory and experimental field of the Department of Agronomy, University of Bengkulu, Indonesia, from December 2019 to July 2020. The allelochemicals in jering pods and sorghum biomass extracts and their combination with the herbicides were tested on seed germination, and weed control was tested on corn grown in polybags. The results showed that aqueous extracts of jering pods and sorghum biomass combined with the herbicide mixtures of atrazine and mesotrione did not inhibit the seed germination of corn but suppressed the length and the weight of the radicles and plumules. The study of the efficacy of jering pods and sorghum biomass extracts on the weeds (total of grasses and broadleaves) revealed that the two agents, when applied separately, suppressed weed biomass by 27 and 32%, respectively. When the two extracts were combined, their combined efficacy increased to 56%. Furthermore, the plant height, stem diameter, and corn stover weight increased with the allelochemicals and herbicide treatments. The cobs yield per plant increased from 19 to 22% with the separate application of the allelochemicals found in the jering pods and sorghum biomass, respectively, and from 27 to 34% when the allelochemicals were combined with the herbicides. This research provided a novel approach using the allelochemical extracts from jering pods and sorghum biomass as natural herbicides for weed control.

Development of the soybean root system under the influence of weeds, nitrogen mineral fertilizers and herbicides

Aim. The research was to examine the effectiveness of tank mixtures of soil and post-emergence herbicides on the background of mineral and symbiotic nitrogen for implementation of optimal conditions for the functioning and development of the soybean root system. The article presents the results of research on the development of the root system of soybeans under the compatible effect of herbicides and the backgrounds of nitrogen nutrition. Methods. Field research was carried out on the lands of the stationary crop rotation of the Agronomic Research Station of the National University of Life and Environmental Sciences of Ukraine. The cultural plant cultivation technology is generally accepted for the zone. Results. The research results indicate a significant negative impact of crop weed infestation on the formation of the root system of soybeans: the decrease in its raw weight compared to plants in areas free from weeds (with two manual weedings) amounted to 35–44% and the total capacity – by 41–47%. The use of a tank mixture of soil herbicides Zenkor (0.4 l/ha) and Kommand (0.2 l/ha) in the system of protecting soybean crops from weeds resulted in an increase in raw weight and volume of the root system by 1.2–1.5 times with an efficiency close to manual weeding. Pre-sowing seed inoculation had a significant effect on the development of the soybean root system – symbiotic nitrogen increased the raw weight and volume of the root system by 32% and 40% appropriately. The application of the tank mixture Zenkor + Kommand provided the maximum growth upon these biometric indicators within the combined background of mineral and symbiotic nitrogen, where the total volume of the root system increased more than twice. Close correlations were found between both parameters of the soybean root system (r = 0.896). Conclusions. A high correlation dependence (r = 0.785) of soybean productivity on the extent of development of its root system was established. It was noted that while an effective combination of protection and fertilization systems soybeans are able to accumulate in the soil a significant amount of valuable biomass enriched with biological nitrogen, which in field experiments reached 5.6–5.9 t/ha, which was almost three times higher than in the absolute control (2.1 t/ha).

Analysis and management of herbicidal mixtures in a high-intensity agricultural landscape in Belgium.

Water bodies located in anthropogenically influenced environments, such as agricultural landscapes, may be exposed to different chemicals simultaneously or sequentially. Yet, current environmental risk assessments focus on single active substances for unintended mixtures. For 3.5 years, the present study monitored the mixture of herbicides, within an intensively managed agricultural catchment, accompanied by a stewardship program. Twelve herbicides and one metabolite were monitored on a daily to sub-daily basis, generating a unique, high temporal resolution data set, enabling an assessment of cumulative exposure in a worst-case scenario. Analyses focused on the number of events at which the herbicide mixture concentration exceeded the regulatory accepted concentration for algae and macrophytes, based on concentration addition, and the potential factors influencing the frequency of these events are considered. A low number of individual herbicides drove the toxicity and only two of these overlapped for the two organism groups, algae and macrophytes. The observed exceedance events coincided with seasonal influences, and low rainfall during the 2011 season correlated with a highly reduced number of these events. The major influence was found to be the implementation of the stewardship program, which directed farmers to use more advanced farming techniques, avoid spillages, and other point sources. The number of exceedance events was reduced by more than half for algae (9% of the daily mean samples in 2010 and 4% in 2013) and by approximately 10 times for macrophytes (36% in 2010 to 3% in 2013). This high-resolution monitoring data set illustrates how knowledge of the influencing factors can help reduce unintended exposure to chemicals and achieve real-world improvements. Overall, a single-substance assessment is protective of mixture effects. Where mixture effects do play a role, local measures to manage point sources are more effective than changes to the desk-based environmental risk assessments that focus on diffuse sources. Integr Environ Assess Manag 2023;19:1297-1306. © 2022 Cambridge Environmental Assessments RSK ADAS Ltd and Bayer AG. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).

The timing of oilseed flax sowing in the steppe zone of Western Siberia

In the steppe zone of the Omsk region from 2020 to 2022 two sowing periods (May, 15 and 25) of Severny oilseed flax with a seeding rate of five million germinated seeds per hectare on four chemicalization backgrounds were tested. With the norm for the steppe zone of the HTC 0.78 all the years of the experiments this indicator was only 0.37-0.58. Having sowed in the third decade of May, the yield of oilseed flax seeds with the use of a tank mixture of herbicides (Agritox, WC 1 l/ha and Legion, EC 0,4 l/ha) with a working fluid flow rate of 200 l/ha 0.868 tons of oilseeds were obtained from 1 ha and 1.009 t/ha were obtained with the help of a complex chemicalization, where Lingohumate 100 g/ha was used during the leaf development phase in a mixture of herbicides and Isagry Bor 0.5 l/ha during the building phase. They provided a profitability level of 197 %. Similar results were obtained having used only herbicides – 179.9 %. Ammophos’s introduction during sowing did not bring a significant increase in yield and reduced economic indicators. Having sowed in the second decade of May, the annual oilseeds yield was significantly lower and, accordingly, the level of profitability was decreasing sharply from 27.8 to 87.8 %.

Comparison of the competitive ability of legumes against weeds

Background. Legumes are a very important element of crop rotation, they have a high potential for protein production. Reducing weed infestation of these plants during the critical period of competition is essential for crop success, previous crop value and high seed yields. Evaluation of the competitive ability of legumes grown in Poland against weeds can be a valuable indication of which species to grow in conditions of increased weed infestation of fields, reduced doses of herbicides, unfavorable weather conditions, or systemic limitations of weed control technology. Material and methods. In a two-factor field experiment carried out in 2014–2015, the competitive ability of edible and fodder peas, yellow and white lupines and soybean against weeds was assessed. The reaction of these plants to chemical weed control and its lack was compared. Results. Abandonment of herbicide protection, compared to the application of a mixture of soil herbicides containing linuron and clomazone immediately after sowing, significantly increased the number and weight of weeds. Lack of weed control of selected legume plants resulted in a proven decrease in seed yield of: edible pea by 20%, fodder pea by 23%, yellow lupine by 32%, white lupine by 23% and soybean by 77%%. The yield of the tested legume plants was negatively correlated with the weight and number of weeds. Conclusion. The tested legume plants – edible pea, fodder pea, yellow lupine, white lupine and soybean – differed in their competitive ability against weeds. Soybean was the most sensitive to the presence of weeds, followed by yellow and white lupines, and the least sensitive were edible and fodder peas. In conditions of high weed infestation of fields and difficulties in keeping stands clean, the legume plant most recommended for cultivation is pea. Its cultivation allows obtaining seed yields of more than 3 Mg·ha-1, even in the absence of weed control.

EFFECTIVENESS OF HERBICIDES IN CORN AGROCENOSES

Maize is one of the least competitive crops with weeds in its crops, so cultivated plants can lose their productivity potential most during the initial stages of growth and development. The critical period of the impact of weeds on corn is 40–50 days, it lasts from germination to the shedding of panicles - flowering. Counting weeds on the experimental sites on average over two years of research showed that the number of grass and dicotyledonous weeds was within 159 pcs./m2. Application of Astral + Kideka herbicides at rates (0.9 l/ha + 1.1 l/ha) in the phase of 3-5 leaves of corn in combination with the biopreparation Agrinos B showed that the level of weediness, compared to the control without herbicides, decreased by 73.6% 30 days after application of the drugs, and by 99.3% during the period of corn harvesting. The number of weeds in the control plots of the experiment (without application of herbicides) for the period of corn grain harvesting was within 142 pieces/ha, and the air-dry weight was equal to 3207 g/m2, while in the areas where herbicides were applied, the air-dry weight was 19-130 g/m2. Reduction to control in the range of 96.0-99.4%. The highest rates of corn grain yield were noted in the areas where the tank mixture of Astral + Kideka herbicides was applied, at the rate of application of 0.9 l/ha + 1.1 l/ha + Agrinos B, at the rate of consumption of 1.0 l/ha in the phase of 3-5 leaves of corn. In these areas, on average, over two years of research, the yield of corn grain was within 7.03 t/ha, which is 4.79 t/ha or 213.8% more than the control areas. The use of tank mixtures of herbicides and biological preparations is an economically beneficial measure. In addition, the dose of chemical preparations is reduced, which helps to reduce the pesticide load on the environment.

Primena kombinacije herbicida tritosulfuron i florasulam bespilotnom letelicom u usevu ozime pšenice

Wheat is one of the most important agricultural crops used in human nutrition worldwide. Depending on the level of weediness, weedy plants can lead to significant yield losses, which according to some estimates can reach up to 10% worldwide. Unmanned aerial vehicles (UAVs) are widely used in chemical crop protection, but so far the effectiveness of herbicides applied by UAVs has not been sufficiently studied. The aim of this work was to investigate the possibility of using UAVs in the application of the herbicide combination tritosulfuron and florasulam in the protection of winter wheat from weeds. Efficacy of the abovementioned combination of herbicides was tested in the case of application of a low volume of treatment by UAV, as well as by means of a field sprayer. Combination of herbicides tritosulfuron and florasulam applied by an UAV (volume rate 30 l ha-1) showed high efficiency in controlling the weed species Capsella bursa-pastoris, Lactuca serriola, Sinapis arvensis and Viola arvensis, while the efficiency of the same combination was lower in the case of application with a field sprayer. Based on the results of the experiment, which indicated good efficacy of the tested herbicide mixture, we can conclude that from the aspect of successful protection of winter wheat from weeds, the use of UAV is fully justified.

Bio-efficacy of herbicide mixtures on weed dynamics in direct wet-seeded rice

Bio-efficacy of herbicide mixtures on weed dynamics in direct wet-seeded rice

Sublethal effects of the herbicides atrazine and glyphosate at environmentally relevant concentrations on South American catfish (Rhamdia quelen) embryos

The objective of this work was to evaluate the effects following exposure (96 h) of South American catfish (R. quelen) embryos to active ingredients and commercial formulations from atrazine and glyphosate, isolated and in mixtures, at environmentally relevant concentrations. While the survival rates were not affected, sublethal effects were evidenced after exposure. The most frequent deformities were fin damage and axial and thoracic damage. The mixture of active ingredients caused an increase in SOD and GST, differing from the treatment with the mixture of commercial formulations. The activity of AChE was significantly reduced following the treatment with the active ingredient atrazine and in the mixture of active ingredients. In general, herbicide mixtures were responsible for causing more toxic effects to R. quelen embryos. Therefore, these responses showed to be suitable biomarkers of herbicides’ exposure, in addition to generating more environmentally relevant baseline data for re-stablishing safety levels of these substances in aquatic bodies.

Effectiveness of using the mixtures of herbicides flumioxazine and fluorochloridone in sunflower crops

Aim. This work is devoted to the search for potential partners for the integrated application of flumioxazine in sunflower crops. This herbicide is an inhibitor of protoporphyrinogen oxidase (PPO) in weed plants. The resistance to this class of herbicides is not yet common today, compared to other classes. Therefore, the work is aimed at de- veloping flumioxazine-based herbicide compositions that effectively prevent the emergence of herbicide-resistant weed biotypes. Methods. The interaction effects, weed control efficiency, and crop selectivity were studied when flumioxazine was used in the mixtures with herbicides acetochlor and propisochlor (long-chain fatty acid synthesis (LCFAS) inhibitors), promethrin (electron transport (ET) inhibitor in photosystem 2 (PS 2) of chloroplasts) and fluorochloridone (inhibitor of carotenoid synthesis by blocking the activity of phytoendesaturases (PDS)) both in the experiments on sunflower crops and in greenhouse experiments using the model objects. Results. The studies have shown that when flumioxazine is applied with the ET inhibitor, promethrin, the interaction is antagonistic, resulting in poor weed control efficiency and sunflower yield decrease. The tank mixtures of flumioxazine with LCFAS inhibitors acetochlor and propisochlor provide high weed control efficiency but are low in selectivity for sunflowers. The interaction between flumioxazine and fluorochloridone within the recommended application rates is additive. The tank mixture of flumioxazine and fluorochloridone herbicides at the application rates of 55 and 500 g/ha, respectively, is selective for sunflowers. In terms of control efficiency of annual dicotyledons, this mixture of herbicides exceeded, and in terms of control efficiency of annual cereal weed species was only slightly inferior to the control integrated herbicide (metolachlor + terbuthylazine). In these application rates, flumioxazine and fluo- rochloridone provided sunflower yield on par with this complex herbicide. Сonclusions. Among the investigated herbicides, the optimal partner of flumioxazine for complex use in sunflower crops was the herbicide, inhibitor PDS, fluorochloridone. Given that flumioxazine and fluorochloridone differ in their phytotoxicity mechanisms but share a common spectrum of controlled weed species, the use of a mixture of these herbicides is a factor that minimizes the likelihood of the emergence of herbicide-resistant weed biotypes.

Sequential application of herbicide options for controlling Conyza sumatrensis in soybean pre-sowing

The aim of this study was to evaluate the efficacy of sequentially applied herbicides to control Conyza sumatrensis, one of the most widely distributed weeds worldwide, in soybean pre-sowing burndown. The study was conducted under field conditions in the state of Paraná, Brazil, at 2018-2019 growing season. The experiment consisted of a randomized block design with four replicates, with 12 treatments consisting of different herbicide mixtures applied before sowing. Control of C. sumatrensis, injury to soybean plants, and variables related to agronomic performance were evaluated. The control levels were high for all treatments, except for the one that was free of saflufenacil in either of the two applications. These results highlight the importance of saflufenacil in the control of C. sumatrensis and show promise for the use of saflufenacil/imazethapyr when considering the system and other weeds. All studied treatments were selective to soybean, which showed higher injury values in the presence of diclosulam; however, this did not compromise the agronomic performance of soybean. Highlights • Application of systemic herbicides with sequential application of burndown herbicides, is essential for the control of Conyza sumatrensis (>15 cm height).• Saflufenacil, flumioxazin, and imazethapyr stand out in the control of Conyza sumatrensis.• Protox and ALS inhibitors can replace paraquat in sequential application with equal efficacy in the control of Conyza sumatrensis.

Efficacy of New Herbicide Mixtures on Weed Control, Yield, and Economics in Transplanted Rice

Aim: To evaluate the efficacy of new herbicide mixtures on the weed control and performance of transplanted rice.
 Study Design: Randomized Complete Block Design.
 Place and Duration of Study: AlI India Coordinated Research Project on Weed Management, PJTSAU, Hyderabad between August to December, 2021.
 Methodology: The efficacy of herbicide mixtures either ready mix or as tank mixtures were evaluated for effective and broad spectrum weed control in transplanted rice during kharif season, 2021 at AICRP on Weed Management, PJTSAU, Rajendranagar, Hyderabad. The experiment was laid out in a randomized complete block design with nine treatments and three replications. The treatments included five ready mixes (RM) one tank mix combination of new herbicides tested against one single herbicide, weedy check and hand weeding twice at 20 and 40 DAT.
 Results: The results of the study revealed that bispyribac sodium 10% SC 25 g ha-1+ penoxsulam 1.02% (20 g ha-1) (tank mix) as post-emergence (POE) fb hand weeding (HW) at 40 DAT or penoxsulam 0.97% (20 g ha-1) + butachlor (38.8%) @ 820 g ha-1 (RM) as POE fb HW at 40 DAT or penoxsulam 1.02% (20g ha-1) + cyhalofop butyl 5.1% (100 g ha-1 ) (RM) as POE fb HW at 40 DAT or bensulfuron methyl 0.6% (60 g ha-1) + pretilachlor 6% (600g ha-1) GR (RM) as pre-emergence (PE) fb HW at 40 DAT were equally effective to hand weeding twice at 20 and 40 DAT with respect to suppression of weeds at 60 DAT. The yield attributes like a number of tillers/m2, panicles no, panicle length, grains panicle-1 and test weight were found to be higher with penoxsulam 1.02% (20 g ha-1) + cyhalofop butyl 5.1% (100 g ha-1) as POE fb HW at 40 DAT which also recorded higher grain yield, straw yield, gross returns, net returns and B-C ratio but it was found to be at par with other herbicide combinations.
 Conclusion: It can be concluded that new herbicide mixtures either as ready mix or tank mix performed better than sole application or hand weeding alone.

Effect of herbicide tank mixes on crop infestation and yield of spring wheat

The article presents the results of studies of tank mixtures of herbicides in the sowing of spring wheat variety Novosibirskaya 15. The results of the studies showed that the studied tank mixtures of herbicides effectively fought against weeds - the technical efficiency of the tank mixture of herbicides Lastik Top, MKE + Magnum Super, VDG was 90.2 %, tank sweep Lastik Extra, EC + Ballerina Super, SE - 89.1 %. Reducing the adverse effects of weeds contributed to an increase in yield - the use of a tank mix of herbicides Lastik Top, MKE + Magnum Super, VDG allowed to obtain an increase in yield of 1.06 t/ha or 39.6 %, a tank mix of Lastik Extra, KE + Ballerina Super, SE – 1.08 t/ha or 40.0 % in comparison with the control variant.

CONTROL OF CORN POLLUTION IN THE CONDITIONS OF THE RIGHT-BANK FOREST STEPPE

This article presents the results of studies of the main elements and methods of controlling the development of weeds in corn crops and the identified changes in water and nutrient properties of the soil. The optimal tank mixtures and technological combinations of new soil and insurance herbicides have been determined, which provide a high level of technical efficiency on a wide species spectrum of weeds that clog corn crops. In particular, for farm conditions, the complex nature of the formation of the type of weediness, which changes during the growing season of the crop, was noted. The results of assessments of the dynamics of weed vegetation indicate a gradual increase in cenotic tension due to the gradual transition of dominant species of weeds, such as Chenopodium album L., Amaranthus retroflexus L., Echinochloa crus-galli L., Elytrigia repens (L.) Gould , Sonchus arvensis L, Cirsium arvense L., Convolvulus arvensis L. in the middle tier of sowing with a simultaneous increase in the frequency of their determination by 1.1-1.3 times. It was established that the best growth and development of the total leaf surface of corn plants (2.15-2.26 pcs./m2) was noted on the herbicide agro background and complete removal of weeds, and with natural weediness of the crops - a negative effect on growth processes, size and duration of functioning of leaves (1.14 pcs./m2). According to the research results, the technical efficiency against weeds of the first wave reached 100% when combining soil and insurance herbicides - Dual Gold - 1.5 l/ha (before sowing) + Stellar - 1.25 l/ha + Surfactant Metolate - 1.25 l/ha (by stairs); during the second and subsequent waves of weeds, protection systems that combine vegetative and soil deterrent effects are best controlled (Stellar - 0.8 l/ha + Akris - 1.5 l/ha + Surfactant Metolate - 0.8 l/ha and Kelvin Plus - 0.3 kg/ha + Akris - 1.5 l/ha + PA Hasten - 1 l/ha). The highest yield of corn grain (6.98 t ha-1 and 6.81 t ha-1) was obtained from the combination of soil and insurance preparations Akris (before sowing) + Kelvin Plus and PAR Hasten (after the steps) and Dual Gold (before sowing) + Stellar and surfactant Metolat (by stairs); Akris + Stellar + metolat surfactant (yield - 6.68 t ha-1) was singled out among post-emergence herbicide mixtures; with autonomous use of the preparations Stellar and Kelvin Plus, the yield was 6.35 t ha-1 and 6.22 t ha-1, respectively. The identical economic expediency of using such variants of herbicide application on corn Akris, 1.5 l/ha + Stellar, 0.8 l/ha + Metolat surfactant, 0.8 l/ha and Stellar, 1.25 l/ha + Metolat surfactant, has been confirmed ,1.25 l/ha, which was 43% higher than in the control with natural weeding and 33.2-33.4% higher than in the option of inter-row cultivation with manual weeding.

The effect of tank mixture of herbicides on the contamination of crops and productivity of spring wheat

Relevance. The main advantage of this method is its high biological efficiency (up to 90% or more) against the background of a quick payback from a significant increase in production due to the stored harvest. At the same time, in some cases, it becomes possible to manipulate the timing of the use of herbicides, taking into account their selectivity, operational qualities, as well as the industrial employment of the forces and means of an agricultural enterprise engaged in weed control. Therefore, the study and selection of modern herbicides in the fight against weeds is an urgent task of great practical importance.Methods. The object of research is a variety of spring soft wheat Zlata. The predecessor is potatoe. The seeding rate is 5.5 million. The scheme of the experiment included 2 options: 1) control (without the use of herbicides); 2) the use of a tank mixture of herbicides («Ballerina»+ «Bomba» + «Lastic Extra»). The sowing area of the crop is 3 ha, the area of the accounting plots is 50 m2, the repetition of the experiment is 3 times.Results. The conducted studies have shown that under experimental conditions, the share of juvenile monocotyledonous weeds in spring wheat crops accounted for 68.9%, of juvenile dicotyledonous weeds — for 31.1% of the total number. The most widespread among them were: Echinochla crusgalli — 68.9%, Chenopodium album — 13.1%, Amaranthus retroflexus — 6.2% and Galeopsis tetrahit — 5.2%. The use of a tank mixture of herbicides «Ballerina» + «Bomba» + «Lastic Extra» made it possible to reduce the number of weeds by 90.4–94.1%, reduce the loss of biological grain yield by 14%, ear weight —by 7%, productive bushiness — by 5%, weight of 1000 grains —by 2%, and also increase the yield of spring wheat grain by 0.68 t/ha and get an additional profit of 1.9 thousand rubles/ha.

Improved Adsorption of the Toxic Herbicide Diuron Using Activated Carbon Obtained from Residual Cassava Biomass (Manihot esculenta).

The production and consumption of cassava (Manihot esculenta) occur in several places worldwide, producing large volumes of waste, mostly in the form of bark. This study sought to bring a new purpose to this biomass through producing activated carbon to use as an adsorbent to remove the herbicide Diuron from water. It was observed that the carbon contains the functional groups of methyl, carbonyl, and hydroxyl in a strongly amorphous structure. The activated carbon had a surface area of 613.7 m2 g-1, a pore volume of 0.337 cm3 g-1, and a pore diameter of 1.18 nm. The Freundlich model was found to best describe the experimental data. It was observed that an increase in temperature favored adsorption, reaching a maximum experimental capacity of 222 mg g-1 at 328 K. The thermodynamic parameters showed that the adsorption was spontaneous, favorable, and endothermic. The enthalpy of adsorption magnitude was consistent with physical adsorption. Equilibrium was attained within 120 min. The linear driving force (LDF) model provided a strong statistical match to the kinetic curves. Diffusivity (Ds) and the model coefficient (KLDF) both increased with a rise in herbicide concentration. The adsorbent removed up to 68% of pollutants in a simulated effluent containing different herbicides. Activated carbon with zinc chloride (ZnCl2), produced from leftover cassava husks, was shown to be a viable alternative as an adsorbent for the treatment of effluents containing not only the herbicide Diuron but also a mixture of other herbicides.

The response of barley varieties and its companion weed to spraying with chemical herbicides

A field experiment was carried out to evaluate the efficiency of selected weed herbicides in controlling the growing weed with barley.The experiment was carried out using randomized complete block design, by split plots arrangement with three replicates. The results showed the superiority of the mixture of herbicides (U 46 1 L.ha-1) + (Axial 1.5 L.ha-1) (H1 ) by giving the best weed control, where this treatment reduced the number of weeds in the experiment to give 0.00 plant.m-2. It also gave the best control percentages by 100% that was reflected in giving the best grain yield of 1.57 ton.ha-1, whose results were close to the treatment of hand weeding. Besides, the variety Iba 265 achieved the best results compared to the other varieties used in the study, as it gave the highest grain yield of 1.82 ton.ha-1 compared to the control treatment which gave the lowest grain yield amounted to 0.98 ton.ha-1.