Mass Of Weeds Research Articles

Эффективность пироксасульфона на посевах сои

The purpose of research is to study the effect of the herbicide Karitori, WSG (850 g/kg), based on the new active ingredient pyroxasulfone, on the weed component in soybean crops in the conditions of the Russian Federation. Objectives: to evaluate the biological effectiveness of the herbicide Karitori, WSG, against a complex of weeds; to assess the safety of using the drug for soybean plants; to carry out crop harvest accounting. The experiments were carried out during two growing seasons, 2018 and 2019. In the Altai Region, experiments were carried out on soybean crops of the Altom variety, in the Astrakhan Region – on soybean crops of the Vilana variety, in the Krasnodar Region - on soybean crops of the Bara variety (in 2018) and Arleta variety (in 2019). Spraying the soil with herbicide was carried out before crop germination. The assessment of weediness was carried out using the quantitative-weight method in accordance with the “Guidelines for registration testing of herbicides in agriculture”. The greatest reduction in the overall infestation of soybean crops was noted in the Altai Region under conditions of severe infestation by common barnyard grass. Application 0.1; 0.2 and 0.3 kg/ha of the drug in this region provided an efficiency of 76.3; 88.7 and 92.3 % respectively. The reduction in overall weed infestation in other regions was smaller – the use of 0.3 kg/ha of the drug provided an efficiency of 66.4–67.4 %. In all regions, the effectiveness of the minimum application rate of the herbicide Karitori, WSG (0.1 kg/ha), exceeded the efficiency of 0.1 kg/ha of the standard Pledge, WP. The noted trend was supported by data on the mass of cereal weeds. The treatments had a positive effect on the amount of soybean yield obtained in the experiments. In all experiments conducted (except for the 2018 experiment in the Astrakhan region), the increase in crop yield due to reduced competition from weeds after the application of herbicides was significant. The most significant increases (from 8.2 to 10.1 c/ha) were obtained in 2019 in an experiment on soybean crops of the Arleta variety in the conditions of the KrasnodarRegion.

INFLUENCE OF METHODS OF BASIC TILLAGE AND FERTILIZERS ON THE YIELD OF SPRING WHEAT IN THE CONDITIONS OF AF "KOLOS" OF THE TETYUSHSKY MUNICIPAL DISTRICT OF THE REPUBLIC OF TATARSTAN

INFLUENCE OF METHODS OF BASIC TILLAGE AND FERTILIZERS ON THE YIELD OF SPRING WHEAT IN THE CONDITIONS OF AF "KOLOS" OF THE TETYUSHSKY MUNICIPAL DISTRICT OF THE REPUBLIC OF TATARSTAN

The Evaluation of Sweetcorn (Zea mays saccharata Sturt.) Infestation of Barnyardgrass (Echinochloa crus-galli) Depending on Weather Conditions and Crop Rotation

This paper focuses on the weed species Echinochloa crus-galli, commonly known as barnyardgrass, which is a persistent threat to crop yield and quality, especially in maize (Zea mays) cultivation. It is one of the most problematic weeds in agricultural fields due to its aggressive growth, adaptability to different environmental conditions and prolific seed production. The incidence of Echinochloa crus-galli in maize fields has increased in recent years. This study aims to provide a comprehensive understanding of the characteristics and behavior of Echinochloa crus-galli, and to suggest effective measures to control it. This research on sweetcorn was conducted from 1992 to 2019 at the Research and Education Center Gorzyń, Złotniki branch, which belongs to the Poznań University of Life Sciences. The evaluation of weed infestation was carried out in experiments focusing on chemical weed control in maize. The experiments were designed as a one-factor randomised block design with four field replications. The condition and the degree of weed infestation (number of weeds and fresh weight of weeds) in the control plots was assessed on an annual basis at the end of June and in July. The aim of the study was to evaluate the dynamic changes in the status and extent of barnyardgrass (Echinochloa crus-galli) infestation in maize grown after various other crops in the Wielkopolska region, with a focus on the weather conditions. The study found that barnyardgrass was most likely to occur when maize was sown after winter wheat in a dry and warm year, and least likely when maize was grown in rotation after winter wheat in a cold year with average rainfall. The proportion of barnyardgrass weed mass in the total weed mass was significantly lower after winter rye than after winter wheat, winter oilseed rape and winter triticale. Further research into the biology and ecology of barnyardgrass is key to effectively controlling this weed and safeguarding sweetcorn yields.

Efficiency of weed control in winter pea in the Right Bank Forest Steppe of Ukraine

Purpose. To analyze the features of weed control in winter pea in the Right Bank Forest Steppe of Ukraine. Methods. The research was conducted at the Salyvonky State Enterprise of the Institute of Bioenergy Crops and Sugar Beet of the National Academy of Agrarian Sciences of Ukraine (Bila Tserkva district, Kyiv region) in 2020–2023. The agronomic practices used in the experiment were conventional for the zone of insufficient moisture of the Right Bank Forest Steppe of Ukraine, with the exception of the studied elements. Results. The development of the concept of autumn weed control for winter pea from requires a fairly competent selection of herbicides, taking into account weather forecasts, the specifics of the effect of active substances on weeds and cultivated plants, etc., as conditions for sowing winter pea do not allow to effectively apply conventional weed control system with the use of soil tillage and, if necessary, the limited application of herbicides during the vegetation season. This is explained by the fact that the terms for soil preparation and sowing are quite limited, and soil herbicides at high air temperatures work unpredictably and have limited efficiency in case of moisture deficit. Herbicide Corum, developed by combination of active substances bentazone (480 g/l) and imazomox (22 g/l), had better indicators in terms of total efficiency at an increased application rate (1.5 l/ha) – 92.9% in the BBCH 12 and 91.7% in the BBCH 14. At the same time, the efficiency of an application rate of 1.25 l/ha was within 80%. The latter is probably related not only to the autumn conditions of application of the [reparation, but also to the fact that such species as Fumaria officinalis, Sinapis arvensis, Solanum nigrum and thistles sprouted later, when the main mass of weeds was already in a development stage that was less sensitive to low rates of the herbicide. Conclusions. The application of Corum herbicide in the BBCH 12 at an application rate of 1.25 l/ha contributed to the destruction of 73.8% and an application rate of 1.5 l/ha resulted in 86.7% of weeds. When the herbicide was applied in BBCH 14, the total efficiency of crop treatment at an application rate of 1.25 l/ha was higher by 2.4% and at a rate of 1.5 l/ha it was higher by 1.2% compared to application in the BBCH 12. This is due to the fact that Chenopodium album, Amaranthus retroflexus, Polygonum convolvulus, Persicaria maculosa, Solanum nigrum, Polygonum lapathifolium and thistles sprouted in the pea crops, and the herbicide was highly effective against them. On the other hand, weed plants that sprouted earlier continued to vegetate and were already less sensitive even to increased application rates of herbicide. The application of the maximum recommended application rates was, for the most part, the most effective measure to reduce the number of weeds in winter pea crops. At the same time, such rates affected crop plants, causing stress, especially in the late periods of growth and development, which further affected the formation of pea yield. Therefore, the use of herbicides in the late phases of crop development should be avoided.

The effectiveness of sulfonylurea-based herbicides against dicotyledonous weed species on spring wheat crops in the Southern forest-steppe of the Trans-Urals

The effectiveness of chemical treatment differs significantly depending on the region and the types of weeds. In this regard, in the Kurgan region in 2018-2020, a comparative assessment of preparations based on sulfonylureas in spring wheat crops was carried out to identify the application features in the conditions of the Trans-Urals. The research was carried out on the experimental field of the Kurgan Research Institute of Agricultural Sciences -of the branch of the FSNSI UrFARC UrB RAS as part of the grain-fallow crop rotation. The purpose of the research was to determine the effectiveness of the use of sulfonylurea-based herbicides in spring wheat crops for the control of dicotyledonous perennial and young weed species. The main task was to determine the herbicide that most completely suppresses weed vegetation and has a positive effect on yield. According to the research results, a good effectiveness of weed control at the level of 74-76% was noted in preparations based on metsulfuronmethyl 10 g/ha, as well as in a mixture of metsulfuron-methyl and tribenuron methyl 12 g/ha. A 64-69% reduction in the mass of weeds was obtained using the tribenuron-methyl and florasulam 30 g/ha variant. The weakest control of weeds was detected in the variant with tribenuronmethyl 20 g/ha (biological efficiency 57%). The tested drugs provided yield increases of +19-24% to the control level.

ПРОСТРАНСТВЕННАЯ СТРУКТУРА ЗАСОРЕННОСТИ ЗЕРНОТРАВЯНО-ПРОПАШНОГО СЕВООБОРОТА НА СЕВЕРО-ЗАПАДЕ РОССИИ

The study was carried out to analyze the spatial distribution of weeds in grain-grass-row crop rotation in the North-West region of the Russian Federation. Based on calculations of the index of pairwise species similarity and the coefficient of commonality of specific abundance, it was revealed, on the one hand, a high similarity in the species composition of weeds within the studied crop rotation (0.81...0.94), on the other hand, significant differences in the structure of weediness in fields (30, 4…70.6). The differences in weediness between some fields, both in terms of the number and above-ground mass of weeds, turned out to be statistically significant. Species abundance varied within 6...10 species/m2, numerical composition - 150...312 specimens/m2, phytomass - 51.2...272.5 g/m2 with an average value of this indicator for crop rotation fields of 8 species/m2, 251 ind./m2 and 161.7 g/m2, respectively. Uneven or aggregated distribution in the crop rotation territory, confirmed by high values of the coefficients of variation (151...567) and aggregation (2.1...16.2), turned out to be characteristic of all widespread species of weeds. Geostatic features of the distribution of their mass species in the area of grain-grass-row crop rotation were quite clearly visible on digital maps compiled using special programs. Significant differences in the weed structure of crop rotation fields and the distribution of individual weed species were a consequence of differences in the agrochemical characteristics of the soil, primarily acidity, the amount of exchangeable bases and the content of organic matter. When using herbicides in crop rotation, it is necessary to take into account the individual characteristics of weediness in each field and the spatial distribution of mass species of weeds, which have developed under the influence of long-term agricultural use.

Doses de glifosato na supressão de Megathyrsus maximus cv. BRS Quênia consorciado com milho transgênico

ABSTRACT In the intercropping of maize with Megathyrsus maximus, the application of herbicides is a technique that can be used to reduce competition between intercrops. This study aimed to evaluate the effect of different glyphosate doses on suppressing the growth of Megathyrsus maximus cv. BRS Quênia intercropped with maize, as well as in weed control. The randomized block experimental design was used and conducted in the field. The treatments consisted of the application of six glyphosate doses, 0; 48; 96; 240; 480; 960 g acid equivalent [a.e.] ha-1, and a maize treatment without the forage with 960 g acid equivalent [a.e.] ha-1. The dose of 260.87 g a.e. ha-1 provides a 50% response to the forage production variable; therefore, it has the potential to suppress M. maximus cv. BRS Quênia. The presence of forage reduces the density and dry mass of weeds, with the species in the weed community: Ricinus communis, Eleusine indica, Alternanthera tenella, Commelina benghalensis, Conyza sp., and Digitaria horizontalis.

Implementation and Use of Green Manures for Weed Suppression in Sequential Maize Cropping

The ground cover produced by green manures has a direct influence on weed suppression and, in addition, the biomass produced by these same plants influences crop growth. This study was carried out to compare the effect of green manure species on the incidence of weeds, in sequence, in order to evaluate the effects of the use of green manure cover on the productive characteristics of maize plants. A completely randomised experimental design was used, with 11 treatments and 4 replications. The treatments were cover crops Canavalia ensiformis (T1), Cajanus cajan (T2), Stizolobium pruriens (T3), Crotalaria juncea (T4), Phaseolus vulgaris (T5), Stizolobium trigre (T6), Stizolobium aterrimum (T7), Crotalaria retusa (T8), Crotalaria breviflora (T9), Dolichos lablab (T10), and conventional system (T11). Ninety days after sowing, the green manures were cut, and 30 days after the green manures were cut, the hybrid maize Crop Top 520 was sown. The variables evaluated in relation to the planting of green manures were the green and dry biomass of green manures, alongside the green biomass of weeds and suppression of weeds. Concerning maize plants, the variables evaluated were plant height at 60 DAS, stalk diameter at 60 DAS, number of grain rows per ear, number of grains per grain row, and yield. The averages were subsequently analyzed using Tukey’s test at 95% significance level. The use of green manure significantly reduces the green mass of weeds up to 90 days due to lack of access to light of the weeds, which reduces their appearance and growth. Stizolobium aterrimum showed the best results both as a dry mass producer and weed suppressor and also as a yield enhancer in maize crops.

Ameliorative effect of natural floating island as fish aggregating devices on heavy metals distribution in a freshwater wetland

Growing human population and climate change are leading reasons for water quality deterioration globally; and ecologically important waterbodies including freshwater wetlands are in a vulnerable state due to increasing concentrations of pollutants like heavy metals. Given the declining health of these valuable resources, the present study was conducted to evaluate the effect of natural floating island in the form of fish aggregating devices (FADs) made of native weed mass on the distribution of heavy metals in the abiotic and bio compartments of a freshwater wetland. Lower concentrations of surface water heavy metals were observed inside the FADs with a reduction of 73.91%, 65.22% and 40.57–49.16% for Cd, Pb and other metals (viz. Co, Cr, Cu, Ni and Zn), respectively as compared to outside FAD. These led to 14.72–55.39% reduction in the heavy metal pollution indices inside the FAD surface water. The fish species inside the FADs were also found less contaminated (24.07–25.07% reduction) with lower health risk indices. The study signifies the valuable contribution of natural floating island as FADs in ameliorating the effect of heavy metals pollution emphasizing the tremendous role of the natural floating islands in sustainable maintenance of freshwater wetlands for better human health and livelihood.

The contribution of factors to the formation of pollution of grain-grass-rowed crops in the north-west of the Russian Federation

The study was carried out to evaluate the influence of natural and anthropogenic factors on the formation of weed infestation of fields in the crop rotation including cereals, row crops and grasses to understand the possibilities to manage the species composition and population of weed plants in the North- West of the Russian Federation. The experiments were performed in 2012-2018 in the Leningrad region during the fifth rotation with the following crops: narrow-leaved lupin, winter rye, spring barley with sowing of perennial grasses (red clover and timothy-grass), perennial grasses of 1 and 2 years, potato, spring rape. Weed infestation of fields in the crop rotation was depended more on biological features of cultivated cultures (species abundance 76,1 %, initial density 29,6 %, phytomass after harvest 21,0 %) than on individual parameters of weed infestation (3,5, 8,3, 17,7 %). The weather conditions were of decisive importance in weed initial formation (49,7 %), and, to a lesser degree, for such parameters as species abundance (30,7 %) and aboveground biomass of weeds (20,6 %). Weather conditions influenced the effects associated with the use of mineral fertilizers (interaction 4,0…11,9 %) and integrated plant protection system (interaction 2,9…12,0 %). Among the studied factors of crop production intensification application of herbicides in the variant with integrated plant protection system most affected the species abundance (26 %) and final phytomass of weed plants (26,2 %), whereas long term application of mineral fertilizers affected the initial weed infestation of agrocenoses (10,2 %), that was statistically sufficient in every year of the research (23,0…67,8 %). The combined effect of mineral fertilizers and herbicides most influenced the formation of the aboveground mass of weeds (interaction 0,9…5,0 %), especially in years with excessive humidity.

Phytosanitary indicators of fodder crops under using organic cultivation technology

The article provides data based on a four-year study of five cultivation technologies of different intensity, including organic. On the example of seven crops of fodder crop rotation, the effectiveness of controlling phytosanitary indicators - the number and mass of weeds, the spread of diseases and the number of insect pests, which are an obstacle to the widespread use of ecological cultivation technologies, was studied. The results of the research made it possible to recommend perennial grasses up to 3 years of use for inclusion in fodder crop rotations in order to improve the phytosanitary condition of crops, and corn in order to obtain high fodder crop rotation productivity. For the cultivation of forage crops, the use of organic technology is fully justified, as it contributed to the reduction in the abundance of weeds, minimized the prevalence of diseases of annual and perennial grasses, corn, reduced the number of pests; provided increase in productivity compared to extensive technology.

Effectiveness of herbicide application with plant growth regulators and microfertilizer in late crops of winter wheat

Goal. To establish the features of the formation of weed complex, yield and grain quality of winter wheat sown on the late sowing period, depending on the application of post-emergence herbicides, plant growth regulators and microfertilizers.
 Methods. Field, measuring and weighing, statistical, laboratory, analytical.
 results. According to the results of investigations in 2016—18, 30 species of weed plants were found in late crops of winter wheat: late spring grasses (3 species); early and late dicotyledonous (14 species); dicotyledonous wintering, winter and biennial (7 species); dicotyledonous perennials (6 species). In terms of quantity, late spring grasses weeds dominated (40.6%), and in terms of raw mass dicotyledonous perennials dominated (87.6%). Technical efficiency of tank mixture of anti-perennial herbicides Dekabrist 480 SL (0.15 l/ ha) + Gryzny, W.G. (15 g/ha) + Talant, surface-active substance (0.2 l/ha), when applied at the tillering stage (standard) against the total raw mass of dicot annual and perennial weeds was 96.7 and 69.2%, respectively. The low level of control of dicotyledonous perennial species by this tank mixture was associated with the partial regrowth of root-sprouting weeds, especially sow thistles, after the introduction of the specified herbicides, namely during the booting period. The application of plant growth regulators Emistym C, w.-a.s. (10 ml/ha) and Vermiiodis, w.s. (6.0 l/ha) at the booting stage, against the background of application of herbicides at the tillering stage, stimulated the growth of the raw weight of dicotyledonous perennials and the total raw weight of all weeds, compared to their application in a tank mixture with herbicides at the tillering stage. At the same time, these indicators, when applying microfertilizer Nanomix, s. (2.0 l/ha) in a tank mixture with herbicides at the tillering stage, were higher, compared to applying the preparation separately from herbicides at the booting stage. An increase in the level of raw mass of weeds against the background of the use of stimulating preparations led to a decrease in grain yield in most variants with these preparations, compared to the standard. No effect of the studied preparations on the protein content of the grain, as well as the germination energy and laboratory germination of the grown grain was found.
 Conclusions. The application of post-emergence herbicide compositions with plant growth regulators and microfertilizers in late crops of winter wheat stimulates the growth of the raw mass of weeds, which negatively affects the grain yield of the crop.

Domestic three-component herbicide Arizona for the protection of corn crops in the central zone of the Krasnodar Territory

Field experiments were carried out to determine the biological and economic e ectiveness of the herbicide Arizona, OD (75 g/l mesotrion + 30 g/l nicosulfuron + 3.5 g/l orasulam), on crops of the hybrid corn Krasnodar 291 AMV in Krasnodar Krai. The experiments were carried out on the experimental eld of the Federal State Budgetary Scienti c Institution "Federal Research Center ofBiological Plant Protection" in 2020-2021 in accordance with the guidelines for testing herbicides in agriculture. The soil cover of the experimental plots is leached chernozem. The ow rate of the working uid is 200 l/ha. In the experiments, plots with an area of 25 m2 were used with a four-fold repetition with a randomized arrangement. The scheme of the experiment assumed the use of the tested herbicide Arizona, OD in the norms of 1.0 and 2.0 l/ha, standards Elumis, OD (2.0 l/ha) and Octave, OD (1.0 l/ha), control (without herbicides). During the period of 3…5 leaves of the culture, herbicides were applied. The initial contamination of corn crops averaged 125 copies/m2. The e ectiveness of the drugs was evaluated by reducing the number, mass of weeds and the di erence in the yield of grain crops in comparison with the option without the use of herbicides. The types of weeds in the experiments (ragweed sagebrush, сalifornia durnishnik, tilted schiritsa, bristly body, gray bristle, common hedgehog) demonstrated high sensitivity to the herbicide being tested. In the variants with the introduction of 1.0 and 2.0 l / ha of the drug Arizona, OD, an 82…100 % herbicidal e ect was observed without a negative e ect on the crop and a reliable preserved corn grain yield (87.0 and 102.2 %). The reference preparations for the e ectiveness of cereals were at the level of the tested preparation (2.0 l/ha), but were inferior in e ect to dicotyledonous weeds.

Soil herbicides in sunflower crops in the Eastern Forest-Steppe of Ukraine

Goal. To determine the influence of soil herbicides with different active substances on crop weediness and sunflower seed yield in the conditions of the Eastern Forest Steppe of Ukraine.
 Methods. Field, measuring and weighting, and statistical.
 Results. In 2019, with 13 mm of precipitation in the first period after applying soil herbicides, the effectiveness of herbicides in reducing the number and raw mass of weeds in sunflower crops was 60% and 45%, respectively, and in 2021 with 81 mm of precipitation, it was 89% and 95%. In 2021, there was phytotoxic suppression of culture plants by Kharnes, e.c. (acetochlor, 900 g/l), 2.5 l/ha. Despite this, Kharnes was the most effective in controlling the total number of weeds (91% and 96% for the first and second counts, respectively) and their raw mass (95%). Other preparations provided the following indicators: Proponit 720, EC (propisochlor, 720 g/l), 3.0 l/ ha (by quantity — 84% and 90%, by weight — 84%); Selefit, SC (promethrin, 500 g/l), 4.0 l/ha (by quantity — 79% and 81%, by weight — 70%); Prymekstra TZ Hold 500 SC (S-metolachlor, 312.5 g/l + terbuthylazine, 187.5 g/l), 4.5 l/ha (by quantity — 68% and 73%, by weight — 66%); Stomp 330, e.c. (pendimethalin, 330 g/l), 5.0 l/ha (by quantity — 51% and 63%, by weight — 60%); Komandyr, EC (clomazon, 480 g/l), 0.15 l/ha (26% and 52% by quantity, 37% by weight). Ambrosia artemisiifolia L. was resistant to the above soil herbicides. It was established that sunflower is a powerful competitor in agrophytocenosis. Its share in the total raw mass of agrophytocenosis, depending on the period of accounting, was from 65.8 to 82.0%, and in dry mass — from 61.8 to 80.2%. In addition, it was established that losses of the sunflower crop from weeds coincide with the specific share of weeds in the total mass of the agrophytocenosis. Soil herbicides provided the following increases in the yield of sunflower seeds (t/ha): Kharnes — 0.53; Proponit 720 — 0.46; Stomp 330 — 0.44; Prymekstra TZ Hold 500 SC and Selefit — 0.39; Komandyr — 0.17. It was found that sunflower was the most tolerant to Stomp 330, and the least — to Komandyr.
 Conclusions. In terms of the level of weed death in sunflower crops and the increase in the yield of its seeds, Kharnes was the best among soil herbicides, and Komandyr was the worst.

The effectiveness of the use of analogue preparations with the active substance rimsulfuron on potatoes in the conditions of the Tyumen region

Relevance. The study of the effectiveness of protection methods, herbicides with different content and composition of active substances, their influence on the crop, weed component, yield and related factors is important for clarifying the regulations for use, production decisions in the manufacture of preparations and their use.Methods. The study of the effect of various analogues of herbicides with the active ingredient rimsulfuron on weed suppression and crop development was carried out on the experimental field of the Research Institute of Agriculture of the Northern Trans-Urals, the northern forest-steppe of the Tyumen region under the conditions of 2021. The object of research was 4 preparations of herbicidal action from different manufacturers with the main active ingredient rimsulfuron 250 g/kg for use on potato crops to suppress weeds of perennial and annual cereal type and annual dicotyledonous type.Results. The initial study of the clogging of experimental plots before treatment with the studied herbicides showed the presence of an average number of processing showed the presence of a total number of weeds according to the variants of the experiment 60–70 pcs/m2 with a quantitative advantage of 4 types of weeds еchinochloa crus-galli, Elymus repens, Thlaspi arvense, Chenopódium álbum. On the variants of herbicide application, the mass of weeds was 8–20 times less and amounted to 20–55 g/m2. As a result of the use of the studied herbicides against weeds, a stable and high efficiency of 86–97% during the entire growing season on options Herbicide 3, 4.

Іnfluence of crop pollution on development i maize productivity

Goal. To study the reserves of weed seeds in the soil and to determine the influence of weediness of crops on the development and productivity of corn.
 Methods. Informational and analytical (collection of materials and analysis of literary sources), field and laboratory research (setting up experiments, soil analysis, monitoring plant development, determination of biometric indicators, accounting for the number of weeds, collection and determination of crop structure), mathematical and statistical (processing of research results). The design of the field experiment included weeded and weed-protected plots.
 Results. In the forest-steppe zone of Ukraine, with intensive corn cultivation technology, the average number of weeds in the soil from emergence to row closure was at the level of 250—425 weeds/m2. Determining the number and species composition of segetal vegetation made it possible to establish that the corn crops are dominated by a mixed type of weediness with the dominance of annual dicotyledonous and grassy weeds. The number of dominant weeds at the beginning of the corn growing season in the experimental plots of NUBiP (Kyiv) was: Chenopodium album L. — 16 pcs./ m2, Amaranthus retroflexus L. — 23 pcs./m2, Portulaca oleracea L. — 78 pcs./ m2. In the fields of the agricultural station (Fastivskyi district), the dominant weeds were Polygonum convolvulus L., Setaria glauca L., Chenopodium album L., the number of which in the phase of 4—5 leaves was 32, 20 and 10 pcs./m2, respectively. Weeds significantly limited the growth of corn both in terms of plant height and development phases. In the phase of 9—10 leaves of corn in the weeded area, some types of weeds reached the height of the corn, accumulated a significant vegetative mass and began to form reproductive organs. The above-ground mass of weeds at the beginning of grain formation reached 995 g/m2. The pollution of the crops significantly affected the reduction of the corn yield and its structure.
 Conclusions. Significant reserves of weed seeds in corn crops cause the development of segetal vegetation during its growing season. The high competitiveness of weeds was manifested in the suppression of the growth and development of the culture and the formation of the crop. Weeds form a significant vegetative mass and reproductive organs at the beginning of the development of the corn grain. On weedy crops, the yield of corn decreased by an average of 32—35%.

Remediation and recovery of Kariba weed as emerging contaminant in freshwater and shellfish aquaculture system via solvothermal liquefaction

Fast growing Kariba weed causes major problems and pollution on freshwater and shellfish aquaculture systems by interfering with nutrient uptake of crops, restricting sunlight penetration, and decreasing water quality due to massive biomass of Kariba weed remnants. Solvothermal liquefaction is considered an emerging thermochemical technique to convert waste into high yield of value-added products. Solvothermal liquefaction (STL) of Kariba weed as an emerging contaminant was performed to investigate the effects of different types of solvents (ethanol and methanol) and Kariba weed mass loadings (2.5–10 % w/v) on treating and reducing the weed via conversion into potentially useful crude oil product and char. Up to 92.53 % of Kariba weed has been reduced via this technique. The optimal conditions for crude oil production were found to be at 5 % w/v of mass loading in methanol medium, resulting in a high heating value (HHV) of 34.66 MJ/kg and yield of 20.86 wt%, whereas the biochar production was found to be optimum at 7.5 % w/v of mass loading in methanol medium, resulting in 29.92 MJ/kg of HHV and 25.38 wt% of yield. The crude oil consisted of beneficial chemical compounds for biofuel production such as hexadecanoic acid, methyl ester (65.02 peak area %) and the biochar showed high carbon content (72.83 %). In conclusion, STL as a remediation for emerging Kariba weed is a feasible process for shellfish aquaculture waste treatment and biofuels production.

The potential for using wood mulch for agricultural production

Abstract Making woody mulch (WM) from organic waste is one solution for repurposing waste. Our work had two primary objectives. First, we wanted to destermine the current use of WM as a soil cover, barriers to use, benefits, and possible motivations for adopting the use of WM by home and commercial growers for cultivating crops in Barbados and the Baltimore-Washington, DC metropolitan region in the USA. To accomplish this objective, we administered a survey to growers in both regions. Second, we wanted to determine the benefits of using WM in agricultural production for sweet potatoes (both regions) and Hungarian hot wax peppers (USA). We measured whether WM influenced crop survival, crop yield, crop nutrients, weed mass, and soil characteristics in replicated plots covered with a layer of WM or left bare. Growers reported that expense, availability, and ease of application were barriers to using WM. Despite the barriers, many growers were using, or had previously used, WM and reported myriad benefits, including improving plant yield and/or nutrients, preventing weed growth, maintaining soil moisture and reducing irrigation needs, improving soil fertility, reducing soil erosion, reducing compaction from heavy rain, and maintaining soil temperature. Our data from replicated field trials verified some of the potential benefits reported by growers. WM in some cases promoted higher crop survival and yield of sweet potatoes, suppressed weeds, conserved soil moisture, and maintained higher soil temperature. Understanding which crops benefit from WM and the longer-term effects of WM on crops and soil are deserving of future study.

Влияние некоторых агроэлементов технологии возделывания на эффективность выращивания подсолнечника в условиях степной зоны Кабардино-Балкарии

The article presents the results of long-term (2016–2018) studies conducted on the Ciscaucasian (carbonate) chernozems of the steppe zone of the Ka-bardino-Balkarian Republic. The efficiency (technical – the degree of weed suppression, economic – the yield of sunflower oil seeds, economic – the revenue from the sale of products, the amount of net income, cost, profitability, etc.) of some elements in sunflower cultivation technologies has been studied. A high degree of weed suppression in the crops of the studied sunflower varieties has been proven using normal (63.0–77.6%) and intensive (82.5–91.4%) technologies by the end of the growing season of the crop. In the variant with extensive technology, this indicator did not exceed 60.8 % in the variety Lakomka and 43.3% of weed death in the variety Belochka. The crude aboveground mass of weeds, determined 30 days after the treatment of sowings, was also the smallest in variants with normal (35.0–43.0 g/m2) and intensive (15.0–35.0 g/m2) agrotechnologies. On the background of extensive technology, these results exceeded 87.0 and 93.0 g/m2, respective-ly, for sunflower varieties. The different degree of contamination of sowings had an impact on the yield of sunflower oil seeds. Therefore, in the variant with extensive technology, it did not exceed 2.1 and 1.8 t/ha in the Lakomka and Belochka, respectively. On the background of normal and intensive technologies, these data were 2.7–3.5 t/ha for the Lakomka and 2.5–2.8 t/ha for the Belochka, respectively. In a production test (2020) conducted with sunflower sowings of the Lakomka variety, the high economic efficiency of intensive technology with a seed yield of 2.9 t/ha at a gross product value of 72.5 thousand rubles/ha with a net income of 37.0 thousand rubles/ha and a profitability of 104.0% was confirmed. For the variant with normal technology, gross output in monetary terms amounted to 57.5 thousand ru-bles/ha with a net income of 33.8 thousand rubles/ha with a profitability of 143.0%. On the variant of extensive technology, the gross product value was 35.0 thousand rubles/ha with the amount of production costs of 18.6 thousand rubles/ha. Under these conditions, both the amount of net income (16.4 thousand rubles/ha) and profitability (88.0%) of production were the lowest.

The Positive Effects of Mechanical and Chemical Treatments with the Application of Biostimulants in the Cultivation of Solanum tuberosum L.

The aim of the study was to determine the effect of mechanical and chemical treatments with the application of biostimulants on the effectiveness of weed infestation reduction and potato yielding. A three-year field research study was conducted at the Agricultural Experimental Station Zawady (52°03′ N; 22°33′ E). The field experiment was set up in a split-plot design with three replicates. The first factor was the two edible potato cultivars, and the second was five methods of mechanical and chemical treatments with biostimulants: (1) control object—mechanical weeding, (2) the herbicide Avatar 293 ZC (clomazone + metribuzin), (3) the herbicide Avatar 293 ZC and the biostimulant PlonoStart, (4) the herbicide Avatar 293 ZC and the biostimulant Aminoplant, (5) the herbicide Avatar 293 ZC and the biostimulant Agro-Sorb Folium. Before emergence, the control object was double ridging and single ridging with harrowing and double ridging after emergence. On other objects (2–5) before emergence, two ridgings were applied. The assessment of weed infestation was performed using the quantitative weight method on two dates: about 2 weeks after the application of the herbicide and biostimulants and before the potato tubers harvest. The herbicide and the herbicide with biostimulants applied to the potato crop showed a positive influence in reducing the number and fresh weight of weeds compared to mechanical-only treatments. The highest effectiveness, calculated on the basis of the number and fresh mass of weeds, was found on the fifth object. It was, on average, 70.5 and 71.6% for cultivars, respectively. Research into the use of biostimulants in potato cultivation will continue due to the pro-environmental nature of biostimulants and the importance of this crop. It is certain that the methodology of future field experiments will meet the challenges of sustainable development.