Cirsium Arvense Research Articles

Federal Scientific Agroengineering Center VIM, Moscow, Russian Federation

The degradation of unused agricultural lands is noted to cause significant damage to agricultural production such as plot overgrowing with weeds, blackened surface layer emergence, the existing microrelief disturbance, soil self- compaction and acidification, soil infiltration properties deterioration, and water erosion. (Research purpose) The research aims to determine the technological and physical and mechanical properties of the blackened soils in the Ryazan region, being out of active use for 2-6 years. (Materials and methods) The parameters of various unused soil plots were studied in the Ryazan region: in particular, the composition of the herbage, the thickness of the blackened soil layer, the degree of soil blackening, its density and moisture, and infiltration properties. (Results and discussion) It was found that a 6-year increase in the period of overgrowth in an unused site leads to an increase in the amount of weeds. The most common species of many-year-old weeds are dog grass (Elymus caninus L) with the occurrence of 13 percent, field grass (Cirsium arvense L.) with the occurrence of 11 percent, creeping wheatgrass (Elitrigia repens L.) with the occurrence of 10 percent, shoot-forming vole (Agrostis stolonifera L.) with the occurrence of 9 percent. It was determined that an increase in the period of plot overgrowing from 2 to 6 years results in the soil recompaction, an increase in its density from 1.32 to 1.56 grams per cubic centimeter, the blackened soil layer thickening from 3 to 11 centimeters, an increase in the soil blackening degree from 13 to 44 grams per cubic decimetre. It was found that the coefficient of variation in the soil blackening degree decreases from 21.0 to 5.1 percent, and the coefficient of variation in the blackened soil layer thickness declines from 25.3 to 6.6 percent. (Conclusions) The dependence between the soil infiltration intensity and its blackening degree was established: even being waterlogged in the blackened upper layer (0-10 centimeters), with the absolute moisture of 45 percent, this indicator remains within 20-25 percent in the lower layer (20-30 centimeters).

Regularities of weeding in crop rotation fields against the background of different tillage systems

It was found that during the research in winter wheat crops, 40 species of weeds of different biological groups and classes were registered. The most common weeds in the research are: spring (Polygonum aviculare, Fumaria officinalis); winter (Descurainiasophia, Capsella bursa-patoris, Veronica hederifolia, Thlaspiarvense), perennial (Cirsium arvense, Convolvulus arvensis). All of these weeds are non-parasitic weeds. They have roots, stems and green leaves, resulting in an independent diet. It is shown that on average for 5 years of research the least number of weeds was recorded after black fallow (53,7 pcs / m²). Weeds were 22,0 % higher after winter weeds, 55,9 % more after a mixture of peas and mustard, and 95,3 % higher after peas for grain. In the experiments, almost identical results on weediness of winter wheat crops were obtained with two tillage schemes, namely tillage and chisel tillage. However, there is a slight tendency to reduce the number of weeds (0,8 %) during chisel tillage. There was an increase in the number of weeds on the 2nd (83,5 pcs / m2) and on the 4th (76,6 pcs / m2) crops compared to the 1st (64,3 pcs / m2). The highest tweediness (83,5 units / m2) of winter wheat crops was observed in the 2nd crop. This indicates a large potential contamination of the arable soil layer. Key words: crop rotation, tillage, black fallow, green fallow, weeds, winter wheat, oats.

Effects of Landscape and Local Factors on the Diversity of Flower-Visitor Groups under an Urbanization Gradient, a Case Study in Wuhan, China

Urbanization is one of the primary forces driving worldwide pollinator decline. Moderate urban expansion with appropriate green space planning can help in maintaining pollinator diversity and pollination service. We investigated the relative effects of landscape and local factors on the diversity of flower-visitor functional groups in a moderately urbanized city, Wuhan, located in central China. We found that the proportion of impervious surface had no significant effect on the number of visitations, but it was negatively associated with the diversity of flower-visitor groups. The number of visitations by Halictidae and Lepidoptera correlated positively with local flower density and flowering plant species richness, respectively. Flowering plant species richness was also positively correlated with the diversity of flower-visitor groups. The proportion of green space was negatively associated with the visitation number of Muscidae and the overall diversity of flower-visitor groups, revealing the potential influence of green space quality on pollinator assemblage. The pollination networks under three urbanization levels (with a total of 11 flower visitor groups and 43 plant species) were asymmetric, highly nested, and generalized. The suburb sites contained the highest diversity of interactions. Core flowering plants (Oenothera speciosa, Coreopsis grandiflora and Cyanus segetum) are exotic species with attractive flowers. Improving green space quality (high flower density and flowering plant species richness) and using attractive native flowering plants (Nandina domestica, Rosa chinensis, Astragalus sinicus, Cirsium arvense var. integrifolium, and Zabelia biflora) would enhance the function of urban green space to maintain pollinator diversity and ecosystem stability.

The disproportionate value of ‘weeds’ to pollinators and biodiversity

Abstract Agricultural intensification has been implicated in global biodiversity declines. In the European Union, agri‐environmental schemes are designed to address this. For pollinating insects, funding has been provided to sow wildflower mixes. However, previous research indicates that a suite of agricultural weeds are also of great importance to pollinators. Here, we compare the biodiversity associated with the species which are considered harmful to agricultural production and legally deemed as ‘injurious’ by the United Kingdom 1959 Weeds Act (common ragwort Jacobaea vulgaris, creeping thistle Cirsium arvense, spear thistle C. vulgare, curled dock Rumex crispus and broadleaved dock R. obtusifolius), with plant species recommended for pollinator‐targeted agri‐environmental options. In our field study, the abundance and diversity of pollinators visiting the weed species averaged twice that of the recommended plants and included the main insect orders (Coleoptera, Diptera, Hymenoptera and Lepidoptera). This relationship was also seen in a meta‐analysis of literature data, which indicates that fourfold more flower‐visitor species and fivefold more conservation‐listed species are associated with the weeds. Additionally, the literature shows that twice the number of herbivorous insect species are associated with these plants. We suggest that several factors are responsible for this pattern. Injurious weed species are widely distributed, their flower morphology allows access to a wide variety of pollinator species, and they produce, on average, four times more nectar sugar than the recommended plant species. Freedom of information requests to public bodies such as local councils, Natural England and Highways England indicate that c. £10 million per year is spent controlling injurious weeds. Meanwhile, the cost of the four pollinator‐targeted agri‐environmental options in the United Kingdom exceeds £40 m annually. Synthesis and applications. Our results clearly show that weeds have an underappreciated value to biodiversity. Unfortunately, current UK agricultural policy encourages neither land sparing for nor land sharing with weeds. The UK government is, however, currently committed to overhauling agricultural payments to encourage more wildlife‐ and climate‐friendly practices. Thus, the challenge of reconciling the conflicts between agricultural production and these native and biodiverse species should be a renewed priority to land managers, researchers and policymakers.

The effect of natural salt with herbicidal activity on the agrochemical properties of soil and Cirsium Arvense

In a field experiment, an assessment of the effect of solutions of natural salt with herbicidal activity on the agrochemical properties of ordinary chernozem and a phytocenosis heavily contaminated with pink thistle (Cirsium Arvense, Asteraceae family) was given. To study the mechanism of action of 20, 30 and 40% solutions of natural salt on the “plant-soil” system and changes in the chemical state of the soil, we used crude natural brines from the Troitsk deposit in the Krasnoyarsk Territory. The results of the research found that the use of various solutions of natural salt as a herbicide determined alkalinization of the soil by 0.2-0.3 units. pH while maintaining the neutral reaction of the soil solution and changing the composition of the salts of the aqueous extract. The control soil contained a high amount of humus. Treatment of plants with natural salt contributed to an increase in the indicator by 6-11%, depending on the concentration of the salt solution used. Common chernozem was characterized by a very low and low supply of mineral forms of nitrogen, a very high supply of exchangeable potassium and an increased and high supply of mobile phosphorus, depending on the variant of the experiment. When processing the pink thistle in the growing season before its flowering with solutions of salts of different concentrations, the biological efficiency of the solution of 20% concentration was 58%, and the treatment of this weed with 30 and 40% concentration of natural salt led to its death by - 82 and 88% to the control, respectively.

Korovi u proizvodnji suncokreta u Hrvatskoj i njihovo suzbijanje

Sunflower is the most important oil crop in the Republic of Croatia. In the last two decades, it has been grown on average on 33,506 ha with a average grain yield of 2.66 t/ha. Weeds represent one of the most important causes of biotic stress, and their action is reflected in the competition for nutrients, water, light and space. The weed flora in sunflower crops in Croatia is extremely diverse, and we will most often meet: Polygonum persicaria L., Polygonum lapathifolium L., Ambrosia artemisiifolia L., Chenopodium polyspermum L., Amaranthus retroflexus L., Solanum nigrum L. emend Miller, Abutilon theophrasti Medik, Datura stramonium L., Xanthium strumarium L., Convolvulus arvensis L., Cirsium arvense (L.) Scop., Echinochloa crus-galli (L.) Pb., Setaria glauca (L.) Pb., Setaria viridis (L.) Pb., Digitaria sanguinalis (L.) Scop., Panicum spp. and Sorghum halepense (L.) Pers. For many years, weed control was based on the intensive use of chemical preparations, which were most often used after sowing and before emergence, in double or triple combinations. In addition to a number of advantages of using chemicals in sunflower production, the problem of broadleaf weeds was not satisfactorily solved until the advent of Clearfield, Clearfield plus and Express sun technology, i.e. hybrids tolerant to herbicides from the group of imidazolinone (imazamox) and sulfonyl-urea (tribenuron-methyl) at the beginning of this century. Integrated plant protection, including integrated weed management, with its holistic approach and greater application of direct and indirect non-chemical measures, is only environmental quality solution for controlling weeds in sunflowers.

Сообщества с Heracleum sosnowskyi Manden. в Курской области

Сообщества с Heracleum sosnowskyi Manden. в Курской области

Experimental Treatment of Biopreparation Based on Pseudomonas Syringae pv. Tagetis for Weeds Control

Cirsium arvense is one of the worst weeds in agriculture. As actual herbicides are not very effective and not accepted by organic farming or in order to reduce the cantity of herbicides used, possible biocontrol agents have been investigated since many decades. The work carried out aimed at obtaining and assessing the herbicidal potential of bacterial preparation based on Pseudomonas syringae pv. tagetis (PST) for biological control of Cirsium arvense (L.) Scop. Silibase 2848P, an organosilicone surfactant, was required to facilitate PST penetration into creeping thistle leaves. The experiments were conducted under controlled conditions (growth chamber) to determine the concentration of Silibase 2848P required for the maximum penetration of PST into creeping thistle leaves. As well as to evaluate disease incidence in emerging leaves, and to quantify the effects of inundative foliar application on fresh and dry weights of shoots. In field conditions, efficacy of PST applications was assessed in terms of disease incidence and effect on shoot height, number of flower buds and survival of C. arvense. Maximum disease severity were recorded when PST was applied at a concentration of 10 x 108 cfu/ml + Silibase 0.3%.

Vegetation structure of bio-belts as agro-environmentally-climatic measures to support biodiversity on arable land: A case study

<abstract> <p>Loss of biological diversity is one of the greatest challenges that our civilization must face nowadays. Reaction to the diminishing biodiversity of agricultural landscapes is various measures promoting free-living organisms. The study deals with the vegetation composition and structure of agro-environmental-climatic measures applied on arable land in operating conditions (intensively farmed regions of the Czech Republic). Additional study focus was applied to a popular measure of the feeding bio-belts. Bio-belts are not only hiding places for free-living animals but can provide them a rich food offer in the period from the harvest of main crops until winter. Thanks to the bio-belts, the landscape gains in biodiversity, and sloping sites can be protected from soil erosion. The vegetation of land parts used as bio-belts was assessed using phytocoenological relevés. Dominant plant species sown in the bio-belts were <italic>Avena sativa, Panicum miliaceum</italic>, <italic>Brassica oleracea</italic> var. <italic>acephala, Fagopyrum esculentum, Phacelia tanacetifolia</italic>, and <italic>Pisum arvense</italic>. Apart from the sown plants, there were also weeds occurring in the bio-belts, of which the most abundant were <italic>Chenopodium album</italic>, <italic>Amaranthus retroflexus</italic>, <italic>Setaria verticillata</italic>, <italic>Cirsium arvense</italic>, <italic>Equisetum arvense</italic>, etc. Risks connected with the realization of feeding bio-belts in respect of weeds occurring on arable land are negligible. Weeds from bio-belts have only a limited potential to spread to adjacent arable land. A potential spreading of weeds from the bio-belts to adjacent arable land was not demonstrated. On the contrary, thanks to its composition, the vegetation of bio-belts has the potential to extend the food offer for animals. Thus, bio-belts are useful for supporting biodiversity in regions intensively used for agriculture.</p> </abstract>

Application of arbuscular mycorrhizal fungi to inhibit nitrogen uptake of weeds within crop fields

Invasive species cost the agriculture industry billions of dollars each year in lost revenue and control costs. This research addresses the potential neutralizing effects of arbuscular mycorrhizal fungi (AMF) on the invasive species and aggressive agricultural weed, Cirsium arvense, by limiting its nitrogen uptake from the soil. A total of 36 C. arvense plants and 24 Glycine max soybean plants were grown in a controlled laboratory environment, with G. max being used to create a simulated crop field. We hypothesized that introducing AMF to C. arvense would reduce its ability to absorb nitrogen, therefore reducing the plant's growth. If AMF significantly reduces C. arvense’s capability to thrive, it is possible that AMF could be incorporated into commercial and private crop fields to serve as a natural herbicide against C. arvense. Growth data were collected for every plant including height, root length, and dry mass. Each sample was tested for its usable total nitrogen content. C. arvense plants grown with AMF displayed no significant difference in growth compared to those plants grown without AMF. No significant difference in the cohabitated groups was found. However, a significant difference in nitrogen content was found in all experimental groups. These results demonstrate that AMF has an effect on the nitrogen content of C. arvense, but does not affect the growth in the seedling stage.

Effectiveness of Some Herbicides and Herbicide Combinations Applied to Chickpea (Cicer Arietinum L.) Culture

The purpose of this work is to establish the effectiveness of herbicides or combinations of herbicides under the influence of different climatic conditions in the study years (2019-2021). In this regard, ARDS Teleorman has established an experiment with the application of herbicides and combinations of herbicides, applied in different doses, in different application periods, placed according to the method of randomized blocks in three repetitions, on a chernozem cambic soil with clay content over 42%. The Burnas variety, a chickpea variety created by ARDS Teleorman, was used. Based on the frequency, the following specific problems were identified: Digitaria sanguinalis, Echinochloa crus-galli, Setaria spp., Amaranthus retroflexus, Chenopodium album, Solanum nigrum, Hibiscus trionum, Polygonum convolvulus, Sinapis arvensis, Stellaria media, Veronica spp., Xitalicum Cirsium arvense, Convolvulus arvensis, Sonchus arvensis. On average, over the three years of experimentation, the combination of herbicides applied to the V8 variant [312.5 g/l S-metolaclor; 87.5 g/l terbutilazin applied in a dose of 4.0 l/ha in pre-emergence + isoxaflutol 240 g/l Ciprosulfamida (safener): 240 g/l applied in a dose of 0.3 l/ha in pre-emergence] 98%, variant V5 [960 g/l S-metolaclor isoxaflutol 240 g/l applied in a dose of 1.2 l/ha in pre-emergence + isoxaflutol 240 g/l Ciprosulfamida (safener): 240 g/l in a dose of 0.2 l/ha in pre-emergence] 96.4% and in variant V3 [50g/l quizalofop-p-ethyl at a dose of 1.2 l/ha post-emergence + isoxaflutol 240 g/l Ciprosulfamida (safener): 240 g/l at a dose of 0.15 l/ ha post-emergence] 96%. Of all the tested variants, the variant with the application of 312.5 g/l S-metolaclo; 187.5 g/l terbutilazin herbicides (4.0 l/ha) + isoxaflutol 240 g/l; Ciprosulfamida (safener): 240 g/l (0.3 l/ha) in pre-emergence, with a high level of production, which does not allow its recommendation in weed control in chickpeas.

The Effect of the Timing of Manure Application in Combination with Mineral Fertilizers and Planting Density on the Weediness of Potato Plantings

Potatoes are one of the most responsive crops for grooming techniques since in the period from seedlings before closing rows are easily suppressed by weeds that take away nutrients, water, light from it. The factor that causes high harm to potatoes is weed. By absorbing a large number of nutrients and moisture from the soil, weeds inhibit the growth and development of plants, reducing their potential productivity. The purpose of the study was to establish the effect of the timing of the introduction of bedding manure in conjunction with mineral fertilizers and planting density on the weediness of potato plantings. Studies were provided to identify the impact of the timing of bedding manure together with mineral fertilizers and planting density for weed planting potatoes. Experiments were laid by the systematic method with a tiered arrangement of variants in the experiment with a 3-fold repetition. We used cattle manure on straw bedding for autumn-winter harvesting. The following types of fertilizers were used: ammonium nitrate, double superphosphate, potassium chloride. Determination of the amount and biomass of weeds in potato plantings was carried out in the flowering phase and before harvesting. The application of manure was accompanied by an increase in the number and weight of weeds. Annual weeds predominated in potato plantings: Amaranthus retroflexus L., 1753 and Amaranthus blitoides S. Watson, 1877, Chenopodium album L. Chenopodium album L., 1753, Setaria P. Beauv, 1812 and Setaria viridis (L.) P. Beauv, 1812, Echinochloa crus-galli (L.) BEAUV., 1812 and others, perennials included Cirsium arvense (L.) SCOP. 1772 and Sonchus arvensis L., 1753, (Elytrigia repens (L.) DESV. ex NEVSKI, 1933 and others. Planting density also has a definite effect on the development of weeds. When manure was applied in autumn under the plow, the number of weeds increased in comparison with other options, where only mineral fertilizers were applied. The application of manure over frozen plow and in winter over snow leads to a slight decrease (2.3-2.5 pcs/m2) of weeds. The greatest number of weeds is observed during the spring application of manure for plowing the fall plow. Nevertheless, studies aimed at clarifying the composition and structure of weediness, the number and weight of weeds in potato plantings are of great practical importance for local agricultural producers. These data should contribute to the development of an effective weed control system and high yields of potatoes in the region

Weed and pest species composition in spring barley sowings and the grain yield loss under different preceding crops

Purpose. To study the influence of predecessors on the formation of weed and pest species composition in spring barley sowings and the grain yield loss. Methods. Field, physical, mathematical and statistical. Results. The most common weed species in spring barley sowings during vegetation season are the following: Cirsium arvense, Sonchus oleraceus, Ambrosia artemisiifolia, Elymus repens, Sinapis arvensis, Consolida regalis, and Polygonum lapathifolium. The number of weeds per 1 m2 of spring barley sowings affected the amount of grain losses. After pealosses, the lowest grain loss (0.01 to 0.24 t/ha) was at the number of weeds from 5 to 10 per m2. The increase in the number of weeds has contributed to the increase in the grain loss. However, this figure varied over weed species. Thus, under the infestation with Sinapis arvensis and Consolida regalis, the grain yield loss was significantly lower compared to the control with the largest number of weeds. The largest grain loss occurred from Cirsium arvense and Sonchus oleraceus reaching 0.53–0.53 t/ha in at the number of weeds 20 per m2. Given the Polygonum lapathifolium, Ambrosia artemisiifolia, Sinapis arvensis, and Elymus repens, this figure ranged from 0.19 to 0.34 t/ha. When spring barley was grown after sugar beet, grain yield loss was significantly lower than under the number of weeds from 12 to 20 per 1 m2. However, the trend of falling grain yield caused by weeds was similar. The smallest grain loss caused Sinapis arvensis and Consolida regalis, while the largest one was caused by root and shoot and rhizome weeds. The number of pests in spring barley crops varied from 1.0 to 1.8 per 1 m2 (plant). In the case of spring barley cultivation after pea, the grain yield loss varied from 0.52 to 0.73 t/ha, while after sugar beet from 0.34 to 0.41 t/ha, varying over the years of the study. Because the air temperature was similar during the pest development period, the number of pests varied little. Lower grain yield loss after sugar beet was due to fewer common pests. Conclusions. It was found that the largest grain yield loss was caused by such weeds species as Cirsium arvense, Sonchus oleraceus, Ambrosia artemisiifolia, and Elymus repens ranging between 0.47 and 0.55 t/ha in the amount of 20 plants per m2. Sinapis arvensis and Consolida regalis caused the lowest grain loss ranging from 0.26 to 0.28 t/ha. Under Sinapis arvensis, this figure ranged from 0.02 to 0.34 t/ha, depending on the weed number. In the sowing of spring barley, Schizaphis graminum Rond., Lema lichenis Voet., Phyllotreta vittula Redt, Carabidae, Aelia acuminata, and Eurygaster integriceps Put. were found. Pest control in spring barley sowings provides 0.52 to 0.73 t/ha of grain yield growth after pea cultivation and 0.34 to 0.41 t/ha after sugar beet.

Influence of basic tillage, fertilizers and herbicides on weediness of pea crops for grain in stationary crop rotation

Goal. To establish the influence of the methods of basic tillage, fertilization system and herbicides on the weediness of pea crops for grain during cultivation in a stationary steam-grain-row crop rotation of the eastern part of the Forest-Steppe of Ukraine.
 Methods. The research was carried out by route surveys of pea crops for grain in the field crop rotation.
 Results. According to the research of 2016—18, 52 types of weeds and contaminants (spring early and late were 54%; wintering, winter and biennials were 23%; perennials were 23%) were found in pea crops for grain after spring cereal crops (spring barley, spring wheat, spring triticale) as forecrop. The largest number of them was noted on the organic-mineral background (manure aftereffect, 30 t/ha + N30P30K30) for the application of fertilizers for plowing (33 species) and chisel tillage (35 species). The weeds found in the pea crops for grain belonged to 20 families, of which the aster family (17 species) was the most represented. The main weeds in the crops were Setaria glauсa (L.) Beauv., Echinochloa crus-galli (L.) Roem. et Schult., Chenopodium album L., Amaranthus retroflexus L., Solanum nigrum L., Ambrosia artemisiifolia L., Stachys annua L., Xanthium strumarium L., Galium aparine L., Viola arvensis Murr., Cirsium arvense (L.) Scop., Sonchus arvensis L. and Convolvulus arvensis L. The use of herbicides and their compositions in the cultivation of peas for grain has significantly influenced the dominance and subdominance of certain weed species in the years of research. The fertilization system and the methods of basic tillage in crop rotation had a significant impact on the type and level of weediness of crops. The type of weed control crops (without fertilizers) differed significantly from organic and organo-mineral fertilizer backgrounds. For the most part, the version with chisel tillage had a higher level of weeding compared to plowing.
 Conclusions. Methods of basic tillage, fertilizer system and herbicides significantly affect the weediness of pea crops for grain in steam-grain-row crop rotation, which should be taken into account by farmers when developing methods of its control in the eastern part of the Forest-Steppe of Ukraine.

Winter cover crops favor cereal crop in N competition against creeping thistle Cirsium arvense (L.) Scop

Weed control is important to improve crop yield in organic farming. In Northern Europe, the use of mechanical weed control restricts the ability to use green manure-cover crops that could be a key source of N supply. In a two-year experiment repeated twice, the objective of this study was to compare the effect of cover crop- and autumn tillage-based systems on N uptake of the succeeding barley crop (Hordeum vulgare L.) and creeping thistle (Cirsium arvense (L.) Scop.). Each autumn, a 15NO3- tracer was applied to the topsoil, and in spring its recovery was measured in the soil, barley and thistle. The effect of cover crops on soil N distribution was significant: 66–85% of the total recovered 15NO3- was in the upper 0.5 m after the cover crop treatments, while after the autumn tillage treatment only 4–8% of the recovered 15NO3- was in this soil layer. The 15NO3- retained by cover crops in the topsoil postponed its availability to the deep-rooted thistle, while making it available to the shallow-rooted spring barley, thus strengthening the barley’s ability to compete against thistle. In contrast, following autumn tillage, 15NO3- clearly leached downward; much of it leached below the barley root zone, but remained at depths where it could be taken up by thistle. Cover cropping was found to have a post-harvest control effect on perennial weeds.

Weed communities with alien plant species on the south-east area of the Orenburg Region

The presence of agrocoenotic factors constantly acting on segmental (weed-field) communities leads to a high level of community invasion a potential opportunity to accept new species. In many cases, it is through synanthropic communities that invasions of alien species occur in the Urals, which cause significant damage to both agriculture and the entire economy of the region as a whole. The aim of investigation is to survey and identify the coenotic diversity of communities involving alien species in the steppe zone of the southeastern part of the Orenburg Region. The paper provides data on weed communities with the participation of Acroptilon repens, the Sisymbrium volgense and Artemisia sieversiana. Communities were identified in spring wheat crops in the southeast of the Orenburg Region (Dombarovsky and Svetlinsky administrative districts). Communities develop on dark chestnut soils in arid conditions of the steppe zone. As a result of a synaxonomic analysis, communities were classified into three new variants of the association Lactucetum tataricae Rudakov in Mirkin et al. 1985 previously described in the Republic of Bashkortostan. Perennial weed species prevail in the agrobiological spectrum of the coenoflora nucleus of the studied segetal communities, the share of which is 70%. The most active of them are root-sprung perennials, which are found with high constancy and often dominate: Acroptilon repens, Fallopia convolvulus, Cirsium arvense, Convolvulus arvensis, Lactuca tatarica, Euphorbia virgata. Using the indirect ordination method (DCA), the features of ecological differentiation of communities are demonstrated. The studied phytocoenoses are associated with the driest habitats with poor soils.

Linking functional diversity, trait composition, invasion, and environmental drivers in boreal wetland plant assemblages

AbstractQuestionsA range of landscape and local environmental factors, including invasion, interact with species functional diversity and trait composition to shape biodiversity patterns and ecosystem function of wetlands. A trait‐based, mechanistic understanding of community assembly holds promise for wetland conservation, but this has been rarely examined across scales. We examined: (a) the relative influence of climate, landscape matrix, and local physicochemistry on invasion intensity and functional diversity in boreal wetland plant assemblages; and (b) the ecological traits linked to these environmental factors.LocationOne hundred fifty‐three wetlands across the Boreal Forest of Alberta, Canada.MethodsWe used data on invasion intensity, using two terrestrial invaders (Sonchus arvensis and Cirsium arvense), and environmental factors at local and landscape levels. We used eight traits from 366 vascular plants to assess functional diversity and invasion responses to environmental gradients (generalized linear models) and individual species trait–environment relationships (community‐weighted mean redundancy analysis, fourth‐corner analysis).ResultsLandscape matrix and the degree of invasion were the primary drivers of functional diversity, while invasion intensity was driven by physicochemistry and functional diversity. Community trait–environment patterns clearly separated wetlands by invasion status. Uninvaded wetlands were surrounded by lowland conifers and composed of stress‐tolerant associated traits, while invaded wetlands contained high levels of disturbance and traits associated with high resource availability and reproduction rates. This division was further supported by individual trait–environment relationships.ConclusionsLandscape matrix was the dominant driver of functional diversity and composition pattern, while the local physicochemistry and surrounding land‐cover matrix helped explain invasion. Our analysis revealed some of the mechanistic relationships shaping plant community assembly across boreal wetlands, information that can help resource managers identify, predict, and alleviate possible threats from landscape anthropogenic disturbances to wetland ecological integrity.

Pre-harvest weed mapping of Cirsium arvense L. based on free satellite imagery – The importance of weed aggregation and image resolution

New data platforms have made satellite data freely available and farmers can now produce variable rate application (VRA) maps for nitrogen fertilisers and other inputs based on satellite images. The data platforms are currently attracting attention for site-specific weed management because they are free and user-friendly. Satellite imagery is mainly relevant for detecting large, dense weed patches that have unique spectral characteristics in low-resolution images. The objective of this study was to examine whether Sentinel-2 images are useful in the detection of Cirsium arvense and other green vegetation in pre-harvest cereals. It was hypothesised that there is a lower limit for detection and that weeds in large patches are easier to detect than weeds in small patches. Fifteen fields infested with C. arvense were used to evaluate the possibilities of utilising the normalised difference vegetation index (NDVI) from Sentinel-2 images as a weed classifier. High-resolution RGB images from unmanned aerial vehicles (UAV) were used as ground-truthing after classifying green pixels as weeds with C. arvense as the main contributor. The study showed that C. arvense-dominated weed populations were much less aggregated than previously reported. On average, 90 % of the weeds occurred on 50 % of the field area, in a range from 21 % to 72 %. The potential herbicide savings using Sentinel-2 images were in the range of 6 % to 46 %, averaging 24 %. The low weed aggregation combined with low image resolution limited the prospects of using Sentinel-2 images for weed detection. The study showed that UAV imagery offers much greater potential for herbicide savings due to higher image resolution, allowing the detection of individual C. arvense shoots.

Recognition of weeds at asparagus fields using multi-feature fusion and backpropagation neural network

In order to solve the problem of low recognition rates of weeds by a single feature, a method was proposed in this study to identify weeds in Asparagus (Asparagus officinalis L.) field using multi-feature fusion and backpropagation neural network (BPNN). A total of 382 images of weeds competing with asparagus growth were collected, including 135 of Cirsium arvense (L.) Scop., 138 of Conyza sumatrensis (Retz.) E. Walker, and 109 of Calystegia hederacea Wall. The grayscale images were extracted from the RGB images of weeds using the 2G-R-B factor. Threshold segmentation of the grayscale image of weeds was applied using Otsu method. Then the internal holes of the leaves were filled through the expansion and corrosion morphological operations, and other interference targets were removed to obtain the binary image. The foreground image was obtained by masking the binary image and the RGB image. Then, the color moment algorithm was used to extract weeds color feature, the gray level co-occurrence matrix and the Local Binary Pattern (LBP) algorithm was used to extract weeds texture features, and seven Hu invariant moment features and the roundness and slenderness ratio of weeds were extracted as their shape features. According to the shape, color, texture, and fusion features of the test samples, a weed identification model was built. The test results showed that the recognition rate of Cirsium arvense (L.) Scop., Calystegia hederacea Wall. and Conyza sumatrensis (Retz.) E. Walker were 82.72% (color feature), 72.41% (shape feature), 86.73% (texture feature) and 93.51% (fusion feature), respectively. Therefore, this method can provide a reference for the study of weeds identification in the asparagus field. Keywords: weeds recognition, image processing, feature extraction, multi-feature fusion, BP neural network, asparagus field DOI: 10.25165/j.ijabe.20211404.6135 Citation: Wang Y F, Zhang X D, Ma G X, Du X X, Shaheen N, Mao H P. Recognition of weeds at asparagus fields using multi-feature fusion and backpropagation neural network. Int J Agric & Biol Eng, 2021; 14(4): 190–198.

GC-MS EXAMINATION OF METHANOLIC FLOWER EXTRACT OF Cirsium arvense

Cirsium arvense (L.) Scop., commonly known as creeping thistle, is a weed of Asteraceae. This study was undertaken to explore various phytoconstituents present in flower of this weed. To achieve this goal, the dried flowers of this weed were soaked in methanol for one week and filtered. This methanolic extract was subjected to GC-MS analysis and 7 compounds were identified. These included olean-12-en-3-ol, acetate, (3β)- (63.87%), lanosta-8,24-dien-3-ol, acetate, (3β)- (12.12%), β-amyrin (6.19%), γ-sitosterol (6.09%), α-amyrin (5.24%), stigmasterol (3.29%) and carbonic acid, 2-ethylhexyl heptadecyl ester (3.16%). Literature survey showed that these compounds possess anti-inflamatory, antimicrobial, antidiabetic, antioxidant and/or anticancer activities.