Cirsium Arvense Research Articles

Free range characteristics and use by chickens from two genetic lines

Abstract The free-range system improves chicken’s welfare and enriches their diet. There is little information about influence of chickens on the sward quality. The aim of the study was to identify differences in the chemical and botanical composition of the pasture sward used by chickens and to assess if frequency of chicken exits outdoors is associated with the botanical composition of the ranging areas. One hundred twenty non-beak trimmed mixed sex birds of Green-legged Partridge (GP) and Sasso line C44 (S) were used. Each pen had direct access to an individual outdoor range providing 10.5 m2 per chicken, video-recorded continuously. Vegetation coverage regarding botanical composition was determined based on botanical-weight analysis from three control plots, while range use was calculated from the video material. The data were analysed by ANOVA model in SAS software (v 9.4). Regarding chemical composition, fiber content was higher in dry matter from the control pastures. Significantly more Dactylis glomerata (L.) and Alopecurus pratensis (L.) were observed on ranges used by Sasso. The higher share (%) of weeds and grasses was at the ranges used by chickens (weeds: S:8.66 (1.42) and GP:7.61 (0.59) and grasses: S:10.36 (0.96) and GP:12.10 (0.65)) as compared to control plots (1.45 (1.34)) and 3.86 (2.97), respectively) in contrast to legumes ((S:0.01 (0.01) and GP:0.32(0.26)) and sedges (S:0.64 (0.48) and GP: 0.09 (0.06)) most present in the control plots (10.88 (1.55)). Positive association between range use frequency and proportion of Heracleum sphondylium (L.), Rumex acetosa (L.), Festuca rubra (L.), and Lolium perenne (L.) was observed for Sasso, while foe Green-legged Partridges with proportion of Armoracia rusticana (L.), Stellaria media (L.), Ranunculus repens (L.), Cirsium arvense (L.) and Rumex crispus (L.). Concluding, the sward quality of the ranging areas was affected by the presence of the chickens and it differed between genotypes. Unknown remain if birds used the pasture more frequently depending on its botanical composition or if the pasture composition depended on the frequency of its uses by the birds.

Monitoring Patch Expansion Amends to Evaluate the Effects of Non-Chemical Control on the Creeping Perennial Cirsium arvense (L.) Scop. in a Spring Wheat Crop

The creeping perennial weed species Cirsium arvense (L.) Scop. occurs in patches. Expanding creeping roots allow these patches to increase their covered area. This characteristic has rarely been addressed when investigating the effects of control options in arable fields. We designed a three-year field experiment (2019–2021) in north-eastern Germany, accounting for existing patch patterns. The experimental setup included an untreated control, a competition treatment (cover crop, CC), two disturbance treatments by mouldboard ploughing (PL), root cutting (RC), and four combined applications (RC + CC, PL + CC, PL + RC, PL + RC + CC). Root cutting was performed by a prototype tillage machine produced by “Kverneland”. Plots were defined by the species growth pattern and mapped by GPS and UAV. The experiment investigates the thistle response variables: “Expansion”, “Density”, “Coverage”, and “Height”. Treatments including disturbance by ploughing (PL, PL + CC, PL + RC, PL + RC + CC) reduced “Density” by the factor 0.15 and “Expansion” by 0.25, while those without ploughing (CC, RC, RC + CC) only reduced “Density” by the factor 0.68 and “Expansion” by 0.71. Adding root cuttings or cover crops did not further increase the reduction effect of ploughing. Treatments with competition by cover crops impacted “Expansion” more clearly than “Density”. When cover crops were combined with root cutting (RC + CC), “Expansion” was almost additively reduced, resulting in a reduction comparable to that of ploughing. The “Height” of the shoots was significantly reduced in four treatments (PL, RC + CC, PL + RC, PL + RC + CC), while “Coverage” did not change significantly. UAV patch monitoring proved to be accurate enough for thistle “Expansion” but not for thistle “Density” within the patch. The results of this study demand innovative research when controlling patch-forming creeping perennial weeds. The need for patches will limit small-scale experimental set ups.

Invasive Cirsium arvense displays different resource-use strategies along local habitat heterogeneity in thetrans-Himalayan region of Ladakh.

Climate change and anthropogenic pressures have resulted in a significant shift in the invasion susceptibility and frequency of non-native species in mountain ecosystems. Cirsium arvense (L.) Scop. (Family: Asteraceae) is an invasive species that spreads quickly in mountains, especially in the trans-Himalayan region of Ladakh. The current study used a trait-based approach to evaluate the impact of local habitat heterogeneity (soil physico-chemical properties) on C. arvense. Thirteen plant functional traits (root, shoot, leaf, and reproductive traits) of C. arvense were studied in three different habitat types (agricultural, marshy, and roadside). Functional trait variability in C. arvense was higher between, than within habitats (between different populations). All the functional traits interacted with habitat change, except for leaf count and seed mass. Soil properties strongly affect C. arvense's resource-use strategies across habitats. The plant adapted to a resource-poor environment (roadside habitat) by conserving resources and to a resource-rich environment (agricultural and marshy land habitat) by acquiring them. The ability of C. arvense to use resources differently reflects its persistence in introduced habitats. In summary, our study shows that C. arvense invades different habitats in introduced regions through trait adaptations and resource-use strategies in the trans-Himalayan region.

Influence of Factors Determining Weeds’ Plant Tissue Reaction to the Electric Pulse Damage Impact

Due to the emerging danger to the life of animals and people, today there is a turn to safe technologies for controlling weeds by physical methods, both from the point of view of ecology and food safety, which include the destruction of plants using an electric current, in particular, high-voltage electrical pulses. The purpose of the study presented in the article is to identify and evaluate the effect of high-voltage electrical pulses on the irreversible damage to the intracellular structures of the plant tissue of weeds and unwanted grasses during their electric weed control, characterizing and evaluating the parameters and modes associated with such processing. Experimental studies were carried out using a laboratory experimental setup that consists of a pulse voltage generator, a control circuit for a spherical forming spark gap, and schemes for measuring the electrical resistance of the plant tissue of the weed sample. The lesion level made it possible to control the depth of irreversible damage to the internal structure of the plant tissue of weeds by measuring its tolerance (the conductivity of the tissue increased with increasing damage to the cellular components of the tissue).The irreversible damage to the plant tissues of weeds for weeds of various biological groups, which is characterized by reaching the value of at least 4.0–7.5 degrees of damage to their tissues, can be acted on them with high-voltage electrical pulses in the treated tissue of an electric field intensity of at least 3.74 kV/cm, while ensuring specific processing electric energy for the reliable processing of weeds: for Euphórbia virgáta, thise quals 5.2…17.5 J/cm3; for Amaránthus retrofléxus, it is 3.5…7.7 J/cm3; for Cirsium arvense, it is 2.7…10.9 J/cm3;for Sónchus arvénsis, it is 3.7…15.8 J/cm3; and for Lactúca tatárica, it is 3.3…8.1 J/cm3.

Impact of Puccinia punctiformis on Cirsium arvense performance in a simulated crop sequence

Cirsium arvense (Canada thistle) is a perennial weed that causes significant economic losses in agriculture. An extensive rhizomatous root system makes C. arvense difficult to manage, particularly in agricultural systems that use tillage as a primary management tool. There is a need for the development of integrated weed management toolsets that include C. arvense biological controls. Puccinia punctiformis (thistle rust) is an autoecious fungal pathogen that systemically infects C. arvense, with the potential to reduce host vigor over time. The goal of this study was to integrate the P. punctiformis biocontrol with a simulated annual cropping sequence in a greenhouse environment and evaluate C. arvense’s above-and belowground biomass production, and its competitive ability. Repeated P. punctiformis inoculations produced systemically infected C. arvense stems in greenhouse pots over time. Cirsium arvense that was inoculated with P. punctiformis had 1.6 grams/pot (p = 0.0019) less aboveground biomass and 5.6 grams/pot (p< 0.001) less belowground biomass, compared to the non-inoculated (control). Puccinia punctiformis and crop competition interacted additively to lower aboveground (p<0.001) and belowground (p<0.001) C. arvense biomass more than individual use of either the biocontrol or competition alone. The aboveground competition intensity of C. arvense in a mixed crop sequence, relative to non-inoculated C. arvense grown in a monoculture, was moderately impacted by the P. punctiformis biocontrol (p = 0.0987). These results indicate that systemic infection can reduce biomass production and the competitive ability of C. arvense. Overall, P. punctiformis can be integrated into competitive annual cropping sequences with the potential to reduce C. arvense vigor over time.

Weediness of spring barley crops depending on the forecrop in the Eastern Forest-Steppe of Ukraine

Goal. To determine the species composition of weeds, their dominant role, and to establish the type and level of weediness of spring barley crops grown after sugar beet, corn for grain ½ + soybean ½ and spring barley as forecrops in the conditions of the Eastern Forest-Steppe of Ukraine.
 Methods. The investigations were conducted in field experiments, in a stationary field, fixed nine-course-fallow-grain-row crop rotation and in monoculture of spring barley by means of route surveys.
 results. According to our research during 2011—17, in spring barley crops 56 species of weed plants were revealed. In the conditions of crop rotation, 47 and 50 species were found, respectively, in the fields of culture after sugar beets and corn for grain ½ + soybean ½ as forecrops, and 29 species in monoculture. Spring early and late weed plants are represented in the largest number (48.0—65.5%), and the second and third places were respectively occupied by wintering, winter and biennial (24.1—32.0%), and perennial (10.4—21.3%). The main species of weeds in spring barley crops were: Setaria glauсa, Echinochloa crus-galli, Chenopodium album, Amaranthus retroflexus, Solanum nigrum, Ambrosia artemisiifolia, Polygonum lapathifolium, Stachys annua, Fallopia convolvulus, Malva neglecta, Polygonum aviculare, Cirsium arvense, Convolvulus arvensis after sugar beets as forecrop; S. glauсa, E. crus-galli, C. album, A. retroflexus, S. nigrum, A. artemisiifolia, P. lapathifolium, S. annua, Xanthium strumarium, C. arvense, C. arvensis after corn for grain ½ + soybean ½ as forecrops; S. glauсa, E. crus-galli, A. retroflexus, S. nigrum, X. strumarium, Avena fatua, C. arvense, C. arvensis after spring barley as forecrop. In spring barley crops, the largest proportion of dominance and subdominance (in total) was: A. retroflexus (72%) after sugar beets as forecrop; S. nigrum (72%) and C. arvense (71%) after corn for grain ½ + soybean ½ as forecrops; S. glauсa (72%) and E. crus-galli (71%) in monoculture. The type of weediness of spring barley crops depended on the forecrop, and the level of weediness depended on the year of research.
 Conclusions. It was established that in the conditions of the Eastern Forest-Steppe of Ukraine, the forecrop significantly affects the species composition of weeds, their dominant role and the type of weediness of spring barley crops.

The Invasive Plant Impatiens glandulifera Manipulates Microbial Associates of Competing Native Species.

Impatiens glandulifera or Himalayan balsam is one of the most invasive weeds across Europe and can seriously reduce native plant diversity. It often forms continuous monocultures along river banks, but the mechanisms of this arrested succession are largely unknown. Here, we investigated the effect of arbuscular mycorrhizal (AM) fungi on balsam competitive ability with two native plant species, Plantago lanceolata and Holcus lanatus. We also studied how competition with Impatiens affects colonisation by foliar endophytes and mycorrhizas of two other co-occurring native species, Urtica dioica and Cirsium arvense. Mycorrhizal colonisation reduced balsam growth when the plants were grown singly, but appeared to have little effect when balsam experienced intra- or interspecific competition. Competition with balsam together with the addition of mycorrhizas had no effect on P. lanceolata biomass, suggesting that the fungi were beneficial to the latter, enabling it to compete effectively with balsam. However, this was not so with H. lanatus. Meanwhile, competition with Impatiens reduced endophyte numbers and mycorrhizal colonisation in U. dioica and C. arvense, leading to enhanced susceptibility of these plants to insect attack. Himalayan balsam is known to degrade soil fungal populations and can also reduce foliar beneficial fungi in neighbouring plants. This allows the plant to compete effectively with itself and other native species, thereby leading to the continuous monocultures.

Effects of Phytotoxic Nonenolides, Stagonolide A and Herbarumin I, on Physiological and Biochemical Processes in Leaves and Roots of Sensitive Plants

Phytotoxic macrolides attract attention as prototypes of new herbicides. However, their mechanisms of action (MOA) on plants have not yet been elucidated. This study addresses the effects of two ten-membered lactones, stagonolide A (STA) and herbarumin I (HBI) produced by the fungus Stagonospora cirsii, on Cirsium arvense, Arabidopsis thaliana and Allium cepa. Bioassay of STA and HBI on punctured leaf discs of C. arvense and A. thaliana was conducted at a concentration of 2 mg/mL to evaluate phenotypic responses, the content of pigments, electrolyte leakage from leaf discs, the level of reactive oxygen species, Hill reaction rate, and the relative rise in chlorophyll a fluorescence. The toxin treatments resulted in necrotic and bleached leaf lesions in the dark and in the light, respectively. In the light, HBI treatment caused the drop of carotenoids content in leaves on both plants. The electrolyte leakage caused by HBI was light-dependent, in contrast with that caused by STA. Both compounds induced light-independent peroxide generation in leaf cells but did not affect photosynthesis 6 h after treatment. STA (10 µg/mL) caused strong disorders in root cells of A. thaliana leading to the complete dissipation of the mitochondrial membrane potential one hour post treatment, as well as DNA fragmentation and disappearance of acidic vesicles in the division zone after 8 h; the effects of HBI (50 µg/mL) were much milder. Furthermore, STA was found to inhibit mitosis but did not affect the cytoskeleton in cells of root tips of A. cepa and C. arvense, respectively. Finally, STA was supposed to inhibit the intracellular vesicular traffic from the endoplasmic reticulum to the Golgi apparatus, thus interfering with mitosis. HBI is likely to have another main MOA, probably inhibiting the biosynthesis of carotenoids.

<sup>137</sup>Cs Pollution in Soils and Plants of Urban Ecosystems Near the Elektrostal Heavy Machinery Plant

In urban ecosystems to the west of the Elektrostal Heavy Machinery Plant, 6 years after the radiation incident, local areas with a total area of 0.2 km2 with an increased equivalent dose rate of γ radiation of 0.15–0.40 μSv/hour and a high specific activity of 137Cs reaching 8328–8740 Bq/kg in the upper soil horizons were identified. Statistically significant direct correlations were noted between the specific activity of 137Cs in a layer of 0–10 cm of soil and the equivalent dose rate of γ radiation at the surface and height of 1 meter. The types of vertical distribution of 137Cs in soils of polluted urban ecosystems, including those on which earth decontamination works were carried out, have been determined. The calculated 137Cs transfer coefficients increase in row of tree: Salix alba Sórbus aucupária Ácer platanoídes Malus domestica Alnus incana Ácer negúndo; and grassy vegetation: Týpha angustifólia Artemísia vulgáris Tussilágo fárfara Cirsium arvense Urtíca dióica.

Canada thistle injury with spring‐applied herbicides in infrequently mowed fine fescue in Pennsylvania

Core Ideas Aminopyralid + 2,4‐D provided equal or greater injury to Canada thistle compared to clopyralid‐containing products. Triclopyr + 2,4‐D produced Canada thistle injury comparable to triclopyr + clopyralid. Metsulfuron was slow to injure Canada thistle but provided acceptable control within 40 to 55 d.

Anti-glutamatergic Effects of Three Lignan Compounds: Arctigenin, Matairesinol and Trachelogenin - An ex vivo Study on Rat Brain Slices.

Arctigenin is a bioactive dibenzylbutyrolactone-type lignan exhibiting various pharmacological activities. The neuroprotective effects of arctigenin were demonstrated to be mediated via inhibition of AMPA and KA type glutamate receptors in the somatosensory cortex of the rat brain. The aim of this study was to compare the effects of arctigenin with matairesinol and trachelogenin on synaptic activity in ex vivo rat brain slices. Arctigenin, matairesinol and trachelogenin were isolated from Arctium lappa, Centaurea scabiosa and Cirsium arvense, respectively, and applied on brain slices via perfusion medium at the concentration range of 0.5 - 40 µM. The effects of the lignans were examined in the CA1 hippocampus and the somatosensory cortex by recording electrically evoked field potentials. Arctigenin and trachelogenin caused a significant dose-dependent decrease in the amplitude of hippocampal population spikes (POPS) and the slope of excitatory postsynaptic potentials (EPSPs), whereas matairesinol (1 µM and 10 µM) decreased EPSP slope but had no effect on POPS amplitude. Trachelogenin effect (0.5 µM, 10 µM, 20 µM) was comparable to arctigenin (1 µM, 20 µM, 40 µM) (p > 0.05). In the neocortex, arctigenin (10 µM, 20 µM) and trachelogenin (10 µM) significantly decreased the amplitude of evoked potential early component, while matairesinol (1 µM and 10 µM) had no significant effect (p > 0.05). The results suggest that trachelogenin and arctigenin act via inhibition of AMPA and KA receptors in the brain and trachelogenin has a higher potency than arctigenin. Thus, trachelogenin and arctigenin could serve as lead compounds in the development of neuroprotective drugs.

Genome Characterization and Development of Real-Time PCR Assays for Ditylenchus Dipsaci and D. Weischeri.

The stem and bulb nematode Ditylenchus dipsaci is a destructive nematode pest on many crops and is internationally quarantined in many countries, whereas Ditylenchus weischeri, only known to infect a weed plant (Cirsium arvense), is an unregulated nematode species with no known economic importance. In this study, we used comparative genomics to identify multiple gene regions and developed novel real-time PCR assays for the detection of D. dipsaci and D. weischeri. We sequenced the genomes of two mixed-stage nematode populations of D. dipsaci and two mixed-stage nematode populations of D. weischeri. The assembled genomes of D. dipsaci were 228.2 Mb and 239.5 Mb, and the genomes of D. weischeri were 177.0 Mb and 196.3 Mb. Depending on the species, 21,403-27,365 gene models were predicted. Using orthologous group analysis, single-copy and species-specific genes were identified. Primers and probes were designed targeting two species-specific genes in each species. The assays detected as low as 12 pg of DNA from the target species, or as few as five nematodes, with a Cq of 31 cycles or less. Our study provides genome data for two additional D. dipsaci isolates and two D. weischeri isolates, and four new and validated molecular assays to be used for rapid detection and identification of the two species.

Phenologies of Canada thistle (Cirsium arvense) andCirsiumspecies native to the upper Midwest: implications for the ecological host range of the biocontrol agentHadroplontus litura

AbstractNativeCirsiumspecies play an important role in landscapes across North America.Hadroplontus litura(F.) (formerlyCeutorhynchus litura), the stem-mining weevil and biological control agent of Canada thistle [Cirsium arvense(L.) Scop.] can complete its life cycle on fiveCirsiumspecies native to the upper Midwest. Although these fiveCirsiumspecies are within the fundamental host range ofH. litura, as determined by host-range tests, we wanted to explore whether phenological differences amongCirsiumspecies help define the field ecological host range ofH. litura. The objective of this study was to determine the phenology ofCirsiumspecies native to the upper Midwest in relation toC. arvenseandH. litura.Our goal was to explore whether shoots of nativeCirsiumspecies could escapeH. liturashoot oviposition in spring due to delayed shoot emergence relative toC. arvense. Soil cumulative growing degree days (GDD) were a superior predictor of shoot emergence for perennialCirsiumspecies or initiation of leaves in biennialCirsiumspecies, with a 2.4 times larger effect on time to emergence relative to air GDD. All nativeCirsiumspecies initiated new leaves or shoots beforeC. arvenseshoot emergence, even when nativeCirsiumspecies growth was delayed in the spring. In turn,C. arvenseshoots emerged approximately 1 to 3 wk before femaleH. liturabegan to lay eggs. As such, all nativeCirsiumplants had shoots available forH. lituraoviposition. There was no phenological separation between nativeCirsiumandC. arvenseshoot emergence or initiation that would render nativeCirsiumspecies safe fromH. lituraattack. Based on the phenology of shoot emergence or initiation in the spring, all testedCirsiumspecies native to the upper Midwest would be within the ecological host range ofH. litura.

Solanum carolinense L.

<i>Solanum carolinense</i> L.

Efikasnost herbicida u suzbijanju korova u lucerki

Alfalfa is one of the most important perennial fodder crops, and it is also the most economical. Alfalfa provides first class fodder that is suitable for feeding all livestock, especially ruminants. Grass and broadleaf weeds are a serious threat to the quality and viability of alfalfa stands. Weeds can reduce the nutritional value of the crop and cause significant reductions in yield, as they compete aggressively for water, nutrients, sunlight, and space. In this study, herbicides (Butoxone DB, Agil, Basagran, Corum, Fusilade forte, Pulsar and Focus ultra) were used for controlling weeds in alfalfa. The presence of annual and perennial weeds, typical of alfalfa plantations: Capsella bursa-pastoris, Stellaria media, Lamium amplexicaule, Viola arvensis, Amaranthus retroflexus, Setaria spp., Sorghum halepense, Cirsium arvense, Plantago lanceolate, Rumex crispus and others, was observed on the tested surfaces. Our research has shown that the most effective herbicides are Basagran, Butoxone DB and Corum, which are intended to suppress broadleaf weeds. Meanwhile, herbicides Fusilade forte and Pulsar proved to be very effective in controlling grass weeds. A very good reaction was also observed with the combinations of herbicides Pulsar + Fusilade forte and Pulsar + Basagran, as these combinations expand the spectrum of activity to the grass and broadleaf weeds. The aim of this paper was to determine which herbicide is most effective in controlling weeds in alfalfa.

Determination of Densities and Frequencies of Problematic Weed Species in Onion Planting Areas of Ankara and Çorum Provinces

This study was conducted in 2019 in order to determine the weed species, their densities and frequency of occurrences in the onion production areas of Ankara and Çorum Provinces. The surveys were carried out in 78 fields, 55 in Ankara and 23 in Çorum. As a result of the surveys, 75 weed species, two of which are parasite, belonging to 28 families and 64 genera, were determined in the onion fields of Ankara Province. The families with the most species were listed as Asteraceae (11), Poaceae (9), Fabaceae (6), Chenopodiaceae (5) and Apiaceae (5). Other families were determined between 1-3 species. Of these weeds, Convolvulus arvensis L. (1.2 plants/m2), Xantium strumarium L. (0.50 plants/m2), Amaranthus retroflexus L. (0.40 plants/m2), Cuscuta sp. (0.37 parazited onion/m2), A. blitoides S. Watson (0.36 plants/m2) were the 5 most intense species. According to the frequency of occurrence, the first five species are determined as; C. arvensis L. (90.90%), X. strumarium L. (65.45%), A. retroflexus L. (54.54), Chenopodium album L. (52.72%), A. albus L. (47.27%). In the onion cultivation areas of Çorum Province, 61 weed species one of which is parasite, belonging to 24 families and 51 genera were determined. The families with the most species were listed as Asteraceae (9), Poaceae,(8) Apiacea (5), Polygonaceae (4), Fabaceae (4); as for other families, between 1-3 species were determined. Considering the densities per m2 of these weeds, the 5 most common weed species are determined as C. arvensis L. (0.80 plants/m2), Anethum graveolen L. (0.56 plants/m2), A. retroflexus L. (0.41 plants/m2), Chrozophora tinctoria (L.) Raf. (0.32 plants/m2), X. spinosum L. (0.31 plants/m2), the first five species in terms of frequency of incidence are; C. arvensis L. (86.95), A. refroflexus L. (56.52%), X. strumarium L. (56.52%), Cirsium arvense (L.) Scop. (52.17%), C. album L. (52.17%).

STUDIES ON THE APPLICATION OF HERBICIDES IN RASPBERRY CULTURE TECHNOLOGY

Weed control in raspberry cultivation helps to reduce the economic impact of the weed control link on the technological cycle, as well as to eliminate competition for water, nutrients and sunlight, thus allowing their growth and development in normal parameters. Cultivation, mulching and herbicide are the most practical control measures. It is necessary to know both the density of weeds and the dominant species in order to establish the strategy to reduce weeding by plowing, herbicide or integrated measures, so that weed invasion falls below the economic damage threshold (PED). The application of herbicides to reduce the degree of weeding is based on the knowledge of the weed species existing in the crop, as well as the state of coverage of the plantation. In order to establish effective measures to reduce the invasion below the economic damage threshold, it is necessary to determine the density of weeds by the method of mapping them and to establish the predominant species. The mapping action took place in the period 2020-2021 and an attempt was made to cover the entire spectrum of weeds in the plantation, then averaging by species. Following the mapping of weeds in the raspberry plantation, the presence of 22 weeds identified inside the metric frame belonging to both the dicotyledonous and monocotyledonous classes was observed, most of them coming from the first group (Capsela bursa-pastoris, Lamium amplexicaule, Cirsium arvense, Cardaria draba, Setaria glauca, Agropyron repens, Cynodon dactylon.

RESEARCHES ON USE OF SOME POST-EMERGENT HERBICIDES TO CONTROL WEEDS IN THE BEARING APPLES ORCHARDS

Mono and dicotyledonous weeds are the competitors of fruit species, in terms of growth, bearing and fruit quality. Therefore, in fruit growing, the aim is to keep the spectrum of weeds below the economic damage threshold (EDT). In this sense, different methods are used: biotechnical (mulching), mechanical (mowing), agrotechnical (black field worked, weeding between rows) or chemical (pre- or post-emergent herbicide use). The paper presents the results of research undertaken between 2019-2021 on the effectiveness of 6 post-emergent herbicides (4 total, based on glyphosate and 2 including other molecules - cycloxidim 100 g / l and oxifluorfen 240 g / l). The application of the products was carried out in an experimental module with the apple varieties 'Jonathan / M9' and 'Idared / M9', 5-7 years old, in variants and replications arranged randomly. Observations and determinations were performed according to the European Weed Research Society (EWRS) scale showed that, from the whole spectrum of weeds followed in the experimental device, the most difficult or difficult to control were the dicotyledonous weeds such as: Equisetum arvense (note 8-9), Cirsium arvense, Gallium aparine, Galinsoga parviflora, Malva neglecta, Matricaria chamomilla, Ranunculus repens, Rumex spp., Stelaria media (note 5). Among the monocotyledons difficult to control were: Agropyron repens, Lolium perene and Cynodon dactylon, requiring the application of herbicides twice vegetation season, or the integrated control of weeds.

Species and quantitative composition of weeds in wheat agrophytocenosis in the conditions of the forest-steppe zone of the Trans-Urals

The article analyzes the species and quantitative composition of weeds in wheat agrophytocenosis. From 16 species of weeds in different years prevailed: from perennial – Cirsium arvense, Glechoma hederacea, Convolvulus arvensis, Sonchus arvensis, from juvenile wintering – Erodium cicutarium, Matricaria perforata, Viola arvensis, Thlaspi arvense. From spring juveniles – Amaranthus retroflexus, Spergula arvensis, Galeopsis speciosa, Chenopodium album, Fumaria officinalis, Galium aparine, Stellaria media. Field observations in 2017-2020 made it possible to establish some features in the change in the composition and abundance of different biological groups of weeds during the growing season. It is necessary to study the species composition of weeds in order to control, predict and regulate their abundance. In the tillering phase, the number of weeds in different years of research varied from 15.3 to 16.1 pcs/m2, which, according to the scale of determining the degree of clogging of fields, corresponds to a weak degree of clogging of 2.55-13.4%. Before cleaning, the degree of clogging increased by 0.2% in 2018, by 0.15% in 2019, and in 2017 and 2020, the degree of clogging remained at the same level – 3.4%, which was also characterized by a weak degree. Comparison of the contamination over different years allows us to identify the dynamics of the quantitative and specific composition of weeds in crops and adjust the system of measures to combat them.

Organic oat production (Avena sativa L.) in the conditions of Northeastern Bulgaria

Abstract. The study took place in the period 2018 - 2020 in the village of Milanovo, Shumen region. In the period March 23 - 30, in accordance with the climatic factors of each year, the spring oat variety Scorpion was sown at a sowing rate of 3000 - 4000 germinating seeds per ha. Oats were sown after a predecessor crop of nettle. The aim of the present study is to prove that the oat variety Scorpio is suitable for organic production and it gives a quality product for direct consumption. The cultivation method and the finished product processing are also described in the study. The soil is gray-brown forest soil (Luvisols, Lessive - FAO UNESCO). Oats were grown following the requirements for field crop organic cultivation. In the period of vegetation, the crop was watered twice at a rate of 0.4 - 0.6 mᶾ /ha. The crop was harvested for green mass, at the maturity stage, as mowing was done in late June in two stages with a herb mower. The harvested area was 1.23 ha, and the green mass yield obtained was 10 t, on average for the period. The green mass followed a drying process in the sun, as a result of which 2470 kg of dry oat stalks were obtained. After that, we could prepare bundles measuring the length of 20 - 25 cm, packed in nylon and also aligned at the rear end. Each bundle weight varied from 100 to 300 g. After the dedusting process of bundles we were able to obtain a product for direct consumption showing fiber length of 0.4 - 3 mm. The sown area was identified as having the following groups of weeds: winter-spring (Chamomilla recutita Rauchert, Consolida regalis SPGray, Centaurea cyanus L. and Papaver rhoeas L.), early spring (Sinapis arvensis L., Bifora radians MB, Polygonum convolvulus L., Galium tricorne With, Avena fatua L.), ephemeral (Veronica hederifolia L., Stellaria media (L.), Holosteum umbelatum toothed swan) and root-shoot (Cirsium arvense Scop., Convolvulus arvense L. Cardaria draba L.). We could not detect any fungal disease attacks by: Puccinia coronata, Ustilago avenae, Ustilago hordei, Fusarium sp. Powdery mildew (Erysiphe graminis De Candole f. Sp. Avenae) and striped leaf spots (Pyrenospora avenae) had a weak effect on the crop (up to 25%). The study period showed the average content in the crop as follows: protein - 10.56%, starch - 43.62%, ash - 4.24%, and fiber - 13.47%.