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Chenopodium album L. (CAL) is an excellent vegetable crop that is rich in nutrients and possesses potential pharmaceutical value. However, the research on the secondary metabolites and the processing utilization of CAL has been rarely reported. In this study, the polyphenol content, microstructure and secondary metabolite composition of aerial parts of CAL (AC), including stems, leaves, inflorescence and grain, before and after fermentation were investigated. The results showed that the polyphenol content of fermented AC (FAC) was significantly higher than that of AC (increased by 38.62%). The AC had a compact surface, while FAC had a loose and cracked surface with large holes. A total of 545 secondary metabolites, including 89 alkaloids, 179 flavonoids, 25 lignans and coumarins, 163 phenolic acids, 35 terpenoids, 9 quinones, 6 tannins and 39 others, were identified in the AC and FAC by UHPLC-QQQ-MS metabolomics. Differential metabolites analysis reviewed 285 differential metabolites (117 upregulated and 168 downregulated) between AC and FAC. The decrease in parts of toxic alkaloids accompanied with the increase in some biologically active substances with small molecules, such as quercetin, kaempferol, p-coumaric acid and protocatechuic acid, indicated that fermentation is beneficial to enhance the bioavailability of AC. This study provides a reference value for the identification of secondary metabolites from AC and the application of fermentation in the deepness development of AC.

Low-diversity weed communities are dominated by few species that are highly competitive to crops. The management of such weed communities should rely upon sustainable cultural and non-chemical practices, especially in crops such as spinach (Spinacia oleracea L.), where very few herbicides are available. A two-year field trial (2020 and 2021) was conducted to evaluate different fertilization practices (broadcast and banded), intra-row spacings (15 cm, 11 cm, 7 cm), and mechanical weed control treatments (untreated, one treatment, two treatments) for the management of a low-diversity weed community in spinach. Weed competition severely affected spinach commercial biomass (R2 = 0.845). Compared to broadcast fertilization, banded fertilization reduced weed biomass and improved spinach yield and nitrogen use efficiency. Narrow intra-row spacing (7-cm) reduced weed biomass by 28 and 45% compared to intra-row spacings of 11-cm and 15-cm, respectively. Two mechanical weed control treatments resulted in 49% lower weed biomass compared to a single treatment. Commercial biomass increased with decreasing intra-row spacing (R2 = 0.881) and increasing the number of mechanical treatments (R2 = 0.911). More cultural and non-chemical practices should be evaluated for weed management in spinach, especially at sites infested with low-diversity weed communities.

This paper describes the antigerminant capacity of water extracts of silver fir needles created by means of hydrodynamic cavitation processes. Fir needles (2 kg fresh weight) collected in the winter were blended and crushed in ice, poured in water only (120 L) and processed in a controlled hydrodynamic cavitation device based on a fixed Venturi-shaped reactor. The A. alba water extract (AWE), comprising an oil-in-water emulsion of silver fir needles’ essential oil (100% AWE), was diluted in distilled water to 75% and 50% AWE, and all aqueous solutions were tested as antigerminant against four weeds and four horticultural species and compared to control (distilled water). This study shows the effective inhibitory effect of pure AWE on germination, which mainly contains limonene (15.99 ng/mL) and α-pinene (11.87 ng/mL). Seeds showed delayed germination and inhibition but also a reduction in radicle elongation in AWE treatments as compared to control. This combined effect was particularly evident in three weeds (C. canadensis, C. album and A. retrofllexus) while horticultural species showed mainly effects on the radicle elongation as found in L. sativa, P. crispum and S. lycospermum, which showed on average 58%, 32% and 28%, respectively, shorter radicles than in the control. P. sativum was not affected by AWE, thus raising the hypothesis that seed characteristics and nutrition reserve might play a role in the resistance to terpenes inhibitory effect.

Irrigation is an agronomic practice of major importance in alfalfa (Medicago sativa L), especially in the semiarid environments of Southern Europe. Field experimentation was conducted in Western Greece (2016–2018) to evaluate the effects of irrigation timing on weed presence, alfalfa yield performance, and forage quality. In a randomized complete block design (four replications), two cultivars (“Ypati 84” and “Hyliki”) were the main plots, while three irrigation timings were the subplots (split-plot). The irrigation timings were IT-1, IT-2, and IT-3, denoting irrigation 1 week before harvest, 1 week after harvest, and 2 weeks after harvest, respectively. IT-1 reduced Solanum nigrum L. density by 54% and 79% as compared to IT-3 and IT-2, respectively. Chenopodium album L. density was the highest under IT-2. IT-3 resulted in 41% lower Amaranthus retroflexus L. density in comparison to IT-2, while the lowest values were observed under IT-1. Stand density and stems·plant−1 varied between years (p ≤ 0.05). Mass·stem−1 and alfalfa forage yield were affected by the irrigation timings (p ≤ 0.001). Total weed density and forage yield were negatively correlated in both the second (R2 = 87.013%) and the fourth (R2 = 82.691%) harvests. IT-1 and IT-3 increased forage yield, leaf per stem ratio, and crude protein as compared to IT-2. Further research is required to utilize the use of cultural practices for weed management in perennial forages under different soil and climatic conditions.

Morphological leaf traits are frequently used to quantify, understand and predict plant and vegetation functional diversity and ecology, including environmental and climate change responses. Although morphological leaf traits are easy to measure, their coverage for characterising variation within species and across temporal scales is limited. At the same time, there are about 3100 herbaria worldwide, containing approximately 390 million plant specimens dating from the 16th to 21st century, which can potentially be used to extract morphological leaf traits. Globally, plant specimens are rapidly being digitised and images are made openly available via various biodiversity data platforms, such as iDigBio and GBIF. Based on a pilot study to identify the availability and appropriateness of herbarium specimen images for comprehensive trait data extraction, we developed a spatio-temporal dataset on intraspecific trait variability containing 128,036 morphological leaf trait measurements for seven selected species. After scrutinising the metadata of digitised herbarium specimen images available from iDigBio and GBIF (21.9 million and 31.6 million images for Tracheophyta; accessed date December 2020), we identified approximately 10 million images potentially appropriate for our study. From the 10 million images, we selected seven species (Salix bebbiana Sarg., Alnus incana (L.) Moench, Viola canina L., Salix glauca L., Chenopodium album L., Impatiens capensis Meerb. and Solanum dulcamara L.) , which have a simple leaf shape, are well represented in space and time and have high availability of specimens per species. We downloaded 17,383 images. Out of these, we discarded 5779 images due to quality issues. We used the remaining 11,604 images to measure the area, length, width and perimeter on 32,009 individual leaf blades using the semi-automated tool TraitEx. The resulting dataset contains 128,036 trait records. We demonstrate its comparability to trait data measured in natural environments following standard protocols by comparing trait values from the TRY database. We conclude that the herbarium specimens provide valuable information on leaf sizes. The dataset created in our study, by extracting leaf traits from the digitised herbarium specimen images of seven selected species, is a promising opportunity to improve ecological knowledge about the adaptation of size-related leaf traits to environmental changes in space and time.

The amount of maize yield depends on many factors. Among them, plant health plays a significant role. Herbicide selectivity (of mesotrione, 2,4-D, and bromoxynil) for different maize varieties was assessed in greenhouse experiments. The effectiveness of herbicides (MCPA, 2,4-D + dicamba) and spraying mixture of the herbicide MCPA with mepiquat chloride was tested on Chenopodium album L. and self-seeding winter oilseed rape (Brassica napus L.). The genetic distance between selected maize varieties and species composition of pathogens of the genus Fusarium isolated from the seeds of the discussed crop were examined. Research results indicated that individual herbicides differed in the selectivity in relation to maize, which depended on the crop variety. The selected herbicides showed high efficacy against the plants used in the experiment. The addition of mepiquat chloride to the composition of the spraying liquid did not affect the level of weed control. No relationship was found between the genetic distance of maize varieties and their sensitivity to selected herbicides. The presence of Fusarium subglutinans, Fusarium proliferatum, and Fusarium verticillioides was found in the samples of maize varieties.

Rapid industrialization and increasing population are continuously adding contaminants to our environment. Among those, heavy metals are considered to be one of the serious threats to the ecosystem due to their persistent nature. Microbe assisted phytoremediation is an effective tool for metal remediation as microbes enhance the metal availability and uptake to the host plants or reduce it by binding them intracellularly or extracellularly. An endophytic fungus, Trametes hirsuta, was isolated from Chenopodium album L. plant growing in the lead (Pb) contaminated soil of an industrial area. This is the first study citing Trametes hirsuta, as a root endophyte of Chenopodium album L. This endophytic fungus was found to be tolerant to high concentration of Pb i.e., 1500 mg L−1, when tested in-vitro. Wheat (Triticum aestivum L.) seedlings were infected by Trametes hirsuta and Pb tolerance was observed. With the fungal inoculation plants cumulative growth and total chlorophyll content increased by 24% and 18%, respectively as compared to their respective non-inoculated controls at 1000 mg kg−1 Pb. Similary, 50% more Pb accumulation was measured in the shoots of fungal inoculated plants at 1500 mg kg−1 Pb as compared to control. Thus, the results of the present study suggest that mutualism with endophytic fungi can improve the survival of host plants in metal contaminated soils, additionally it can also assist the phytoextraction of heavy metals from polluted sites by increasing their uptake by the host plants., Trametes hirsuta; Endophytic fungi; Pb tolerance; Metal accumulation; Triticum aestivum L., Rhizosphere; Soil microbiology; Soil pollution; Environmental chemistry; Environmental toxicology, Environmental science, Microbiology, Chemistry, Toxicology.

Weeds account for losses in crop yields, and this event might be exacerbated by salinity. Therefore, we investigated the responses of Chenopodium album L. and soybean (Glycine max (L.) Merr.) to salt stress, as well as interferences between species. Ten-day old plants were grown for 1 week in a single- or mixed-species set-up, either with or without 100 mM of NaCl. C. album reduced the biomass of soybean similarly to salt stress, while its growth was unaffected under any condition. C. album decreased the crop protein content when salinity was applied. This effect was ascribed to altered protein metabolism and/or N usage to produce other N metabolites, including osmolytes. The two species did not reciprocally affect the capacity to accumulate Na+, but the weed contained two-fold more Na+ in the leaves. Elevated initial K+ concentration and high K+ delivery to the shoot likely explained the better acclimation of C. album to salinity. C. album produced more phenolics and proline and exhibited greater antioxidant activity, but low lipid peroxidation, in the mixed set-up under salinity. Thus, it is possible that the weed could become more resilient to salinity when growing in a soybean field. In the long term, this might cause significant losses in soybean productivity as expected by the dramatic decline in crop protein content.

Chenopodium album L. is a common edible herb distributed in China that has been used as a traditional Chinese medicine for antiviral, antifungal, anti-inflammatory and cancer treatment. However, to the best of our knowledge no previous reports have investigated its the function of its phytochemical extracts in lung cancer cells. The purpose of the present study was to assess the anticancer activities of the phytochemical extracts of C. album L. on human non-small cell lung cancer A549 cells. The present findings demonstrated that the petroleum ether (PE) extract of C. album L. exhibited significant growth inhibitory effects on A549 with an IC50 value of 33.31±2.79 µg/ml. As determined by MTT and colony formation assays, its growth inhibitory effects were dose- and time-dependent. Furthermore, PE extract-treated A549 cells exhibited dose-dependent cell growth arrest at the G1 phase of the cell cycle and cell apoptosis was induced. These results provide useful data on the anticancer activities of C. album L. in human lung cancer and demonstrated the novel possibilities of this plant in developing lung cancer therapies.

The application of minimal doses of herbicides is very popular due to concerns about the negative impacts of herbicides on the environment and public health. Studies were conducted to estimate the possibility of using quick and non- destructive methods to investigate Chenopodium album L. and Abutilon theophrasti Medik. response to mesotrione. The studies were conducted in a controlled environment to determine the response of C. album and A. theophrasti to mesotrione using dose-response curves created based on plant dry weight, chlorophyll fluorescence parameters and chlorophyll content. The obtained effective dose values showed that the studied weeds were susceptible to reduced doses of mesotrione. ED95 values estimated for both species for dry weight and chlorophyll fluorescence parameters were lower than the recommended dose rate (120 g a.i. ha(-1)), with less than 85 g a.i. ha(-1) needed to achieve a reduction of 95%, compared with untreated plants, while ED95 value (A. theophrasti: 182 g a.i. ha(-1) and C. album: 180 g a.i. ha(-1)) for chlorophyll content for both species was above the recommended dose rates. Consequently, dry weight and the chlorophyll fluorescence parameters are suitable for estimating the plant response to mesotrione, while chlorophyll content is not.

Vlaga u tlu jedan je od glavnih vanjskih čimbenika koji utječe na nicanje korovne vrste Chenopodium album (loboda). Cilj ovog istraživanja bio je utvrditi biološki vodni potencijal (Ψb), odnosno minimalnu količinu vlage u tlu koja je potrebna za klijanje lobode. Za potrebe istraživanja sjeme lobode sakupljeno je 2016. na pokušalištu Šašinovec. U svrhu simulacije vodnog stresa u tlu korišteno je sedam različitih koncentracija otopina polietilenglikola (PEG): -0,05, -0,10, -0,25, -0,38, -0,50, -0,80, -1,00 MPa i kontrolni tretman (0,00 MPa) prekriven samo destiliranom vodom. Sjeme lobode posijano je u plastične posude i postavljeno u klima komoru pri konstantnoj temperaturi od 25°C i s fotoperiodom od 12 sati dan: 12 sati noć. Rezultati istraživanja ukazuju da bijela loboda klije dobro na koncentracijama od -0,05 MPa (48%) do -0,50 MPa (44%), odnosno u tom rasponu nije utvrđena statistički značajna razlika u klijavosti. Klijavost statistički značajno pada tek pri -0,80 MPa (28%) i -1,00 MPa (11%). Dinamika klijanja razlikovala se ovisno o istraživanoj koncentraciji PEG-a. Povećanjem koncentracije povećavao se i broj dana potrebnih za klijanje, pa je tako najkraći period potreban za početak klijanja (t10) iznosio 2,0 dana, a najdulji period 4,5 dana. Razdoblje potrebno za 50%-tno klijanje (t50) kretalo se od 3,4 do 9,6 dana, dok je za 90%-tno klijanje (t90) bilo potrebno od 5,4 do 21,4 dana. Utvrđen biološki vodni potencijal za vrstu Chenopodium album za područje kontinentalne Hrvatske, lokalitet Šašinovec, iznosi -1,38 MPa. Utvrđena je statistički značajna razlika između biološkog vodnog potencijala „hrvatskog“ ekotipa lobode u odnosu na „talijanski“ ekotip, lokalitet Veneto, iste korovne vrste (-0,96 MPa). Soil moisture is one of the main external factors that affect the growth of Chenopodium album (common lambsquarter). The aim of this study was to determine the biological water potential (Ψb), i.e. the minimum amount of moisture in the soil required for germination. The seeds of the common lambsquarter used in this study were collected in 2016 at the experimental station Šašinovec. For the purpose of simulating water stress in the soil seven different concentrations of polyethylene glycol (PEG) solutions were used: -0,05, -0,10, -0,25, -0,38, -0,50, -0,80, -1,00 MPa and a control (0,00 MPa) covered only with distilled water. The common lambsquarter seeds were planted in plastic containers and placed in a climatic chamber at a constant temperature of 25 ° C with a photoperiod of 12 hours day: 12 hours night. The results of the study indicate that the common lambsquarter germinates well at concentrations between -0,05 MPa (48%) and -0,50 MPa (44%), i.e. in this range there was no statistically significant difference in germination. A statistically significant decrease in germination quality was seen only at -0,80 MPa (28%) and -1,00 MPa (11%). The dynamics of germination differed depending on the concentration. As the concentration increased, decereased also the number of days required for germination. The shortest period required for germination (t10) was 2,0 days and the longest 4,5 days. The center of germination (t50) ranged from 3,4 to 9,6 days, while the germination time (t90) was 5,4 to 21,4 days. The biological water potential for Chenopodium album in continental Croatia, the locality of Šašinovec, was determined to be -1,38 MPa. There was also a statistically significant difference between the biological water potential of the “Croatian” ecotype of common lambsquarter and the “Italian”, locality of the Veneto, ecotype of the same species (-0,96 MPa).

Grapevine Pinot gris Virus (GPGV) is a single stranded RNA of the genus Trichovirus infecting grapevine (Vitis vinifera) and associated with stunting, chlorotic mottling and leaf deformation symptoms. During a monitoring of GPGV infection in vineyards of the Trentino region in Italy, we have detected the virus in the herbaceous plants Silene latifolia subsp. Alba (Mill.) (bladder campion) and Chenopodium album L. (white goosefoot), which showed symptoms of viral infection. The full-length GPGV RNA genome, amplified from these infected hosts, was sequenced and a phylogenetic analysis revealed that its closest relative is the strain SK13, recently isolated in Slovakia. Our results indicate that herbaceous plants can be considered as a reservoir for the GPGV virus. This finding is important for studying the epidemiological aspects of GPGV disease and to formulate appropriate control measures.

Background: The study of allelopathic properties of plants is one of up-to-date biological and ecological methods, which can lead to discover the bio-herbicides and growth inhibitors. Objective: In order to study the allelopathic effects of harmal (Peganum harmala L) on seed germination and seedling growth on purslan (Portulaca oleracea L.) and black weed (Chenopodium album L.), these experiments were conducted. Methods: The aqueous extracts of harmal different organs including capsule, leaf, stem and root were applied at five concentration levels (0 as control, 1, 5, 10 and 15%) through a factorial experiment based on a completely randomized design with three replications. Results: The results showed that different organ extracts had different negative effects on seed germination and seedling growth of the two species in such a way that capsules extracts had the highest inhibitory effect. With increasing extract concentrations of harmal, the seed germination and seedling growth of the two species was reduced significantly. The minimum amount of seed germination and growth of the seedlings were observed at 15% extracts concentration of capsules. Also, purslan seedlings appeared to be more sensitive to harmal extracts than black weed seedlings. Conclusion: The aqueous extracts of harmal different organs had inhibitory effects on seed germination and seedlings growth of purslan and black weed. Also, the highest inhibitory effects were related to capsule extracts.

Cilj istraživanja bio je utvrditi učinak preporučene doze i umanjenih doza (2/3, 1/2, 1/4 i 1/8 preporučene doze) topramezona u kombinaciji s adjuvantima (neionski surfaktant - NIS, koncentrirano biljno ulje – COC i modificirano biljno ulje – MSO) na korovne vrste Chenopodium album L. i Echinochloa crus-gali L. u usjevu kukuruza. Poljski pokus proveden je tijekom 2013. godine na pokušalištu Agronomskog fakulteta Šašinovečki Lug po shemi slučajnog bloknog rasporeda u 4 ponavljanja. Ocjena učinka istraživanih tretmana utvrđena je subjektivnom vizualnom ocjenom oštećenja biljke te brojem jedinki na jedinici površine i masom nadzemne biljne mase korova. Topramezon primijenjen u preporučenoj dozi bez dodatka adjuvanata iskazao je nezadovoljavajuće djelovanje na obje korovne vrste. Primjenom adjuvanta MSO-a s reduciranim dozama topramezona nadzemna masa lobode reducirana je od 91, 5 % (1/8 doze) do 99, 1 % (2/3 doze). Kombinacija s adjuvantom NIS-om postiže zadovoljavajući učinak samo s 2/3 (95, 1 %) i 1/2 (93, 8 %) preporučene doze topramezona. Visoki učinci na redukciju mase nadzemne biljne mase vrste Echinochloa crus-galli postižu se jedino primjenom 2/3 doze topramezona uz dodatak adjuvanta MSO (93, 3 %).

Cilj istraživanja bio je utvrditi učinak preporučene doze i umanjenih doza (2/3, 1/2, 1/4 i 1/8 preporučene doze) topramezona u kombinaciji s adjuvantima (neionski surfaktant - NIS, koncentrirano biljno ulje–COC i modificirano biljno ulje – MSO) na korovne vrste Chenopodium album L. i Echinochloa crus-galli L. u usjevu kukuruza. Poljski pokus proveden je tijekom 2013. godine na pokušalištu Agronomskog fakulteta Šašinovečki Lug po shemi slučajnog bloknog rasporeda u 4 ponavljanja. Ocjena učinka istraživanih tretmana utvrđena je subjektivnom vizualnom ocjenom oštećenja biljke te brojem jedinki na jedinici površine i masom nadzemne biljne mase korova. Topramezon primijenjen u preporučenoj dozi bez dodatka adjuvanata iskazao je nezadovoljavajuće djelovanje na obje korovne vrste. Primjenom adjuvanta MSO -a s reduciranim dozama topramezona nadzemna masa lobode reducirana je od 91,5 % (1/8 doze) do 99,1 % (2/3 doze). Kombinacija s adjuvantom NIS-om postiže zadovoljavajući učinak samo s 2/3 (95,1 %) i 1/2 (93,8 %) preporučene doze topramezona. Visoki učinci na redukciju mase nadzemne biljne mase vrste Echinochloa crus-galli postižu se jedino primjenom 2/3 doze topramezona uz dodatak adjuvanta MSO (93,3 %)., Field trial was conducted in 2013 in maize at the Šašinovečki Lug to establish efficacy of herbicide topramezone using recommended dose and reduced doses of topramazone (2/3, 1/2 , 1/4 i 1/8). Only reduced doses were combined with three different adjuvants: nonionic surfactant - NIS (Break thru), concentrated vegetable oil – COC (White oil) and modified vegetable oils - MSO (Dash HC). In this study percentage of damage or efficacy of topramezone was observed on two weed species Chenopodium album L. and Echinochloa crus-gali L. Results indicate that application of reduced topramezone doses with proper type of adjuvant is effective on investigated weed species. Chenopodium album was equally controlled (91, % -99,1 %) with all reduced topramezone rates when applied with MSO. Echinochloa crus -galli control was influenced by type of adjuvant added to topramezone, but only when 2/3 topramezone rate was applied with MSO (93,3 %) good efficacy was achieved.

Los componentes activos del polen a partir del cual se obtienen los extractos alergénicos pueden variar considerablemente de acuerdo al momento, el lugar dónde se recolecta y el período comprendido entre la recolección y su utilización. El presente trabajo pretende evaluar si la temperatura de conservación del grano de polen influye en la expresión de proteínas y en la antigenicidad de las mismas, al momento de preparar un extracto alergénico. La especie elegida para estudio fue Chenopodium album L. ya que es de gran interés alergológico en la ciudad de Bahía Blanca. Los granos de polen se conservaron a temperatura ambiente, 4 °C y -18 °C por el término de dos meses. El contenido proteico de los extractos se determinó por el Método de Bradford. La expresión proteica y la antigenicidad se estudiaron mediante electroforesis vertical Tricina-PAGE-SDS 12, 5 % e Inmunoblot respectivamente. Los resultados obtenidos demuestran que la concentración proteica total fue menor para los extractos obtenidos del polen conservado a temperatura ambiente que para las otras dos condiciones. La expresión de proteínas varía cuantitativamente en todos los extractos y si bien la expresión cualitativa prácticamente se conserva, aparece para el polen conservado a temperatura ambiente, una banda de PM menor a 12 kDa. Esta banda podría ser consecuencia de la degradación proteica que experimenta el polen a esa temperatura de almacenamiento. En cuanto a la antigenicidad de los extractos no hay diferencias cualitativas aunque pueden apreciarse diferencias cuantitativas significativas. Concluimos que la conservación del polen a 4°C o a -18°C serían las más adecuadas, ya que permiten obtener una mayor concentración proteica partiendo de la misma masa de polen. The active components from which pollen allergen extracts are obtained can change considerably according to the time or the place where collect and the time period between harvesting and use. This work aims to assess if the storage temperature of the pollen grain influences protein expression and its antigenicity when preparing an allergen extract. The species chosen for our study was Chenopodium album L, since it is of great allergologic interest in the city of Bahía Blanca. Pollen grains were stored at room temperature 4ºC and -18ºC , for a period of two months. The protein content of the extracts was determined by the Bradford method. Protein expression and antigenicity were studied by vertical electrophoresis Tricine SDS-PAGE 12, 5% and Immunoblot. The obtained results show that the total protein concentration was lower in the extracts of pollen stored at room temperature than in those under two conditions. Protein expression differs quantitatively in all extracts and even if the qualitative expression is kept practically the same, in the Tricine SDS-PAGE gel and the pollen stored at room temperature there appear a band of MW inferior to 12 kDa. This band could result from the protein degradation experienced by pollen stored at that temperature. As regards extract antigenicity, there are no qualitative differences even though there are significant quantitative differences. We conclude that pollen preservation at 4ºC or -18ºC would be the most appropriate since it allows greater protein concentration for the same mass of pollen. Fil: Bianchimano, Andrea Susana. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Laboratorio de Inmunología; Argentina Fil: Murray, María Gabriela. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Laboratorio de Plantas Vasculares; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Ciencias Biológicas y Biomédicas del Sur. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Instituto de Ciencias Biológicas y Biomédicas del Sur; Argentina Fil: Prat, María Inés. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Laboratorio de Inmunología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

Summary: Resume: Zusammenfassung Data collected from field trials carried out in different years and environments were used to determine competitive ability and threshold levels of Ammi majus L., Chenopodium album L. and Sinapis arvensis L. The hyperbolic model showed a good fit to the experimental data. The three broadleaf weeds showed low and similar competitive indices (i ranging from 1–08 to 1–75), supporting the hypothesis of a high sunflower competitive ability. The economic threshold was four to six plants m−2 for all three weeds in the case of weed control by hoeing and about six plants m−2 for S. arvensis in the case of a postemergence treatment with imazamethabenz. Limitations and approximations in estimating competitive parameters are pointed out and discussed. Aptitude a la competition et seuils de nuisibilite de trois mauvaises herbes dicotyledones dans le tournesol Des donnees recueillies dans des experimentations au champ conduites dans differents environnements et au cours de differentes annees ont ete utilisees pour determiner l'aptitude a la competition et les seuils de nuisibilite de Ammi majus L., Chenopodium album L. et Sinapis arvensis L. Le modele hyperbolique fournissait un bon ajustement aux donnees. Les trois mauvaises herbes avaient des indices de competition bas et similaires (i de 1,08 a 1,75) ce qui conforte l'hypothese d'une forte aptitude a la competition du tournesol. Les seuils economiques etaient 4–6 plantes m−2 pour toutes les mauvaises herbes dans le cas de desherbage mecanique et environ 6 plantes m−2 pour S. arvensis dans le cas de traitement de post-levee avec l'imazamethabenz. Les limitations et les approximations dans l'evaluation des parametres de la competition sont identifies et discutes. Konkurrenzkraft und Schadensschwellen von drei dikotylen Unkrautarten in Sonnenblume Anhand von Ergebnissen aus Freilandversuchen in verschiedenen Jahren auf verschiedenen Standorten wurden die Konkurrenzkraft und die Schadensschwellen von Ammi majus L., Chenopodium album L., und Sinapis arvensis L, bestimmt. Die Ergebnisse liesen sich mit einer hyperbolischen Gleichung gut beschreiben. Die Konkurrenzindices i von 1,08 bis 1,75 waren fur alle 3 Arten ahnlich niedrig, worin sich die starke Konkurrenz der Sonnenblume widerspiegelt. Bei mechanischer Unkrautbekampfung lagen die Schadensschwellen fur alle 3 Unkrauter zwischen 4 und 6 Pflanzen m−2, fur Nachauflaufbehandlung mit Imazametabenz fur Sinapis arvenis bei 6 Pflanzen m−2. Grenzen und Annaherung der Bestimmung von Konkurrenzparametern werden eingehend diskutiert.

L. (sirken), Portulaca oleracea L. (semizotu) ve Cyperus rotundus L. (topalak) yabancı otlarıyla saksı denemeleri yürütülmüştür. Çalışmada herbisit önerilen ve yarı dozda gün içerisinde 5 farklı zamanda uygulanmış (saat 06.00, 10.00, 14.00, 18.00 ve 21.00) ve çalışma farklı iklim koşullarının hakim olduğu 3 farklı dönemde yürütülmüştür. Denemeler esnasında sıcaklık, nem, ışık değerleri kaydedilmiştir. ıklim koşulları ile herbisit etkinliği arasındaki ilişkiler gerek 3 denemenin birbiriyle karşılaştırılmasıyla gerekse her bir deneme içerisinde farklı saatlerde yapılan uygulamaların karşılaştırması şeklinde değerlendirilmiştir. Sonuçlar herbisit etkinliği ile iklim parametreleri arasındaki ilişkilerin yabancı ot türüne bağlı olarak farklılık gösterebileceğini ortaya koymuştur. Genellikle günlük ortalama sıcaklık ve hava nemi değerlerinin, saatlik değerlere oranla daha önemli oranda herbisit performansını etkilediği kanısına varılmıştır. Tek yıllık yabancı otlar olan sirken ve semizotuna karşı uygulama döneminde nispeten düşük sıcaklık ve yüksek hava nemi koşullarında yüksek etki sağlanırken, çok yıllık yabancı ot olan topalak'ta ise yüksek sıcaklıklarda yapılan uygulamaların daha etkili olduğu ortaya çıkmıştır. Gün içi uygulama saatlerinde ise genellikle sıcaklık ve nemin nispeten daha düşük olduğu sabah erken saatlerde (06.00-10.00) yapılan ilaçlamaların daha yüksek etki gösterdiği ortaya konulmuştur. Pot experiments were carried out with weed species Chenopodium album L., Portulaca oleracea L. and Cyperus rotundus L. to investigate the relationships between climatic conditions and herbicidal efficacy of foramsulfuron. The herbicide was applied at the recommended and half dose in 5 different times within a day (06.00, 10.00, 14.00, 18.00 and 21.00) and study was replicated three times under different climatic conditions. During experiments, temperatures, humidity and light intensity was recorded. Relationship between climatic conditions and herbicide efficacy was evaluated by comparing three experiments with each other, as well as the treatment times within each application date. Results showed that the relationship between herbicide efficacy and climatic parameter is variable depending on the weed species. In general it was concluded that the daily mean temperature and humidity values had more influence on herbicide efficacy than time of day values. Annual weed species such as C. album and P. oleracea were more sensitive to herbicide when applied under relative low temperature and high humidity conditions, while the temperature was more important in the case of perennial weed C. rotundus. Studies concerning time of day treatments showed that herbicide provided generally better effect in the morning times (06.00-10.00) under relatively low temperature and high humidity conditions.

A possibility of using physiological parameters for differentiating resistant and susceptible plants was investigated. Intensity of transpiration diffusive resistance and chlorophyll concentrations were measured. The experiments were carried out in the greenhouse. Seeds were collected from an area continually treated with atrazine over a period often years (locality Veliki Crljeni) and from treatment-free fields (locality Belgrade). A referent resistant population was obtained from Great Britain. Atrazine was applied (2,4 and 8 kg/ha) when plants were in a 2-4 leaf growth stage. Parameters were measured on the 7th and 15th post-treatment days. The results showed no significant change in the physiological parameters of the treated referent plants. On the other hand, treated plants from the localities of Veliki Crljeni and Belgrade showed a significant decrease in the intensity of transpiration and chlorophyll concentration, and increase in diffusive resistance, compared to untreated plants. Comparing the parameters analyzed, statistically significant differences were found between the domestic populations and the resistant referent population. Based on the variations found in plant responses to atrazine treatments (intensity of transpiration and diffusive resistance) in the populations investigated, we believe that assessment of these physiological parameters alone cannot provide sufficiently reliable data for differentiating between resistant and susceptible plants. U radu je ispitivana mogućnost korišćenja fizioloških parametara kao osnove za razdvajanje rezistentnih od osetljivih populacija Chenopodium album L. na atrazin. Praćeni su intenzitet transpiracije, otpor prema difuziji i relativni sadržaj ukupnog hlorofila. Semena su prikupljena sa površine na kojoj je atrazin korišćen 10 godina (lokalitet Veliki Crljeni) i sa površine na kojoj nikad nisu primenjivani herbicidi (lokalitet Beograd). Referentna rezistentna populacija dobijena je iz laboratorije iz Velike Britanije. Biljke su gajene u kontrolisanim uslovima i tretirane atrazinom (2, 4 i 8 kg/ha) u fazi 2-4 lista. Promene ispitivanih parametara su merene 7. i 15. dana od primene atrazina. Dobijeni rezultati su pokazali da kod referentne rezistentne populacije tretirane herbicidom nema značajnih promena na nivou posmatranih parametara. Međutim, kod populacija sa lokaliteta V.Crljeni i Beograd došlo je do značajnog smanjenja intenziteta transpiracije i relativnog sadržaja hlorofila, i do povećanja otpora prema difuziji. Statistička obrada podataka je pokazala da se na osnovu svih parametara može izvršiti razdvajanje osetljivih i rezistentih populacija Ch. album prema atrazinu, s tim što se relativni sadržaj ukupnog hlorofila u poređenju sa druga dva parametra pokazao kao pouzdaniji parametar. Prirodna dnevna dinamika fizioloških procesa i njihova zavisnost od velikog broja činilaca (sadržaja 07 i CO, u vazduhu, vlažnosti vazduha, otvorenosti stoma i sl.) umanjuju pouzdanost intenziteta transpiracije i otpor prema difuziji kao parametara.

The aim of our investigation was to establish the degree of atrazine resistance in plants of Chenopodium album L. population from Serbia and resistance population from Great Britain. Seeds used in experiments were collected from the corn grown areas treated with atrazine for over ten consecutive years (Surčin and Veliki Crljeni), while the control seeds were collected from untreated areas nearby Belgrade (Belgrade). As a referent population resistant seeds of Chenopodium album L. from Great Britain were used. Plants in fully emerged third leves, from all population, were sprayed with different doses (2, 4 and 8 kg ha-1) of atrazine (Gesaprim, 90% a.i. atrazine). As a non destructive methods we used SPAD-meter for measuring chlorophyll content and fluorometer for chlorophyll a fluorescence which is expressed as ratio between variable (Fv) and maximal (Fm) chlorophyll fluorescence. Both parameters were measured at the same leaf before and 1, 2, 3, 4 and 5 days after atrazine treatments. Results shown that the most sensitive method is by using method of chlorophyll fluorescence. SPAD-meter is not adequate for distinguishing triazine resistant and susceptible plants. In populations of Chenopodium album L.- collected from Serbia (Veliki Crljeni, Surcin and Belgrade) atrazine resistance is not confirmed.

10 pages, 2 figures, 5 tables., Chenopodium album L. was found to be one of the initial plant species colonising a heavy metal-contaminated site, polluted by pyritic (sulphide-rich) waste from the Aznalcóllar mine spill (South-western Spain). This indicates its importance in the re-vegetation of this soil. In a pot experiment, C. album was sown in soil collected from the contaminated site, either non-amended or amended with cow manure or compost produced from olive leaves and olive mill wastewater, in order to study the effect on heavy metal bioavailability and soil pH. In non-amended and compost-amended soils, soil acidification, probably resulting from oxidation and hydrolysis of sulphide, led to increases in the concentrations of soluble sulphate and plant-available Cu, Zn and Mn in the soil (extractable with 0.1 M CaCl2). Under these conditions, shoot growth of C. album was negligible and shoot concentrations of Zn (2420–5585 μg g−1) and Mn (5513–8994 μg g−1) were phytotoxic. Manure application greatly increased shoot growth and reduced the shoot concentrations of Cu, Zn, and Mn, and their plant-available concentrations in the soil. These effects appeared to be related to an increase of soil pH, due to an inhibition of sulphide oxidation/hydrolysis, relative to the non-amended soil. For metal sulphides-contaminated soil, liable to acidification, manure application appears to be able to enhance the initial stages of re-vegetation, by species such as C. album., This work was financed by the Spanish Ministry of Science and Technology (project no. REN2001-1113-C02-02), and by the Junta de Andaluc ía.

The aim of our investigation was to establish the level of atrazine resistance of Chenopodium album L. and Amaranthus retrqflexus L. populations collected from different localities in Serbia. Resistant population of the same weed species from Great Britain was used as a known reference. We measured chlorophyll a fluorescence and relative chlorophyll content using SPAD-meter, as a nondestructive method in order to compare the resistance in weed species. Our results showed that chlorophyll fluorescence was most sensitive method for distinguishing triazine resistant and susceptible plants compared with SPAD-Meter. In the populations of Chenopodium album L. and Amaranthus retrqflexus L. - collected from Zemun Polje, Surcin and Belgrade atrazine resistance was not confirmed. Ispitivanja su bila usmerena na utvrđivanje nivoa rezistentnosti različitih populacija Chenopodium album L. i Amaranthus retroflexus L. prikupljenih na lokalitetima u Srbiji prema atrazinu. Kao referentne rezistentne populacije korišćene su populacije istih vrsta korova dobijene iz laboratorije u Velikoj Britaniji. Poređenje rezistentnosti korova rađeno je ne destruktivnim tehnikama: merenjem fluorescencije hlorofila a i merenjem relativnog sadržaja hlorofila pomoću SPAD-metra. Merenje fluorescencije hlorofila, računato kao odnos Fv/Fm, se pokazala kao najosetljivija metoda za razdvajanje rezistentnih i osetljivih populacija. Nasuprot ovome merenje sadržaja hlorofila SPAD-metrom se pokazalo kao manje pouzdan metod, jer nisu uvek dobijene jasne razlike između tretiranih i ne tretiranih biljaka. Kod ispitivanih populacija Chenopodium album L. sa lokaliteta Zemun Polje, Surčin i Beograd i populacija Amaranthus retroflexus L. sa lokaliteta Zemun Polje i Beograd nije potvrđena rezistentnost na atrazin.

SUMMARY The recently introduced empirical model for early prediction of crop loss by weed competition based on the relative leaf area of the weeds shortly after crop emergence (Kropff & Spitters, 1991), assumes a maximum yield loss of 100% at high weed infestations. This is biologically not realistic. If weeds have a shorter life cycle than the crop, when they emerge much later than the crop or when they are unable to overtop the crop, maximum yield loss at high weed infestations is expected to be less than 100%. A two parameter model is introduced in this paper that accounts for a variable maximum crop yield loss by weed competition. The parameters are the “relative damage coefficient”q, and a parameter that describes the maximum yield loss caused by the weeds (m). The one and two parameter models were evaluated with data on the effects of weeds on rice, sugarbeet and tomato. Both models were able to describe the data on the effect of different weed densities and periods between crop and weed emergence fairly well. The introduction of the second parameter resulted in a significantly better description of observed data in five out of nine datasets. The value of the parameter q depends on the time of observation of the relative leaf area. The change in the value of q in time could be estimated from the difference in relative growth rate of the species. The accuracy of this estimation is strongly determined by the variability in the relative growth rate of the leaf area of single plants. Possibilities for scientific and practical application of the model are discussed.