Galium Aparine Research Articles

Potential ecological effects of Piriformospora indica, a possible biocontrol agent, in UK agricultural systems

Piriformospora indica (syn. Serendipita indica), a root endophytic fungus, was originally isolated from an arid sub-tropical soil. P. indica forms mutualistic symbioses with a broad range of host plants, increases biomass production, resistance and tolerance to fungal pathogens and abiotic stresses. These characteristics make it a very attractive component of more sustainable agriculture. So, it is desirable to understand its wider ecosystem effects. We determined how long P. indica could survive in the soil and how it interacts with other soil microorganisms and some important arable weeds.Survival of P. indica in the soil, under winter and summer conditions in the UK was tested by isolating DNA and RNA of P. indica from pots of soil which had been left open to winter-summer weather conditions without host plants, followed by PCR and reverse transcription-PCR (RT-PCR) with P. indica-specific primers. P. indica effects on other soil and root microorganisms were tested by PCR-denaturing gradient gel electrophoresis analysis of DNA extracted from soil and roots from pots in which P. indica-infected wheat had been grown. The effect of P. indica on growth of black-grass (Alopecurus myosuroides), wild-oat (Avena fatua) and cleavers (Galium aparine) was tested alone and in competition with wheat.In soil P. indica-mRNA and DNA could still be detected after eight months, but not after 15months. Soils from P. indica-inoculated pots had distinct fungal and bacterial species communities which were more diverse than non-inoculated controls. P. indica infected A. myosuroides and A. fatua but was not detected in G. aparine. The average above-ground competitiveness of the weeds with wheat was decreased.If applied to field crops in the UK, P. indica would be persistent for up to 15months and likely to alter competitive relations within vegetation. Increased soil microbial diversity during the first eight weeks after inoculation, although usually desirable, could alter soil composition or functioning.

Efficacy of Five Herbicides for Weed Control in Rain-Fed Lentil (Lens culinarisMedik.)

Lentil is vulnerable to weed competition because of its short stature, slow establishment, and limited vegetative growth. Although the vast majority of lentil production is under rain-fed conditions, there is a little published information on weed control with herbicides in rain-fed lentils. Field experiments were conducted to determine the efficacy of nine herbicide treatments including fomesafen, imazethapyr, linuron, pendimethalin, and pyridate alone or in combination compared with one or two hand weeding(s) on weed control and yield response in rain-fed lentil in Khorramabad, Iran in 2012 and 2013. Weed species included catchweed bedstraw, cowcockle, haresear mustard, hoary cress, wild mustard, and wild safflower. Total weed dry biomass in weedy check plots averaged 156 and 170 g m−2in 2012 and 2013, respectively, and weed density and biomass were reduced in all treatments compared to the weedy check in both years. Plots that were hand weeded twice reduced weed biomass the greatest, whereas fomesafen, linuron, or one hand weeding did not control weeds satisfactorily. Noncontrolled weeds reduced lentil yield by 67% both years compared to the weed-free control. Lentil yield in 2013 (1,370 kg ha−1) was higher than in 2012 (1,150 kg ha−1). All herbicides tested injured lentil slightly, with pyridate (1,200 g ai ha−1) and pendimethalin (660 g ai ha−1plus imazethapyr at 250 to 500 g ai ha−1) causing the least injury. Across all treatments, imazethapyr plus pendimethalin PRE, pyridate POST, and two hand-weeding treatments had the best performance for weed control and lentil yield.

Seasonal variability of biomass, total leaf area and specific leaf area of forest understory herbs reflects their life strategies

Seasonal variability of forest understory herbs is not well understood and there are almost no data about seasonal changes of individual plant biomass and specific leaf area (SLA) of this functional group, even though they are a crucial element of forest ecosystem plant biodiversity. The aim of the study was to characterize the seasonal variation of individual aboveground standing biomass, total leaf area and SLA of understory herbaceous species during a growing season. The study was conducted in the Czmoń Forest (W Poland; 52°15′N, 17°05′E) and covered 12 plant species, i.e. Aegopodium podagraria, Alliaria petiolata, Anemone nemorosa, Anemone ranunculoides, Asarum europaeum, Corydalis cava, Ficaria verna, Galium aparine, Galeobdolon luteum, Hepatica nobilis, Maianthemum bifolium and Paris quadrifolia. Plants were harvested 14 dates, between the 109th and 287th day of year. In all species there were statistically significant differences (p<0.05) in SLA and total leaf area among harvest dates and in individual plant biomass for all except two species (A. ranunculoides and G. aparine). Changes in SLA and total leaf area were related to changes in light conditions during the growing season. However, responses of the species studied to seasonal changes of light availability were different: those species which persisted through the whole sampling period differed from spring ephemerals, which resulted in different patterns of biomass production and SLA seasonal variation. In most cases, flowering individuals had lower SLA than vegetative plants, which may indicate that light availability is more important than light use efficiency for their generative propagation.

Separation and purification and in vitro anti-proliferative activity of leukemia cell K562 of Galium aparine L. petroleum ether phase

To explore material basis of in vitro anti-proliferative activity of leukemia cell K562 of petroleum ether phase of product resulting from Galium aparine L. 60% ethanol extraction, the experiment adopts column chromatography combined with thin layer preparation, isolates and purifies petroleum ether, conducts structural identification of obtained single compound and applies MTT method for viability assay of in vitro anti-proliferative activity of leukemia cell K562. Experimental results show that G. aparine L. petroleum ether contains mainly β-sitosterol, daucosterol and dibutyl phthalate and other substances. Under experimental conditions, the three could inhibit the proliferation of leukemia cell K562 with dose-effect and time-effect relationship, of which dibutyl phthalate has strongest activity. Dibutyl phthalate with excellent activity, β-sitosterol with rich content and moderate effect should be the main contributor to its biological activity.

Мульчування як захист енергетичної верби від бур'янів

Species composition of weeds in energy willow plantations was under the effect of such factors as current land use, soil conditions and weed seeds stock. Thus, in control treatment dominated the following species (number of plants per m 2 ): (i) dicots – goosefoot ( Chenopodium album L.) 13.8 and green amaranth ( Amaranthus retroflexus L.) 10.4, with their proportion in total weeds of 30.5%; (ii) monocots – barnyardgrass ( Echinochloa crus-galli L.) 7.6 and foxtail grey ( Setaria glauca L.) 11.5. Together these four weed species accounted for 64.0%. Other dicot species presented in the field were field pennycress ( Thlaspi arvense L.) 5.1 (6.4%), catchweed ( Galium aparine L.) 4.2 (5.3%), black nightshade ( Solanum nigrum L.) 3.4 (4.3%), wild buckwheat ( Polygonum convolvulus L) 7.4 (9.3%), spotted ladysthumb ( Polygonum persicaria L.) 3.2 (4.0%), other 5.3 (6.7%). Total number of weeds in the control treatment made up about 79.6. When using winter wheat straw as a screening material (layer thickness 5 cm) the total number of weeds decreased significantly to 16.8. High efficiency of the mulching marked sprouts of goosefoot, green amaranth (within 90%) and monocots species (85-86%). Whereas the number of black nightshade sprouts (2.6) and field pennycress (1.9) decreased by only 49 and 44%, respectively. The number of spotted ladysthumb (1.3) decreased by 60%. In a treatment with 10 cm of mulching straw, weed sprouts number decreased to 3.3. Dicots reduced their number by 87.5-97.3% and monocots by 97.4-99.1% compared with control treatment. Under these conditions, the number of field pennycress plants was 0.9, green amaranth, barnyard grass and spotted ladysthumb 0.4. When applying 15 cm of mulching straw there were few sprouts of green amaranth, field pennycress (0.1 and 0.2, respectively) left, which impose no significant damage to energy willow plantations. Green mass of weeds on 20-91 July in the control treatment made up 2418 g/m 2 . To this, the most contributing species were wild buckwheat (417 g/m 2 ), black nightshade (336 g/m 2 ) and barnyardgrass (324 g/m 2 ). When applying 5 cm straw, green mass of weeds decreased by 7.7 times (to 314 g/m 2 ). Goosefoot produced the above-ground mass of 117 g/m 2 , which exceeded all other species by more than 3.0 times as much. Covering inter-row space with 10 cm straw reduced weed green mass to 116 g/m 2 , whereas 15 cm straw ­­ to 3 g/m 2 . Treatment with 5 cm straw provided reducing weeds number 4.7 times compared to the control treatment. However, the number of weeds in the growing season made up 16.8 per m 2 . Better results provided screening with 10 and 15 cm of straw, which significantly reduced both the number of weeds and their weight, which makes it possible to prevent energy willow plantations from weed infestation.

Effects of Galium aparine extract on the cell viability, cell cycle and cell death in breast cancer cell lines

Ethnopharmacological relevanceGalium species have been traditionally used for its anti-cancer, antioxidant, anti-inflammatory, antimicrobial and cardioprotective effects in the folk medicine. Galium aparine (GA) is a typical climbing plant growing widespread in Anatolia. Aim of the studyTo investigate the potential anti-proliferative and apoptotic effect of GA methanol (MeOH) extract on MCF-7 and MDA-MB-231 human breast cancer cells and MCF-10A untransformed breast epithelial cells. Materials and methodsFirst, the extract was characterized by both liquid chromatography/quadrupole time-of-flight mass spectrometry (LC/Q-TOF/MS) and gas chromatography-mass spectrometry (GC-MS) analyses. Then, cell viability and cell cycle distribution were investigated by XTT assay and PI staining by flow cytometry, respectively. Cell death was determined by Annexin V FITC/7-AAD staining. ResultsA total of 14 major phytochemicals were identified by LC/Q-TOF/MS and 34 volatile compounds were determined by GC-MS. The extract was cytotoxic in both breast cancer cell lines in a concentration and time dependent manner and showed G1 block after 72h extract treatment. However, it was not cytotoxic to MCF-10A breast epithelial cells. Flow cytometry analyses revealed that apoptosis was induced in MDA-MB-231 cells; however, necrosis was induced in MCF-7 cells. ConclusionOur study suggests that GA MeOH extract may have potential anti-cancer effects against breast cancer cells without impairing normal breast epithelial cells. Ability to induction of non-apoptotic cell death besides apoptotic cell death by this complex plant-derived mixture may enable the killing of apoptosis resistant breast cancer cells but further studies should be conducted to investigate the bioavailability and metabolism of it in vivo.

The silence of the lambs? Plant diversity in abandoned sheep pens

This study aimed at investigating the species composition and richness of the flora of abandoned sheep pens in comparison to their immediate neighbourhood. Field research was conducted in the Wielkopolska province of western Poland on 25 circular plots (20 m2) located in the middle of abandoned pens within sheep farms, paired with 25 reference plots established in nearby grasslands. Physicochemical properties of the topsoil were modified considerably by sheep in the past, so some effects continue to this day. Abandoned sheep pens did not differ significantly in plant species richness from control plots, but Urtica dioica, Galium aparine and Rumex obtusifolius, were significantly associated with sheep pens. Similar values of Shannon index and the low Jaccard index of similarity between plot types indicate that although these habitats are not richer in plant species, they are refuges of some characteristic plant species, which are absent or infrequent in neighbouring habitats. Moreover, the changes in physicochemical properties of the soil (higher average ammonium NH4+-N and nitrate NO3--N content) and vegetation structure are very deep, as they have persisted for 25 years.

Changes in weed infestations on plantations of sugar beet (Beta vulgaris L. subsp. vulgaris) cultivated on black soil near Wrocław in 1989–1995 and 2006–2012

&lt;p&gt;Field studies were carried out in 1989–1995 and 2006–2012 on plantations of sugar beet (&lt;em&gt;Beta vulgaris&lt;/em&gt; L. subsp. &lt;em&gt;vulgaris&lt;/em&gt;). During this period, 542 phytosociological relevés were made using the Braun-Blanquet method. In total, 46 weed species were found. In 1989–1995, the occurrence of 36 segetal species was reported. The highest cover indices were determined for &lt;em&gt;Chenopodium album&lt;/em&gt; and &lt;em&gt;Amaranthus retroflexus&lt;/em&gt;. &lt;em&gt;Galium aparine&lt;/em&gt;, &lt;em&gt;Echinochloa crus-galli&lt;/em&gt;, and &lt;em&gt;Elymus repens&lt;/em&gt; were the dominant species, as well. Analysis of the frequency of occurrence revealed one constant species (&lt;em&gt;Chenopodium album&lt;/em&gt;), two frequent species (&lt;em&gt;Amaranthus retroflexus&lt;/em&gt; and &lt;em&gt;Galium aparine&lt;/em&gt;), and two medium-frequent species (&lt;em&gt;Echinochloa crus-galli&lt;/em&gt; and &lt;em&gt;Matricaria maritima&lt;/em&gt; ssp. &lt;em&gt;inodora&lt;/em&gt;).&lt;/p&gt;&lt;p&gt;In 2006–2012, the occurrence of 40 weed species on the sugar beet plantations was recorded. The plantations were clearly dominated by &lt;em&gt;Chenopodium album&lt;/em&gt;, accompanied by &lt;em&gt;Polygonum persicaria&lt;/em&gt; and &lt;em&gt;Polygonum lapathifolium&lt;/em&gt; ssp. &lt;em&gt;lapathifolium&lt;/em&gt;. Other dominant species comprised &lt;em&gt;Setaria viridis&lt;/em&gt;, &lt;em&gt;Galinsoga parviflora&lt;/em&gt;, &lt;em&gt;Brassica napus&lt;/em&gt; ssp. &lt;em&gt;napus&lt;/em&gt;, and &lt;em&gt;Fallopia convolvulus&lt;/em&gt;. The &lt;em&gt;Chenopodium album&lt;/em&gt; was a constant component of the sugar beet plantations. In turn, no frequent species were observed and six medium-frequent species were found (&lt;em&gt;Setaria viridis&lt;/em&gt;, &lt;em&gt;Galinsoga parviflora&lt;/em&gt;, &lt;em&gt;Brassica napus&lt;/em&gt; ssp. &lt;em&gt;napus&lt;/em&gt;, &lt;em&gt;Echinochloa crus-galli&lt;/em&gt;, &lt;em&gt;Amaranthus retroflexus&lt;/em&gt;, and &lt;em&gt;Capsella bursa-pastoris&lt;/em&gt;).&lt;/p&gt;&lt;p&gt;Noteworthy, the presence of previously unreported species, e.g., &lt;em&gt;Abutilon theophrasti&lt;/em&gt;, &lt;em&gt;Hyoscyamus niger&lt;/em&gt;, or &lt;em&gt;Artemisia vulgaris&lt;/em&gt;, was revealed. These species are rare components in sugar beet crops. A reverse phenomenon, i.e., the disappearance of some species such as &lt;em&gt;Euphorbia helioscopia&lt;/em&gt;, &lt;em&gt;Malva neglecta&lt;/em&gt;, &lt;em&gt;Rumex acetosella&lt;/em&gt;, &lt;em&gt;Sinapis arvensis&lt;/em&gt;, or &lt;em&gt;Sisymbrium officinale&lt;/em&gt;, was also observed.&lt;/p&gt;

Antimicrobial Activity of the Genus Galium L.

Introduction: The common use of Galium L. plants (family Rubiaceae Juss.) in Ukrainian folk medicine for treating infectious diseases became the basis for the study of antimicrobial activity of lipophilic complexes obtained from the Galium species. Materials and Methods: The samples of herbs of Galium verum, Galium salicifolium, Galium dasypodum, Galium aparine, Galium carpaticum and Galium pseudomollugo harvested at flow ering stage became the objects of the present research. Lipophilic complexes have been obtained by the exhaustive extraction of herbal drugs with chloroform in the Soxhlet apparatus. The complexes have been used as 2% alcohol solutions in 96% ethyl alcohol. The study was conducted in vitro by the agar diffusion method. Standard strains of micro-organisms were used to assess the antimicrobial activity. Results: Staphylococcus aureus was most sensitive to the studied lipophilic complexes. Escherichia coli and Proteus vulgaris showed low sensitivity. Pseudomonas aeruginosa and Bacillus subtilis have shown moderate sensitivity. The highest activity against Candida albicans has been observed in complexes of Galium aparine, Galium dasypodum, Galium pseudomollugo. Conversly, Galium verum manifested no activity against Candida albicans. The minimum bactericidal and inhibitory concentrations were determined. The correlation between the content of individual groups of biologically active substances and the level of activity of the complexes was established. All complexes were non-toxic. Conclusion: The results obtained provided us the basis for further in-depth studies of antimicrobial and antifungal activity of the lipophilic complexes of the genus Galium L.

Researches on the Germination Biology of Some Common Weed Seeds in Turkey

Weeds in agricultural production is one of the most important factors affecting yield. They causes yield lose ranging from 25% to 35% by competing with cultivated plants especially for nutrient, water, light and place. This data show the significance of weeds in agricultural areas. It is necessary to control the weeds to remove their harm. Principally the meaning of control is to know their biology. With this research the germination biology conditions (minimum, optimum and maximum germination temperature, germination period and germination rate) of some common weeds that are widespread in the agriculture in Turkey have been examined. According to the research results, minimum, optimum and maximum germination temperatures were 7-10 °C, 30-40 °C and 43-45 °C (no germination at 45 °C) for Amaranthus retroflexus L., respectively. These parameters for Chenopodium album L. were 0-2 °C, 15-25 °C and 40 °C; for Alhagi camelorum Fisch. (without fruit) they were 7-10 °C, 25-40 °C and 40-43 °C (no germination at 43 °C); for Galium aparine L. they were 0-2 °C, 5-25 °C and 25-30 °C ( no germination at 30 °C); for Taraxacum officinale Weber. they were 0-2 °C, 10-30 °C and 40 °C; for Heliotropium europaeum L. they were 20-35 °C, 40 °C and 40-43 °C (no germination at 43 °C); for Peganum harmala L. they were 7-10 °C, 20-30 °C and 43-45 °C. There was no germination in Alhagi camelorum Fisch. seeds at any temperatures.

The spontaneous development of understory vegetation on reclaimed and afforested post-mine excavation filled with fly ash

We studied the spontaneous development of understory vegetation in a reclaimed fly ash landfill. Plots were reclaimed 11years earlier with sewage sludge, and boulder clay mixed with fly ash, and then afforested. Additionally, fertilisation with different doses of NPK was used. The treatments resulted in differences in the success of afforestation and in the spontaneous development of understory vegetation. Fifty-five understory species were found in total across all treatments. Nearly half of these species consisted of synanthropic vegetation, 20% represented meadow species, and 20% forest species. Sparse vegetation developed on raw fly ash without fertilisation and on plots shaded by tall trees. The most abundant understory vegetation was linked with the presence of two expansive grasses. Calamagrostis epigejos invaded plots with NPK-fertilised fly ash. Elymus repens, in part growing together with Galium aparine, developed dense stands in plots with fly ash covered with sewage sludge. The abundant growth of both grasses caused a significant reduction in understory species diversity. Canonical correspondence analysis (CCA) showed that the addition of sewage sludge and boulder clay had a stronger influence on understory species composition than fertilisation or shade from the tree canopy. The results of this study indicate that spontaneous succession combined with the technical reclamation measures and afforestation may be advantageous for the development of dense and relatively species-rich vegetation on fly ash landfills.

Weed growth and crop yield loss in wheat as influenced by row spacing and weed emergence times

Reducing crop row spacing and delaying time of weed emergence may provide crops a competitive edge over weeds. Field experiments were conducted to evaluate the effects of crop row spacing (11, 15, and 23-cm) and weed emergence time (0, 20, 35, 45, 55, and 60 days after wheat emergence; DAWE) on Galium aparine and Lepidium sativum growth and wheat yield losses. Season-long weed-free and crop-free treatments were also established to compare wheat yield and weed growth, respectively. Row spacing and weed emergence time significantly affected the growth of both weed species and wheat grain yields. For both weed species, the maximum plant height, shoot biomass, and seed production were observed in the crop-free plots, and delayed emergence decreased these variables. In weed–crop competition plots, maximum weed growth was observed when weeds emerged simultaneously with the crop in rows spaced 23-cm apart. Less growth of both weed species was observed in narrow row spacing (11-cm) of wheat as compared with wider rows (15 and 23-cm). These weed species produced less than 5 seeds plant−1 in 11-cm wheat rows when they emerged at 60 DAWE. Presence of weeds in the crop especially at early stages was devastating for wheat yields. Therefore, maximum grain yield (4.91 t ha−1) was recorded in the weed-free treatment at 11-cm row spacing. Delay in time of weed emergence and narrow row spacing reduced weed growth and seed production and enhanced wheat grain yield, suggesting that these strategies could contribute to weed management in wheat.

Vliv rozdílné technologie zpracování půdy na druhové spektrum plevelů v ozimé řepce

A community of weeds and crops is affected by a number of factors, including, among other things, also tillage. In the years 2000–2002, the composition of weed species in rape stands was evaluated on the fields with the total area of 551 hectares (1 hectar equals to some 2.47 acres). The evaluation was carried out with the application of methodology developed by Kühn (1982). On the fields located in the cadastral area of Olomouc – Holice, which had been cultivated in a traditional manner, 115 relevés were recorded. On the fields in the cadastral area of Bohuňovice, which had been cultivated with the application of reduced tillage, 97 relevés were recorded and evaluated. All of the above fields were subjected to the application of chemical agents reducing the occurrence of weeds. The data thus received were processed by means of multidimensional analysis of ecological data with the application of a RDA method (Redundancy Analysis). In the course of three years, 75 weed species were found on the fields under conventional tillage, on the average, 8.2 species per a relevé, while 66 weed species were found during the same period of time on the fields cultivated by means of reduced tillage, on the average, 8.6 species per a relevé. The application of RDA analysis enabled us to sort out the selected species of weeds (i.e. those the frequency of occurrence of which exceeded 15 %) into three groups. The conditions provided by the conventional tillage appeared to be more satisfactory for the weed species included in the first group (Arctium tomentosum, Elytrigia repens, Helianthus tuberosus, Chenopodium album, Lolium perenne and Papaver rhoeas). The species included in the second group, i.e. Alsinula media, Apera spica-venti, Atriplex patula, Bromus sterilis, Capsella bursa-pastoris, Equisetum arvense, Fallopia convolvulus, Myosotis arvensis and Thlaspi arvense., responded to reduced tillage by the increase in cover or by increased frequency of occurrence. The third group consists of species such as: Cirsium arvense, Chamomilla recutita, Galium aparine, Lactuca serriola, Matricaria maritima, Triticum aestivum and Viola arvensis. Their cover and frequency of occurrence were in a more degree influenced by factors different from the type of tillage. The manner of tillage appears to be only one of a number of factors that affect the occurrence of weed species. It influences them together with other factors and it is a factor of polyfunctional nature.

Evaluation of Weed Efficacy and Crop Safety of Fluorochloridone in China

Dinitroaniline and amide herbicides have been continually applied in garlic in China, leading to the change of weed community and dominant weed species. Catchweed bedstraw, shepherd's-purse, and flixweed have become major troublesome weeds. Crop safety of fluorochloridone to 18 crops (at rates of 500 and 1,000 g ai ha−1) and weed efficacy against 35 weeds (at rates of 125 and 250 g ha−1) were determined in greenhouse studies. Visual estimate indicated that fluorochloridone was not safe to many crops, especially cruciferous crops. Among all of the trial crops, garlic was the only crop which was not injured in both PRE and POST application at rate of 500 g ha−1, even when treated with 1,000 g ha−1. Fluorochloridone showed high efficacy against most weeds tested in this experiment when applied PRE, but could not offer a satisfactory control when applied POST. Further rate-response study of fluorochloridone to garlic and six weeds was also investigated. PRE application of fluorochloridone to garlic was safer than POST, and the rates for 10% growth reductions (GR10s) were 1,959 g ha−1for PRE and 537 g ha−1for POST. When applied PRE, GR90s of shepherd's-purse and flixweed were 19.2 and 70.3 g ha−1, respectively. Though GR90of catchweed bedstraw was 541 g ha−1, it could be totally controlled without injuring garlic. On the basis of these results, fluorochloridone has an excellent prospect for weed control in garlic fields.

Impact of site-specific weed management in winter crops on weed populations

This work is focused on evaluating the effects of site-specific weed management (SSWM) on weed populations over a 4-year period. SSWM was used on a 3.07 ha experimental field during 2011&amp;ndash;2014 in a rotation of winter wheat and winter oilseed rape. The area was split into application cells of 6 &amp;times; 10 m and weed abundance was evaluated manually in each cell. Four different herbicide treatments were tested. Standard whole-field herbicide application (blanket spraying) was treatment 1. Treatments 2, 3 and 4 comprised SSWM using different thresholds for post-emergent herbicide applications. SSWM resulted in herbicide savings of 6.3&amp;ndash;100% for Galium aparine, 0&amp;ndash;84.4% for other dicotyledonous weeds, and 31.3&amp;ndash;90.6% for annual monocotyledonous weeds. SSWM led to significantly increased density of G. aparine and Tripleurospermum inodorum in the final experimental year when compared to the blanket treatment. Negative correlation coefficients between 2011 and 2014 plant densities found in SSWM treatments (&amp;minus;0.237 to &amp;minus;0.401) indicate that Apera spica-venti does not establish a long-term soil seed bank.

VLIV ODLIŠNÉHO ZPRACOVÁNÍ PŮDY NA ZAPLEVELENÍ JARNÍHO JEČMENE V PODMÍNKÁCH SRÁŽKOVĚ SUŠŠÍ OBLASTI ČESKÉ REPUBLIKY

The impact of soil tillage on weeds in spring barley was observed on the field trial. The field trial was established in very warm and dry climatic region (experimental field station in Žabčice, Mendel University of Agriculture and Forestry Brno, Czech Republic). In the experiment there was used 7-strip crop rotation and three variants of soil tillage: conventional tillage (CT), minimum tillage (MT), when soil is shallow loosened and no tillage (NT) what means direct sowing without any soil tillage. The weed infestation was evaluated by counting method before herbicide application. Analysis of va­rian­ce (ANOVA) and then LSD methods, DCA (Detrended Correspondence Analysis) and CCA (Canonical Correspondence Analysis) were used for evaluation of results. The obtained results showed, that different soil tillage did not statistically influenced weed infestation in spring barley. The number of weed species depended on the depth of soil tillage, the variant of minimum tillage had lower number of weed species. These species were more common on the variant of conventional tillage: Chenopodium album, Silene noctiflora, Sinapis arvensis, Veronica polita. The variant of minimum tillage was more suitable for these species: Cirsium arvense, Convolvulus arvensis, Amaranthus sp., Galium aparine. On the variant of direct so­wing there appeared mainly these species: Sonchus oleraceus, Lactuca serriola, Tripleurospermum inodorum.

Effect of the relative time of emergence on the growth allometry ofGalium aparinein competition withTriticum aestivum

The impact of the relative time of emergence on the growth allometry ofGalium aparineL. (cleavers) in competition withTriticum aestivumL. (spring wheat) was studied in a greenhouse experiment. The hypothesis that changes in growth allometry, particularly in the leaf area/height ratio, caused by a shift in the relative time of emergence, could lead to plants overcoming the competition or to competitive suppression was tested. The plant height, dry weight, total leaf area and vertical distribution were analyzed during the first 83 days of growth. The late emergence ofG. aparinesubstantially influenced the growth dynamics for the dry weight and total leaf area. The dynamics of height growth were affected only following a significant delay inG. aparineemergence. The ratio of dry weight to total leaf area was almost unaffected by the competition. By contrast, the allometric relationship between the plant height and total leaf area was highly sensitive to the relative time of emergence. The results suggest that height is the most important growth trait for the plants to resist increasing competition. Even though the plants responded to competition with elongation, the physiological costs linked with “shade avoidance” caused reductions in the dry weight and leaf area growth that resulted in the total suppression of the late‐emerging individuals, in particular when their emergence was &gt;10 days after that of the crop.

Effects of Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) on understorey layer species diversity in managed forests

In total, 67 parallel plots were chosen from the database of 153 phytosociological relev&amp;eacute;s made in the Douglas-fir and parallel Norway spruce, European Beech and oak-dominated stands to find influences of this introduced tree species on the understorey layer in totally 12 localities in the whole Czech Republic territory. Douglas-fir stands influence their habitats, which was indicated by species composition changes in the ground vegetation, as well as by abundance and dominance of particular species. Douglas-fir cultivation increases species diversity of the stands, but decreases their abundance. Described differences in understorey are not so noticeable when European beech and sessile oak stands are substituted by Douglas-fir once. But even the significant phenomenon of striking nitrophilous species such as Geranium robertianum, Urtica dioica and Galium aparine occurs here. This indicates a high content of available nitrates in the humus and top-soil horizons. &amp;nbsp;

Long‐term changes in weed occurrence, yield and use of herbicides in maize in south‐western Germany, with implications for the determination of economic thresholds

SummaryIn 393 field experiments in Baden‐Württemberg region in south‐western Germany, herbicide efficacy, yield loss and crop tolerance of maize (Zea mays) were investigated between 1981 and 2011. The collected data served to determine changes in weed frequencies, in herbicide use, yield loss functions and economic thresholds (ETs). Over 60 weed species were reported. Chenopodium album and Galium aparine were the most frequent broad‐leaved weeds, the former becoming more frequent over time. Species of the genera Lamium, Polygonum, Veronica and Matricaria occurred in about every fifth trial. Alopecurus myosuroides and Echinochloa crus‐galli were the most frequent grass weeds; the former declining in frequency by 1.1% per year, the latter increasing by 1.5%. Results suggest a weed population shift towards thermophilic species. aceto‐lactate‐synthase and 4‐HPPD‐inhibitor herbicides became important in the 1990s. Pendimethalin and bromoxynil have been integral components of weed control since the 1980s. ETs, the point at which weed control operations provide economic returns over input costs, ranged between 3.7% and 5.8% relative weed coverage. Without weed control, no yield increase was found over 24 years. Yield increased by 0.2 t ha−1 year−1, if weeds were controlled chemically. Despite intensive use of effective herbicides in maize, problematic weed species abundance and yield losses due to weed competition have increased in Baden‐Württemberg over a period of 30 years.

Bioinspired hook surfaces based upon a ubiquitous weed (Galium aparine) for dry adhesion

Galium aparine is a plant noted for its ability to attach to solid objects through its microscopic hooked trichomes via a hook and loop mechanism. This dry adhesive behaviour has been mimicked using a simple and inexpensive epoxy resin replica moulding technique. Enhancement of adhesion strength is achieved by varying the epoxy resin replicas’ Young’s modulus in order to provide strong hook and loop interlocking, whilst retaining sufficient bulk material flexibility for subsequent detachment via a hook uncurling mechanism.