The Biology of Canadian Weeds. 131. \u3cem\u3ePolygonum aviculare\u3c/em\u3e L.

A review and assessment of biological information as well as personal data are provided for Polygonum aviculare in Canada. The species has been revised taxonomically and the six subspecies that occur in Canada are presented. Three of the subspecies, P. aviculare subsp. aviculare, P. aviculare subsp. neglectum and P. aviculare subsp. depressum are weeds introduced to Canada from Europe. A fourth subspecies, P. aviculare subsp. buxiforme is apparently native to North America. The geographical distribution of the latter four subspecies is very wide. Plants exhibit a high phenotypic plasticity and genetic variability, and they easily adapt to a multitude of agrestal and ruderal habitats. The seeds have a variable dormancy and polymorphic germination as a result of heterocarpy, genetic and environmental factors. In other areas (Europe), the species has developed resistance to triazines. Plants are hosts to nematodes, viruses, and fungi that also affect cultivated plants

Unlocking the in vitroanti- inflammatory and antidiabetic potential of Polygonum maritimum

Context: Several Polygonum species (Polygonaceae) are used in traditional medicine in Asia, Europe and Africa to treat inflammation and diabetes. Objective: Evaluate the in vitro antioxidant, anti-inflammatory and antidiabetic potential of methanol and dichloromethane extracts of leaves and roots of the halophyte Polygonum maritimum L. Material and methods: Antioxidant activity was determined (up to 1mg/mL) as radical-scavenging activity (RSA) of 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), copper (CCA) and iron (ICA) chelating activities and iron reducing power (FRAP). NO production was measured in lipopolysaccharide (LPS)-stimulated macrophages for 24 h at concentrations up to 100 mu g/mL and antidiabetic potential was assessed by alpha-amylase and alpha-glucosidase inhibition (up to 10 g/mL) assays. The phytochemical composition of the extracts was determined by gas chromatography-mass spectrometry (GC-MS). Results: The methanol leaf extract had the highest activity against DPPH center dot (IC50 = 26 mu g/mL) and ABTS1(+)center dot (IC50 = 140 mu g FRAP (IC50 = 48 mu g/mL) and CCA (IC50 = 770 mu g/mL). Only the dichloromethane leaf extract (LDCM) showed anti-inflammatory activity (IC50 = 48 mu g/mL). The methanol root (IC50 = 19 mu g/mL) and leaf (IC50 = 29 mu g/mL) extracts strongly inhibited baker's yeast alpha-glucosidase, but LDCM had higher rat's alpha-glucosidase inhibition (IC50 = 2527 mu g/mL) than acarbose (IC50 = 4638 mu g/mL). GC-MS analysis identified beta-sitosterol, stigmasterol, 1-octacosanol and linolenic acid as possible molecules responsible for the observed bioactivities. Conclusions: Our findings suggest P. maritimum as a source of high-value health promoting commodities for alleviating symptoms associated with oxidative and inflammatory diseases, including diabetes.XtremeBio project - Foundation for Science and Technology (FCT) [PTDC/MAR-EST/4346/2012]; Portuguese National Budget; FCT [CCMAR/Multi/04326/ 2013, IF/00049/2012, SFRH/BPD/86071/2012, UID/Multi/00612/2013

Organic wheat survey (OF0107)

A four year study to monitor fourteen organic farms for weed incidence throughout England and Wales began in summer 1993. Two farms were selected from each of the ‘former ADAS’ regions these being; East, Midlands and West, North, South East (Reading), South East (Wye), South West (Bristol) and South West (Starcross). Each pair of farms had been using organic production for different periods of time. On each farm, five fields were selected at random and assessed for weed incidence and severity in December, March, May and July. If a field was in wheat, a sample of fifty tillers was collected at random at GS 75 (July) from a diagonal traverse. Samples were assessed for severity of all foliar, stem-base and ear diseases. Details of cultivations, sowing date and crop husbandry practices were taken for each field. Soil samples were taken in March 1994 and assessed for pH, organic matter, and nutrient status. The mean number of fields assessed at each assessment date was 58, the differences in numbers assessed was due to lack of crop in the field or the field being grazed by animals. Over all farms the most frequently occurring weed was Stellaria media (64% of fields) then poa annua (49%), veronica persica, matricaria spp., and rumex spp. in approximately 30% of fields. Elymus repens, polygonum persicaria, avena fatua, avena sativa and triticum aestivum were the least frequently occurring weeds, occurring in under 10% of fields. Farms were divided into those converted to organic farming pre-1985 and those converted post-1985, this gave approximately 50% of the total farms surveyed in each category. In fields converted to organic farming pre-1985 there was a greater weed incidence overall. Stellaria media was still the most frequently occurring weed but was present in 81% of fields converted pre-1985 and only 59% of fields converted after this date. Actual weed populations were greater in fields converted to organic cropping pre-1985. Papaver rhoeas, stellaria media and matricaria spp. had higher populations in fields converted pre-1985 but alopecurus myosuroides had higher populations in fields converted post this date. Soil type and rotation type had very little effect on weed incidence. The main findings of the work were; the spectrum the most common weeds of organic crops was very similar to that of conventional crops; long periods of organic farming has lead to the build up of specific weeds and the demise of others; weed levels in organic situations were high enough to significantly contribute to economic yield losses in crops; the survey was not large enough to form a complete picture of weeds in organic cropping. Future work should encompass further surveys of both conventional, integrated and organic crops to provide information on the current situation. This would provide information on changes in the national agricultural weed flora and an early warning system on the build up of resistance in specific weeds that may not be noticed in a local situation

The Potential Use of Organically Grown Dye Plants in the Organic Textile Industry: Experiences and Results on Cultivation and Yields of Dyers Chamomile (Anthemis tinctoria L.), Dyers Knotweed (Polygonum tinctorium Ait.) and Weld (Reseda luteola L.)

The organic cultivation of dye plants for the certified natural textiles industry is an emerging and promising sector of organic farming. In 1999 a field trial was done with different provenances of Dyer’s Chamomile (Anthemis tinctoria L.), Dyer’s Knotweed Polygonum tinctorium Ait.), and Weld (Reseda luteola L.) on two organic farms in Lower Austria. Yields, dyestuff content, and quality parameters were analyzed. Dry matter yields of Weld ranged between 0.7 and 2.7 t ha-1, of Dyer’s Chamomile (flower heads) between 1.1 and 1.8 t ha-1. Significant differences were found between seed Weld provenances as well as between those of Dyer’s Chamomile. The total leaf dry matter of Dyer’s Knotweed (2 cuts) ranged at both sites on average 3.1 t ha-1. Seed provenances did not show differences. The total flavonoid content of Weld ranged between 1.53 and 4.00%, of Dyer’s Chamomile between 0.84 and 1.5%. The content of indican in Dyer’s Knotweed ranged between 0.50 and 1.45% of leaf dry matter, the calculated theoretical content of indigo ranged between 0.22 and 0.64% of leaf dry matter. The general use fastness properties differ according to species and provenance. Both high and low values were achieved. The data on the cultivation of dye plants in organic farming show promising results. Research should address improvement in yields and quality, development of dyestuff extracts, and optimization of dyeing methods. Research on dye plants needs a systemic look at the whole chain including producers, processors, trade, and consumers

Impact of Land Use Changes and Dynamic Vegetation Changes on Vascular Flora Diversity in Małków-Bartochów (The Warta River Valley)

The paper presents the changes of vascular plant flora in the Małków-Bartochów peatland area (the Warta River valley) which took place over a 40-year period. Vanishing, permanent and new components of the flora are presented with a special focus on valuable (protected by the law, threatened and locally rare) species. Changes in the share of ecological groups are estimated and discussed. Anthropogenic and natural factors, directly or indirectly influencing (in the past and at present) flora composition, are noted and analyzed

Impact of the quality of organic amendments on size and composition of the weed seed bank

In addition to improving the soil quality, organic amendments of soils may affect weed seed survival, emergence, growth and reproduction. This study evaluated the effects of applications of different qualities of organic amendments on size and composition of the weed seed bank in a field under sequential cropping over 4 years. Fertilisation systems tested included farmyard manure, vegetable fruit and garden waste compost, two types of farm compost differing in carbon:nitrogen (C:N) ratio, cattle slurry and mineral fertiliser. All organically amended plots received equal amounts of C. Crop growth was equalised on all plots by applying supplemental mineral N. Seed bank sampling took place in May 2009 to a depth of 10 cm. The weed seed bank was analysed using the seedling emergence method. Despite equal crop growth in fertilised plots, total seed bank density was lowest in plots amended with compost with low C:N ratio and highest in slurry-amended plots. Observed differences in seed bank densities reflected differences in soil organic carbon content and microbial biomass. At plot level, hard-coated seeds in the seed bank (e.g. Chenopodium spp.) were inversely related to soil microbial activity. Observed differential responses of species to applied fertilisers might be attributed to interspecific differences in resistance against microbial seed degradation. Compost-based fertilisation systems could be sustainable tools for incorporation into integrated weed control strategies aiming at depleting the weed seed bank

Interactions between pre- and post-emergence weed harrowing in spring cereals

Pre- and post-emergence weed harrowing were studied in spring cereals in different environments and with two types of harrows in Norway during 2004–2006. The objectives were to investigate interactions between pre and post-emergence weed harrowing and the importance of harrow type. We hypothesised that pre- and post-emergence harrowing interact positively, that a combination gives more stable weed control effects than pre- and post-emergence weed harrowing used alone, and that a harrow type with bent tines is more aggressive and suitable on hard-packed soils than a harrow with strait tines. The results only supported the last of these hypotheses. Post-emergence weed harrowing controlled a certain percentage of the present weeds, and this percentage was not dependent on pre-emergence weed harrowing. On average, pre-emergence harrowing reduced weed density by 26% and weed biomass by 22%, while the average effect of postemergence harrowing was 47% on weed density and 41% on weed biomass. The combined effect of pre- and post-emergence weed harrowing was 61% on weed density and 54% on weed biomass. The combination did not give more stable weed control effects than preand post-emergence weed harrowing used alone. Preemergence harrowing increased the average crop yield by 6.2%, post-emergence harrowing by 4.0% and the combined effect was 10%. Crop yield was mainly increased on hard-packed soils. Weed and crop responses varied strongly among experiments, but the efficacy of pre- and post-emergence weed harrowing was positively correlated across experiments. Weed species composition was of minor importance regarding weed control. The study indicates that one aggressive postemergence cultivation may be as good as one preemergence and one less aggressive post-emergence cultivation. However, little is known about the interactions between cultivation at different crop and weed growth stage

Effect of Polygonum Minus (Knotweed) Leaves Extract on the Histopathological Changes of Kidney in Mice (Mus Musculus) Induced by Mercuric Chloride

This research was conducted to investigate the protective effect Polygonum minus leaves extract on the histopathological changes of kidney induced by mercuric chloride in mice (Mus musculus). Thirty male mice were divided into five groups and were administered via intragastric gavage with different treatments for 21 days. The treatment were C- (CMC Na 0.5% solution + aquadest), C+ (CMC Na 0.5% solution + 8 mg/kg bw of mercuric chloride), T1, T2, and T3 (200, 400, and 800 mg/kg bw of Polygonum minus leaves extract respectively + 8 mg/kg bw of mercuric chloride). The histopathological changes of kidney were examined by using Arshad Scoring method. Then the data was analysed using Kruskal Wallis and continued with Mann-Whitney test. The result showed Polygonum minus leaves extract could protect mice kidney from the damage effect of mercuric chloride. The best dose of Polygonum minus on this research was 400 mg/kg bw. Keywords: Polygonum minus, mercuric chloride, Mus musculus, kidne

Pharmacognostical, phytochemical and anthelmintic activity of Polygonum muricatum

Polygonum muricatum is widely used by the local people of Meghalaya for anthelmintics. An attempt has been made to evaluate the pharmacognostical, preliminary phytochemical and pharmacological parameters of leaves of Polygonum muricatum. The physicochemical constants like moisture content, ash values such as total ash, acid insoluble ash and water soluble ash, extractive values such as water soluble extractive value and alcohol soluble extractive value were determined. The extract obtained by successive solvent extraction was subjected to preliminary phytochemical analysis to find out the presence of compounds. The plant Polygonum muricatum leaves were extracted with the solvent benzene, acetone, ethanol and water by soxhlet apparatus method. The extract was evaluated for anthelmintic activity with Indian earthworm. Ethanol extract of the plant Polygonum muricatum has shown the significant activity