| toxicological and nutritional evaluation of velvetleaf seed: subchronic 90-day feeding study and protein efficiency ratio assay. | velvetleaf seed, a common weed contaminant in grain, was fed to male and female rats (20 per group) in a 90-day subchronic feeding study. diets contained 0, 2.5, 5.0 or 10.0% seed. gross clinical observations, body weights, and feed and water intake data were recorded weekly. after 91-93 days, all of the animals were autopsied, organ weights were obtained, and clinical chemistry analyses, haematology and bone-marrow evaluation for evidence of clastogenic effects were performed. tissues from cont ... | 1990 | 2341094 |
| microevolutionary responses in experimental populations of plants to co2-enriched environments: parallel results from two model systems. | despite the critical role that terrestrial vegetation plays in the earth's carbon cycle, very little is known about the potential evolutionary responses of plants to anthropogenically induced increases in concentrations of atmospheric co2. we present experimental evidence that rising co2 concentration may have a direct impact on the genetic composition and diversity of plant populations but is unlikely to result in selection favoring genotypes that exhibit increased productivity in a co2-enriche ... | 1995 | 11607574 |
| engineering hypervirulence in a mycoherbicidal fungus for efficient weed control. | agents proposed for biocontrol of major weeds in arable row-crop agriculture have not met expectations because an evolutionary balance has developed between microorganism and weed, even when the mycoherbicide is used inundatively at very high levels (>10(4)spores/cm<(2)). sufficient virulence can be achieved by transferring genes to the microorganism, tipping the evolutionary balance. virulence was increased ninefold and was more rapidly effected; furthermore, the requirement for a long duration ... | 2002 | 12355116 |
| detection of the biocontrol agent colletotrichum coccodes (183088) from the target weed velvetleaf and from soil by strain-specific pcr markers. | diagnostic molecular markers, generated from random amplified polymorphic dna (rapd) and used in polymerase chain reaction (pcr), were developed to selectively recognize and detect the presence of a single strain of the biocontrol fungus colletotrichum coccodes (183088) on the target weed species abutilon theophrasti and from soil samples. several isolates of c. coccodes, 15 species of colletotrichum, a variety of heterogeneous organisms and various plant species were first screened by rapd-pcr, ... | 2003 | 14499995 |
| differential rhizosphere establishment and cyanide production by alginate-formulated weed-deleterious rhizobacteria. | the effects of pseudomonas putida ath2-1ri/9 and acidovorax delafieldii ath2-2rs/1 on rhizosphere colonization, cyanide production, and growth of velvetleaf and corn was examined. when formulated in alginate beads and inoculated onto velvetleaf and corn plants (10(9) cfu/plant), only p. putida ath2-1ri/9 consistently reduced velvetleaf growth. neither isolate inhibited corn growth. interestingly the levels of p. putida ath2-1ri/9 in the velvetleaf rhizosphere were 1000-fold higher (7 x 10(7) cfu ... | 2005 | 15883876 |
| protoporphyrin ix content correlates with activity of photobleaching herbicides. | several laboratories have demonstrated recently that photobleaching herbicides such as acifluorfen and oxadiazon cause accumulation of protoporphyrin ix (ppix), a photodynamic pigment capable of herbicidal activity. we investigated, in acifluorfen-treated tissues, the in vivo stability of ppix, the kinetics of accumulation, and the correlation between concentration of ppix and herbicidal damage. during a 20 hour dark period, ppix levels rose from barely detectable concentrations to 1 to 2 nanomo ... | 1989 | 16666869 |
| carboxylesterase activities toward pesticide esters in crops and weeds. | proteins were extracted from maize, rice, sorghum, soybean, flax and lucerne; the weeds abutilon theophrasti, echinochloa crus-galli, phalaris canariensis, setaria faberii, setaria viridis, sorghum halepense and the model plant arabidopsis thaliana and assayed for carboxylesterase activity toward a range of xenobiotics. these included the pro-herbicidal esters clodinafop-propargyl, fenoxaprop-ethyl, fenthioprop-ethyl, methyl-2,4-dichlorophenoxyacetic acid (2,4-d-methyl), bromoxynil-octanoate, th ... | 2006 | 17078983 |
| performance of potential non-crop or wild species under oecd 208 testing guideline study conditions for terrestrial non-target plants. | the inclusion of 52 potential non-crop or wild species in new oecd guidelines for terrestrial non-target plant (tntp) testing led to a ring test conducted by four laboratories experienced in regulatory testing. species selected had shown potential to meet validity criteria of emergence for tntp studies in a previous evaluation of the 52 species. oecd 208 guideline conditions were applied, with and without seed pretreatments recommended to enhance germination. these species were abutilon theophra ... | 2007 | 17171722 |
| evaluation of ostrinia nubilalis (lepidoptera: crambidae) neonate preferences for corn and weeds in corn. | choice tests were conducted to determine feeding preferences of european corn borer, ostrinia nubilalis (hübner) (lepidoptera: crambidae), neonates for 15 species of plants. percentage of neonates accepting (found on) each leaf disc after 24 h was measured using choice tests. initially, nine species of plants were evaluated. the following year, 10 plant species were evaluated during o. nubilalis first generation and 11 species during the second generation. pennsylvania smartweed, polygonum penns ... | 2006 | 17195664 |
| effect of fertilization on the weediness of maize in a long-term field experiment. | we carried our examination in a long-term fertilization field experiment in 2005. in the experiment we had opportunity to compare the weediness in npk and npk + fym1 treatments, and we could study the effect of increasing n dosis on the weeds and maize. the bi-factorial trial was arranged in split plot design with three replications. the weed survey was made 25 days after seeding in the 27th of may. for the weed survey the balázs-ujvárosi method was applied. after the weed survey we collected al ... | 2006 | 17390821 |
| characterizing natural cellulose fibers from velvet leaf (abutilon theophrasti) stems. | velvet leaf (abutilon theophrasti) that is currently considered a weed and an agricultural problem could be used as a source for high quality natural cellulose fibers. the fibers obtained from the velvet leaf stems are mainly composed of approximately 69% cellulose and 17% lignin. the single cells in the fiber have lengths of approximately 0.9 mm, shorter than those in common bast fibers, hemp and kenaf. however, the widths of single cells in velvet leaf fibers are similar to the single cells in ... | 2008 | 17583497 |
| metallothionein and bzip transcription factor genes from velvetleaf and their differential expression following colletotrichum coccodes infection. | abstract colletotrichum coccodes is a biocontrol agent of velvetleaf (abutilon theophrasti), a noxious weed of corn and soybean. metallothioneins (mts) and basic region/leucine zipper motif (bzip) are heavy-metal-binding proteins and transcription factors, respectively, that have been related to several plant processes, including the responses of plants to pathogen attack. previous investigation of the determinants involved in the velvet-leaf-c. coccodes interaction had shed light on particular ... | 2006 | 18943500 |
| transforming a nep1 toxin gene into two fusarium spp. to enhance mycoherbicide activity on orobanche--failure and success. | the nep1 gene encoding a fungal toxin that successfully conferred hypervirulence when transformed into colletotrichum coccodes (wallr.) hughes attacking abutilon theophrasti (l.) medic. was tested to ascertain if it would enhance pathogenicity of fusarium species to orobanche aegyptiaca pers. parasitising crops. | 2009 | 19291699 |
| severe outbreak of tomato yellow leaf curl sardinia virus on pepper in southern italy. | during summer and autumn 2008 a severe outbreak of pepper leaf curl disease (plcd) was observed in pepper crops under plastic tunnels in the ionic coast of basilicata region. its incidence reached, in some cases, values close to 50%. the beginning of infections was recorded along the perimeter of the tunnels, where it reached a percentage of almost 100%. the infection then progressively spread towards the central areas of the greenhouses. large populations of whiteflies, identificated as bemisia ... | 2009 | 20222578 |
| population-level responses to nutrient heterogeneity and density by abutilon theophrasti (malvaceae): an experimental neighborhood approach. | an experimental approach was used to examine the effects of spatial nutrient heterogeneity and planting density on the sizes of plants within populations of abutilon theophrasti. planting locations were generated using random numbers and replicated among populations growing on two different scales of heterogeneity and homogeneous soils. the same quantity of nutrients (dehydrated cow manure) was added to each population, regardless of the spatial nutrient distribution. the higher density was achi ... | 1998 | 21680329 |
| study of the pest community of velvetleaf (abutilon theophrasti medic.). | velvetleaf (abutilon theophrasti medicus 1787) is one of the most economically threatening weed plant in hungary. researching biological control against it, and identifying a possible and effective biocontrol agent is an important challenge, as chemical control is difficult and expensive, and there is an increasing claim to practice slight plant protection. entomological studies were made in several parts of the world, for evaluating the species, occuring in velvetleaf, but none of these kind of ... | 2011 | 22696962 |
| abutilon theophrasti's defense against the allelochemical benzoxazolin-2(3h)-one: support by actinomucor elegans. | abutilon theophrasti medik., previously found to be rather insensitive to benzoxazinoid containing rye mulch and the allelochemical benzoxazolin-2(3h)-one (boa), can be associated with the zygomycete actinomucor elegans, whereby the fungus colonizes the root relatively superficially and mainly in the maturation zone. the fungus mitigates necrosis of the cotyledons when seedlings are incubated with 2 mm boa, in contrast to those that lack the fungus. in liquid cultures of the fungus, tryptophan w ... | 2014 | 25432667 |
| application of phosphate-solubilizing bacteria for enhancing bioavailability and phytoextraction of cadmium (cd) from polluted soil. | in this study, phosphate-solubilizing bacteria (psb), bacillus megaterium, were used to enhance cd bioavailability and phytoextractability of cd from contaminated soils. this strain showed a potential for directly solubilizing phosphorous from soils more than 10 folds greater than the control without inoculation. the results of pot experiments revealed that inoculation with b. megaterium significantly increased the extent of cd accumulation in brassica juncea and abutilon theophrasti by two fold ... | 2012 | 22472099 |
| antibacterial activity of hibicuslide c on multidrug-resistant pseudomonas aeruginosa isolates. | pseudomonas aeruginosa is a gram-negative bacterium that is frequently related to natural resistance to many drugs. in this work, the inhibition of growth against p. aeruginosa and multidrug-resistant p. aeruginosa (mdrpa) isolated from patients at kyungpook national university was confirmed for hibicuslide c, essential oil components from abutilon theophrasti. hibicuslide c has antifungal activity with membrane disruption and apoptotic response against candida albicans. however, its antibacteri ... | 2016 | 27368232 |
| hibicuslide c-induced cell death in candida albicans involves apoptosis mechanism. | to provide the observation that hibicuslide c-induced cell death in yeast candida albicans involves apoptosis mechanism. | 2014 | 25176011 |
| antifungal property of hibicuslide c and its membrane-active mechanism in candida albicans. | in this study, the antifungal activity and mode of action(s) of hibicuslide c derived from abutilon theophrasti were investigated. antifungal susceptibility testing showed that hibicuslide c possessed potent activities toward various fungal strains and less hemolytic activity than amphotericin b. to understand the antifungal mechanism(s) of hibicuslide c in candida albicans, flow cytometric analysis with propidium iodide was done. the results showed that hibicuslide c perturbed the plasma membra ... | 2013 | 23816874 |
| khellin and visnagin, furanochromones from ammi visnaga (l.) lam., as potential bioherbicides. | plants constitute a source of novel phytotoxic compounds to be explored in searching for effective and environmentally safe herbicides. from a previous screening of plant extracts for their phytotoxicity, a dichloromethane extract of ammi visnaga (l.) lam. was selected for further study. phytotoxicity-guided fractionation of this extract yielded two furanochromones, khellin and visnagin, for which herbicidal activity had not been described before. khellin and visnagin were phytotoxic to model sp ... | 2016 | 27936681 |
| synthesis and herbicidal activity of α-(substituted phenoxybutyryloxy or valeryloxy)alkylphosphonates and 2-(substituted phenoxybutyryloxy)alkyl-5,5-dimethyl-1,3,2-dioxaphosphinan-2-one. | on the basis of our work on the modification of alkylphosphonates 1, a series of α-(substituted phenoxybutyryloxy or valeryloxy)alkylphosphonates (4-5) and 2-(substituted phenoxybutyryloxy)alkyl-5,5-dimethyl-1,3,2-dioxaphosphinan-2-one (6) were designed and synthesized. the bioassay results indicated that 14 of title compounds 4 exhibited significant postemergence herbicidal activity against velvetleaf, common amaranth, and false daisy at 150 g ai/ha. compounds 5 were inactive against all tested ... | 2016 | 27530975 |
| synthesis and evaluation of substituted 3-(pyridin-2-yl)benzenesulfonamide derivatives as potent herbicidal agents. | in an attempt to obtain novel candidate compound for weed control, a series of newly substituted 3-(pyridin-2-yl)benzenesulfonamide derivatives 2 were designed and synthesized using compound ii7 as a lead compound by intermediate derivatization methods and their herbicidal activities were evaluated. the herbicidal activity assay in greenhouse tests showed several compounds (2g, 2i, 2j, 2k, 2l, 2m, 2n and 2o) exhibited significant herbicidal activity for controlling velvet leaf (abutilon theophra ... | 2016 | 26385445 |
| weeds ability to phytoremediate cadmium-contaminated soil. | an alternative method to other technologies to clean up the soil, air and water pollution by heavy metals is phytoremediation. therefore, a pot culture experiment was conducted at the college of agriculture, ferdowsi university of mashhad, mashhad, iran, in 2014 to determine the potential absorption of cadmium by portulaca oleracea (common purslane), solanum nigrum (black nightshade), abutilon theophrasti (velvetleaf) and taraxacum officinale (dandelion). the type of experiment was completely ra ... | 2016 | 26125671 |
| sarmentine, a natural herbicide from piper species with multiple herbicide mechanisms of action. | sarmentine, 1-(1-pyrrolidinyl)-(2e,4e)-2,4-decadien-1-one, is a natural amide isolated from the fruits of piper species. the compound has a number of interesting biological properties, including its broad-spectrum activity on weeds as a contact herbicide. initial studies highlighted a similarity in response between plants treated with sarmentine and herbicidal soaps such as pelargonic acid (nonanoic acid). however, little was known about the mechanism of action leading to the rapid desiccation o ... | 2015 | 25904929 |
| synthesis and biological evaluations of a series of thaxtomin analogues. | thaxtomins are a unique family of phytotoxins with unique 4-nitroindole and diketopiperazine fragments possessing potential herbicidal activities. this work presents the total synthesis of natural product thaxtomin c and its analogues. the extensive structure-activity relationship study screens four effective compounds, including thaxtomin a and thaxtomin c. it is indicated that 4-nitro indole fragment is essential for phytotoxicity, while benzyl and m-hydroxybenzyl substituents on the diketopip ... | 2015 | 25804187 |
| relationships between some soil parameters and weed community (case study: winter wheat fields of uremia-iran). | in order to find relationships between weed species distribution and soil ph, calcium carbonate (caco₃), electrical conductivity (ec), and organic matter percentage (om %), fields surveys were done in 50 wheats (triticum aestivum l.) fields of uremia county (one of the northwest counties of iran) in 2013. data sampling of weeds was conducted from the beginning of stem elongation until the end of heading stages of wheat. in each field, 20 quadrates (0.25 m²) were randomly placed along a "w" patte ... | 2015 | 27145592 |
| optimization of ionic liquid based simultaneous ultrasonic- and microwave-assisted extraction of rutin and quercetin from leaves of velvetleaf (abutilon theophrasti) by response surface methodology. | an ionic liquids based simultaneous ultrasonic and microwave assisted extraction (ils-umae) method has been proposed for the extraction of rutin (ru), quercetin (qu), from velvetleaf leaves. the influential parameters of the ils-umae were optimized by the single factor and the central composite design (ccd) experiments. a 2.00 m 1-butyl-3-methylimidazolium bromide ([c4mim]br) was used as the experimental ionic liquid, extraction temperature 60°c, extraction time 12 min, liquid-solid ratio 32 ml/ ... | 2014 | 25243207 |
| phytochemical analysis and bioactivity of the aerial parts of abutilon theophrasti (malvaceae), a medicinal weed. | phytochemical investigations of aerial parts of abutilon theophrasti yielded (6s,9r)-roseoside (1) and (6s,9s)-roseoside (2) which are new for the genus. the elucidation of the chemical structures was established by mass spectrometry, 1d and 2d nmr experiments. although methanol extracts contained 48.5 ± 7.2 mg of caffeic acid equivalents and 15.87 ± 4.6 mg of quercetin equivalents, the antioxidant activity, as revealed by dpph and abts assays, was of medium strength (ec50 of 306.2 ± 16.3 and 39 ... | 2014 | 25050787 |
| densities of eggs and nymphs and percent parasitism of bemisia tabaci (hemiptera: aleyrodidae) on common weeds in west central florida. | the density of eggs and nymphs of bemisia tabaci (gennadius) biotype b and the percent parasitism of the nymphs were measured from specimens collected on nine species of weeds, commonly found in west central florida during the spring and summer of 2012 and 2013. the weeds were direct seeded in 2012 and grown as transplants in 2013 for randomized complete block design experiments. the leaf area of each whole-plant sample was measured and the b. tabaci density parameters were converted to numbers ... | 2014 | 26462945 |
| synthesis and evaluation of heterocyclic analogues of bromoxynil. | one attractive strategy to discover more active and/or crop-selective herbicides is to make structural changes to currently registered compounds. this strategy is especially appealing for those compounds with limited herbicide resistance and whose chemistry is accompanied with transgenic tools to enable herbicide tolerance in crop plants. bromoxynil is a photosystem ii (psii) inhibitor registered for control of broadleaf weeds in several agronomic and specialty crops. recently at the university ... | 2014 | 24354444 |
| the mechanism of methylated seed oil on enhancing biological efficacy of topramezone on weeds. | methylated seed oil (mso) is a recommended adjuvant for the newly registered herbicide topramezone in china and also in other countries of the world, but the mechanism of mso enhancing topramezone efficacy is still not clear. greenhouse and laboratory experiments were conducted to determine the effects of mso on efficacy, solution property, droplet spread and evaporation, active ingredient deposition, foliar absorption and translocation of topramezone applied to giant foxtail (setaria faberi her ... | 2013 | 24086329 |
| first report of fingerprinting dried herbal products using a subtractive diversity array. | introduction sequence - independent microarrays have never been used to identify and authenticate dried herbal plants. | 2013 | 23828332 |
| biochar mitigates negative effects of salt additions on two herbaceous plant species. | addition of pyrolyzed biomass ("biochar") to soils has commonly been shown to increase crop yields and alleviate plant stresses associated with drought and exposure to toxic materials. here we investigate the ability of biochar (at two dosages: 5 and 50 t ha(-1)) to mitigate salt-induced stress, simulating road salt additions in a factorial glasshouse experiment involving the broadleaved herbaceous plants abutilon theophrasti and prunella vulgaris. salt additions of 30 g m(-2) nacl to unamended ... | 2013 | 23796889 |
| hplc quantification of nine chemical constituents from the five parts of abutilon theophrasti medic. | a method of reversed-phase high-performance liquid chromatography (rp-hplc) was established for the simultaneous determination of gallic acid, protocatechuic acid, catechin, vanillic acid, caffeic acid, ferulic acid, rutin, quercetin and syriacusin a in the ethanolic extracts from the five parts (roots, stems, leaves, seeds and exocarps) of abutilon theophrasti medic. the nine components in the sample were extracted with 70% ethanol solution in an ultrasonic bath for 25 min and chromatographical ... | 2014 | 23580704 |
| systemicity of chlorantraniliprole in velvetleaf (abutilon theophrasti). | the systemicity of chlorantraniliprole was investigated and evidence was collected for formulating strategies in controlling vegetable or rice pests. systemicity of chlorantraniliprole was investigated through chlorantraniliprole application on velvetleaf (abutilon theophrasti) leaves as well as through hydroponic experiments. the roots of velvetleaf were incubated in chlorantraniliprole solution with a concentration of 50 microg/ml; the concentrations of chlorantraniliprole in xylem above the s ... | 2013 | 23513948 |
| evaluation of sulfuryl fluoride as a soil fumigant in china. | root-knot nematodes and soil-borne diseases constrain the rapid development of protected agriculture in china, especially while phasing out methyl bromide (mb). the fumigant sulfuryl fluoride (sf) is currently used as an alternative to mb for the disinfestation of buildings and post-harvest commodities. our experiments aimed to evaluate a novel application of sf as a soil fumigant in greenhouses in china. | 2014 | 23512505 |
| solution-phase parallel syntheses of herbicidal 1-phenyl-2,4,5- imidazolidinetriones and 2-thioxo-4,5-imidazolidinediones. | in order to find new herbicidally active compounds, a fifteen-member library, focusing on the variation of 3- position substituents of 2,4,5-imidazolidine-trione or 2-thioxo-4,5-imidazolidinedione, was designed and prepared in parallel by the reaction of various ureas or thioureas with oxalyl chloride using solution-phase technology. an interesting and, to the best of our knowledge, unprecedented finding is that a by-product of 1-phenyl-3-propylcarbodiimide was formed during the addition of oxal ... | 2013 | 23190576 |
| enhanced uv-b radiation increases glyphosate resistance in velvetleaf (abutilon theophrasti). | depletion of the ozone layer leads to increasing uv-b radiation on the earth's surface, which may affect weeds and their responses to herbicides. however, the effect of increased uv-b radiation on weeds and the interaction of weeds and herbicides are still obscure. the objective of this study was to compare glyphosate efficacy on velvetleaf that was grown under with and without increased uv-b radiation. leaf area, dry weight and net photosynthesis of velvetleaf seedlings were adversely affected ... | 2015 | 22943570 |
| synthesis and herbicidal activity of 2-(substituted phenoxyacetoxy)alkyl-5,5-dimethyl-1,3,2-dioxaphosphinan-2-one. | a series of 2-(substituted phenoxyacetoxy)alkyl-5,5-dimethyl-1,3,2-dioxaphosphinan-2-ones iia-s were designed and synthesized on the basis of the previous work for the modification of alkylphosphonates i, and their structures were confirmed by (1)h nmr, (31)p nmr, (13)c nmr, ir, ms, and elemental analysis. their herbicidal activities against seven species of weeds were evaluated in a greenhouse. a part of the title compounds such as iia-g, iik, iio, and iir exhibited significant postemergence he ... | 2012 | 22816730 |
| boa detoxification of four summer weeds during germination and seedling growth. | a recent greenhouse study revealed a significant reduction of germination and growth of redroot pigweed (amaranthus retroflexus) and common purslane (portulaca oleracea) by rye mulch, whereas velvetleaf (abutilon theophrasti) and common lambsquarters (chenopodium album) were not suppressed. since boa detoxification by metabolic alteration may influence the relation between the benzoxazinoid content of the soil mulch and weed suppression, we tested the dynamics in boa detoxification in different ... | 2012 | 22614450 |
| accuracy mass screening and identification of phenolic compounds from the five parts of abutilon theophrasti medic. by reverse-phase high-performance liquid chromatography-electrospray ionization-quadrupoles-time of flight-mass spectrometry. | a rapid and resolutive reverse-phase high-performance liquid chromatography-electrospray ionization-quadrupoles-time of flight-mass spectrometry method was established for the screening and identification of the phenolic compounds in the 70% ethanolic extracts from the five parts (roots, stems, leaves, seeds, and exocarps) of abutilon theophrasti medic.. separation and detection conditions were optimized by using a 22 mixing standard, which included phenolic acids, flavonoids and a naphthalene c ... | 2012 | 22275244 |
| evaluation of the combination of 1,3-dichloropropene and dazomet as an efficient alternative to methyl bromide for cucumber production in china. | the combination of 1,3-dichloropropene (1,3-d) and dazomet (dz) offers a potential alternative to methyl bromide (mb) for soil disinfection. mb is scheduled to be withdrawn from routine use by 2015 in developing countries. combination treatments of 1,3-d + dz were evaluated in a laboratory study and in two commercial cucumber fields. | 2012 | 22228481 |
| synthesis and herbicidal activity of diphenyl ether derivatives containing unsaturated carboxylates. | a series of novel diphenyl ether derivatives containing unsaturated carboxylates were designed and synthesized. their structures were identified by (1)h nuclear magnetic resonance and elemental analyses. the bioassays indicated that the compounds 5b and 5c exhibited good herbicidal activities against velvetleaf at a concentration of 30-40 g/hm(2). the relationship between structure and herbicidal activity was also discussed. among unsaturated carboxylates group, butenoate is the most promising o ... | 2011 | 21958315 |
| effect of different fertilizers on the germination and growth of velvetleaf (abutilon theohrasti medic.). | velvetleaf (abutilon theophrasti medic.) is one of the most important and invasive weed species in hungary and also in europe. its dangerousness derives from its germination biology characteristics and its strong competitive and allelopathic ability. in wide line space crops such as corn, sunflower and soybean it may reduce the yield significantly, according to some authors, this yield reducing ability is lower with bigger nutrient supplies. our experiment was carried in keszthely, hungary (46 d ... | 2011 | 22696961 |
| plants integrate information about nutrients and neighbors. | animals regularly integrate information about the location of resources and the presence of competitors, altering their foraging behavior accordingly. we studied the annual plant abutilon theophrasti to determine whether a plant can demonstrate a similarly complex response to two conditions: presence of a competitor and heterogeneous resource distributions. individually grown plants fully explored the pot by using a broad and uniform rooting distribution regardless of soil resource distributions ... | 2010 | 20576883 |
| phytoremediation and microbial community structure of soil from a metal-contaminated military shooting range: comparisons of field and pot experiments. | in this study, the heavy metal uptake ability of two plant species, barnyard grass and indian mallow, and the effects of associated micro-communities on the rhizosphere of these plants were investigated in metal-contaminated sites. in addition, the effectiveness of phytoremediation using these plants was compared under field and pot conditions. to accomplish this analysis, phytoremediation of general military shooting range soil was conducted for 8 weeks under the two conditions. the results sho ... | 2010 | 20390882 |
| effect of seed depth on germination and growth of velvetleaf (abutilon theophrasti medic.). | importance of several weed species has been considerably increased during the last few decades in hungary. velvetleaf (abutilon theophrasti medic.) belongs to this spreading weed group as well. this weed species was in the 27th position in the course of the fourth hungarian weed survey, but at the time of the fifth weed survey in 2007-2008 it stepped forward to the 10th position in the cornfields of zala county. requiring a warm climate, global climate warming plays a significant role in its rap ... | 2010 | 21542475 |
| synthesis and herbicidal activity of isoindoline-1,3-dione substituted benzoxazinone derivatives containing a carboxylic ester group. | a carboxylic ester group was introduced to three series of isoindolinedione substituted benzoxazinone derivatives. some of these analogues exhibited good herbicidal activities, and the injury symptoms against weeds included leaf cupping, crinkling, bronzing, and necrosis, typical of protox inhibitor herbicides. structurally, they were classified as chemical group a (4-carboxylic ester group-6-isoindolinyl-benzoxazinones), b (4-carboxylic ester group-7-isoindolinyl-benzoxazinones), and c (4-carbo ... | 2009 | 19772294 |
| physiological and growth responses of c3 and c4 plants to reduced temperature when grown at low co2 of the last ice age. | during the last ice age, co2 concentration ([co2]) was 180-200 micromol/mol compared with the modern value of 380 micromol/mol, and global temperatures were approximately 8 degrees c cooler. relatively little is known about the responses of c3 and c4 species to long-term exposure to glacial conditions. here abutilon theophrasti medik. (c3) and amaranthus retroflexus l. (c4) were grown at 200 micromol/mol co2 with current (30/24 degrees c) and glacial (22/16 degrees c) temperatures for 22 d. over ... | 2008 | 19017126 |
| phytoremediation of soil co-contaminated with heavy metals and tnt using four plant species. | we investigated the germination, growth rates and uptake of contaminants of four plant species, barnyard grass (echinochloa crusgalli), sunflower (helianthus annuus), indian mallow (abutilon avicennae) and indian jointvetch (aeschynomene indica), grown in soil contaminated with cadmium (cd), lead (pb) and 2,4,6-trinitrotoluene (tnt). these contaminants are typically found at shooting ranges. experiments were carried out over 180 days using both single plant cultures and cultures containing an eq ... | 2007 | 17990167 |
| use of growth regulator of cytokinin type for enhancement and modification of herbicide activity. | the herbicidal action of betanal express (bpam) on chine jute (abutilon theophrasti) weed was studied in the presence of a new plant growth regulator of urea type, n-phenyl-n-(1,2,4-triazol-4-yl)urea (phenyltriazolylurea, ptu). in the past years, chine jute has become a major limiting factor in sugar beet production in the southern russia due to its resistance to bpam which is an essential herbicide widely used for sugar beet protection. when ptu was added to bpam, the combination appeared to be ... | 2006 | 17390827 |
| comparison of efficacy, absorption and translocation of three glyphosate formulations on velvetleaf (abutilon theophrasti). | growth analysis, absorption and translocation studies were conducted to compare a 1-aminomethanamide dihydrogen tetraoxosulfate (gly-a) formulation of glyphosate with two isopropylamine (gly-ipa-1, gly-ipa-2) formulations of glyphosate on velvetleaf. the two isopropylamine formulations differed by the presence of a surfactant in the formulation, gly-ipa-1 containing surfactant whereas gly-ipa-2 did not. four- to six-leaf velvetleaf was treated with gly-a and gly-ipa-1 and gly-ipa-2 (0, 50, 67, 8 ... | 2006 | 16981248 |
| how do leaf hydraulics limit stomatal conductance at high water vapour pressure deficits? | a reduction in leaf stomatal conductance (g) with increasing leaf-to-air difference in water vapour pressure (d) is nearly ubiquitous. ecological comparisons of sensitivity have led to the hypothesis that the reduction in g with increasing d serves to maintain leaf water potentials above those that would cause loss of hydraulic conductance. a reduction in leaf water potential is commonly hypothesized to cause stomatal closure at high d. the importance of these particular hydraulic factors was te ... | 2006 | 16898024 |
| [absorption and accumulation of heavy metals by plants around a smelter]. | the study on the absorption and accumulation of heavy metals lead, zinc, copper and cadmium by 8 plant species around a smelter showed that the metals accumulation by plants differed with plant species, their parts, and kinds of metals. abutilon theophrasti had a higher capability of absorbing and accumulating pb, conyza canadensis, ambrosia trifida, polygonumn lapathifolium, a. theophrasti, solanum nigrum, chenopodium acuminatum and helianthus tuberosus had a higher capability of absorbing and ... | 2006 | 16724753 |
| weed control in sunflower (helianthus annuus l.) with post-emergent herbicides. | sunflower is the most important oil crop in hungary, is the base of the production of cooking oil and moreover takes an important part in production of margarine too. extracted sunflower groats as a secondary product origining from the mentioned procedure can be used in forage successfully. the amount of harvested sunflower reaches the 20-25% of the eu's yield. the sowing area approaches 500 thousand hectares. the essential condition of successful crop production is the perfect weed control. sow ... | 2005 | 16637218 |
| [effects of tillage method and herbicide on cornfield weed community]. | by the method of community ecology, this paper surveyed the weed community in a cornfield at the shenyang experimental station of ecology, cas, and studied the effects of tillage method and herbicide on the weed composition, species diversity, and biomass at the experimental site. the results showed that the dominant weed species in the cornfield were eriochloa villosa, abutilon theophrasti, bidens frondosa and commelina communis, of which, eriochloa villosa had the highest important value. in n ... | 2005 | 16422507 |
| factors modulating the levels of the allelochemical sorgoleone in sorghum bicolor. | sorgoleone is the major component of the hydrophobic root exudate of sorghum [sorghum bicolor (l.) moench]. the presence of this allelochemical is intrinsically linked to root growth and the development of mature root hairs. however, factors modulating root formation and the biosynthesis of sorgoleone are not well known. sorgoleone production was independent of early stages of plant development. the optimum temperature for root growth and sorgoleone production was 30 degrees c. seedling developm ... | 2006 | 16402225 |
| enhanced degradation of 2,4,6-trinitrotoluene (tnt) in a soil column planted with indian mallow (abutilon avicennae). | phytoremediation of soil contaminated with 2,4,6-trinitrotoluene (tnt) was studied by growing indian mallow (abutilon avicennae) in a soil column reactor with 2 kg of tnt contaminated soil (120 mgtnt/kg) in the top and 18 kg of uncontaminated soil in the bottom. after 50 d, tnt remaining in the column with indian mallow was 23.2% of the initial tnt, while 48.1% of the initial tnt remained in the column without indian mallow. in the tnt contaminated column, the growth of indian mallow decreased b ... | 2004 | 16233599 |
| synthesis and herbicidal activity of 2-(7-fluoro-3-oxo- 3,4-dihydro-2h-benzo[b][1,4]oxazin-6-yl)isoindoline-1,3-diones. | the mode of action of 2-(7-fluoro-3-oxo-3,4-dihydro-2h-benzo[b][1,4]oxazin-6-yl)-4,5,6,7-tetrahydro-2h-isoindoline-1,3-diones, including the commercial herbicide flumioxazin, had been identified as inhibition of protoporphyrinogen oxidase (protox). as part of continuous efforts to search for new herbicides with high efficacy, broad-spectrum activity, and safety to crops, flumioxazin and its iodo analogue (b2055) were used as lead compounds for further optimization. series of novel compounds were ... | 2005 | 16190649 |
| flavonoids from abutilon theophrasti flowers. | nine flavonoid compounds: kaempferol 3-0-beta-(6"-p-coumaroyl)-glucopyranoside, myricetin 3-o-beta-glucopyranoside, quercetin 3-0-beta-glucopyranoside, quercetin 3-0-alpha-rhamnopyranosyl (1-->6)-beta-glucopyranoside, kaempferol 3-0-beta-glucopyranoside, kaempferol 3-0-alpha-rhamnopyranosyl (1-->6)-beta-glucopyranoside, quercetin 7-0-beta-glucoside, quercetin 7-0-beta-diglucoside, kaempferol 7-0-beta-diglucoside were isolated and identified from the flowers of abutilon theophrasti. | 2005 | 16161355 |
| photosynthetic and growth responses of zea mays l and four weed species following post-emergence treatments with mesotrione and atrazinet. | we compared photosynthesis and growth of zea mays l (corn) and four weed species, setaria viridis (l) beauv (green foxtail), echinochloa crus-galli (l) beauv (barnyardgrass), abutilon theophrasti medic (velvetleaf), and amaranthus retroflexus l (redroot pigweed), following foliar applications with atrazine, mesotrione, or a combination of atrazine and mesotrione in two greenhouse experiments. plant responses to the three herbicide treatments were compared with responses of untreated plants (cont ... | 2004 | 15532681 |
| molecular and morphological differentiation between the crop and weedy types in velvetleaf (abutilon theophrasti medik.) using a chloroplast dna marker: seed source of the present invasive velvetleaf in japan. | a comparison of chloroplast dna (cpdna) sequences was carried out between the crop and weed types of abutilon theophrasti to clarify the seed source of the present weedy velvetleaf in japan. a sequencing analysis of approx. 6% of the chloroplast genome (ca 10 kbp) detected three nucleotide substitutions, one six-base-pair insertion/deletion (indel) and one 30-base pair inversion, which distinguish two haplotypes of cpdna. a pcr-based survey of the indel and the inversion revealed that the 93 acc ... | 2004 | 15354188 |
| interactive effects of lateral shade and wind on stem allometry, biomass allocation, and mechanical stability in abutilon theophrasti (malvaceae). | the effects of lateral shade and wind on stem allometry, whole-plant biomass allocation, and mechanical stability were examined for abutilon theophrasti in a fully factorial glasshouse experiment. lateral shade from neighboring plants increased stem height by 33% relative to control plants grown individually, despite a decrease in plant dry mass. intermittent wind decreased stem height by 18% in unshaded plants, but by only 3% in shaded plants. surprisingly, both lateral shade and wind caused de ... | 2002 | 21665588 |
| decoupling of light intensity effects on the growth and development of c3 and c4 weed species through sucrose supplementation. | light availability has a profound effect on plant growth and development. one of the ways to study the effects of light intensity on plant growth and development without the confounding problem of photosynthate availability is sucrose injection/supplementation. a greenhouse experiment was conducted to evaluate the effects of light levels (0% and 75% shade) and sucrose injection (distilled water or 150 g sucrose l(-1)) on three weed species: redroot pigweed (amaranthus retroflexus l., c4), lambsq ... | 2002 | 12177133 |
| superspreading driven by marangoni flow. | the spontaneous spreading (called superspreading) of aqueous trisiloxane ethoxylate surfactant solutions on hydrophobic solid surfaces is a fascinating phenomenon with several practical applications. for example, the ability of trisiloxane ethoxylate surfactants to enhance the spreading of spray solutions on waxy weed leaf surfaces, such as velvetleaf (abutilion theophrasti), makes them excellent wetting agents for herbicide applications. the superspreading ability of silicone surfactants has be ... | 2002 | 11908793 |
| phenotypic plasticity early in life constrains developmental responses later. | plastic stem-elongation responses to the ratio of red:far-red (r:fr) wavelengths enable plants to match their phenotype to local competitive conditions. however, elongation responses early in the life history may occur at the cost of reduced plasticity later in the life history, because elongation influences both allocation patterns and structural integrity. a common-garden experiment was performed to test whether seedling responses to r:fr affect biomass allocation. biomass accumulation, and su ... | 2001 | 11430653 |
| limits to adaptive plasticity: temperature and photoperiod influence shade-avoidance responses. | in plants, the ratio of red to far-red wavelengths (r:fr) reliably indicates neighbor proximity and influences stem elongation. enhanced elongation increases light interception and fitness under crowded conditions. however, many environmental factors vary simultaneously such that responses to r:fr may be affected by abiotic conditions or maternal environmental conditions. this study examines the effects of temperature, photoperiod, and maternal environment on stem-elongation responses to r:fr. f ... | 2000 | 11080117 |
| plasticity versus canalization: population differences in the timing of shade-avoidance responses. | the reliability of environmental cues and costs of a fixed phenotype are two factors determining whether selection favors phenotypic plasticity or environmental specialization. this study examines the relationship between these two factors and the evolution of plant competitive strategies (plastic vs. fixed morphologies). in natural plant populations, shifts in light quality associated with foliar shade reliably indicate the presence of neighbors. these cues mediate plastic stem-elongation respo ... | 2000 | 10937221 |
| differing selection in alternative competitive environments: shade-avoidance responses and germination timing. | under competitive conditions, stem elongation in plants is thought to enhance fitness by increasing light interception. however, the onset of competition should vary with the species of competitor due to interspecific differences in timing of emergence and plant growth form. the fitness benefits of elongation may therefore depend on the timing of this plastic response. phenotypic selection analyses and path analysis were used to evaluate selection acting on stem elongation at early and late life ... | 2000 | 10937189 |
| plasticity of seed output in response to soil nutrients and density in abutilon theophrasti: implications for maintenance of genetic variation. | seed output is determined by two processes: resource acquisition and the allocation of resources to seeds. in order to clarify how the reaction norm of seed output is controlled by the phenotypic expression of its two components, we examined the genetic components of plasticity of seed dry mass, plant size, and reproductive allocation under different conditions of soil nutrient availability and conspecific competition among eight families of abutilon theophrasti. without competition, the reactio ... | 1997 | 28307372 |
| defoliation of the annual herb abutilon theophrasti: mechanisms underlying reproductive compensation. | a number of studies have shown that under some conditions plants may fully or partially compensate for leaf tissue loss; however, the mechanisms underlying compensatory responses are not well understood. previous work demonstrated that the annual herb abutilon theophrasti fully compensated for 75% defoliation, but only when grown in the absence of stem competition. we examined potential mechanisms of compensatory response and how they are influenced by resource limitation (i.e., competition for ... | 1997 | 28307998 |
| phenotypic plasticity and similarity of dna among genotypes of an annual plant. | when measured directly, rather than inferred from pedigree analyses, the relationship between similarity in phenotype and similarity in dna sequence was detectable at the level of members of a single population and strongly depended on the environmental context. genetic divergence among 27 co-occurring genotypes of abutilon theophrasti, a common annual plant, was less than 5 per cent as revealed by rapd-pcr analysis based on over 400 bands per genotype. nevertheless, within this narrow range, th ... | 1997 | 9054688 |
| effects of co2 elevation on canopy development in the stands of two co-occurring annuals. | elevated co2 may increase dry mass production of canopies directly through increasing net assimilation rate of leaves and also indirectly through increasing leaf area index (lai). we studied the effects of co2 elevation on canopy productivity and development in monospecific and mixed (1:1) stands of two co-occurring c3 annual species, abutilon theophrasti, and ambrosia artemisiifolia. the stands were established in the glasshouse with two co2 levels (360 and 700 μl/l) under natural light conditi ... | 1996 | 28307832 |
| isolation and identification of (3-methoxyphenyl)acetonitrile as a phytotoxin from meadowfoam (limnanthes alba) seedmeal. | ethyl ether, ethanol, and water extracts of meadowfoam (limnanthes alba hartweg ex. benth.) seedmeal were prepared and bioassayed against velvetleaf (abutilon theophrasti medicus) and wheat (triticum aestivum l. "cardinal"). both the ethyl ether and ethanol fractions, but not the water extract, inhibited velvetleaf and wheat radicle elongation. fractionation of the extracts indicated that (3-methoxyphenyl)acetonitrile (3-mpan) was the active compound from both extracts, comprising >97% of the ac ... | 1996 | 24227117 |
| phytotoxic and antimicrobial activity of 5,7-dihydroxychromone from peanut shells. | a flavonoid decomposition product that is present in peanut (arachis hypogaea) shells, 5,7-dihydroxychromone (dhc), was found to inhibit the radial growth of cultures of the soil pathogenic fungirhizoctonia solani andsclerotium rolfsii with i50 (the concentrations of dhc required to inhibit growth 50%) values of 18 and 26µm, respectively. radicle elongation of velvetleaf, corn, peanut, and wheat was inhibited by dhc with i50 values of 30, 50, 65 and 200µm, respectively. dhc had no effect on the ... | 1995 | 24234013 |
| effects of low and elevated co2 on c3 and c4 annuals : ii. photosynthesis and leaf biochemistry. | abutilon theophrasti (c3) and amaranthus retroflexus (c4), were grown from seed at four partial pressures of co2: 15 pa (below pleistocene minimum), 27 pa (pre-industrial), 35 pa (current), and 70 pa (future) in the duke phytotron under high light, high nutrient, and wellwatered conditions to evaluate their photosynthetic response to historic and future levels of co2. net photosynthesis at growth co2 partial pressures increased with increasing co2 for c3 plants, but not c4 plants. net photosynth ... | 1995 | 28306971 |
| effects of low and elevated co2 on c3 and c4 annuals : i. growth and biomass allocation. | in order study c3 and c4 plant growth in atmospheric co2 levels ranging from past through predicted future levels, abutilon theophrasti (c3) and amaranthus retroflexus (c4) were grown from seed in growth chambers controlled at co2 partial pressures of 15 pa (below pleistocene minimum), 27 pa (pre-industrial), 35 pa (current) and 70 pa (predicted future). after 35 days of growth, co2 had no effect on the relative growth rate, total biomass or partitioning of biomass in the c4 species. however, th ... | 1995 | 28306970 |
| herbicidal activity of sulforaphene from stock (matthiola incana). | a herbicidal compound was isolated from extracts ofmatthiola incana and identified as sulforaphene (4-methylsulfinyl-3-butenyl isothiocyanate). the ed50 of this compound against velvetleaf seedlings was approximately 2×10(-4) m. glucoraphenin, the glucosinolate that is the natural precursor of sulforaphene, was less phytotoxic, with an ed50 of near 6×10(-3)m. | 1993 | 24248575 |
| elevated co2 alters deployment of roots in "small" growth containers. | previously we examined how limited rooting space and nutrient supply influenced plant growth under elevated atmospheric co2 concentrations (mcconnaughay et al. 1993). we demonstrated that plant growth enhancement under elevated co2 was influenced more by the concentration of nutrients added to growth containers than to either the total nutrient content per pot or amount or the dimensions of available rooting space. to gain insight into how elevated co2 atmospheres affect how plants utilize avail ... | 1993 | 28313997 |
| limitations to co2-induced growth enhancement in pot studies. | recently, it has been suggested that small pots may reduce or eliminate plant responses to enriched co2 atmospheres due to root restriction. while smaller pot volumes provide less physical space available for root growth, they also provide less nutrients. reduced nutrient availability alone may reduce growth enhancement under elevated co2. to investigate the relative importance of limited physical rooting space separate from and in conjunction with soil nutrients, we grew plants at ambient and d ... | 1993 | 28313996 |
| phenolic acids affect photosynthesis and protein synthesis by isolated leaf cells of velvet-leaf. | the effects ofp-coumaric, ferulic, chlorogenic, and vanillic acids on photosynthesis and protein synthesis by isolated leaf cells of velvetleaf (abutilon theophrasti medik) were investigated. photosynthesis and protein synthesis were measured in cell suspensions by the incorporation of(14)co2 and [(14)c]leucine, respectively. none of the tested phenolic acids except vanillic reduced photosynthesis by more than 50% at the highest concentration and 30 min of incubation. at 100μm concentrations and ... | 1993 | 24249162 |
| mycorrhizal symbiosis increases growth, reproduction and recruitment of abutilon theophrasti medic. in the field. | we examined in the field the effect of the vesicular-arbuscular (va) mycorhizal symbiosis on the reproductive success of abutilon theophrasti medic., an early successional annual member of the malvaceae. mycorrhizal infection greatly enhanced vegetative growth, and flower, fruit and seed production, resulting in significantly greater recruitment the following year. in addition, the seeds produced by mycorrhizal plants were significantly larger and contained significantly more phosphorus than see ... | 1993 | 28313854 |
| elevated co2 and plant nitrogen-use: is reduced tissue nitrogen concentration size-dependent? | plants often respond to elevated atmospheric co2 levels with reduced tissue nitrogen concentrations relative to ambient co2-grown plants when comparisons are made at a common time. another common response to enriched co2 atmospheres is an acceleration in plant growth rates. because plant nitrogen concentrations are often highest in seedlings and subsequently decrease during growth, comparisons between ambient and elevated co2-grown plants made at a common time may not demonstrate co2-induced red ... | 1993 | 28313607 |
| a rapid method for isolating glandular trichomes. | a physical method is described for the rapid isolation of plant trichomes, with emphasis on stalked glandular types. the technique involved breaking frozen trichomes with powdered dry ice and collection of glandular heads by sieving from larger tissue fragments. this method was applied to several plants that bear similar stalked trichomes: geranium (pelargonium), potato (solanum tuberosum), tomato (lycopersicon esculentum), squash (cucurbita pepo), and velvetleaf (abutilon theophrasti). the tiss ... | 1992 | 16668834 |
| alteration of components of leaf water potential and water content in velvetleaf under the effects of long-term humidity difference. | velvetleaf (abutilon theophrasti medik.) was grown in growth chambers set at 45 or 85% relative humidity at 30 degrees c, co(2) 350 microliters per liter and 1000 micromoles per square meter per second of photosynthetically active radiation. soil water potential was maintained at -0.05 megapascal by subirrigation with half strength hoagland solution. the third, fourth, and fifth leaves from the base of 21- and 25-day-old plants were used for pressure-volume measurements. components of leaf water ... | 1992 | 16668772 |
| herbicide clomazone does not inhibit in vitro geranylgeranyl synthesis from mevalonate. | clomazone reduced the chlorophyll and carotenoid contents of spinach (spinacia oleracea l.), barley (hordeum vulgare l.), velvetleaf (abutilon theophrasti medik.), and soybean (glycine max l. merr.) seedlings. the order of species sensitivity was velvetleaf > spinach > barley > soybean. clomazone (100 micromolar) did not affect the in vitro activities of spinach isopentenyl pyrophosphate isomerase or prenyl transferase. clomazone also did not affect the synthesis of isopentenyl pyrophosphate fro ... | 1992 | 16668657 |
| phytotoxicity of sorgoleone found in grain sorghum root exudates. | root exudates ofsorghum bicolor consist primarily of a dihydroquinone that is quickly oxidized to ap-benzoquinone named sorgoleone. the aim of this investigation was to determine the potential activity of sorgoleone as an inhibitor of weed growth. bioassays showed 125μm sorgoleone reduced radicle elongation oferagrostis tef. in liquid culture, 50-μm sorgoleone treatments stunted the growth oflemna minor. over a 10-day treatment period, 10μm sorgoleone in the nutrient medium reduced the growth of ... | 1992 | 24254628 |
| isolation of substance from sweet potato (ipomoea batatas) periderm tissue that inhibits seed germination. | chromatographic procedures were used to isolate inhibitors of seed germination from sweet potato root periderm tissue. the inhibitory activity of all fractions was monitored using a proso millet seed germination bioassay. a single hplc peak, representing approximately 1.2% of the periderm dry weight, accounted for most of the inhibitory activity. the active fraction was labile in methanolic solution. further fractionation of this peak by hplc methods was not successful. in vitro seed germination ... | 1991 | 24259077 |
| atrazine resistance in a velvetleaf (abutilon theophrasti) biotype due to enhanced glutathione s-transferase activity. | we previously reported that a velvetleaf (abutilon theophrasti medic) biotype found in maryland was resistant to atrazine because of an enhanced capacity to detoxify the herbicide via glutathione conjugation (jw gronwald, andersen rn, yee c [1989] pestic biochem physiol 34: 149-163). the biochemical basis for the enhanced atrazine conjugation capacity in this biotype was examined. glutathione levels and glutathione s-transferase activity were determined in extracts from the atrazine-resistant bi ... | 1991 | 16668137 |
| mycorrhizal fungi and the nutrient ecology of three oldfield annual plant species. | three oldfield annual species (abutilon theophrasti medic., ambrosia artemisiifolia l. and setaria lutescens (weigel) hubb.) were investigated. all three developed substantial mycorrhizal infections when inoculated with glomus etunicatum becker & gerd. mycorrhizal infection dramatically increased phosphorus content and dry weight of both abutilon and ambrosia, but did not significantly affect dry weight and only modestly increased phosphorus content of setaria. these results were consistent with ... | 1991 | 28312046 |
| density-dependent response to mycorrhizal infection in abutilon theophrasti medic. | one purpose of this study was to determine whether an increase in plant density would result in a decrease in response to mycorrhizal infection (particularly as measured by phosphorus content). increases in plant density generally result in increases in root density in the volume of soil occupied by the plants. root density, in turn, largely determines phosphorus uptake. if mycorrhizal plants had significantly higher effective root densities than non-mycorrhizal plants due to the fungal hyphae a ... | 1991 | 28312044 |
| uptake and accumulation of the herbicide bentazon by cultured plant cells. | cellular absorption of the herbicide bentazon, a weak acid with pk(a) 3.45, was investigated using suspension-cultured cells of velvetleaf (abutilon theophrasti medic.). bentazon accumulated rapidly to concentrations approximately four times that of the external medium. bentazon accumulation against a concentration gradient was not due to its conversion to metabolites, partitioning into lipids, or binding onto cellular constituents. bentazon uptake was related linearly to the external bentazon c ... | 1990 | 16667379 |
| uptake and metabolism of clomazone in tolerant-soybean and susceptible-cotton photomixotrophic cell suspension cultures. | studies were conducted to determine the uptake and metabolism of the pigment synthesis inhibiting herbicide clomazone in tolerant-soybean (glycine max [l.] merr. cv corsoy) and susceptible-cotton (gossypium hirsutum [l.] cv stoneville 825) photomixotrophic cell suspensions. soybean and cotton on a whole plant level are tolerant and susceptible to clomazone, respectively. preliminary studies indicated that i(50) values for growth, chlorophyll (chl), beta-carotene, and lutein were, respectively, > ... | 1990 | 16667349 |
| natural products phytotoxicity a bioassay suitable for small quantities of slightly water-soluble compounds. | a large variety of secondary metabolites that can inhibit germination and/or seedling growth are produced by plants in low quantities. the objective of this study was to develop a bioassay capable of reliably assessing reductions in germination percentage and seedling length of small-seeded plant species caused by exposure to minute quantities of these compounds. the germination and growth of alfalfa (medicago saliva), annual ryegrass (lolium multiflorum), and velvetleaf (abutilon theophrasti) w ... | 1990 | 24263494 |
| effects of velvetleaf plant residues on seedling growth and soil microbial activity. | | 1989 | 2506957 |
| using growth analysis to interpret competition between a c3 and a c4 annual under ambient and elevated co2. | detailed growth analysis in conjunction with information on leaf display and nitrogen uptake was used to interpret competition between abutilon theophrasti, a c3 annual, and amaranthus retroflexus, a c4 annual, under ambient (350 μl l(-1)) and two levels of elevated (500 and 700 μl l(-1)) co2. plants were grown both individually and in competition with each other. competition caused a reduction in growth in both species, but for different reasons. in abutilon, decreases in leaf area ratio (lar) ... | 1989 | 28312859 |
| growth consequences of plasticity of plant traits in response to light conditions. | we present a method for quantifying the growth advantage, if any, that results from the plasticity of plant traits in response to growth in high vs. low resource levels. the method, which uses two phenotypes and two resource levels, quantifies the average advantage that a phenotype has, in its own set of conditions, over the other phenotype. the method is applied to the growth of two phenotypes of abutilon theophrasti, induced by high and low light intensity, in response to two levels of inciden ... | 1989 | 28312181 |
| quantification of plasticity of plant traits in response to light intensity: comparing phenotypes at a common weight. | plasticity of plant traits is commonly quantified by comparing different phenotypes at the same age. in this paper, we present a method in which the effect of resource conditions on plant weight is used as a basis for quantifying the plasticity of individual plant traits. abutilon theophrasti individuals were grown in, and some transferred between, high and low intensity light conditions, resulting in four phenotypes. plant traits were found to exhibit different degrees of plasticity, decreasing ... | 1989 | 28312180 |