Germination of Exhumed Weed Seed in Nebraska

Weed Science ◽  
1981 ◽  
Vol 29 (5) ◽  
pp. 577-586 ◽  
Author(s):  
Orvin C. Burnside ◽  
Charles R. Fenster ◽  
Larry L. Evetts ◽  
Robert F. Mumm
Keyword(s):  
Amaranthus Retroflexus ◽  
Setaria Viridis ◽  
Weed Species ◽  
Kochia Scoparia ◽  
Asclepias Syriaca ◽  
Rapid Loss ◽  
Digitaria Sanguinalis ◽  
Redroot Pigweed ◽  
Green Foxtail ◽  
Panicum Dichotomiflorum

An experiment was initiated in 1970 and continued through 1979 by exhuming and germinating seed of 12 economic weed species buried beneath 23 cm of soil in eastern and western Nebraska. Loss in germination of exhumed seeds over years is mathematically characterized by the formula for the rectangular hyperbola, which represents many shapes of curves that have zero as their lower limit. Of the 12 weed species, only fall panicum (Panicum dichotomiflorumMichx.) and redroot pigweed (Amaranthus retroflexusL.) seed germination did not drop significantly over the 10-yr burial period. Germination of redroot pigweed seed was higher when buried in eastern Nebraska, but was higher for smooth groundcherry (Physalis subglabrataMack&Bush.) and velvetleaf (Abutilon theophrastiMedic.) when buried in western Nebraska. Germination of the other nine species were not affected by burial location. The 12 weed species can be ranked as those showing most to least rapid loss of germination during burial for 10 yr as follows: honeyvine milkweed [Ampelamus albidus(Nutt.) Britt.], hemp dogbane (Apocynum cannabinumL.), kochia [Kochia scoparia(L.) Schrad.], sunflower (Helianthus annumL.), large crabgrass [Digitaria sanguinalis(L.) Scop.], common milkweed (Asclepias syriacaL.), musk thistle (Carduus nutansL.), velvetleaf, fall panicum, redroot pigweed, green foxtail [Setaria viridis(L.) Beauv.], and smooth groundcherry.

Selectivity of Nitrofen among Rape, Redroot Pigweed, and Green Foxtail

Weed Science ◽  
1971 ◽  
Vol 19 (1) ◽  
pp. 42-44 ◽  
Author(s):  
D. Hawton ◽  
E. H. Stobbe
Keyword(s):  
Brassica Campestris ◽  
Amaranthus Retroflexus ◽  
Water Soluble ◽  
Setaria Viridis ◽  
Weed Species ◽  
Differential Effects ◽  
Redroot Pigweed ◽  
Green Foxtail

The selectivity of 2,4-dichlorophenylp-nitrophenyl ether (nitrofen) among rape (Brassica campestrisL., var. Echo) and two weed species, redroot pigweed (Amaranthus retroflexusL.) and green foxtail (Setaria viridis(L.) Beauv.), was determined quantitatively by a replicated dosage-response experiment. On an ED50basis, green foxtail and redroot pigweed were, respectively, 5.8 and 63.3 times more susceptible than rape. Selectivity was divided into three parameters; viz., differential spray retention, differential penetration, and differential effects within the plant. Differences in retention were measured with the use of a water-soluble dye, while differences in penetration were determined with14C-labelled nitrofen. Spray retention on green foxtail was 66% of that on the rape and 64% as much nitrofen penetrated redroot pigweed as penetrated rape. Under the conditions of these tests it was estimated that green foxtail and redroot pigweed were, respectively, 9 and 99 times more susceptible to nitrofen than was rape.

Effect of Early Competition on Growth of Common Milkweed

Weed Science ◽  
1975 ◽  
Vol 23 (1) ◽  
pp. 1-3 ◽  
Author(s):  
L. L. Evetts ◽  
O. C. Burnside
Keyword(s):  
Sorghum Bicolor ◽  
Amaranthus Retroflexus ◽  
Setaria Viridis ◽  
Light Competition ◽  
Asclepias Syriaca ◽  
Redroot Pigweed ◽  
Light Soil ◽  
Green Foxtail ◽  
Shoot Weight ◽  
Annual Weeds

Four modes of competition were studied in relation to early development of common milkweed (Asclepias syriacaL.) alone and in competition with green foxtail [Setaria viridis(L.) Beauv], redroot pigweed (Amaranthus retroflexusL.), and sorghum [Sorghum bicolor(L.) Moench ‘RS-626’]. The three species were used to study the effect of no competition, light competition, soil competition, and light and soil (full) competition on common milkweed. Common milkweed height was significantly reduced by soil and full competition with the three species, while only green foxtail caused a significant reduction in height due to light competition. Shoot weight of common milkweed was significantly reduced by light, soil, and full competition by the three species. Reproduction percentage of common milkweed roots was most severely reduced by light and full competition from green foxtail and redroot pigweed. An environment conducive to the establishment of the perennial common milkweed from seed exists when annual weeds are removed by herbicides.

The Fate of Nitrofen in Rape, Redroot Pigweed, and Green Foxtail

Weed Science ◽  
1971 ◽  
Vol 19 (5) ◽  
pp. 555-558 ◽  
Author(s):  
D. Hawton ◽  
E. H. Stobbe
Keyword(s):  
Light Intensity ◽  
Brassica Campestris ◽  
Molecular Size ◽  
Amaranthus Retroflexus ◽  
High Light ◽  
Setaria Viridis ◽  
Light Conditions ◽  
Ether Linkage ◽  
Redroot Pigweed ◽  
Green Foxtail

The fate of 2,4-dichlorophenyl p-nitrophenyl ether (nitrofen) in the foliage of rape (Brassica campestris L. ‘Echo’), redroot pigweed (Amaranthus retroflexus L.), and green foxtail (Setaria viridis (L.) Beauv.) was investigated with the aid of 14C-nitrofen. Only limited amounts of the label were translocated in these species. Plants treated with 14C-nitrofen under high light conditions produced several labelled compounds of different molecular size and chromatographic properties. The time at which these compounds were first detectable depended on light intensity. At least two of these compounds are lipid-nitrofen conjugates or nitrofen polymers and others may be formed by cleavage of nitrofen at the ether linkage.

Uptake, Movement, and Metabolism of Cyanazine in Fall Panicum, Green Foxtail, and Corn

Weed Science ◽  
1975 ◽  
Vol 23 (4) ◽  
pp. 277-282 ◽  
Author(s):  
A. D. Kern ◽  
W. F. Meggitt ◽  
Donald Penner
Keyword(s):  
Zea Mays ◽  
Root System ◽  
Foliar Uptake ◽  
Setaria Viridis ◽  
Weed Species ◽  
Root Absorption ◽  
Corn Roots ◽  
Green Foxtail ◽  
Panicum Dichotomiflorum

In greenhouse studies root absorption after postemergence applications of cyanazine 2-[[4-chloro-6-(ethylamino)-s-triazine-2-yl] amino]-2-methylpropionitrile enhanced phytotoxicity to fall panicum (Panicum dichotomiflorumMichx.), green foxtail (Setaria viridisL.), and corn (Zea maysL.). Less14C-cyanazine was taken up by the foliage of corn than by the weed species. A lower concentration of parent cyanazine in corn leaves was also evident. The addition of a phytobland oil to the treatment solution increased foliar cyanazine absorption 1 and 5 days following treatment. Although rapid metabolism occurred in corn roots, the large amount of cyanazine absorbed via the root system resulted in internal concentrations of parent cyanazine similar to that observed in the weed species. Cyanazine translocation was mainly acropetal from the point of application. The basis of selectivity is not solely based on the differential foliar uptake of cyanazine, but also on the proportion taken up by the foliage and roots. Under conditions favoring uptake by roots, the margin of selectivity may be reduced.

scholarly journals Differential susceptibility of agricultural weeds to ultraviolet-B radiation

2002 ◽  
Vol 82 (4) ◽  
pp. 789-796 ◽  
Author(s):  
N. H. Furness ◽  
M. K. Upadhyaya
Keyword(s):  
Leaf Area ◽  
Chenopodium Album ◽  
Amaranthus Retroflexus ◽  
Ultraviolet B ◽  
Setaria Viridis ◽  
Stellaria Media ◽  
Redroot Pigweed ◽  
Green Foxtail ◽  
Lamb’S Quarters ◽  
Polygonum Persicaria

Differential morphological sensitivity of weed species to ultraviolet-B (UV-B) radiation (290–320 nm) may alter competitive relationships among weeds and associated crop species as the level of this radiation changes. In order to determine relative sensitivity of common chickweed [Stellaria media (L.) Vill.], green foxtail (Setaria viridis L.), lady's-thumb (Polygonum persicaria L.), lamb's-quarters (Chenopodium album L.), redroot pigweed (Amaranthus retroflexus L.), and shepherd's-purse (Capsella bursa-pastoris L.) to this radiation, seedlings were grown under 0, 7, and 11 kJ m-2 d-1 of biologically effective UV-B radiation in a greenhouse for 6 wk. The influence of UV-B radiation on seedling growth and morphology was investigated. UV-B radiation reduced shoot height in green foxtail (by up to 41%), lamb's-quarters, and redroot pigweed, and increased tillering in green foxtail seedlings. Leaf area and leaf biomass in common chickweed, green foxtail, lamb's-quarters, and shepherd's-purse, and stalk biomass in common chickweed, green foxtail, lamb's-quarters, redroot pigweed and shepherd's-purse declined in response to UV-B radiation. In common chickweed, leaf area was reduced by 74% at 11 kJ m-2 d-1. Root biomass was reduced by UV-B radiation in all species (up to 68% at 11 kJ m-2 d-1 in common chickweed) except lady's-thumb. Specific leaf weight increased and leaf area ratio declined in response to UV-B radiation in common chickweed and shepherd's-purse. Exposure to UV-B radiation increased the leaf weight ratio in common chickweed. Shoot:root ratios increased in response to UV-B radiation in common chickweed and redroot pigweed. Scanning electron microscopy revealed collapsed epidermal cells in occasional necrotic regions on adaxial leaf surfaces of redroot pigweed grown under 11 kJ m-2 d-1 UV-B radiation. Morphology and growth of lady's-thumb were not affected by UV-B radiation. This study suggests that common agricultural weeds have differential morphological and growth responses to UV-B-enhanced environments. Sensitivity to UV-B radiation was greatest for common chickweed and least for lady's-thumb and redroot pigweed. Key words: ultraviolet-B, Amaranthus retroflexus, Capsella bursa-pastoris, Chenopodium album, Polygonum persicaria, Setaria viridis, Stellaria media

Control of Three Weed Species in Sugarbeets (Beta vulgaris) with an Electrical Discharge System

Weed Science ◽  
1981 ◽  
Vol 29 (1) ◽  
pp. 93-98 ◽  
Author(s):  
R. G. Wilson ◽  
F. N. Anderson
Keyword(s):  
Beta Vulgaris ◽  
Electrical Discharge ◽  
Chenopodium Album ◽  
Field Studies ◽  
Amaranthus Retroflexus ◽  
Weed Species ◽  
Kochia Scoparia ◽  
Discharge System ◽  
Common Lambsquarters ◽  
Redroot Pigweed

An electrical discharge system (EDS) was evaluated in field studies conducted in 1977 through 1979 in western Nebraska for its ability to control weed escapes in sugarbeets (Beta vulgarisL. ‘Mono Hy D2′). Nine weeks after sugarbeets were planted, kochia [Kochia scoparia(L.) Schrad.] had attained a height above sugarbeets sufficient for EDS treatment. Redroot pigweed (Amaranthus retroflexusL.) and common lambsquarters (Chenopodium albumL.) generally attained sufficient height above sugarbeets 11 and 13 weeks after sugarbeet planting. Sugarbeet root yields were reduced 40, 20, and 10% from competition by kochia, common lambsquarters, and redroot pigweed, respectively. Treatment of kochia, redroot pigweed, and common lambsquarters with EDS in some cases resulted in a reduction in weed height. The EDS treatments reduced the stand of all weeds 32, 39, and 47% for 1977, 1978, and 1979, respectively. Although the EDS treatments failed to kill many weeds, it did suppress the competitive ability of the three weeds to the extent that sugarbeet yields were higher in areas receiving EDS treatments than areas receiving no EDS treatment.

Weed Control in Sugarbeets (Beta vulgaris) by Mixtures of Cycloate and Ethofumesate

Weed Science ◽  
1979 ◽  
Vol 27 (5) ◽  
pp. 516-519 ◽  
Author(s):  
E. E. Schweizer
Keyword(s):  
Beta Vulgaris ◽  
Soil Texture ◽  
Chenopodium Album ◽  
Field Studies ◽  
Amaranthus Retroflexus ◽  
Setaria Viridis ◽  
Kochia Scoparia ◽  
Common Lambsquarters ◽  
Green Foxtail ◽  
Herbicide Mixtures

Response of weeds and sugarbeets (Beta vulgaris L. ‘Mono Hy D2′) to preplanting treatments of mixtures of cycloate (S-ethyl N-ethylthiocyclohexanecarbamate) and ethofumesate [(±)-2-ethoxy-2,3-dihydro-3,3-dimethyl-5-benzofuranyl methanesulfonate] was evaluated in five field studies. A mixture containing 1.7 kg/ha of each herbicide reduced the stand of common lambsquarters (Chenopodium album L.) 90%, green foxtail [Setaria viridis (L.) Beauv.] and yellow foxtail [Setaria lutescens (Weigel) Hubb.] 97 to 99%, kochia [Kochia scoparia (L.) Schrad.] 64 to 77%, and redroot pigweed (Amaranthus retroflexus L.) 82 to 99%. The response of weeds to preplanting applications of mixtures of cycloate and ethofumesate was independent of soil texture, whereas response of sugarbeets was dependent on soil texture. The herbicide mixtures significantly reduced the pre-thinning stand of sugarbeets and root and sucrose yields on two sandy loams, but not on a clay loam.

Response of Sugarbeets (Beta vulgaris) and Four Weed Species to Dinitramine

Weed Science ◽  
1979 ◽  
Vol 27 (1) ◽  
pp. 28-31 ◽  
Author(s):  
E. E. Schweizer
Keyword(s):  
Beta Vulgaris ◽  
Amaranthus Retroflexus ◽  
Solanum Nigrum ◽  
Setaria Viridis ◽  
Weed Species ◽  
Time Of Application ◽  
Black Nightshade ◽  
Green Foxtail ◽  
Setaria Glauca ◽  
Better Than

Dinitramine (N4,N4-diethyl-α,α,α-trifluoro-3,5-dinitrotoluene-2,4-diamine) applied at 0.37 kg/ha controlled black nightshade (Solanum nigrumL.) better than did trifluralin (α,α,α-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine) at 0.56 kg/ha. Dinitramine applied at 0.37 kg/ha was equal to 0.56 kg/ha of trifluralin for control of green foxtail [Setaria viridis(L.) Beauv.], yellow foxtail [Setaria glauca(L.) Beauv.], and redroot pigweed (Amaranthus retroflexusL.). Dinitramine produced more root aberrations in sugarbeets (Beta vulgarisL. ‘Mono Hy D2′) than did trifluralin when sprayed on nonexposed or exposed hypotcotyledonary tissues of seedlings. When soil surrounded most of the hypocotyls at the time of application, 0.56 kg/ha of dinitramine affected 57 to 87% of the roots, whereas the same rate of trifluralin affected 1 to 8% of the roots. When the hypocotyls were exposed at the time of application, 100% of the roots were affected by dinitramine compared to 25% of all roots treated with trifluralin. Dinitramine applied at 0.37, 0.42, and 0.56 kg/ha lowered the quality and yield of sugarbeet roots, with the highest rate significantly reducing percentage purity, percentage sucrose, and recoverable sucrose. Trifluralin did not affect these parameters.

scholarly journals Optimization of foramsulfuron doses for post-emergence weed control in maize (Zea mays L.)

2016 ◽  
Vol 14 (3) ◽  
pp. e1005 ◽  
Author(s):  
Euro Pannacci
Keyword(s):  
Weed Control ◽  
Growth Stage ◽  
Amaranthus Retroflexus ◽  
Recommended Dose ◽  
Weed Species ◽  
Common Lambsquarters ◽  
Black Nightshade ◽  
Redroot Pigweed ◽  
Wild Mustard ◽  
Green Foxtail

Four field experiments were carried out from 2011 to 2014 in order to evaluate the effects of foramsulfuron, applied at the recommended (60.8 g a.i./ha) and reduced doses (1/3 and 2/3), on the efficacy against several of the most important weeds in maize. For each “year-weed” combination, dose-response curves were applied to estimate the dose of foramsulfuron required to obtain 90% and 95% weed control (ED90 and ED95). Foramsulfuron phytotoxicity on maize and crop yield were assessed. Foramsulfuron at 1/3 of the recommended dose (20.3 g a.i./ha) provided 95% efficacy against redroot pigweed (Amaranthus retroflexus L.), green foxtail (Setaria viridis (L.) Beauv.), wild mustard (Sinapis arvensis L.) and black nightshade (Solanum nigrum L.). Velvetleaf (Abutilon theophrasti Medik.), common lambsquarters (Chenopodium album L.) and barnyardgrass (Echinochloa crus-galli (L.) Beauv.) were satisfactorily controlled (95% weed efficacy) with ED95 ranged from 20 to 50 g/ha of foramsulfuron (about from 1/3 to 5/6 of the recommended dose) depending on growth stage. The recommended dose was effective against pale smartweed (Polygonum lapathifolium L.) at 2-4 true leaves (12-14 BBCH scale), but this dose did not kill plants larger than 2-4 true leaves. The ranking among weed species based on their susceptibility to foramsulfuron was: redroot pigweed = green foxtail = wild mustard = black nightshade > velvetleaf = common lambsquarters = barnyardgrass > pale smartweed. Dose of foramsulfuron can be reduced below recommended dose depending on weed species and growth stage. Foramsulfuron showed a good crop selectivity and had no negative effect on maize yield.

scholarly journals Potential new tool for weed control in organically grown agronomic crops

2007 ◽  
Vol 52 (2) ◽  
pp. 95-104 ◽  
Author(s):  
Stevan Knezevic ◽  
Santiago Ulloa
Keyword(s):  
Field Experiments ◽  
Logistic Models ◽  
Amaranthus Retroflexus ◽  
Sorghum Halepense ◽  
Setaria Viridis ◽  
Agronomic Crops ◽  
Green Foxtail ◽  
Baseline Information ◽  
Weed Tolerance ◽  
Organically Grown

Field experiments were conducted during summer 2007 to determine a baseline information on crop and weed tolerance to broadcast flaming utilizing different rates of propane. The species evaluated were: maize (Zea mays), sorghum (Sorghum halepense), soybean (Glycine max), sunflower (Helianthus annuus), barnyardgrass (Echinocloa crus-galli), green foxtail (Setaria viridis), velvetleaf (Abutilon theophrasti) and redroot pigweed (Amaranthus retroflexus). The propane rates applied were 0, 12.1, 30.9, 49.7, 68.5 and 87.22 kg/ha. The response of the plants to propane rates were described by log-logistic models. Plant response to flame varied depending on the species, growth stage and propane rate. Broadleaf weeds were more susceptible to flames than grasses. Field maize and sorghum were less susceptible, while soybean and sunflower were severely injured. Of all crops tested, broadcast flaming has the most potential for use in field maize.

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