Germination of Amaranthus retroflexus, Portulaca oleracea and other weed species under laboratory, greenhouse, and field conditions

Relatively pure stands of eight weed species were maintained under field conditions on a Goldsboro loamy sand at Lewiston, North Carolina, for all or part of a 6-year period. Herbicides evaluated as preemergence surface treatments for these species were 2-sec-butyl-4,6-dinitrophenol (dinoseb), isopropyl m-chlorocarbanilate (chloropropham), 3-(3,4-dichlorophenyl)-1,1-dimethyl-urea (diuron), 2-chloro-4,6-bis(ethylamino)-s-triazine (simazine), and 3-amino-2,5-dichlorobenzoic acid (amiben). S-ethyl dipropylthiocarbamate (EPTC) and a,a,a-trifluro-2,6-dinitro-N,N-dipropyl-p-toluidine (trifluralin) were evaluated as preemergence incorporated treatments. The first four herbicides were evaluated in 1961, 1964, and 1966 while the last three were evaluated in 1962, 1963, and 1965. A series of rates was used for each chemical with three replications. With the exception of diuron which failed to control goosegrass (Eleusine indica (L.) Gaertn.), all of the herbicides provided at least a moderate degree of control of goosegrass, smooth crabgrass (Digitaria ischaemum (Schreb.) Muhl.), and redroot pigweed (Amaranthus retroflexus L.) at the respective typical field use rates. In general, trifluralin and amiben gave the best grass control and dinoseb the poorest. None of the herbicides effectively controlled common cocklebur (Xanthium pensylvanicum Wallr.) or ivyleaf morningglory (Ipomoea hederacea (L.) Jacq.). Trifluralin and EPTC did not control Pennsylvania smartweed (Polygonum pensylvanicum L.), common ragweed (Ambrosia artemisiifolia L.), and common lambsquarters (Chenopodium album L.). Chloropropham was ineffective on common ragweed. Simazine, chloropropham, and amiben controlled Pennsylvania smartweed while diuron, simazine, dinoseb, and amiben were especially effective on common lambsquarters. Distinctive patterns of nematode infestations were observed as a function of weed species.

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The actual consumption of water by selected cultivated and weed species of plants and the actual values of evapotranspiration of the stands as determined under field conditions

Soil and Water Research ◽

10.17221/476-swr ◽

2010 ◽

Vol 4 (Special Issue 2) ◽

pp. S39-S48 ◽

Cited By ~ 2

Author(s):

J. Pivec ◽

V. Brant

Keyword(s):

Zea Mays ◽

Brassica Napus ◽

Hordeum Vulgare ◽

Beta Vulgaris ◽

Sap Flow ◽

Amaranthus Retroflexus ◽

Field Conditions ◽

Actual Evapotranspiration ◽

Weed Species ◽

Lactuca Serriola

In the years 2005 to 2008, the consumption of water by selected cultivated and weed species under the field conditions and the values of the actual evapotranspiration in selected stands of cultivated crops were evaluated. The values of the transpiration flow were measured with a T4.2 EMS Brno (CZ) 12 channel sap-flow meter, and the actual evapotranspiration by BREB method (Bowen Ratio-Energy Balance) using the equipment of the same firm. The recording of the values obtained during the measurements was carried out in 10-min intervals. The sap flow was measured on the following weed plants Amaranthus retroflexus, Artemisia vulgaris, Cirsium arvense, Conyza Canadensis, and Lactuca serriola as weeds in the cultivated crops of Brassica napus and Zea mays. The actual evapotranspiration using the BREB method was determined over the stands of Beta vulgaris, Brassica napus, Hordeum vulgare, Medicago sativa, and Zea mays. On the basis of the measurements carried out, the average daily values of the sap flow of the evaluated plants ranged from 0.016 to 0.193 kg/day of water per plant. The maximum daily values ranged from 0.025 to 0.309 kg/day of water per plant. The average daily value of the evapotranspiration flow in Hordeum vulgare during the period under observation amounted to 2.9 mm, while the daily values ranged from 1.2 to 4.6 mm H2O/day. In the other evaluated plants, the daily values of evapotranspiration ranged from 0.9 mm to 5.9 mm/day of water, on average 3.4 mm/day of water (Beta vulgaris), and from 1.7 mm to 5.2 mm/day of water, on average 3.2 mm/day of water (Brassica napus).

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Effect of Clay, Soil Organic Matter, and Soil pH on Initial and Residual Weed Control with Flumioxazin

Agronomy ◽

10.3390/agronomy11071326 ◽

2021 ◽

Vol 11 (7) ◽

pp. 1326

Author(s):

Calvin F. Glaspie ◽

Eric A. L. Jones ◽

Donald Penner ◽

John A. Pawlak ◽

Wesley J. Everman

Keyword(s):

Organic Matter ◽

Soil Organic Matter ◽

Weed Control ◽

Soil Ph ◽

Organic Matter Content ◽

Amaranthus Retroflexus ◽

Matter Content ◽

Weed Species ◽

Soil Organic Matter Content ◽

Field Soils

Greenhouse studies were conducted to evaluate the effects of soil organic matter content and soil pH on initial and residual weed control with flumioxazin by planting selected weed species in various lab-made and field soils. Initial control was determined by planting weed seeds into various lab-made and field soils treated with flumioxazin (71 g ha−1). Seeds of Echinochloa crus-galli (barnyard grass), Setaria faberi (giant foxtail), Amaranthus retroflexus (redroot pigweed), and Abutilon theophrasti (velvetleaf) were incorporated into the top 1.3 cm of each soil at a density of 100 seeds per pot, respectively. Emerged plants were counted and removed in both treated and non-treated pots two weeks after planting and each following week for six weeks. Flumioxazin control was evaluated by calculating percent emergence of weeds in treated soils compared to the emergence of weeds in non-treated soils. Clay content was not found to affect initial flumioxazin control of any tested weed species. Control of A. theophrasti, E. crus-galli, and S. faberi was reduced as soil organic matter content increased. The control of A. retroflexus was not affected by organic matter. Soil pH below 6 reduced flumioxazin control of A. theophrasti, and S. faberi but did not affect the control of A. retroflexus and E. crus-galli. Flumioxazin residual control was determined by planting selected weed species in various lab-made and field soils 0, 2, 4, 6, and 8 weeks after treatment. Eight weeks after treatment, flumioxazin gave 0% control of A. theophrasti and S. faberi in all soils tested. Control of A. retroflexus and Chenopodium album (common lambsquarters) was 100% for the duration of the experiment, except when soil organic matter content was greater than 3% or the soil pH 7. Eight weeks after treatment, 0% control was only observed for common A. retroflexus and C. album in organic soil (soil organic matter > 80%) or when soil pH was above 7. Control of A. theophrasti and S. faberi decreased as soil organic matter content and soil pH increased. Similar results were observed when comparing lab-made soils to field soils; however, differences in control were observed between lab-made organic matter soils and field organic matter soils. Results indicate that flumioxazin can provide control ranging from 75–100% for two to six weeks on common weed species.

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Evaluation of Imazethapyr for Weed Control in Leafy Vegetable Crops

Weed Technology ◽

10.1017/s0890037x00039907 ◽

1996 ◽

Vol 10 (2) ◽

pp. 253-257 ◽

Cited By ~ 4

Author(s):

Joan A. Dusky ◽

William M. Stall

Keyword(s):

Regression Analysis ◽

Weed Control ◽

Crop Yield ◽

Relative Sensitivity ◽

Leafy Vegetable ◽

Field Conditions ◽

Vegetable Crops ◽

Weed Species ◽

Common Lambsquarters ◽

Common Purslane

Imazethapyr was evaluated PRE and POST in five lettuce types and chicory under Florida field conditions. The relative sensitivity of leafy crop vigor (most sensitive to most tolerant) to imazethapyr PRE, based on 20% inhibition determined using regression analysis, was as follows: Boston > bibb > crisphead > romaine > leaf > escarole > endive. Leafy crop injury increased as the rate of imazethapyr applied POST increased, with all leafy crops responding in a similar manner. Surfactant addition increased imazethapyr phytotoxicity. Imazethapyr PRE treatments at 0.067 kg ai/ha provided greater than 80% control of livid amaranth, common purslane, flatsedge, and common lambsquarters. Imazethapyr POST at 0.067 kg/ha, with surfactant provided control greater than 85% of all weed species. Greater than 85% spiny amaranth control was provided by imazethapyr POST at 0.017 kg/ha. Use of surfactant with imazethapyr did not improve spiny amaranth control over imazethapyr with no surfactant. POST treatments did not decrease leafy crop yield compared with the hand-weeded check. Imazethapyr applied PRE reduced crop yield compared to the POST treatments and the hand-weeded control.

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Weed Interference Affects Dry Bean Yield and Growth

Notulae Scientia Biologicae ◽

10.15835/nsb437810 ◽

2012 ◽

Vol 4 (3) ◽

pp. 70-75 ◽

Cited By ~ 1

Author(s):

Hossein GHAMARI ◽

Goudarz AHMADVAND

Keyword(s):

Chenopodium Album ◽

Growing Season ◽

Amaranthus Retroflexus ◽

Growth And Yield ◽

Weed Competition ◽

Weed Species ◽

Dry Bean ◽

Logistic Equations ◽

Weed Interference ◽

Minimum Number

Dry bean is one of the most important pulse crops in Iran. Field study was conducted in 2011 to evaluate effects of weed competition from a natural flora on growth and yield of dry bean (Phaseolus vulgaris L.). The treatments consisted of weed infestation and weed removal periods (10, 20, 30, 40 and 50 days) after crop emergence. Control plots kept weed-infested and weed-free throughout growing season. To assess the weed competition effect on crop characteristics, Richards, Gompertz and logistic equations were fitted to the data. The most abundant weed species were Chenopodium album and Amaranthus retroflexus. Increase in duration of weed interference decreased the stem height of dry bean. At the end of the growing season, dry bean was 20 cm taller in season-long weed-free treatment compared to the season-long weed-infested treatment. As the number of days of weed interference increased, a declining trend of LAI and number of pods was observed. The minimum number of pods was obtained in season-long weed-infested treatment (5.01 pods/plant). Weed interference during the whole growing season, caused a 60% reduction in yield. Considering 5% and 10% acceptable yield lost, the critical period of weed competition was determined from 20 to 68 and 23 to 55 days after planting (DAE), respectively.

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Assessment of weed establishment risk in a changing European climate

Agricultural and Food Science ◽

10.23986/afsci.6321 ◽

2012 ◽

Vol 21 (4) ◽

pp. 348-360 ◽

Cited By ~ 12

Author(s):

Terho Hyvönen ◽

Miska Luoto ◽

Pertti Uotila

Keyword(s):

Explanatory Power ◽

Climate Scenario ◽

Amaranthus Retroflexus ◽

Range Size ◽

Weed Species ◽

European Climate ◽

Arable Weed ◽

Temperate Europe ◽

The Alps ◽

Moderate Climate

We aimed at assessing establishment risk for 25 arable weed species in a changing European climate for the period 2051–2080. An increase (0.3–46.7%) in the range size was projected for the 14 species and a decrease (1.2–67.4%) for the 11 species in a future climate. The inclusion of the land use data increased the explanatory power of the models. The greatest increases in range sizes were projected for Amaranthus retroflexus, Papaver hybridum and Fumaria parviflora, and declines for Sinapis arvensis, Cerastium semidecandrum and Chenopodium rubrum. Application of a more severe climate scenario (HadCM3A2) affected decline (0.5–18.5%) for 12 species and increase (2.2–31.5%) for 13 species in the range size projections compared with the less severe (HadCM3B2) scenario. Both model scenarios projected high percentage species loss in Mediterranean and temperate Europe, but high species gain in the Alps, Carpathians and in boreal Europe. The results suggest that even under moderate climate scenarios drastic changes in the weed establishment risk can be expected to take place in Europe in the future.

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Comparison of weed communities in Manitoba ecoregions and crops

Canadian Journal of Plant Science ◽

10.4141/p99-175 ◽

2000 ◽

Vol 80 (4) ◽

pp. 963-972 ◽

Cited By ~ 17

Author(s):

R. C. Van Acker ◽

A. G. Thomas ◽

J. Y. Leeson ◽

S. Z. Knezevic ◽

B. L. Frick

Keyword(s):

Weed Management ◽

Amaranthus Retroflexus ◽

Weed Species ◽

Canada Thistle ◽

Wild Mustard ◽

Polygonum Convolvulus ◽

Weed Communities ◽

Green Foxtail ◽

Poaceae Family ◽

Weed Survey

In 1997, a weed survey was conducted during July and August in fields of wheat, barley, oat, canola and flax in Manitoba. Field selection was based on a stratified-random sampling methodology using ecodistricts as strata. Species in the Poaceae family were most commonly observed in the survey, followed by species in the Polygonaceae, Asteraceae and Brassicaceae families. The six most abundant weed species were green foxtail [Setaria viridis (L.) Beauv.], wild oats (Avena fatua L.), wild buckwheat (Polygonum convolvulus L.), Canada thistle (Cirsium arvense L.), redroot pigweed (Amaranthus retroflexus L.) and wild mustard (Sinapis arvensis L.). The survey highlighted significant differences between ecoregions and between crops in residual weed infestations. The weed community in the Boreal Transition ecoregion was dominated by seven species, whereas fields in the Aspen Parkland and Lake Manitoba Plain ecoregions were dominated by two species and the Interlake Plain ecoregion was dominated by only one species. Although significant differences were found between the weed communities in crops, they were not as great as differences between ecoregions. The Manitoba residual weed community in 1997 was very similar to that reported for 1978–1981 and 1986, suggesting that the same species should remain a focus for weed management. Key words: Weed survey, weed relative abundance, weed distributions, Manitoba ecoregions

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Response of Weeds to Soil pH

Weed Science ◽

10.1017/s004317450006505x ◽

1975 ◽

Vol 23 (6) ◽

pp. 473-477 ◽

Cited By ~ 29

Author(s):

G. A. Buchanan ◽

C. S. Hoveland ◽

M. C. Harris

Keyword(s):

Soil Ph ◽

Sandy Loam ◽

Plantago Lanceolata ◽

Warm Season ◽

Amaranthus Retroflexus ◽

Low Ph ◽

Sandy Loam Soil ◽

Weed Species ◽

Stellaria Media ◽

Loam Soil

Ten warm-season and six cool-season weed species were grown in the glasshouse on Hartsells fine sandy loam soil and Lucedale sandy loam soil at pH levels from 4.7 to 6.3. Growth of species varied widely in response to soil pH as measured by herbage yield. Showy crotalaria (Crotalaria spectabilis Roth), coffee senna (Cassia occidentalis L.), and large crabgrass (Digitaria sanguinalis (L.) Scop.] were highly tolerant to low pH soils. Sicklepod (Cassia obtusifolia L.), annual bluegrass (Poa annua L.), Carolina geranium (Geranium carolinianum L.), and buckhorn plantain (Plantago lanceolata L.), were medium to high in tolerance. Jimsonweed (Datura stramonium L.), tall morningglory [Ipomoea purpurea (L.) Roth], crowfootgrass [Dactyloctenium aegyptium (L.) Richter], and prickly sida (Sida spinosa L.) were medium to low in tolerance to low soil pH. Growth of Florida beggarweed [Desmodium tortuosum (Sw.) DC], redroot pigweed (Amaranthus retroflexus L.), chickweed [Stellaria media (L.) Cyrillo], common dandelion (Taraxacum officinale (Weber), and wild mustard [Brassica kaber (DC.) L.C. Wheeler var. pinnatifida (Stokes) L.C. Wheeler] was severely reduced in soils with low pH.

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Response of Weed Seeds to Ethylene and Related Hydrocarbons

Weed Science ◽

10.1017/s004317450004337x ◽

1979 ◽

Vol 27 (1) ◽

pp. 7-10 ◽

Cited By ~ 49

Author(s):

R. B. Taylorson

Keyword(s):

Chenopodium Album ◽

Active Form ◽

Amaranthus Retroflexus ◽

Weed Species ◽

Hydrocarbon Gases ◽

Common Lambsquarters ◽

Setaria Faberi ◽

Redroot Pigweed ◽

Giant Foxtail ◽

Common Purslane

AbstractGermination of seeds of 10 grass and 33 broadleaved weed species was examined for response to ethylene. Germination was promoted in nine species, inhibited in two, and not affected in the remainder. Of the species promoted, common purslane (Portulaca oleraceaL.), common lambsquarters (Chenopodium albumL.), and several Amaranths, including redroot pigweed (Amaranthus retroflexusL.), were affected most. Transformation of phytochrome to the active form (Pfr) gave interactions that ranged from none to syntergistic with the applied ethylene. In subsequent tests seeds of purslane, redroot pigweed, and giant foxtail (Setaria faberiHerrm.), a species not responsive to ethylene, were examined for germination response to 14 low molecular weight hydrocarbon gases other than ethylene. Some stimulation by the olefins propylene and propadiene was found for purslane and pigweed. Propionaldehyde and butyraldehyde were slightly stimulatory to purslane only.

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Rhythmic Leaf Movements of Some Common Weeds

Weed Science ◽

10.1017/s0043174500044295 ◽

1979 ◽

Vol 27 (4) ◽

pp. 401-415 ◽

Cited By ~ 12

Author(s):

Robert N. Andersen ◽

Willard L. Koukkari

Keyword(s):

Chenopodium Album ◽

Continuous Light ◽

Datura Stramonium ◽

Amaranthus Retroflexus ◽

Rhythmic Pattern ◽

Weed Species ◽

Rhythmic Movements ◽

Wild Mustard ◽

Dark Regime ◽

Leaf Movements

In growth chamber studies, we measured the movement of cotyledons and leaves or leaflets in seedlings of nine weed species to determine: the magnitude of movement, whether movements followed a rhythmic pattern, and if rhythmic movements were endogenously controlled. Seedlings were always entrained under a 15-h light:9-h dark regime. Measurements were made at 3-h intervals for 3 to 4 days under four light regimes: alternating 15-h light:9-h dark; continuous light; one 15-h light:9-h dark span, followed by continuous light; and a 15-h light:9-h dark regime, in which the dark span was advanced 9 h (phase shift) when measurements were begun. No clearly defined pattern of leaf movement was found in wild mustard [Brassica kaber(DC.) L. C. Wheeler var.pinnatifida(Stokes) L. C. Wheeler]. Daily rhythmic leaf movements that did not appear to be endogenously controlled were found in redroot pigweed (Amaranthus retroflexusL.) and black nightshade (Solanum nigrumL.). Circadian rhythmic leaf movements that appeared to be under endogenous control were found in jimson-weed (Datura stramoniumL.), common lambsquarters (Chenopodium albumL.), common cocklebur (Xanthium pensylvanicumWallr.), prickly sida (Sida spinosaL.), sicklepod (Cassia obtusifoliaL.), and coffee senna (Cassia occidentalisL.).

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