Longevity of seeds of four annual grass and two dicotyledon weed species as related to placement in the soil and straw disposal technique

Rottboellia cochinchinensis is an annual grass weed species known as itchgrass, or "caminadora" in America´s Spanish speaking countries, and has become a major and troublesome weed in several crops. The application of fluazifop-P-butyl at recommended rates (125 g a.i. ha-1) was observed to be failing to control itchgrass in a field in San José, Upala county, Alajuela province, Costa Rica. Plants from the putative resistant R. cochinchinensis population survived fluazifop-P-butyl when treated with 250 g a.i. ha-1 (2X label rate) at the three- to four-leaf stage under greenhouse conditions. PCR amplification and sequencing of partial carboxyl transferase domain (CT) of the acetyl-CoA carboxylase (ACCase) gene were used to determine the molecular mechanism of resistance. A single non-synonymous point mutation from TGG (susceptible plants) to TGC (putative resistant plants) that leads to a Trp-2027-Cys substitution was found. This Trp-2027-Cys mutation is known to confer resistance to all aryloxyphenoxyproprionate (APP) herbicides to which fluazifop-P-butyl belongs. To the best of our knowledge, this is the first report of fluazifop-P-butyl resistance and a mutation at position 2027 for a Costa Rican R. cochinchinensis population.

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Seed shattering phenology at soybean harvest of economically important weeds in multiple regions of the United States. Part 2: grass species

Weed Science ◽

10.1017/wsc.2020.79 ◽

2020 ◽

pp. 1-19

Author(s):

Lauren M. Schwartz-Lazaro ◽

Lovreet S. Shergill ◽

Jeffery A. Evans ◽

Muthukumar V. Bagavathiannan ◽

Shawn C. Beam ◽

...

Keyword(s):

The United States ◽

Grass Species ◽

Annual Grass ◽

Weed Seed ◽

Weed Species ◽

Seed Shattering ◽

Physiological Maturity ◽

Rate Of Progression ◽

Multiple Regions ◽

Grass Weed

Abstract Seed shatter is an important weediness trait on which the efficacy of harvest weed seed control (HWSC) depends. The level of seed shatter in a species is likely influenced by agroecological and environmental factors. In 2016 and 2017, we assessed seed shatter of eight economically important grass weed species in soybean [Glycine max (L.) Merr.] from crop physiological maturity to four weeks after maturity at multiple sites spread across eleven states in the southern, northern, and mid-Atlantic U.S. From soybean maturity to four weeks after maturity, cumulative percent seed shatter was lowest in the southern U.S. regions and increased as the states moved further north. At soybean maturity, the percent of seed shatter ranged from 1 to 70%. That range had shifted to 5 to 100% (mean: 42%) by 25 days after soybean maturity. There were considerable differences in seed shatter onset and rate of progression between sites and years in some species that could impact their susceptibility to HWSC. Our results suggest that many summer annual grass species are likely not ideal candidates for HWSC, although HWSC could substantially reduce their seed output at during certain years.

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Tolpyralate Efficacy: Part 2. Comparison of Three Group 27 Herbicides Applied POST for Annual Grass and Broadleaf Weed Control in Corn

Weed Technology ◽

10.1017/wet.2018.81 ◽

2018 ◽

Vol 32 (6) ◽

pp. 707-713 ◽

Cited By ~ 4

Author(s):

Brendan A. Metzger ◽

Nader Soltani ◽

Alan J. Raeder ◽

David C. Hooker ◽

Darren E. Robinson ◽

...

Keyword(s):

Effective Dose ◽

Weed Control ◽

Biologically Effective Dose ◽

Annual Grass ◽

Weed Species ◽

Common Ragweed ◽

Common Lambsquarters ◽

Wild Mustard ◽

Percentage Points ◽

Green Foxtail

AbstractTolpyralate is a new Group 27 pyrazolone herbicide that inhibits the 4-hydroxyphenyl-pyruvate dioxygenase enzyme. In a study of the biologically effective dose of tolpyralate from 2015 to 2017 in Ontario, Canada, tolpyralate exhibited efficacy on a broader range of species when co-applied with atrazine; however, there is limited published information on the efficacy of tolpyralate and tolpyralate+atrazine relative to mesotrione and topramezone, applied POST with atrazine at label rates, for control of annual grass and broadleaf weeds. In this study, tolpyralate applied alone at 30 g ai ha−1 provided >90% control of common lambsquarters, velvetleaf, common ragweed, Powell amaranth/redroot pigweed, and green foxtail at 8 weeks after application (WAA). Addition of atrazine was required to achieve >90% control of wild mustard, ladysthumb, and barnyardgrass at 8 WAA. Tolpyralate+atrazine (30+1,000 g ai ha−1) and topramezone+atrazine (12.5+500 g ai ha−1) provided similar control at 8 WAA of the eight weed species in this study; however, tolpyralate+atrazine provided >90% control of green foxtail by 1 WAA. Tolpyralate+atrazine provided 18, 68, and 67 percentage points better control of common ragweed, green foxtail, and barnyardgrass, respectively, than mesotrione+atrazine (100+280 g ai ha−1) at 8 WAA. Overall, tolpyralate+atrazine applied POST provided equivalent or improved control of annual grass and broadleaf weeds compared with mesotrione+atrazine and topramezone+atrazine.

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Utility of Clomazone for Annual Grass and Broadleaf Weed Control in Peanut (Arachis hypogaea)

Weed Technology ◽

10.1017/s0890037x00039142 ◽

1994 ◽

Vol 8 (1) ◽

pp. 23-27 ◽

Cited By ~ 3

Author(s):

David L. Jordan ◽

John W. Wilcut ◽

Leslie D. Fortner

Keyword(s):

Weed Control ◽

Arachis Hypogaea ◽

Field Experiments ◽

Systems Approach ◽

Annual Grass ◽

Weed Species ◽

Common Ragweed ◽

Prickly Sida ◽

Better Than ◽

Large Crabgrass

Field experiments conducted in 1988 and 1989 evaluated clomazone alone and in a systems approach for weed control in peanut. Clomazone PPI at 0.8 kg ai/ha controlled common ragweed, prickly sida, spurred anoda, and tropic croton better than ethalfluralin and/or metolachlor applied PPI. POST application of acifluorfen plus bentazon was not needed to control these weeds when clomazone was used. Acifluorfen plus bentazon improved control of these weeds when clomazone was not used and generally were necessary to obtain peanut yields regardless of the soil-applied herbicides. Alachlor PRE did not improve clomazone control of any weed species evaluated. Fall panicum and large crabgrass control was similar with clomazone or clomazone plus ethalfluralin.

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Effects of Giant Foxtail (Setaria faberi) and Yellow Foxtail (Setaria pumila) Competition on Establishment and Productivity of Switchgrass

Weed Science ◽

10.1614/ws-d-14-00160.1 ◽

2016 ◽

Vol 64 (1) ◽

pp. 129-136 ◽

Cited By ~ 2

Author(s):

Ariel A. D. Larson ◽

Mark J. Renz ◽

David E. Stoltenberg

Keyword(s):

Competitive Ability ◽

Yield Loss ◽

Annual Grass ◽

Weed Species ◽

Setaria Faberi ◽

Giant Foxtail ◽

Plant Densities ◽

Second Year ◽

Cellulosic Bioenergy ◽

The Relationship

Switchgrass is a potential feedstock for cellulosic bioenergy production. Weed competition from annual grass during the establishment year can reduce switchgrass establishment and resulting productivity, but the relationship between early season grass densities and outcomes of competition are not well understood. We measured how a range of giant and yellow foxtail densities in the establishment year influenced switchgrass establishment and resulting productivity in the first production year (second year of the growing season). In two of the three site–yr more than four foxtail plants m−2reduced switchgrass plant densities below documented thresholds of establishment success. A lesser effect of foxtails in the third site–year suggested that higher switchgrass emergence rates reduced foxtail competitive ability during establishment. Effects on yield were consistent over the three site–yr. The yield (10.96 Mg ha−1± 0.77) decreased rapidly as foxtail density increased. One foxtail plant m−2reduced switchgrass yield in the first production year by 25%, and yield loss was 90% or greater at densities > 50 foxtail plants m−2. Although switchgrass can establish in the presence of foxtail competition, these weed species should be controlled to maximize yields in the first production year.

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The Influence of Nozzle Type on Peanut Weed Control Programs

Peanut Science ◽

10.3146/ps17-4.1 ◽

2017 ◽

Vol 44 (2) ◽

pp. 93-99 ◽

Cited By ~ 1

Author(s):

O.W. Carter ◽

E.P. Prostko ◽

J.W. Davis

Keyword(s):

Weed Control ◽

Palmer Amaranth ◽

Annual Grass ◽

Weed Species ◽

Target Movement ◽

Herbicide Resistant ◽

Control Programs ◽

The Past ◽

Auxin Herbicides ◽

Nozzle Type

ABSTRACT The increase in herbicide-resistant weeds over the past decade has led to the introduction of crops that are resistant to auxin herbicides. Strict application procedures are required for the use of auxin herbicides in auxin-resistant crops to minimize off-target movement. One requirement for application is the use of nozzles that will minimize drift by producing coarse droplets. Generally, an increase in droplet size can lead to a reduction in coverage and efficacy depending upon the herbicide and weed species. In studies conducted in 2015 and 2016, two of the potential required auxin nozzle types [(AIXR11002 (coarse) and TTI11002 (ultra-coarse)] were compared to a conventional flat-fan drift guard nozzles [DG11002 (medium)] for weed control in peanut herbicide systems. Nozzle type did not influence annual grass or Palmer amaranth control in non-crop tests. Results from in-crop tests indicated that annual grass control was 5% to 6% lower when herbicides were applied with the TTI nozzle when compared to the AIXR or DG nozzles. However, Palmer amaranth control and peanut yield was not influenced by coarse-droplet nozzles. Peanut growers using the coarse-droplet nozzles need to be aware of potential reduced grass control.

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Occurrence of woolly cupgrass (Eriochloa villosa /Thunb./ Kunth) in Hajdú-Bihar county, Hungary

Acta Agraria Debreceniensis ◽

10.34101/actaagrar/43/2650 ◽

2011 ◽

pp. 119-123

Author(s):

Noémi Somogyi ◽

László Szabó ◽

István Dávid

Keyword(s):

Weed Management ◽

Plant Protection ◽

Deep Layer ◽

Ground Cover ◽

Annual Grass ◽

Weed Species ◽

Maize Field ◽

Woolly Cupgrass ◽

Infected Area ◽

Eriochloa Villosa

Woolly cupgrass (Eriochloa villosa /Thunb./ Kunth) is native to East Asia, it spreads in several parts of the World and causes difficulties in plant protection, especially in maize. Difficulties in control of Eriochloa villosa originated from several reasons: seeds continue to germinate later in the season, significant part of seeds emerges from a deep layer of the soil, and the species is less susceptible to some herbicides applied to maize than other annual grass weeds.The first report on the occurrence of woolly cupgrass in Hungary was published in 2008, and it reported about the appearance of this species near to Gesztely village (Borsod-Abaúj-Zemplén county), however, no information has been added about spread of the weed in Hungary until now.A significant population was discovered next to Debrecen (Hajdú-Bihar county) in summer, 2011, and then weed associations were examined in maize, sunflower and stubble-fields on several km2 in the area to estimate the Eriochloa villosa infection. The weed species was found on every maize field bordering with a ground cover of 0.5-4%. Woolly cupgrass occurred inside of the 50% of maize fields, and reached a ground cover of 76% in case of most infected area, in addition it was found in sunflower and stubble-fields.The spread of woolly cupgrass is expected in this area, which requires the consideration of this species in the planning of weed management technologies.

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Seed retention of winter annual grass weeds at winter wheat harvest maturity shows potential for harvest weed seed control

Weed Technology ◽

10.1017/wet.2019.108 ◽

2019 ◽

Vol 34 (2) ◽

pp. 266-271 ◽

Cited By ~ 5

Author(s):

Neeta Soni ◽

Scott J. Nissen ◽

Philip Westra ◽

Jason K. Norsworthy ◽

Michael J. Walsh ◽

...

Keyword(s):

Winter Wheat ◽

Great Plains ◽

Downy Brome ◽

Annual Grass ◽

Weed Seed ◽

Weed Species ◽

Jointed Goatgrass ◽

Seed Retention ◽

Winter Annual ◽

Feral Rye

AbstractDowny brome, feral rye, and jointed goatgrass are problematic winter annual grasses in central Great Plains winter wheat production. Integrated control strategies are needed to manage winter annual grasses and reduce selection pressure exerted on these weed populations by the limited herbicide options currently available. Harvest weed-seed control (HWSC) methods aim to remove or destroy weed seeds, thereby reducing seed-bank enrichment at crop harvest. An added advantage is the potential to reduce herbicide-resistant weed seeds that are more likely to be present at harvest, thereby providing a nonchemical resistance-management strategy. Our objective was to assess the potential for HWSC of winter annual grass weeds in winter wheat by measuring seed retention at harvest and destruction percentage in an impact mill. During 2015 and 2016, 40 wheat fields in eastern Colorado were sampled. Seed retention was quantified and compared per weed species by counting seed retained above the harvested fraction of the wheat upper canopy (15 cm and above), seed retained below 15 cm, and shattered seed on the soil surface at wheat harvest. A stand-mounted impact mill device was used to determine the percent seed destruction of grass weed species in processed wheat chaff. Averaged across both years, seed retention (±SE) was 75% ± 2.9%, 90% ± 1.7%, and 76% ± 4.3% for downy brome, feral rye, and jointed goatgrass, respectively. Seed retention was most variable for downy brome, because 59% of the samples had at least 75% seed retention, whereas the proportions for feral rye and jointed goatgrass samples with at least 75% seed retention were 93% and 70%, respectively. Weed seed destruction percentages were at least 98% for all three species. These results suggest HWSC could be implemented as an integrated strategy for winter annual grass management in central Great Plains winter wheat cropping systems.

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Seed Longevity of 41 Weed Species Buried 17 Years in Eastern and Western Nebraska

Weed Science ◽

10.1017/s0043174500093589 ◽

1996 ◽

Vol 44 (1) ◽

pp. 74-86 ◽

Cited By ~ 123

Author(s):

Orvin C. Burnside ◽

Robert G. Wilson ◽

Sanford Weisberg ◽

Kenneth G. Hubbard

Keyword(s):

Great Plains ◽

Weed Management ◽

The United States ◽

Decay Rates ◽

Management Systems ◽

Annual Grass ◽

Weed Species ◽

Seed Germinability ◽

Soil Temperatures ◽

Broadleaf Species

Seed of 41 economically important weed species of the Great Plains region of the United States were buried 20 cm deep in soil in eastern and western Nebraska in 1976. The 41 species consisted of 11 annual grass, 14 annual broadleaf, 4 biennial broadleaf, and 12 perennial broadleaf species. Weed seeds were exhumed annually for germination tests the first 9 yr, then after 12 and 17 yr. Germination percentages at the two burial locations averaged over 0, 1 to 4, 5 to 8, and 9 to 17 yr of burial were 57, 28, 9, and 4% for annual grass; 47, 26, 16, and 11 % for annual broadleaf; 52, 49, 44, and 30 % for biennial broadleaf; 36, 18, 13, and 8% for perennial broadleaf; and 47, 26, 16, and 10% for all 41 weed species, respectively. Biennial broadleaf weeds showed the greatest seed germination over years. Annual grass weeds showed less seed germinability over 17 yr of burial than annual broadleaf weeds and perennial broadleaf weed species were intermediate. Weed seed germinability in soil was greater in the reduced rainfall and more moderate soil temperatures of western Nebraska than in the greater rainfall and more fluctuating soil temperatures of eastern Nebraska. The greatest seed survival among the 41 weed species was shown by common mullein, which had 95% germination after 17 yr of burial in western Nebraska. Decay rates of individual weed species in soil will be of most value to weed scientists, agriculturalists, and modelers evaluating past or designing future weed management systems.

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Ethnobotanical Profile of Weed Flora of District Charsadda, Khyber Pakhtunkhwa

RADS Journal of Biological Research & Applied Sciences ◽

10.37962/jbas.v9i1.117 ◽

2018 ◽

Vol 9 (1) ◽

pp. 14-23

Author(s):

Muhammad Nauman Khan ◽

Abdul Razzaq ◽

Fazal Hadi ◽

Naushad Khan ◽

Abdul Basit ◽

...

Keyword(s):

Perennial Herb ◽

Plant Biodiversity ◽

Annual Grass ◽

Weed Species ◽

Parasitic Weed ◽

Khyber Pakhtunkhwa ◽

Weed Flora ◽

Annual Herb ◽

Ethnobotanical Uses ◽

Important Center

District Charsadda is a very important center of plant biodiversity in the central plain of Peshawar valley, Pakistan. The present study was carried out during March 2015 to April 2016 to investigate the ethnobotanical profile of common weed flora present in district Charsadda, KP, Pakistan. The study revealed that there were 40 weed species belonging to 21 families. Among them 25 weeds were annual herb, 9 weeds were perennial herb, three were annual grass, one was climbing herb, one was the parasitic weed, and one was rhizomatic grass. The dominant families were Asteraceae, Fabaceae and poaceae having 5 species (12.5%) each followed by Ranunculaceae 3 species (7.5%). plants were systematically arranged into botanical names, local names, families, habit, habitat, partly used, flowering periods, locality and ethnobotanical uses. The main aim of the study is the documentation and ethnobotanical information of the weed flora growing in the area.

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