Dissipation and Water Activation of UCC-C4243

Field experiments were conducted in 1992 and 1993 to determine the timing and amount of rainfall required to activate UCC-C4243 applied preemergence. UCC-C4243 at 0, 70, and 140 g ai ha−1was applied 1, 7, 14, and 21 d before 0.5 or 2 cm of simulated rainfall. Temporary rainshelters protected field plots from natural rainfall during the 21 d dry period. Herbicide activity was determined in the field by seeding lentil, wheat, common lambsquarters, and field pennycress and in the greenhouse by a sugarbeet bioassay of soil samples (0 to 3 cm depth) taken from all plots immediately before irrigation. UCC-C4243 did not injure wheat; however, lentil population was reduced when simulated rainfall occurred within 7 d after application. Lentil injury was greater with higher herbicide rate and higher water level. UCC-C4243 at 70 and 140 g ha−1reduced populations of both weed species by 75 and 90%, respectively, when either 0.5 or 2 cm simulated rainfall was received within 1 d after herbicide application. Weed control was reduced with a 21 d delay between herbicide application and water activation. The sugarbeet bioassay showed a linear decrease of herbicide activity over time and also with accumulated photosynthetically active radiation. After 17.9 d, herbicide activity on a dry soil surface decreased 50%. Laboratory investigations show that [14C]-UCC-C4243 on glass slides was photodegraded by near ultraviolet light (290 to 400 nm). Volatilization of14C-labeled herbicide from glass slides was less than 5% after exposure to turbulent air for 48 h.

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Foliar and Root Absorption of Atrazine Applied Postemergence to Giant Foxtail

Weed Science ◽

10.1017/s0043174500031441 ◽

1969 ◽

Vol 17 (2) ◽

pp. 251-256 ◽

Cited By ~ 17

Author(s):

Lafayette Thompson ◽

F. W. Slife

Keyword(s):

Field Experiments ◽

Soil Surface ◽

Dry Weight ◽

Field Studies ◽

Simulated Rainfall ◽

Root Absorption ◽

Giant Foxtail ◽

Setaria Faberii ◽

Chamber Studies ◽

Growth Chamber Studies

In growth chamber studies, high relative humidity and rewetting crystalline spray deposits of 2-chloro-4-ethylamino-6-isopropylamino-s-triazine (atrazine) increased absorption by and phytotoxicity to giant foxtail (Setaria faberii Herrm.), but phytotoxicity was restricted to expanded (unrolled) leaves unless some atrazine was absorbed by the roots. Though phytotoxicity was increased by simulated rainfall when root absorption was prevented, an appreciable number of the plants were killed only when atrazine residues were washed into the soil. In field studies, atrazine applied to a wet soil surface was as effective as the same rate of atrazine foliarly applied. In other field experiments, atrazine applied to giant foxtail on a wet soil and followed by simulated rainfall reduced stand and dry weight, but on a dry soil and not followed by simulated rainfall, atrazine reduced dry weight less and did not reduce stand. These results are due to root absorption of atrazine from wet soil. Spray additives increased phytotoxicity.

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Influence of application timing and herbicide rate on the efficacy of tolpyralate plus atrazine

Weed Technology ◽

10.1017/wet.2019.25 ◽

2019 ◽

Vol 33 (03) ◽

pp. 448-458 ◽

Cited By ~ 1

Author(s):

Brendan A. Metzger ◽

Nader Soltani ◽

Alan J. Raeder ◽

David C. Hooker ◽

Darren E. Robinson ◽

...

Keyword(s):

Weed Management ◽

Field Experiments ◽

Integrated Weed Management ◽

Herbicide Application ◽

Weed Species ◽

Common Ragweed ◽

Application Timing ◽

Common Lambsquarters ◽

Green Foxtail ◽

Equivalent Control

AbstractEffective POST herbicides and herbicide mixtures are key components of integrated weed management in corn; however, herbicides vary in their efficacy based on application timing. Six field experiments were conducted over 2 yr (2017–2018) in southwestern Ontario, Canada, to determine the effects of herbicide application timing and rate on the efficacy of tolpyralate, a new 4-hydroxyphenyl pyruvate dioxygenase inhibitor. Tolpyralate at 15, 30, or 40 g ai ha−1 in combination with atrazine at 500 or 1,000 g ai ha−1 was applied PRE, early POST, mid-POST, or late POST. Tolpyralate + atrazine at rates ≥30 + 1,000 g ha−1 provided equivalent control of common lambsquarters and Powell amaranth applied PRE or POST, whereas no rate applied PRE controlled common ragweed, velvetleaf, barnyardgrass, or green foxtail. Common ragweed, common lambsquarters, velvetleaf, and Powell amaranth were controlled equally regardless of POST timing. In contrast, control of barnyardgrass and green foxtail declined when herbicide application was delayed to the late-POST timing, irrespective of herbicide rate. Similarly, corn grain yield declined within each tolpyralate + atrazine rate when herbicide applications were delayed to late-POST timing. Overall, the results of this study indicate that several monocot and dicot weed species can be controlled with tolpyralate + atrazine with an early to mid-POST herbicide application timing, before weeds reach 30 cm in height, and Powell amaranth and common lambsquarters can also be controlled PRE. Additionally, this study provides further evidence highlighting the importance of effective, early-season weed control in corn.

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Scouringrush (Equisetum spp.) control in dryland winter wheat

Weed Technology ◽

10.1017/wet.2019.45 ◽

2019 ◽

Vol 33 (6) ◽

pp. 808-814

Author(s):

Blake D. Kerbs ◽

Andrew G. Hulting ◽

Drew J. Lyon

Keyword(s):

Species Composition ◽

Winter Wheat ◽

Pacific Northwest ◽

Field Experiments ◽

Cropping Systems ◽

Yield Response ◽

Herbicide Application ◽

Weed Species ◽

Herbicide Treatments ◽

Chemical Fallow

AbstractThe adoption of chemical fallow rotations in Pacific Northwest dryland winter wheat production has caused a weed species composition shift in which scouringrush has established in production fields. Thus, there has been interest in identifying herbicides that effectively control scouringrush in winter wheat–chemical fallow cropping systems. Field experiments were established in growers’ fields near Reardan, WA, in 2014, and The Dalles, OR, in 2015. Ten herbicide treatments were applied to mowed and nonmowed plots during chemical fallow rotations. Scouringrush stem densities were quantified the following spring and after wheat harvest at both locations. Chlorsulfuron plus MCPA-ester resulted in nearly 100% control of scouringrush through wheat harvest. Before herbicide application, mowing had no effect on herbicide efficacy. We conclude chlorsulfuron plus MCPA-ester is a commercially acceptable treatment for smooth and intermediate scouringrush control in winter wheat–chemical fallow cropping systems; however, the lack of a positive yield response when scouringrushes were controlled should factor into management decisions.

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Response of Monocot and Dicot Weed Species to Fresnel Lens Concentrated Solar Radiation

Weed Science ◽

10.1017/s0043174500072866 ◽

1989 ◽

Vol 37 (6) ◽

pp. 797-801 ◽

Cited By ~ 2

Author(s):

David W. Johnson ◽

James M. Krall ◽

Ronald H. Delaney ◽

Larry O. Pochop

Keyword(s):

Solar Radiation ◽

Field Experiments ◽

Focal Length ◽

Soil Surface ◽

Fresnel Lens ◽

Weed Species ◽

Concentrate Solar Radiation ◽

Redroot Pigweed ◽

Concentrated Solar Radiation ◽

Dry Soil

Fresnel lenses are used to concentrate solar radiation to a line or point. A linear Fresnel lens (0.91 by 1.52 m, 0.74-m focal length, 0.01- by 1.52-m line focus) was investigated as a method for weed control. Field experiments were conducted to assess the effect of Fresnel lens concentrated solar radiation at various exposure times, stages of plant growth, and soil surface moisture conditions. On a dry soil surface exposure times of 1 to 10 s at 290 C resulted in control of redroot pigweed from 100% for a 1-s exposure at the cotyledon stage to 89% for a 10-s exposure at the 10-leaf stage. Redroot pigweed and kochia control was similar at exposures of 3 to 10 s, but less for kochia at 1 and 2 s. Green foxtail control was less than that of kochia and redroot pigweed. Control was reduced on a moist compared to a dry soil surface. Concentrated solar radiation holds the greatest potential for control of small dicot weeds on a dry soil surface.

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Selectivity of Pyriclor on Witchweed, Tobacco, and Other Plants

Weed Science ◽

10.1017/s0043174500048360 ◽

1971 ◽

Vol 19 (1) ◽

pp. 90-93

Author(s):

Jim E. Dale

Keyword(s):

Acetic Acid ◽

Solanum Tuberosum ◽

Field Experiments ◽

Soil Surface ◽

Irish Potato ◽

Weed Species ◽

Digitaria Sanguinalis ◽

Crop Species ◽

Dichlorophenoxy Acetic Acid ◽

Over The Top

Postemergence directed application of 0.56 kg/ha of 2,3,5-trichloro-4-pyridinol (pyriclor) gave control of witchweed (Striga lutea Lour.) equivalent to 2.24 kg/ha of (2,4-dichlorophenoxy)acetic acid (2,4-D) without injuring corn (Zea mays L.). Pyriclor applied to the soil surface or incorporated did not significantly injure tobacco (Nicotiana tabacum L.) at rates of 2.24 kg/ha and less. Peanut (Arachis hypogaea L.) was not injured by pyriclor incorporated in soil at 0.56 kg/ha; Irish potato (Solanum tuberosum L.) was slightly injured. Treatment with 0.56 kg/ha of pyriclor applied in the same manner killed six crop species and four weed species also included in the experiment. In 2 years of field experiments, application of pyriclor at 0.21 and 0.63 kg/ha to soil before transplanting, or these rates applied over the top of tobacco after transplanting, controlled large crabgrass (Digitaria sanguinalis L. Scop.) until maturity of the tobacco, and did not significantly reduce yield or cause permanent injury to the crop.

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Herbicide Systems in Stale Seedbed Soybean (Glycine max) Production

Weed Technology ◽

10.1017/s0890037x00037817 ◽

1993 ◽

Vol 7 (4) ◽

pp. 816-823 ◽

Cited By ~ 14

Author(s):

Lawrence R. Oliver ◽

Tracy E. Klingaman ◽

Marilyn McClelland ◽

Robert C. Bozsa

Keyword(s):

Glycine Max ◽

Weed Control ◽

Field Experiments ◽

Growing Season ◽

Application Time ◽

Herbicide Application ◽

Soybean Yield ◽

Pitted Morningglory ◽

Herbicide Activity ◽

Better Than

Field experiments were conducted using a stale seedbed production system to determine the effect of herbicide application time on preplant, preplant incorporated (PPI), and at-planting treatments on weed control and soybean yield. Herbicides were applied on the surface preplant (PPL) or PPI at 6 to 7, 4 to 5, and 2 to 3 wk before planting and just prior to planting. The differences in weed control and soybean yield among years were due to rainfall patterns 2 wk after herbicide application and during the growing season. Preplant treatments applied 2 to 5 wk before planting generally controlled common cocklebur and pitted morningglory better than preplant treatments applied 6 to 7 wk before planting due to persistence of herbicide activity or treatments at planting due to a greater chance of obtaining adequate rainfall for herbicide activation, more uniform seedbed at planting, and larger weeds at application. Metribuzin plus chlorimuron was less suited than imazaquin as a preplant treatment when applied more than 2 weeks before planting.

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Postemergence Control of Weeds in Winter Rapeseed,Brassica napus, by DPX-A7881

Weed Science ◽

10.1017/s0043174500056721 ◽

1990 ◽

Vol 38 (4-5) ◽

pp. 389-395 ◽

Cited By ~ 5

Author(s):

Finlay S. Buchanan ◽

Clarence J. Swanton ◽

Terry J. Gillespie

Keyword(s):

Brassica Napus ◽

Growth Stage ◽

Field Experiments ◽

Seed Quality ◽

Herbicide Application ◽

Weed Species ◽

Common Lambsquarters ◽

Wild Mustard ◽

Green Foxtail ◽

Winter Rapeseed

Field experiments were established to determine the dose and timing of DPX-A7881 applied postemergence for control of weeds in winter rapeseed. Wild mustard and shepherdspurse were effectively controlled by DPX-A7881. Control of these weeds by DPX-A7881 was dependent upon growth stage. The later the growth stage at time of herbicide application the poorer the control. Fall applications of DPX-A7881 provided greater control of wild mustard and shepherdspurse seedlings compared to spring applications. The 0.010 kg ai ha-1dose was as effective in controlling susceptible weed species as 0.030 kg ai ha-1. Control of common lambsquarters and redroot pigweed by DPX-A7881 was poor. Regardless of timing or amount of herbicide applied, DPX-A7881 did not significantly reduce dry weights of either barnyardgrass or green foxtail. Doses of DPX-A7881 ranging from 0.010 to 0.030 kg ai ha-1did not injure or adversely affect winter survival of rapeseed seedlings. Rapeseed yield and seed quality were not affected by DPX-A7881 applied postemergence.

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Flat-cutting loosening in the system of fallow cultivation of chernozem soil and weediness of crops

Interdepartmental thematic scientific collection "Agriculture" ◽

10.31073/zem.92.78-84 ◽

2017 ◽

Vol 1 (92) ◽

pp. 78-84

Author(s):

G. Koval ◽

M. Kaliyevskiy ◽

V. Yeshchenko ◽

I. Martyniuk ◽

N. Martyniuk

Keyword(s):

Species Composition ◽

Crop Rotation ◽

Field Experiments ◽

Early Spring ◽

Weed Species ◽

Wild Mustard ◽

Spring Crop ◽

White Campion ◽

Investigation Methods ◽

Top Soil

The article presents the results of field experiments, where on the basis of podsolized heavy loamy chernozem the influence of replacement of mouldboard ploughing with nonmouldboard cultivation over top soil weediness, weediness at the beginning and end of spring crop vegetation and weed species composition before harve sting were studied. Investigation methods of main fall ploughing under spring crops of five-course rotation: soybeans–rape–wheat–flax–barley at the depths of 15-17, 20-22, 25-27 cm were conducted after post-harvest field tillage. Analysis of data on contamination of the top soil with weed seeds have shown that with the replacement of fall main mouldboard ploughing gwith nonmouldboard cultivation the figure before sowing of all crops withdifferent tillage depthat crop rotation average increased by 131-132%. It caused the increase of actual weed infestation of all crops and at the beginning and end of spring crop vegetationafter different depths of fall nonmouldboard cultivation compared with ploughing at crop rotation average it was 120–132 and 123-138%respectively. Species composition of weeds afterthe replacement of main fall mouldboard ploughing with nonmouldboard cultivation remained mainlyunchanged; although in rape plantings the proportion of white campion and early spring weed sincreased, in wheat plantings– wild mustard andscentless mayweed, insoybean plantings– late spring weeds, in flax plantings– white campion, and in barley plantings– scarlet pimpernel.

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Bio-efficacy of post emergence herbicides in boro rice nursery as well as main field and their residual effects on non-target microorganisms

ORYZA- An International Journal on Rice ◽

10.35709/ory.2020.57.3.4 ◽

2020 ◽

Vol 57 (3) ◽

pp. 199-210

Author(s):

Rajib Kundu ◽

Mousumi Mondal ◽

Sourav Garai ◽

Ramyajit Mondal ◽

Ratneswar Poddar

Keyword(s):

Weed Control ◽

Weed Management ◽

Field Experiments ◽

Block Design ◽

Resistance Index ◽

Residual Effects ◽

Cost Ratio ◽

Main Field ◽

Weed Species ◽

Similar Treatment

Field experiments were conducted at research farm of Bidhan Chandra Krishi Viswavidyalaya, Kalyani, West Bengal, India (22°97' N latitude and 88°44' E longitude, 9.75 m above mean sea level) under natural weed infestations in boro season rice (nursery bed as well as main field) during 2017-18 and 2018-19 to evaluate the herbicidal effects on weed floras, yield, non-target soil organisms to optimize the herbicide use for sustainable rice-production. Seven weed control treatments including three doses of bispyribac-sodium 10% SC (150,200, and 250 ml ha-1), two doses of fenoxaprop-p-ethyl 9.3% EC (500 and 625 ml ha-1), one weed free and weedy check were laid out in a randomized complete block design, replicated thrice. Among the tested herbicides, bispyribac-sodium with its highest dose (250 ml ha-1) resulted in maximum weed control efficiency, treatment efficiency index and crop resistance index irrespective of weed species and dates of observation in both nursery as well as main field. Similar treatment also revealed maximum grain yield (5.20 t ha-1), which was 38.38% higher than control, closely followed by Fenoxaprop-p-ethyl (625 ml ha-1) had high efficacy against grasses, sedge and broadleaf weed flora. Maximum net return (Rs. 48765 ha-1) and benefit cost ratio (1.72) were obtained from the treatment which received bispyribac-sodium @ 250 ml ha-1. Based on overall performance, the bispyribac-sodium (250 ml ha-1) may be considered as the best herbicide treatment for weed management in transplanted rice as well as nursery bed.

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Interaction of dicamba, fluthiacet-methyl, and glyphosate for control of velvetleaf (Abutilon theopharsti) in dicamba/glyphosate-resistant soybean

Weed Technology ◽

10.1017/wet.2021.40 ◽

2021 ◽

pp. 1-21

Author(s):

Jose H. S. de Sanctis ◽

Amit J. Jhala

Keyword(s):

United States ◽

Field Experiments ◽

The United States ◽

Application Rate ◽

Herbicide Application ◽

Soybean Yield ◽

Agronomic Crops ◽

Split Plot ◽

Main Plot ◽

Biomass Reduction

Abstract Velvetleaf is an economically important weed in agronomic crops in Nebraska and the United States. Dicamba applied alone usually does not provide complete velvetleaf control, particularly when velvetleaf is greater than 15 cm tall. The objectives of this experiment were to evaluate the interaction of dicamba, fluthiacet-methyl, and glyphosate applied alone or in a mixture in two- or three-way combinations for velvetleaf control in dicamba/glyphosate-resistant (DGR) soybean and to evaluate whether velvetleaf height (≤ 12 cm or ≤ 20 cm) at the time of herbicide application influences herbicide efficacy, velvetleaf density, biomass, and soybean yield. Field experiments were conducted near Clay Center, Nebraska in 2019 and 2020. The experiment was arranged in a split-plot with velvetleaf height (≤ 12 cm or ≤ 20 cm) as the main plot treatment and herbicides as sub-plot treatment. Fluthiacet provided ≥ 94% velvetleaf control 28 d after treatment (DAT) and ≥ 96% biomass reduction regardless of application rate or velvetleaf height. Velvetleaf control was 31% to 74% at 28 DAT when dicamba or glyphosate was applied alone to velvetleaf ≤ 20 cm tall compared with 47% to 100% control applied to ≤ 12 cm tall plants. Dicamba applied alone to ≤ 20 cm tall velvetleaf provided < 75% control and < 87% biomass reduction 28 DAT compared with ≥ 90% control with dicamba at 560 g ae ha−1 + fluthiacet at 7.2 g ai ha−1 or glyphosate at 1,260 g ae ha−1. Dicmaba at 280 g ae ha−1 + glyphosate at 630 g ae ha−1 applied to ≤ 20 cm tall velvetleaf resulted in 86% control 28 DAT compared with the expected 99% control. The interaction of dicamba + fluthiacet + glyphosate was additive for velvetleaf control and biomass reduction regardless of application rate and velvetleaf height.

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