scholarly journals Selectivity and efficacy of herbicides dimethachlor and pethoxamid in rocket crop

2020 ◽  
Vol 56 (No. 4) ◽  
pp. 305-316
Author(s):  
Ivana Doležalová ◽  
Irena Petrželová ◽  
Martin Duchoslav
Keyword(s):  
Field Experiments ◽  
Chenopodium Album ◽  
Application Rate ◽  
Amaranthus Retroflexus ◽  
Residue Level ◽  
Portulaca Oleracea ◽  
Negative Effects ◽  
Weed Density ◽  
Application Rates ◽  
Maximum Residue Level

Field experiments were conducted to evaluate the efficacy, selectivity and health harmlessness of four application rates of two pre-emergent herbicides (pethoxamid and dimethachlor) in the rocket [Eruca vesicaria (L.) Cavanilles)]. Pethoxamid was found to be less efficient on the total weed density (efficacy 86.0–93.3%) in comparison with the effect of dimethachlor (94.9–95.8%). Dimethachlor expressed an excellent efficacy on Echinochloa crus-galli (L.) P. Beauvois, Portulaca oleracea Linnaeus, Amaranthus retroflexus Linnaeus, Lamium purpureum Linnaeus, and Veronica persica Poiret from the lowest tested application rate (800 g/ha). Pethoxamid showed an excellent efficacy on E. crus-galli, Lamium purpureum, Lamium amplexicaule Linnaeus, V. persica, and P. oleracea. In higher application rates, pethoxamid controlled Chenopodium polyspermum Linnaeus and Chenopodium album Linnaeus. In contrast to mostly negative effects of dimethachlor, pethoxamid showed either no effects or positive ones on the rocket yield. Residues of both herbicides in the harvested product were always below a 'default limit', which is the baseline maximum residue level for food. The selectivity of pethoxamid at an application rate of 960 g/ha was good, herbicide residues in the rocket were not detected and the yield of the rocket increased.

Future atmospheric carbon dioxide may increase tolerance to glyphosate

Weed Science ◽  
1999 ◽  
Vol 47 (5) ◽  
pp. 608-615 ◽  
Author(s):  
Lewis H. Ziska ◽  
John R. Teasdale ◽  
James A. Bunce
Keyword(s):  
Weed Control ◽  
Atmospheric Carbon Dioxide ◽  
Chenopodium Album ◽  
Herbicide Tolerance ◽  
Plant Size ◽  
Application Rate ◽  
Amaranthus Retroflexus ◽  
Glyphosate Tolerance ◽  
Time Of Application ◽  
Application Rates

We tested whether the efficacy of chemical weed control might change as atmospheric CO2concentration [CO2] increases by determining if tolerance to a widely used, phloem mobile, postemergence herbicide, glyphosate, was altered by a doubling of [CO2]. Tolerance was determined by following the growth ofAmaranthus retroflexusL. (redroot pigweed), a C4species, andChenopodium albumL. (common lambsquarters), a C3species, grown at near ambient (360 μmol mol−1) and twice ambient (720 μmol mol−1) [CO2] for 14 d following glyphosate application at rates of 0.00 (control), 0.112 kg ai ha−1(0.1 X the commercial rate), and 1.12 kg ai ha−1(1.0 X the commercial rate) in four separate trials. Irrespective of [CO2], growth of the C4species,A. retroflexus, was significantly reduced and was eliminated altogether at glyphosate application rates of 0.112 and 1.12 kg ai ha−1, respectively However, in contrast to the ambient [CO2] treatment, an application rate of 0.112 kg ai ha−1had no effect on growth, and a 1.12-kg ai ha−1rate reduced but did not eliminate growth in elevated [CO2]-grownC. album.Although glyphosate tolerant does increase with plant size at the time of application, differences in glyphosate tolerance between CO2treatments inC. albumcannot be explained by size alone. These data indicate that rising atmospheric [CO2] could increase glyphosate tolerance in a C3weedy species. Changes in herbicide tolerance at elevated [CO2] could limit chemical weed control efficacy and increase weed–crop competition.

scholarly journals Effect of different soil and weather conditions on efficacy, selectivity and dissipation of herbicides in sunflower

2020 ◽  
Vol 66 (No. 9) ◽  
pp. 468-476
Author(s):  
Miroslav Jursík ◽  
Martin Kočárek ◽  
Michaela Kolářová ◽  
Lukáš Tichý
Keyword(s):  
Cation Exchange Capacity ◽  
Chenopodium Album ◽  
Soil Layer ◽  
Weather Conditions ◽  
Growing Season ◽  
Application Rate ◽  
Exchange Capacity ◽  
Vertical Transport ◽  
Application Rates ◽  
High Precipitation

Six sunflower herbicides were tested at two application rates (1N and 2N) on three locations (with different soil types) within three years (2015–2017). Efficacy of the tested herbicides on Chenopodium album increased with an increasing cation exchange capacity (CEC) of the soil. Efficacy of pendimethalin was 95%, flurochloridone and aclonifen 94%, dimethenamid-P 72%, pethoxamid 49% and S-metolachlor 47%. All tested herbicides injured sunflower on sandy soil (Regosol) which had the lowest CEC, especially in wet conditions (phytotoxicity 27% after 1N application rate). The highest phytotoxicity was recorded after the application of dimethenamid-P (19% at 1N and 45% at 2N application rate). Main symptoms of phytotoxicity were leaf deformations and necroses and the damage of growing tips, which led to destruction of some plants. Aclonifen, pethoxamid and S-metolachlor at 1N did not injure sunflower on the soil with the highest CEC (Chernozem) in any of the experimental years. Persistence of tested herbicides was significantly longer in Fluvisol (medium CEC) compared to Regosol and Chernozem. Dimethenamid-P showed the shortest persistence in Regosol and Chernozem. The majority of herbicides was detected in the soil layer 0–5 cm in all tested soils. Vertical transport of herbicides in soil was affected by the herbicide used, soil type and weather conditions. The highest vertical transport was recorded for dimethenamid-P and pethoxamid (4, resp. 6% of applied rate) in Regosol in the growing season with high precipitation.  

LAMB’S-QUARTERS INTERFERENCE WITH DIRECT SEEDED BROCCOLI

1990 ◽  
Vol 70 (4) ◽  
pp. 1215-1221 ◽  
Author(s):  
IRIS BITTERLICH ◽  
MAHESH K. UPADHYAYA
Keyword(s):  
Brassica Oleracea ◽  
Field Experiments ◽  
Chenopodium Album ◽  
Total Yield ◽  
Growth And Yield ◽  
Marketable Yield ◽  
Weed Density ◽  
Weed Interference ◽  
Lamb’S Quarters ◽  
Cole Crop

Field experiments were conducted in 1987 and 1988 to study the effect of lamb’s-quarters (Chenopodium album L.) interference on broccoli (Brassica oleracea L. var. botrytis ’Emperor’) growth and yield. Broccoli growth was initially affected by weed interference at 28–36 d after seeding. Generally, the negative effect of weed interference on broccoli growth increased with increasing weed density and time after seeding. Interference by 15 lamb’s-quarters plants m−2 reduced the biomass of broccoli plants by 71–73% compared to the weed-free control at 57–58 d after seeding. Weed density-crop yield relationship curves showed that one lamb’s-quarters plant m−2 decreased total yield by 18–20% and marketable yield by 22–37%. Lamb’s-quarters reduced the total yield per plot by decreasing the average head weight of broccoli. The number of heads per plot was not affected. Weed interference also reduced the weight of heads classified as marketable (> 10 cm across). However, in 1987 more heads failed to reach a marketable size which resulted in a much smaller marketable yield than in 1988.Key words: Brassica oleracea var. botrytis, broccoli, Chenopodium album L., weed density, weed interference, cole crop

Influence of four commonly used pesticides on the survival, growth, and reproduction of the earthworm Aporrectodea trapezoides (Lumbricidae)

1998 ◽  
Vol 49 (8) ◽  
pp. 1297 ◽  
Author(s):  
L. P. D. Choo ◽  
G. H. Baker ◽  
L. P. D. Choo ◽  
G. H. Baker
Keyword(s):  
Filter Paper ◽  
Field Experiments ◽  
Application Rate ◽  
Normal Rate ◽  
Cocoon Production ◽  
Application Rates ◽  
Aporrectodea Trapezoides ◽  
Growth And Reproduction ◽  
Significant Mortality

The effects of 4 commonly used pesticides, endosulfan (insecticide), fenamiphos (nematicide), methiocarb (molluscicide), and ridomil (fungicide) on the survival, growth, and reproduction of the earthworm Aporrectodea trapezoides (Lumbricidae) were measured in laboratory and field experiments. When the earthworms were exposed to the pesticides on moist filter paper for 48 h, fenamiphos and, to a lesser extent, endosulfan caused significant mortality. In contrast, the survival of A. trapezoides was rarely affected by the pesticides during exposure for 5 weeks in pots and cages containing soil (only noted under 10 × normal application rate of endosulfan against adult worms). However, endosulfan did significantly reduce the weight of juvenile A. trapezoides within 5 weeks when applied to soil at normal application rate in both the field and laboratory. Fenamiphos did so at normal application rate in the field only. Fenamiphos and methiocarb reduced earthworm weight in the laboratory when applied at 10 × normal rate. The clitella of adult earthworms regressed with exposure to endosulfan at normal rate and also exposure to fenamiphos at 10 × normal rate. Cocoon production was inhibited by endosulfan and fenamiphos at normal application rates and methiocarb at 10 × normal rate. The use of some pesticides, in particular endosulfan, could significantly reduce the establishment of abundant and beneficial populations of earthworms in Australian pastures.

scholarly journals Effect of Gypsum Application Rate, Soil Type, and Soil Calcium on Yield, Grade and Seed Quality of Runner Type Peanut Cultivars

2017 ◽  
Vol 44 (1) ◽  
pp. 13-18 ◽  
Author(s):  
J.A. Arnold III ◽  
J.P. Beasley ◽  
G.H. Harris ◽  
T.L. Grey ◽  
M. Cabrera
Keyword(s):  
Field Experiments ◽  
Seed Quality ◽  
Soil Depth ◽  
Application Rate ◽  
Seed Vigor ◽  
Application Rates ◽  
Peanut Cultivars ◽  
Research And Education ◽  
The University ◽  
Gypsum Application

ABSTRACT Calcium (Ca) availability in the 0 to 8 cm soil depth often limits peanut yield and influences grade in the southeastern United States. Field experiments were conducted in 2012 and 2013 at the University of Georgia's Coastal Plain Experiment Station, Tifton, GA (CPES) and the Southwest Georgia Research and Education Center, Plains, GA (SWREC) to determine large-seeded (Georgia-06G) and medium-seed sized (Georgia Greener) runner-type cultivar response to gypsum application rates of 0, 560, 1120, 1650 kg/ha. Peanut pod yield and grade (TSMK) were significantly different between locations with 7610 and 6540 kg/ha at CPES and SWREC, respectively. However, there were no differences between peanut cultivars or gypsum rates. Standard germination, seed vigor (cold germination), and seed Ca content analysis were also conducted on subsamples from each plot. Average peanut seed germination was 97% across all samples. No differences were observed for standard germination or vigor testing. Differences in locations were observed for yield, TSMK, percent jumbo, percent medium kernels, and seed Ca content. Peanut cultivar and gypsum application rate had effects on seed Ca concentration. Seed Ca concentration levels were 825 and 787 mg/kg for Georgia Greener and Georgia-06G, respectively. Seed Ca content increased as field gypsum application rate increased at both locations.

scholarly journals Dynamics of herbicide degradation in cauliflower

2018 ◽  
Vol 64 (No. 11) ◽  
pp. 551-556
Author(s):  
Jaroslav Šuk ◽  
Miroslav Jursík ◽  
Marie Suchanová ◽  
Dana Schusterová ◽  
Kateřina Hamouzová
Keyword(s):  
Active Ingredient ◽  
Field Experiments ◽  
Residue Level ◽  
Herbicide Residues ◽  
Herbicide Degradation ◽  
Maximum Residue Level ◽  
Brassica Vegetables

The aim of this work was to compare the dynamics of the degradation of herbicides commonly used in brassica vegetables. Series of plot field experiments were carried out in planting cauliflower in 2012–2014. The amount of herbicide residues with the maximum residue level (MRL) determined by the Regulation (EC) No. 396/2005 and with requirements of non-residue production (up to 10 µg/kg of active ingredient in harvested product) was compared. Napropamide, clomazone and dimethachlor were applied before planting and pendimethalin, S-metolachlor, pyridate, ethametsulfuron, dimethenamid, metazachlor, quinmerac, picloram, clopyralid, cycloxydim, fluazifop, propaquizafop and quizalofop were applied after planting the cauliflower. Besides fluazifop and quizalofop, all tested herbicides showed a fast degradation and can be recommended for non-residue production. The amount of fluazifop residues did not fall below the MRL even 6 weeks after application. Residues of post-emergently applied quizalofop were detected in cauliflower 10–44 days after application in most of the samples at concentration 9–73 µg/kg(below the MRL).

scholarly journals Dynamics of herbicides degradation in carrot (Daucus carota L.) roots and leaves  

2021 ◽  
Author(s):  
Jaroslav Šuk ◽  
Kateřina Hamouzová ◽  
Jana Hajšlová ◽  
Miroslav Jursík
Keyword(s):  
Daucus Carota ◽  
Field Experiments ◽  
Residue Level ◽  
Withdrawal Period ◽  
Daucus Carota L ◽  
Herbicide Residues ◽  
Maximum Residue Level ◽  
Low Concentrations

This research had two main aims. First, to analyse the degradation dynamics of herbicides commonly used in carrot (aclonifen, clomazone, flufenacet, linuron, metribuzin, pendimethalin, S-metolachlor). Second, to compare the amount of herbicide residues with the maximum residue level and with requirements of non-residual production. The field experiments were conducted in 2012–2016. All tested herbicides resulted in relatively low concentrations of residues in carrot roots (up to 10 µg/kg) when the recommended withdrawal period was followed between application and harvest. The concentration of S-metolachlor in carrot roots exceeded the maximal residual limit (MRL) if the application was carried out four days before harvest. The measured values of other tested herbicide residues in carrot roots did not exceed the MRL in any of the tested samples. Pre-emergent use of clomazone, linuron and flufenacet could be recommended for non-residue carrot production. Post-emergent use of metribuzin can be used for non-residue carrot production if the interval between application and harvest is at least 80 days. Concentrations of herbicide residues in carrot leaves were many times higher than in roots. All tested herbicides can be applied for safe carrot production if applicators adhere to the requirements for use.  

scholarly journals Adjuvants to Improve Phenmedipham + Desmedipham + Ethofumesate Efficacy Against Weeds in Sugar Beet (Beta vulgaris)

2019 ◽  
Vol 37 ◽  
Author(s):  
E. IZADI-DARBANDI ◽  
A. ALIVERDI ◽  
M. ANABESTANI ◽  
A. SHAMSABADI
Keyword(s):  
Sugar Beet ◽  
Weed Management ◽  
Chenopodium Album ◽  
Amaranthus Retroflexus ◽  
Tribulus Terrestris ◽  
Weed Density ◽  
Beet Root ◽  
Significant Difference ◽  
Sugar Beet Root ◽  
Density And Biomass

ABSTRACT: The efficacy of reduced (411.5 and 617.2 a.i. ha-1) and recommended (823.0 g a.i. ha-1) rates of phenmedipham + desmedipham + ethofumesate on the control of Amaranthus retroflexus, Amaranthus blitoides, Chenopodium album, and Tribulus terrestris in sugar beet field was investigated when they were tank-mixed with and without Adigor (0.5% v/v), Ammonium sulphate (2% v/v), Citogate (0.2% v/v), D-Octil (0.3% v/v), Hydro-Max (0.5% v/v), and Volck (0.5% v/v). When the herbicide was applied alone, there was no significant difference between the rates of 617.2 and 823.0 g a.i. ha-1 for reduction of total weed density and biomass. Significantly, the adjuvants decreased total weed density and biomass. However, there was no significant difference among the performance of adjuvants. The sugar beet root and sucrose yields were increased significantly by increasing herbicide rate as a result of an improvement in weed control. Although herbicide efficacy was influenced in a similar manner by all the adjuvants, the best results were found as follows: root yield was increased up to 9.66% (71.31 Mg ha-1) by applying the recommended rate of phenmedipham + desmedipham + ethofumesate plus Adigor compared to weed-free check (64.68 Mg ha-1) whereas sucrose yield was increased up to 26.48% (13.21 t ha-1) by applying the recommended rate of phenmedipham + desmedipham + ethofumesate plus HydroMax compared to weed-free check (10.45 t ha-1). From an economic and ecological standpoint, these two adjuvants can be suggested to optimize the recommended rate of phenmedipham + desmedipham + ethofumesate in weed management.

Residues of 2,4-D in wheat following application after heading

1994 ◽  
Vol 74 (1) ◽  
pp. 199-203 ◽  
Author(s):  
Allan J. Cessna ◽  
F. A. Holm
Keyword(s):  
Growing Season ◽  
Residue Level ◽  
Weed Growth ◽  
Application Rates ◽  
Maximum Residue Level ◽  
Drought Conditions ◽  
Whole Plants ◽  
And Storage ◽  
Dough Stage

When drought conditions persist throughout the early part of the cereal growing season, vigorous weed growth may not occur until the crop is maturing and thus may cause seed harvesting and storage problems. Weed desiccation by application of 2,4-D could alleviate such problems but would also raise concerns regarding the magnitude of 2,4-D residues in the seed. This concern has been addressed in a 2-yr study in which residues of 2,4-D were determined in wheat following application of 526 and 1052 g acid equivalent ha−1 after the crop had headed and was in the soft-dough stage. In both years, residues in the crop (whole plants) immediately after spraying were of the order of 20 and 30 mg kg−1 for the 526 and 1052 g ha−1 application rates, respectively. At maturity, the corresponding maximum residues detected in the straw were 4.63 ± 0.77 and 8.76 ± 0.70 mg kg−1, whereas those in the seed were at or exceeded the maximum residue level of 0.1 mg kg−1 permissible in Canada, being 0.10 ± 0.04 and 0.26 ± 0.03 mg kg−1, respectively. Key words: 2,4-D, wheat, residues, preharvest application

scholarly journals Residues of carbosulfan and its carbofuran metabolites and 3-hydroxy-carbofuran in oranges

2004 ◽  
Vol 26 (2) ◽  
pp. 230-233 ◽  
Author(s):  
Marcos José Trevisan ◽  
Gilberto Casadei de Baptista ◽  
Luiz Roberto Pimentel Trevizan ◽  
Geraldo Papa
Keyword(s):  
Gas Chromatography ◽  
Field Experiments ◽  
Residue Level ◽  
Fruit Consumption ◽  
Low Intensity ◽  
Brazilian Legislation ◽  
Maximum Residue Level ◽  
Nitrogen Phosphorus Detector ◽  
Nitrogen Phosphorus ◽  
Unique Application

The objectives of this study were to evaluate the residues of the insecticide carbosulfan and its carbofuran metabolites and 3-hydroxy-carbofuran in orange compartments (whole fruit, bagasse and juice) and comparison between the residual levels found in fruits with the maximum residue level and the safety interval established by the Brazilian legislation. Two field experiments were carried out, both with the following treatments: a-check; b-one application of 10 g of carbosulfan . 100 L-1 of water; c-one application with twice the rate applied in treatment b; d-four applications with the same rate applied in treatment b. Samples were taken at (-1), zero, 1, 3, 7, 14, 21 and 28 days after the last or unique application. The quantitative determinations were done by gas chromatography technique, using a nitrogen-phosphorus detector. The carbosulfan metabolism to its carbofuran metabolite was rapid (3 days), being both analytes concentrated in the bagasse (peel + flavedo + albedo). However, the metabolism of carbofuran to 3-hydroxy-carbofuran was of low intensity or this metabolite was quickly dissipated. Carbosulfan residues and its metabolites did not penetrate into the fruit, thus not contaminating the juice. The use of the pesticide was adequate, with respect to fruit consumption, in relation to the Brazilian legislation.

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