CHEMICAL WEED KILLERS: I. RELATIVE TOXICITY OF VARIOUS CHEMICALS TO FOUR ANNUAL WEEDS

1937 ◽  
Vol 15c (7) ◽  
pp. 299-323 ◽  
Author(s):  
W. H. Cook
Keyword(s):  
Chenopodium Album ◽  
Lethal Dose ◽  
Ammonium Thiocyanate ◽  
Copper Nitrate ◽  
Toxicity Tests ◽  
Appreciable Effect ◽  
Thlaspi Arvense ◽  
Sodium Bichromate ◽  
Other Substances ◽  
Annual Weeds

Toxicity tests on four annual weeds, Thlaspi arvense L.; Brassica arvensis L. Ktze.; Chenopodium album L.; and Avena fatua L.; showed no definite evidence of a specific susceptibility of a given species to a given substance. The relative resistance of these four weeds to most substances, judging from the certainly lethal dose, was in the order 1:1:2:7. Of the 76 chemicals tested, the following most toxic compounds killed all four species at the dosages employed; selenic and chloric acids, sodium hydroxide, arsenic pentoxide, sodium arsenite, sodium and ammonium chlorate, ammonium thiocyanate, sodium cyanide, zinc chloride, sodium bichromate, sodium selenite, copper nitrate, sodium sulphide, formic acid, gasoline, phenol, creosote, tetralin, sodium benzoate, aniline, benzene and furfural. The residual toxic effect on the soil, three to four weeks after treatment, showed that of the 35 more toxic chemicals tested, only selenic acid and the five chlorates used had any appreciable effect at low and intermediate dosages, while eleven other substances depressed growth following the application of high dosages.

A COMPARISON OF MCP AND 2,4-D FOR THE CONTROL OF ANNUAL WEEDS IN GRAIN CROPS

1957 ◽  
Vol 37 (1) ◽  
pp. 69-83 ◽  
Author(s):  
H. A. Friesen ◽  
D. R. Walker
Keyword(s):  
Chenopodium Album ◽  
Amaranthus Retroflexus ◽  
Seedling Stage ◽  
Dichlorophenoxyacetic Acid ◽  
Growth Stages ◽  
Thlaspi Arvense ◽  
Wild Mustard ◽  
The Difference ◽  
Lamb’S Quarters ◽  
2,4 Dichlorophenoxyacetic Acid

Oats, flax and barley were sprayed with various formulations of MCP (2-methyl-4-chlorophenoxyacetic acid) and 2,4-D (2,4-dichlorophenoxyacetic acid) at a number of Experimental Farms in Western Canada in 1954 and 1955. Each formulation was applied at 4 and 8 ounces of acid equivalent per acre at each of two dates, viz., Date 1, when the weeds were in the seedling stage less than 3 inches in height; and Date 2, at a stage coinciding with the first appearance of buds on the major weed species.Stinkweed (Thlaspi arvense, L.), wild mustard (Brassica kaber (DC.) L.C. Wheeler var. pinnatifida (Stokes) L.C. Wheeler), lamb's quarters (Chenopodium album L.), Russian pigweed (Axyris amarantoides L.), and ball mustard (Neslia paniculata L.), were effectively controlled by each of the MCP and 2,4-D formulations used. Russian thistle (Salsola kali L.), and red-root pigweed (Amaranthus retroflexus L.), were not satisfactorily controlled by MCP, whereas hemp nettle (Galeopsis tetrahit L.) was not controlled by 2,4-D. Wild buckwheat (Polygonum convolvulus L.) was not controlled by any of the treatments. Each treatment was more effective when applied during the seedling stage of the weeds.On the basis of wood control and yield of grain the results of this study favour the use of MCP over 2,4-D with either oats or flax. Oats was significantly more tolerant to MCP, particularly if treated during the early growth stages when weed competition was most critical. With flax, the difference in tolerance was most pronounced in favour of MCP at the later date of treatment. The 2,4-D ester and low volatile ester resulted in a preponderance of plant deformities, lowered the yields of both oats and flax and delayed the maturity of flax significantly. Barley yields in this study were not adversely affected by any of the treatments.

Effects of glyphosate on Fusarium spp.: its influence on root colonization of weeds, propagule density in the soil, and crop emergence

1987 ◽  
Vol 33 (5) ◽  
pp. 354-360 ◽  
Author(s):  
C. André Lévesque ◽  
James E. Rahe ◽  
David M. Eaves
Keyword(s):  
Root Colonization ◽  
Plantago Lanceolata ◽  
Chenopodium Album ◽  
Holcus Lanatus ◽  
Fusarium Spp ◽  
Stellaria Media ◽  
Perennial Weeds ◽  
Colony Forming Units ◽  
Annual Weeds ◽  
Polygonum Persicaria

Glyphosate is a broad spectrum herbicide that can lead to root rot like damage on crops. This study was undertaken to investigate the effect of glyphosate on the root-colonizing Fusarium spp. The research was conducted at two sites. Site one was densely covered with perennial weeds, and site two with annuals. At site one, spraying the weed cover with glyphosate increased (p < 0.05) the level of colonization by Fusarium spp. in Ranunculus repens and Holcus lanatus, but not in Stellaria media and Plantago lanceolata. At site two, glyphosate enhanced colonization in Spergula arvensis, Stellaria media, Echinochloa crusgalli, and Chenopodium album, but not in Capsella bursa-pastoris and Polygonum persicaria. At both sites, the number of colony-forming units of Fusarium spp. per gram of dried soil was increased by the application of glyphosate. Nevertheless, crops subsequently sown in the field containing the annual weeds were not detrimentally affected by glyphosate treatment of these weeds.

scholarly journals AMINO ACID AND PROXIMATE ANALYSES OF WEED SEEDS

1977 ◽  
Vol 57 (1) ◽  
pp. 243-249 ◽  
Author(s):  
RUSSELL TKACHUK ◽  
V. JEAN MELLISH
Keyword(s):  
Amino Acid ◽  
Chenopodium Album ◽  
Essential Amino Acids ◽  
Amaranthus Retroflexus ◽  
Thlaspi Arvense ◽  
Wild Mustard ◽  
Acid Protein ◽  
Weed Seeds ◽  
Lamb’S Quarters ◽  
Amino Acid Balance

Weed seeds commonly found in Western Canadian cereals and oil seeds as dockage were examined for their amino acid, protein, oil and fiber contents. The weeds analyzed were Sinapis arvenis L.(wild mustard), Thlaspi arvense L. (stinkweed), Descurainia sophia (L.) Webb (flixweed), Polygonum convolvulus L. (wild buckwheat), Rumex pseudonatronatus L. (field dock), Avena fatua L. (wild oats), Setaria viridis (L.) Beauv. (green foxtail), Iva xanthifolia Nutt. (false ragweed), Chenopodium album L. (lamb’s-quarters), and Amaranthus retroflexus L. (redroot pigweed). Composite analysis showed that some of the weed seeds are high in protein and oil content. Amino acid analysis showed that many weeds have an excellent essential amino acid balance, and also a higher content of essential amino acids than do the commonly grown cereals. These results suggest that some weed seeds could be excellent sources of protein and oil for feed or food purposes.

REPRODUCTION OF MICE FED LOW GLUCOSINOLATE RAPESEED MEAL CONTAMINATED WITH SCREENINGS MEALS AND WEED SEED MEALS

1982 ◽  
Vol 62 (2) ◽  
pp. 607-616 ◽  
Author(s):  
S. P. ROSE ◽  
J. M. BELL
Keyword(s):  
Body Weight ◽  
Control Diet ◽  
Chenopodium Album ◽  
Rapeseed Meal ◽  
Lactation Period ◽  
Thlaspi Arvense ◽  
Adult Mice ◽  
Equivalent Number ◽  
Three Samples ◽  
Lamb’S Quarters

Three samples of defatted fine rapeseed screenings meals and defatted stinkweed (Thlaspi arvense) seed meal were used at 5 and 15% (wt/wt) to contaminate low glucosinolate rapeseed meal (LG-RSM). Defatted lamb's-quarters (Chenopodium album) and smartweed (Polygonum spp.) seed meals were also used, at levels of 1.7 and 5% (wt/wt) contamination. The contaminated LG-RSM was included at 15% (wt/wt) in diets fed to female adult mice during a 2-wk preliminary period, pregnancy, lactation and the first 18 days of the second pregnancy. There was a nonsignificant trend (P > 0.05) for the female mice fed stinkweed meal to have the lowest body weight throughout the two pregnancies, although those fed the six contaminants, and the uncontaminated LG-RSM control diet had an equivalent number of offspring born in the two pregnancies and surviving to weaning. Male offspring of mice fed the higher levels of contaminants tended to have a lower (P > 0.05) body weight during the early part of the lactation period. A decreased availability of protein and energy in these diets possibly resulted in decreased milk production. The numbers of blastocysts implanted, embryos resorbed, fetal deaths and malformed fetuses were similar among the dietary treatments. Key words: Rapeseed meal, weed seeds, glucosinolates, mice, reproduction

Long-term effects of 2,4-D application on plants. II. Herbicide avoidance by Chenopodium album and Thlaspi arvense

1988 ◽  
Vol 66 (2) ◽  
pp. 230-235 ◽  
Author(s):  
Larry Hume
Keyword(s):  
Life Cycle ◽  
Chenopodium Album ◽  
Herbicide Tolerance ◽  
Long Term Effects ◽  
Annual Life Cycle ◽  
Thlaspi Arvense ◽  
Immature Seeds ◽  
Winter Annual ◽  
Dichlorophenoxy Acetic Acid

Research plots in a wheat–wheat–fallow rotation at Indian Head, Sask., were sprayed annually with 2,4-dichlorophenoxy-acetic acid (2,4-D) for 36 consecutive years. Two species susceptible to 2,4-D, Chenopodium album L. and Thlaspi arvense L., were dominant in these plots. From 1981 to 1983, C. album and T. arvense seedlings that emerged during four periods of the growing season were marked and their mortality, seed production, and size recorded. From these data and other studies, 10 ways in which C. album and T. arvense managed to survive herbicide application were identified. These are intermittent germination, herbicide tolerance, small size of late-emerging seedlings, short life cycle, hardiness, failure of control practices, long-term dormancy, seed dispersal, viability of immature seeds, and winter annual life cycle of T. arvense.

SPECIES COMPOSITION OF WEEDS IN RAPESEED CROPS IN GEOGRAPHICALLY REMOTE REGIONS ON THE EXAMPLE OF LIPETSK AND SVERDLOVSK REGIONS

2020 ◽  
Vol 18 (4) ◽  
pp. 96-107
Author(s):  
N.N. Luneva ◽  
◽  
A.S. Tret'yakova ◽  
P.V. Kondratkov ◽  
V.L. Zakharov ◽  
...  
Keyword(s):  
Species Composition ◽  
Chenopodium Album ◽  
Raphanus Raphanistrum ◽  
Stellaria Media ◽  
Echinochloa Crusgalli ◽  
Erodium Cicutarium ◽  
Thlaspi Arvense ◽  
Species Similarity ◽  
Silene Pratensis ◽  
Heat And Moisture

The aim of the study is to identify differences in the species composition of weeds in spring rapeseed crops in two geographically remote regions of the Russian Federation – Lipetsk (Central black earth region) and Sverdlovsk (Ural region). The analysis was carried out using methods of comparative Floristics and distribution of species by classes of constancy of occurrence. Differences between segetal weed flora elements in the agrophytocenoses of canola compare regions, as in floral structure, consisting of the first two "triads" of the floristic spectra and confirmed the low rate coefficient of species similarity. Species differences are represented by species that pollute rapeseed crops only in one of the compared regions. Among the species common to the agrophytocenoses of rapeseed in the two regions are such species as, Chenopodium album L., Echinochloa crusgalli (L.) Beauv., Silene praténsis (Rafn) Godr., Euphorbia helioscopia L, Fallopia convolvulus (L.) A. Loeve, Viola arvensis Murr. they are characterized by higher rates of occurrence in the Lipetsk region, and Capsella bursa-pastoris (L.) Medik., Cirsium setosum (Willd.) Bess, Erodium cicutarium (L.) L. Her., Thlaspi arvense L. – in the Sverdlovsk region. The dominant species in the Lipetsk region are Raphanus raphanistrum L., Chenopodium album L., Echinochloa crusgalli (L.) Beauv., Silene praténsis (Rafn) Godr., and in the Sverdlovsk region - Galium vaillantii DC., Stellaria media (L.) Vill., Capsella bursa-pastoris (L.) Medik., Thlaspi arvense L., Chenopodium album L., Cirsium setosum (Willd.) Bess. To protect rapeseed crops from weeds in different regions that differ in terms of heat and moisture availability, it is necessary to develop regional protection systems, preceded by mandatory monitoring studies.

Response of Annual Weed Species to Glufosinate and Glyphosate

1999 ◽  
Vol 13 (3) ◽  
pp. 542-547 ◽  
Author(s):  
Brent E. Tharp ◽  
Oliver Schabenberger ◽  
James J. Kells
Keyword(s):  
Weed Management ◽  
Chenopodium Album ◽  
Ambrosia Artemisiifolia ◽  
Weed Species ◽  
Common Ragweed ◽  
Common Lambsquarters ◽  
Setaria Faberi ◽  
Giant Foxtail ◽  
Annual Weeds ◽  
Large Crabgrass

The recent introduction of glufosinate-resistant and glyphosate-resistant crops provides growers with new options for weed management. Information is needed to compare the effectiveness of glufosinate and glyphosate on annual weeds. Greenhouse trials were conducted to determine the response of barnyardgrass (Echinochloa crus-galli), common lambsquarters (Chenopodium album), common ragweed (Ambrosia artemisiifolia), fall panicum (Panicum dichotomiflorum), giant foxtail (Setaria faberi), large crabgrass (Digitaria sanguinalis), and velvetleaf (Abutilon theophrasti) to glufosinate and glyphosate. The response of velvetleaf and common lambsquarters was investigated at multiple stages of growth. Glufosinate and glyphosate were applied to each weed species at logarithmically incremented rates. The glufosinate and glyphosate rates that provided a 50% reduction in aboveground weed biomass, commonly referred to as GR50values, were compared using nonlinear regression techniques. Barnyardgrass, common ragweed, fall panicum, giant foxtail, and large crabgrass responded similarly to glufosinate and glyphosate. Common lambsquarters 4 to 8 cm in height was more sensitive to glufosinate than glyphosate. In contrast, 15- to 20-cm tall-velvetleaf was more sensitive to glyphosate than glufosinate.

scholarly journals Prediction of Human Lethal Doses and Concentrations of MEIC Chemicals from Rodent LD50 Values: An Attempt to Make Some Reparation

2021 ◽  
pp. 026119292199475
Author(s):  
John C. Dearden ◽  
Mark Hewitt
Keyword(s):  
Lethal Dose ◽  
Lethal Concentration ◽  
Toxicity Tests ◽  
Vast Number ◽  
Routes Of Administration ◽  
Animal Toxicity ◽  
Lethal Doses

The prediction of human toxicities from animal toxicity tests is often poor, and is now discouraged and in some cases banned, especially those involving the LD50 test. However, there is a vast number of historical LD50 data in both public and in-house repositories that are being put to little use. This study examined the correlations between human lethality (doses and concentrations) of 36 MEIC chemicals and the median values of a large number of mouse and rat LD50 values obtained for four different routes of administration. The best correlations were found with mouse and rat intraperitoneal LD50 values (r2 = 0.838 and 0.810 for human lethal dose, and r2 = 0.753 and 0.785 for human lethal concentration). The results show that excellent prediction of human lethal dose and concentration can be made, for this series of chemicals at least, by using uncurated rodent LD50 values, thus offering some reparation for the millions of rodent lives sacrificed in LD50 testing.

scholarly journals Response of Annual Weeds to Glyphosate: Evaluation and Optimization of Application Rate Based on Fecundity-Avoidance Biomass Threshold Criterion

Agronomy ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 851
Author(s):  
Eduardo S Leguizamon ◽  
German Ferrari ◽  
Martin M Williams ◽  
Nilda R Burgos ◽  
Ilias Travlos ◽  
...  
Keyword(s):  
Chenopodium Album ◽  
Application Rate ◽  
Growth Stages ◽  
Weed Species ◽  
Weed Biomass ◽  
Evaluation Procedures ◽  
Potting Medium ◽  
Threshold Criterion ◽  
Rate Optimization ◽  
Annual Weeds

The increased availability and high adoption rate of glyphosate-tolerant crops have selected for several glyphosate-resistant weed species. The response of representative weed species to glyphosate was assessed to provide insights and tools for optimizing glyphosate use for economic, agronomic and environmental reasons. Anoda cristata, Chenopodium album, Digitaria sanguinalis, Eleusine indica and Portulaca oleracea were grown outdoors in pots containing commercial potting medium. An increasing dose of glyphosate was applied to these species at three growth stages. Weed response was evaluated visually compared to the nontreated control and shoot dry weights were recorded. Fecundity was also determined. Based on visual evaluations, the dose of glyphosate required to attain 90% control of the species tested exhibited an application rate margin up to 28.5-fold compared to recommended rate, denoting a potential for rate optimization. Except for A. cristata, the recommended dose of glyphosate could be reduced by 30%–60% and still achieve 90% or greater control. The order of species sensitivity, based on effective dose 50 (ED50 )values, was E. indica > C. album > D. sanguinalis > P. oleracea > A. cristata. The ratio of ED90/ED50 was constant, indicating that increasing the glyphosate dose 8.7-fold would reduce weed biomass 1.8-fold. In most cases, the fecundity-avoidance biomass threshold (i.e., the maximum allowable weed biomass for herbicide application in order to prevent weed seed production and dispersal) for glyphosate was below the ED90 value. Complimentary measures such as fecundity-avoidance biomass threshold will improve herbicide evaluation procedures and preserve the effectiveness of herbicides, including glyphosate, on sensitive species, an important issue particularly when action to reduce herbicide resistance development is highly required.

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