scholarly journals Insect damage to and mortality of seedlings of Chenopodium album L. and Fallopia convolvulus (L.) Á.Löve

2009 ◽  
Vol 45 (No. 2) ◽  
pp. 59-65
Author(s):  
J. Štolcová
Keyword(s):  
Species Composition ◽  
Secondary Succession ◽  
Chenopodium Album ◽  
Insect Damage ◽  
Insect Herbivores ◽  
Wild Buckwheat ◽  
Thlaspi Arvense ◽  
Fallow Field

During 1997–1999, the damage and mortality caused by insect herbivores to pigweed (<I>Chenopodium album</I>) and wild buckwheat (<I>Fallopia convolvulus</I>) were studied in an early fallow field at Prague-Ruzyně. The highest abundances of <I>Ch. Album</I> and <I>F. convolvulus</I> (83 and 3.5 plants/m<sup>2</sup>, resp.) were recorded in 1999, the lowest (11.6 and 0.3 plants/m<sup>2</sup>, resp.) in 1998. Mortality was low in 1997 (9.6% and 1.4%, resp.) and 1999 (4.0% and 2.5%, resp.), but high in 1998 (25% and 10%, resp.) due to concurrent drought. In accordance with previous studies on <I>Thlaspi arvense</I>, herbivory and concurrent drought may increase the mortality of <I>Ch. Album</I> and <I>F. convolvulus</I> seedlings, and thereby alter the species composition of the weed community during secondary succession.

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.

scholarly journals Seedling establishment early on an abandoned field

2001 ◽  
Vol 37 (No. 3) ◽  
pp. 121-127
Author(s):  
J. Štolcová
Keyword(s):  
Species Diversity ◽  
Species Composition ◽  
Seedling Establishment ◽  
Dominant Species ◽  
Chenopodium Album ◽  
Amaranthus Retroflexus ◽  
Abandoned Field ◽  
Thlaspi Arvense ◽  
Weed Infestation ◽  
Small Plot

The effect of sporadic cultivation on seedling establishment on a field abandoned for 1–4 years was investigated in small-plot trials at Prague-Ruzyně in the spring periods 1993–1995. Cultivation included autumn ploughing, spring harrowing and rolling on all plots that were subsequently left to spontaneous weed infestation. Some plots were then mowed or shallowly cultivated in mid-June and late July, others were left without treatment. No significant differences in seedling establishment were found between plots with different treatments. The number of species varied between years, but without a trend to species enrichment or impoverishment. In all years most species were annuals, and species composition did not change in the course of the experiment. The dominant species were Amaranthus retroflexus, Lamium amplexicaule, Echinochloa crus-galli, Chenopodium album, Silene noctiflora and Thlaspi arvense. Species diversity during the experimental years increased due to decreasing dominance of A. retroflexus.

Floristic composition and relative abundance of weeds in annual crops of Manitoba

1991 ◽  
Vol 71 (3) ◽  
pp. 831-839 ◽  
Author(s):  
A. G. Thomas
Keyword(s):  
Relative Abundance ◽  
Chenopodium Album ◽  
Floristic Composition ◽  
Sampling Procedure ◽  
Amaranthus Retroflexus ◽  
Wild Buckwheat ◽  
Wild Oats ◽  
Wild Mustard ◽  
Green Foxtail ◽  
Lamb’S Quarters

Annual surveys for weeds of fields seeded to spring wheat, barley, oats, flax, and canola in Manitoba were conducted during 1978, 1979, and 1981. Fields were surveyed during July and early August each year using a stratified random sampling procedure. Data for the crops and years were combined for analysis. The frequency, the area infested, and the density of the infestation were determined for each species. These three measures of the abundance of the weed were combined into a single synthetic value called relative abundance. Nine of the 152 species recorded by the surveyors accounted for 77% of the total relative abundance. Ranked in order by relative abundance, these species were green foxtail (Setaria viridis (L.) Beauv.), wild oats (Avena fatua L.), wild buckwheat (Polygonum convolvulus L.), annual smartweed (Polygonum spp.), Canada thistle (Cirsium arvense (L.) Scop.), lamb's-quarters (Chenopodium album L.), wild mustard (Sinapis arvensis L.), perennial sow-thistle (Sonchus arvensis L.), and redroot pigweed (Amaranthus retroflexus L.). Green foxtail was the predominant weed with an abundance value three times larger than wild oats or wild buckwheat. The pattern of dominance found in Manitoba fields was similar to results from comparable surveys in Saskatchewan and North Dakota. Key words: Relative abundance, weed survey, weed density, green foxtail, wild oats, wild buckwheat

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.

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.

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.

A survey of the occurrence of seedling weeds in spring annual crops in Manitoba

1991 ◽  
Vol 71 (3) ◽  
pp. 811-820 ◽  
Author(s):  
A. G. Thomas ◽  
D. I. Donaghy
Keyword(s):  
Chenopodium Album ◽  
Abundant Species ◽  
Amaranthus Retroflexus ◽  
Canada Thistle ◽  
Perennial Weed ◽  
Wild Buckwheat ◽  
Annual Crops ◽  
Wild Oats ◽  
Wild Mustard ◽  
Green Foxtail

A floristic survey for weeds in spring annual crops throughout Manitoba from 1975 to 1978 indicated the occurrence of a total of 83 species in 654 fields. Field counts were done during June when the crop and weeds were in the seedling stage. In terms of total abundance, the 28 annual dicotyledonous weeds were found to be the most important group among the 50 species occurring in more than 1% of the fields. Wild buckwheat (Polygonum convolvulus L.), wild mustard (Sinapis arvensis L.), redroot pigweed (Amaranthus retroflexus L.), and lamb's-quarters (Chenopodium album L.) were the most widespread and abundant species in this group with mean densities from 9.6 to 16.2 plants m−2. The combined abundance of green foxtail (Setaria viridis L.), wild oats (Avena fatua L.), and barnyard grass (Echinochloa crusgalli (L.) Beauv.), the three major annual monocotyledonous weeds, was nearly equal to that of the annual dicotyledonous weed group. Green foxtail was the most abundant weed, occurring in 89% of the fields at mean densities of 270.5 plants m−2. Canada thistle (Cirsium arvense (L.) Scop.) and perennial sow-thistle (Sonchus arvensis L.) were the most abundant species in the biennial and perennial weed group and had mean densities of 4.4–4.8 plants m−2 in infested fields. Key words: Weed survey, green foxtail, wild oats, wild buckwheat, wild mustard, Canada thistle

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.

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