scholarly journals Reducing herbicide use in spring cereal production

1993 ◽  
Vol 2 (Supplement) ◽  
pp. 1-41
Author(s):  
Jukka Salonen
Keyword(s):  
Species Composition ◽  
Chenopodium Album ◽  
Growth Stages ◽  
Herbicide Application ◽  
Weed Species ◽  
Seeding Rate ◽  
Weed Biomass ◽  
Cereal Production ◽  
Weed Infestation ◽  
Acid Herbicides

A survey was conducted in southern and central Finland from 1982 to 1984 to determine the main weed species affecting spring cereal production. The weed flora was dominated by broad-leaved species. The most common broad-leaved weeds were Chenopodium album L., Galeopsis L. spp., Viola arvensis Murr. and Stellaria media (L.) Vili., and the most common grass weed was Elymus repens (L.) Gould. The density of weeds averaged 170 plants m-2 (median 124), and the dry weight 320 kg ha-1 (median 183). Ordination analyses revealed that the species composition of weed populations varied regionally and was affected by soil characteristics and crop management practices, particularly by long-term use of herbicides. An additional aspect studied in the survey was herbicide efficacy in farmers’ fields. Phenoxy acid herbicides, MCPA, dichlorprop and mecoprop, were the most common active ingredients used in the 252 spring cereal fields surveyed. MCPA alone gave only a moderate control of 65%, determined as a reduction of weed biomass, whereas the efficacy of herbicide mixtures containing MCPA averaged 83%. Inadequate control was in most cases due to a wrong choice of active ingredient for the prevailing weed population. Reduction in the use of herbicides by applying lower doses than recommended was studied in field experiments. Herbicide formulations of MCPA/dichlorprop, MCPA/mecoprop and MCPA/fluroxypyr were screened in spring barley (Hordeum vulgäre L.) and spring wheat (Triticum aestivum L.) fields. The efficacy of herbicides, applied at the lowest recommended dose, averaged 85%. At a 30% lower dose the efficacy still reached 79%. Even lower herbicide doses were often adequate, depending on the herbicide, weed species and the crop. The production of weed biomass was adequately suppressed with reduced doses since the most common and aggressive species, such as Chenopodium album and Galeopsis spp., were efficiently controlled with low doses. Use of reduced herbicide doses for three years in the same field caused neither an increase in the subsequent weed infestation nor changes in the species composition of weed populations compared with the treatments at recommended rates of application. The percentage emergence of weeds averaged 70-75% at the time of herbicide application when the crop was at the 3-4 leaf growth stage. However, spraying during the early growth stages of those weeds that emerge in the main flush is recommended since the competitive ability of the crop is normally sufficient to suppress the growth of late-emerging weed seedlings. At harvest the proportion of weed biomass in unsprayed plots, as a proportion of the total vegetative biomass, averaged 3.1% in barley fields and 3.6% in wheat fields. The growth of weeds was more efficiently suppressed with reduced herbicide doses than by increasing the seeding rate of the crop. The mean yield gain remained below 5% at all rates of herbicide application. No reliable density-based threshold for chemical weed control was established. Instead, site-specific dose adjustment based on the composition and infestation level of the prevailing weed populations is suggested to reduce the total use of herbicides and to maintain the current low levels of weed infestation. Consequently, annual reductions of 30% in use of cereal herbicides are expected. Such a reduction corresponds to monetary savings of approximately FIM 20 million per annum at the national level.

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.

scholarly journals Weed Species Composition of Agrophytocenoses in Altai Krai

2021 ◽  
Vol 7 ◽  
pp. 93-102
Author(s):  
Tatiana A. Terekhina ◽  
Alyona V. Nochevnaya ◽  
Natalia V. Ovcharova ◽  
Irina A. Lapshina
Keyword(s):  
Species Composition ◽  
Chenopodium Album ◽  
Amaranthus Retroflexus ◽  
Lower Percentage ◽  
Weed Species ◽  
Convolvulus Arvensis ◽  
The Road ◽  
Poaceae Family ◽  
Weed Infestation ◽  
Brassicaceae Family

The article reviews the weed species composition of oat, sunflower, wheat, buckwheat, rapeseed and flax agrophytocenoses on 390 fields in 21 districts of Altai Krai: Aleyskiy, Bistroistokskiy, Baevskiy, Burlinskiy, Kamenskiy, Kosikhinskiy, Krutikhinskiy, Kytmanovskiy, Loktevskiy, Mamontovskiy, Novichikhinskiy, Pankrushikhinskiy, Rebrikhinskiy, Rubtsovskiy, Shipunovskiy, Sovetskiy, Tretyakovskiy, Troitskiy, Tyumentsevskiy, Zarinskiy, and Zonalniy. The studied fields were surveyed by the route method, which involved the study of the plot by examining it along two diagonals and four sides, when the area did not exceed 20.0 hectares. Larger fields were divided into plots of 20.0 hectares before the survey. The areas adjacent to roads were examined most carefully, since it is often from the road that the field becomes infested. We used the ArcGis program to compile original maps for the main weed plant species. It was found that out of 45 species encountered, only 10 play a significant role in weed infestation and have a high frequency rate: aboriginal Convolvulus arvensis, Amaranthus retroflexus, Euphorbia virgata, Lathyrus tuberosus, Chenopodium album, as well as such adventive species as Fallopia convolvulus, Setaria pumila, Panicum miliaceum subsp. ruderale, Avena fatua and Echinochloa crusgalli. The largest number of species accounts for the Poaceae family (33.3%). The Brassicaceae family is characterized by a slightly lower percentage of participation in the adventitious flora (27.7%). Other families are not so well represented (by 1-2 species each).

scholarly journals Peculiarities of distribution of unseeded species in crops of perennial grasses, depending on the composition of the grass mixture and the mode of use of the grass

2018 ◽  
pp. 120-127
Author(s):  
V. Olifirovich
Keyword(s):  
Species Composition ◽  
Perennial Grasses ◽  
Weed Species ◽  
Grass Stand ◽  
Weed Infestation

The article investigated the species composition and dynamics of changes in the contamination of agrophytocenoses of perennial grasses, depending on the composition of the grass mixture and the mode of use of the grass stand. In the crops of perennial grasses, 34 weed species belonging to 12 botanical kind were found in the first three years of use of the grass stand. In the structure of weed infestation of perennial grasses, the species of the Astra kind of weeds dominated, which were represented by stanktis annual, dandelion, yarrow, field thistle.

The critical weed-free period in glyphosate-resistant soybean in Ontario is similar to previous estimates using glyphosate-susceptible soybean

2019 ◽  
Vol 99 (4) ◽  
pp. 437-443
Author(s):  
Nader Soltani ◽  
Robert E. Nurse ◽  
Amit J. Jhala ◽  
Peter H. Sikkema
Keyword(s):  
Growth Stage ◽  
Field Experiments ◽  
Yield Loss ◽  
Growth Stages ◽  
Weed Species ◽  
Weed Biomass ◽  
Weed Density ◽  
Weed Interference ◽  
Beginning Of Flowering ◽  
Minimal Reduction

A study consisting of 13 field experiments was conducted during 2014–2016 in southwestern Ontario and southcentral Nebraska (Clay Center) to determine the effect of late-emerging weeds on the yield of glyphosate-resistant soybean. Soybean was maintained weed-free with glyphosate (900 g ae ha−1) up to the VC (cotyledon), V1 (first trifoliate), V2 (second trifoliate), V3 (third trifoliate), V4 (fourth trifoliate), and R1 (beginning of flowering) growth stages, after which weeds were allowed to naturally infest the soybean plots. The total weed density was reduced to 24%, 63%, 67%, 72%, 76%, and 92% in Environment 1 (Exeter, Harrow, and Ridgetown) when soybean was maintained weed-free up to the VC, V1, V2, V3, V4, and R1 soybean growth stages, respectively. The total weed biomass was reduced by 33%, 82%, 95%, 97%, 97%, and 100% in Environment 1 (Exeter, Harrow, and Ridgetown) and 28%, 100%, 100%, 100%, 100%, and 100% in Environment 2 (Clay Center) when soybean was maintained weed-free up to the VC, V1, V2, V3, V4, and R1 stages, respectively. The critical weed-free periods for a 2.5%, 5%, and 10% yield loss in soybean were the V1–V2, VC–V1, and VC–V1 soybean stages in Environment 1 (Exeter, Harrow, and Ridgetown) and V2–V3, V2–V3, and V1–V2 soybean stages in Environment 2 (Clay Center), respectively. For the weed species evaluated, there was a minimal reduction in weed biomass (5% or less) when soybean was maintained weed-free beyond the V3 soybean growth stage. These results shows that soybean must be maintained weed-free up to the V3 growth stage to minimize yield loss due to weed interference.

scholarly journals Isoxaflutole and metribuzin interactions in isoxaflutole-resistant soybean

Weed Science ◽  
2019 ◽  
Vol 67 (05) ◽  
pp. 485-496
Author(s):  
Andrea Smith ◽  
Nader Soltani ◽  
Allan C. Kaastra ◽  
David C. Hooker ◽  
Darren E. Robinson ◽  
...  
Keyword(s):  
Chenopodium Album ◽  
Ambrosia Artemisiifolia ◽  
Herbicide Application ◽  
Weed Species ◽  
Control Efficacy ◽  
Rainfall Events ◽  
Common Lambsquarters ◽  
Herbicide Resistant ◽  
Synergistic Interactions ◽  
Soybean Leaf

AbstractHerbicide-resistant weeds are a growing concern globally; in response, new herbicide resistance traits are being inserted into crops. Isoxaflutole-resistant soybean [Glycine max (L.) Merr.] will provide a new mode of action for use in this crop. Ten experiments were conducted over a 2-yr period (2017, 2018) to determine herbicide interactions between isoxaflutole and metribuzin on soybean injury, weed control efficacy, and soybean yield on a range of soil types. Soybean leaf-bleaching injury caused by isoxaflutole was most severe at sites with higher levels of rainfall after application. Control of weed species with isoxaflutole (52.5, 79, and 105 g ai ha−1) and metribuzin (210, 315, and 420 g ai ha−1) differed by site based on amount of rainfall after application. At sites where there was sufficient rainfall for herbicide activation, isoxaflutole at all rates controlled common lambsquarters (Chenopodium album L.), Amaranthus spp., common ragweed (Ambrosia artemisiifolia L.), and velvetleaf (Abutilon theophrasti Medik.) >90%; metribuzin at all rates controlled Amaranthus spp. and witchgrass (Panicum capillare L.) >80%. Control of every weed species evaluated was reduced when there was limited rainfall after herbicide application. The co-application of isoxaflutole + metribuzin resulted in additive or synergistic interactions for the control of C. album, Amaranthus spp., A. artemisiifolia, A. theophrasti, Setaria spp., barnyardgrass [Echinochloa crus-galli (L.) P. Beauv], and P. capillare. Isoxaflutole and metribuzin can be an effective management strategy for common annual broadleaf and grass weeds in Ontario if timely rainfall events occur after herbicide application.

RESULT OF HERBICIDES APPLIED AGAINST OF WEEDS IN SOYBEAN FIELD

2015 ◽  
Vol 13 (2) ◽  
pp. 76-79
Author(s):  
O Ariunaa ◽  
M Otgonsuren
Keyword(s):  
Chenopodium Album ◽  
Herbicide Application ◽  
Weed Species ◽  
Convolvulus Arvensis ◽  
Couch Grass ◽  
Soybean Field ◽  
Small Areas ◽  
Polygonum Convolvulus ◽  
Perennial Weeds ◽  
Field Bindweed

Herbicides, if used properly, are safe and effective in controlling weeds in soybean. The choice of herbicide, however, depends on the predominant weed species and the availability of the herbicide. Chemical control is currently the most widely used control for soybean crops, due to its ease of control and to the small areas planted in Mongolia. In the soybean field the 15species of weeds belonging to 9 families, 12 genus including 62.5 % annual, 37.5%perennial weeds are distributed.The major grassy weeds; Common millet-(Panicummiliaceum L), Couch grass-(Agropyronrepens L), Bristlegrass-(Seteriaviridis L) sp and broadleaved weeds Redroot Pigweed-(Amaranthtusretro flexus),lambs guarters-(Chenopodium album), AristateGoosfoot-(Chenopodiumaristatum L), Black bindweed-(Polygonum convolvulus), Mallow weed-(Malvamochileviensis Down), Field bindweed-(Convolvulus arvensis), Bristhly thistle-(Cirsiumsetosum ), Dwarf bifurcate cinquefoil -(Potentillabifurca), Perennial Sowthisle-(Sonchusarvensis L) weeds have been distributed in the soybean field.In soybean field the Forward herbicide were applied in doses of 1.0-1.2l/ha have reduced the number of weeds by 90.1-91.6%, weight by 59.5-66.1% and super herbicide Gallantsuper applied in doses of 0.45-0.65l/ha have reduced the number of weeds by 91.0-95.0%, weight by 39.5-59.8% while Cobra herbicide applied in doses of 0.45-0.55l/ha used in broadleaved weed distributed field, have reduced the number of weeds by 90.2-94.6% and weight by 42.7-50.7%. The herbicide application increased of yield hectare by 3.6-9.0 center.Mongolian Journal of Agricultural Sciences Vol.13(2) 2014: 76-79

scholarly journals Sinapis alba L. weed infestation depending on the seeding rate and N fertilizer dose in the steppe Crimea

2020 ◽  
Author(s):  
Ye.N. Rostova ◽  
Keyword(s):  
Crop Yields ◽  
Dry Weight ◽  
Weather Conditions ◽  
Sinapis Alba ◽  
Mineral Fertilizers ◽  
White Mustard ◽  
Weed Species ◽  
Seeding Rate ◽  
Sinapis Alba L ◽  
Weed Infestation

Dense white mustard (Sinapis alba L.) can suppress weeds, however excessive density negatively influences crop yields. The search for the optimal parameters for applying mineral fertilizers and the consumption of seed material will increase the crop yield and will improve its competitive ability. This work aimed to identify the seeding rate and doses of nitrogen fertilization at which white mustard plants can actively suppress weeds without reducing the productivity of the crop. In the course of this research, we established that S. alba sown at a rate of 2, 2.5 and 3 million seeds per ha suppressed the growth and development of weeds as much as possible. On average, in 2017-2019, the dry weight of weeds in the aforementioned variants was the least and reached 57.9; 42.3 and 38.4 g/m2, respectively. Weed species composition and quantitative parameters of weed infestation depended on the weather conditions of the year. The application of nitrogen fertilizer did not affect significantly the weediness of S. alba crops. The optimal density white mustard plant formed at a seeding rate of 2 million units/ha and, on average, for three years of research, the seed yield in this variant was the highest (0.6 t/ha).

scholarly journals STUDY OF WEED INFESTATION IN WHEAT FIELDS AT SOUTH PUNJAB REGION PAKISTAN

2020 ◽  
Vol 4 (2) ◽  
pp. 70-77
Author(s):  
Zahida Parveen ◽  
Shamim Umar ◽  
Muhammad Ajmal ◽  
Bilal Haider ◽  
Amna Zafar Iqbal ◽  
...  
Keyword(s):  
Native Plants ◽  
Cynodon Dactylon ◽  
Chenopodium Album ◽  
Research Work ◽  
Soil Samples ◽  
Wheat Crop ◽  
Weed Species ◽  
Natural Systems ◽  
Weed Infestation ◽  
Ecological Parameters

Weeds are one of the major threats to the natural environment. They are destroying native habitats, threatening native plants and animals, and choking our natural systems including rivers and forests. Aiming to explore the existing situation of weed infestation and assessing its impact, present research work was conducted in south Punjab region, focusing on District Layyah and Muzaffargarh. Weed flora of wheat crop at 3 sites i.e. Nawan Kot, Fethpur, and Karor Lal-e-son in district Layyah; and three sites (Kot Addu, Chowk Sarwar Shaheed, and Sultan Nagar) in district Muzaffargarh was observed using quadrat method. Ten quadrats measuring 1.0 m2 were randomly selected to record the data. From each quadrat soil samples (from top 3 cm) were also taken. Different ecological parameters (i. e. Frequency (%) density (%), (%), relative density (%), relative frequency (%) and important value (%) were worked out using proper formulae. Weed species related to 9 families were classified into different frequency classes. Two most important families of these sites were found Poaceae and Papilionaceae each one represented by four species. Chenopodium album, Cynodon dactylon and Anagallis arvensis were observed the most frequent species at these sites.

scholarly journals The competitive ability of Chenopodium album and Echinochloa crus-galli in maize crops depending on the time of their occurrence or removal

2016 ◽  
Vol 69 (4) ◽  
Author(s):  
Hanna Golebiowska ◽  
Renata Kieloch
Keyword(s):  
Competitive Ability ◽  
Stem Elongation ◽  
Chenopodium Album ◽  
Weed Competition ◽  
Growth Stages ◽  
Competitive Effect ◽  
Leaf Stage ◽  
Weed Infestation ◽  
Small Plot ◽  
Weed Emergence

Small-plot experiments for two levels of infestation (20 and 40 plants per m<sup>2</sup>) with <em>Chenopodium album</em> L. and <em>Echinochloa crus-galli</em> (L.) P. Beav were conducted in the 2009–2011 seasons. In the first variant, the effect of time of weed removal on maize was investigated. Weeds were removed in the following growth stages of maize: one, three, five, and seven leaves, the beginning of stem elongation, and the stage from the fourth to sixth node. The second variant concerned the effect of time of weed emergence on maize and included the same maize growth stages as mentioned above. In both treatments, weed competition was compared to the control – the plot completely free from weeds, as well as to the plot fully covered with weeds. <em>Echinochloa crus-galli</em> in the amount of 20 plants per m<sup>2</sup>, which were not removed until the five-leaf stage or which emerged immediately after the seven-leaf stage of maize, did not show any competitive effect on the growth and development of maize. <em>Chenopodium album</em> was characterized by a similar effect at the same level of weed infestation severity and when not removed until the five-leaf stage as well as in the case of plants that emerged after the seven-leaf stage of maize. Both species present in an amount of 40 plants per m<sup>2</sup> needed to be removed no later than at the three-leaf stage of maize.

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