Green Foxtail (Setaria viridis) and Pale Smartweed (Polygonum lapathifolium) Interference in Field Crops

1994 ◽  
Vol 8 (2) ◽  
pp. 311-316 ◽  
Author(s):  
John T. O'Donovan
Keyword(s):  
Crop Yield ◽  
Field Experiments ◽  
Dry Weight ◽  
Limiting Factor ◽  
Yield Losses ◽  
Weed Density ◽  
Green Foxtail ◽  
Polygonum Lapathifolium ◽  
And Control ◽  
The Relationship

Field experiments were conducted at Vegreville, Alberta in 1984, 1985, 1986, and 1988 to determine the effects of green foxtail and pale smartweed on yield of wheat, barley, and canola. There was considerable variation among years in the response of crop yield to both weeds and in the relationship between weed dry weight and weed density. Mostly relationships between crop yield and either weed density or dry weight were poor, suggesting that the weeds competed weakly with the crops. Thus density or dry weight may be poor predictors of crop yield losses due to green foxtail or pale smartweed. Where the crops emerged ahead of these weeds, and where soil moisture was not a limiting factor, crop yield losses were minimal and control with herbicides probably uneconomical. In some instances, growth and development of the weeds was suppressed by the crops to the extent that little or no weed dry matter was present at crop maturity. This was most evident with barley, and where the crops emerged ahead of the weeds.

Growth Analysis of Cotton in Competition with Velvetleaf (Abutilon theophrasti)

2016 ◽  
Vol 30 (1) ◽  
pp. 123-136 ◽  
Author(s):  
Xiaoyan Ma ◽  
Jinyan Yang ◽  
Hanwen Wu ◽  
Weili Jiang ◽  
Yajie Ma ◽  
...  
Keyword(s):  
Field Experiments ◽  
Fiber Quality ◽  
Dry Weight ◽  
Growth And Yield ◽  
Effective Management ◽  
Cotton Yield ◽  
Seed Cotton ◽  
Weed Density ◽  
Seed Cotton Yield ◽  
The Relationship

Field experiments were conducted in 2013 and 2014 to determine the influence of velvetleaf densities of 0, 0.125, 0.25, 0.5, 1, 2, 4, and 8 plants m−1of row on cotton growth and yield. The relationship between velvetleaf density and seed cotton yield was described by the hyperbolic decay regression model, which estimated that a density of 0.44 to 0.48 velvetleaf m−1of row would result in a seed cotton yield loss of 50%. Velvetleaf remained taller and thicker than cotton throughout the growing season. Both cotton height and stem diameter reduced with increasing velvetleaf density. Moreover, velvetleaf interference delayed cotton maturity, especially at velvetleaf densities of 1 to 8 plants m−1of row, and cotton boll number and weight, seed numbers per boll, and lint percentage were also reduced. Fiber quality was not influenced by weed density when analyzed over 2 yr; however, fiber length uniformity and micronaire were adversely affected in 2014. Velvetleaf intraspecific competition resulted in density-dependent effects on weed biomass, ranging from 97 to 204 g plant−1dry weight. Velvetleaf seed production per plant or per square meter was indicated by a logarithmic response. At a density of 1 plant m−1of cotton row, velvetleaf produced approximately 20,000 seeds m−2. The adverse impact of velvetleaf on cotton growth and development identified in this study have indicated the need for effective management of this species when the weed density is greater than 0.25 to 0.5 plant m−1of row and before the weed seed maturity.

The Effect of Trifluralin Applied Preplant on Grass Weed Control and Establishment and Yield of Barley (Hordeum vulgare)

1997 ◽  
Vol 11 (3) ◽  
pp. 515-519 ◽  
Author(s):  
Julio A. Scursoni ◽  
Emilio H. Satorre
Keyword(s):  
Weed Control ◽  
Field Experiments ◽  
Herbicide Application ◽  
Planting Pattern ◽  
Weed Density ◽  
Time Of Application ◽  
Density And Biomass ◽  
And Control ◽  
Crop Planting ◽  
Grass Weed

The objective of this paper was to evaluate the effect of preplant applications of trifluralin on barley stand and yield, and control of grass weeds in field experiments during 1992 and 1993. Factors examined were: (1) crop planting patterns (conventional drill with rows 15 cm apart and deep-seeder drill with rows 25 cm apart), (2) herbicide application times (22 d before sowing and immediately before sowing), and (3) herbicide application. During 1993, hand-weeded plots also were established. Trifluralin applied preplant at 528 g ai/ha reduced weed density and biomass. Weed control was higher under conventional planting than under the deep planting pattern, and there was no effect of the time of application on herbicide efficacy. There was no herbicide injury to the crop, and grain yield was higher in treated than in untreated plots due to successful weed control.

Dicamba, Chlorsulfuron, and Clopyralid as Sprayer Contaminants on Sunflower (Helianthus annuus), Mustard (Brassica juncea), and Lentil (Lens culinaris), Respectively

Weed Science ◽  
1989 ◽  
Vol 37 (4) ◽  
pp. 616-621 ◽  
Author(s):  
Douglas A. Derksen
Keyword(s):  
Helianthus Annuus ◽  
Lens Culinaris ◽  
Field Experiments ◽  
Yield Loss ◽  
Dry Weight ◽  
Yield Losses ◽  
Crop Tolerance ◽  
Crop Injury ◽  
Untreated Check ◽  
Grass Weed

Simulated sprayer tank residues of the broadleaf weed herbicides dicamba, chlorsulfuron, and clopyralid applied alone and with the grass weed herbicides sethoxydim and diclofop on sunflower, tame mustard, and lentil, respectively, caused visible crop injury and reduced dry weight and yield. Dry weight production in the greenhouse and crop tolerance ratings in the field indicated that the grass weed herbicides enhanced crop injury from dicamba, chlorsulfuron, and clopyralid. Yield reductions in field experiments were also greater when dicamba and clopyralid were mixed with grass weed herbicides and applied on sunflower and lentil, respectively. This did not occur with chlorsulfuron applied to mustard. When mixed with simulated broadleaf weed herbicide residues, diclofop enhanced dry weight reductions and crop injury and reduced yield to a greater extent than sethoxydim. Crop tolerance ratings differentiated treatments and rates but were not a good estimate of the extent of yield loss. When broadleaf weed herbicides were applied at rates simulating sprayer tank residues alone or combined with grass weed herbicides, yield losses ranged up to 40% in sunflower, 70% in mustard, and 95% in lentil, compared to the untreated check.

Weed control and crop tolerance of micro-encapsulated acetochlor applied sequentially in glyphosate-resistant soybean

2015 ◽  
Vol 95 (5) ◽  
pp. 973-981 ◽  
Author(s):  
Amit J. Jhala ◽  
Mayank S. Malik ◽  
John B. Willis
Keyword(s):  
United States ◽  
Weed Control ◽  
Field Experiments ◽  
The United States ◽  
Soybean Yield ◽  
Application Timing ◽  
Common Waterhemp ◽  
Weed Density ◽  
Crop Tolerance ◽  
Green Foxtail

Jhala, A. J., Malik, M. S. and Willis, J. B. 2015. Weed control and crop tolerance of micro-encapsulated acetochlor applied sequentially in glyphosate-resistant soybean. Can. J. Plant Sci. 95: 973–981. Acetochlor, an acetamide herbicide, has been used for many years for weed control in several crops, including soybean. Micro-encapsulated acetochlor has been recently registered for preplant (PP), pre-emergence (PRE), and post-emergence (POST) application in soybean in the United States. Information is not available regarding the sequential application of acetochlor for weed control and soybean tolerance. The objectives of this research were to determine the effect of application timing of micro-encapsulated acetochlor applied in tank-mixture with glyphosate in single or sequential applications for weed control in glyphosate-resistant soybean, and to determine its impact on soybean injury and yields. Field experiments were conducted at Clay Center, Nebraska, in 2012 and 2013, and at Waverly, Nebraska, in 2013. Acetochlor tank-mixed with glyphosate applied alone PP, PRE, or tank-mixed with flumioxazin, fomesafen, or sulfentrazone plus chlorimuron provided 99% control of common waterhemp, green foxtail, and velvetleaf at 15 d after planting (DAP); however, control declined to ≤40% at 100 DAP. Acetochlor tank-mixed with glyphosate applied PRE followed by early POST (V2 to V3 stage of soybean) or late POST (V4 to V5 stage) resulted in ≥90% control of common waterhemp and green foxtail, reduced weed density to ≤2 plants m−2 and biomass to ≤12 g m−2, and resulted in soybean yields >3775 kg ha−1. The sequential applications of glyphosate plus acetochlor applied PP followed by early POST or late POST resulted in equivalent weed control to the best herbicide combinations included in this study and soybean yield equivalent to the weed free control. Injury to soybean was <10% in each of the treatments evaluated. Micro-encapsulated acetochlor can be a good option for soybean growers for controlling grasses and small-seeded broadleaf weeds if applied in a PRE followed by POST herbicide program in tank-mixture with herbicides of other modes of action.

Resistance, tolerance, and yield of western black cottonwood infected by Melampsora rust

1992 ◽  
Vol 22 (2) ◽  
pp. 183-192 ◽  
Author(s):  
J. Wang ◽  
B.J. van der Kamp
Keyword(s):  
Disease Severity ◽  
Volume Growth ◽  
Severe Infection ◽  
Dry Weight ◽  
Stem Volume ◽  
Yield Losses ◽  
Black Cottonwood ◽  
Total Dry Weight ◽  
Significant Discovery ◽  
The Relationship

Potted ramets of 14 western black cottonwood (Populustrichocarpa Torr. & Gray) clones from southern British Columbia were inoculated with Melampsoraoccidentalis H. Jacks to produce a range of disease severities, and their size and dry weight were determined after 1 or 2 years. Response to inoculation varied significantly between clones. Clones from drier interior locations were less resistant than those from coastal or moister interior locations. Local- (within leaf) or systemic-induced resistance was not detected. Yield (total dry weight) decreased linearly with disease severity. Percent reduction in yield was greater than the cumulative percent leaf area infected for all clones. Yield losses were substantial: dry weights of ramets with disease severity levels similar to those experienced by natural cottonwood populations were about 75% of controls; heavily infected ramets were <50% of controls. Stem:root ratios increased rapidly with increasing disease severity in all clones, and at significantly different rates. Severe infection resulted in substantial mortality in the following winter and reduced initial stem volume growth in the following growing season. Tolerance, defined as the relationship between disease severity and yield, varied significantly between clones. The most significant discovery of this study was that tolerance and resistance were correlated, greater tolerance being associated with reduced resistance. The concepts of resistance, tolerance, and disease hazard, as quantified in this study, can be used to predict yield and to select the most appropriate clones for different disease hazard conditions.

Halosulfuron Tank-Mixes Applied PRE in White Bean

2016 ◽  
Vol 30 (1) ◽  
pp. 57-66 ◽  
Author(s):  
Zhenyi Li ◽  
Rene C. Van Acker ◽  
Darren E. Robinson ◽  
Nader Soltani ◽  
Peter H. Sikkema
Keyword(s):  
Weed Control ◽  
Dry Weight ◽  
Visible Injury ◽  
Dry Bean ◽  
Common Lambsquarters ◽  
Weed Density ◽  
Wild Mustard ◽  
Green Foxtail ◽  
White Bean ◽  
Bean Yield

White bean tolerance and weed control were examined by applying halosulfuron alone or in combination with pendimethalin, dimethenamid-P, orS-metolachlor applied PRE. All herbicides applied alone or in combination caused less than 3% visible injury 1 and 4 wk after emergence (WAE). Halosulfuron applied PRE provided greater than 95% control of common lambsquarters, wild mustard, redroot pigweed, and common ragweed and less than 55% control of green foxtail at 4 and 8 WAE. Weed density and dry weight at 8 WAE paralleled the control ratings. Dry bean yields in halosulfuron plus a soil applied grass herbicide did not differ compared to the weed-free control. Green foxtail competition with halosulfuron PRE applied alone resulted in reduced white bean yield compared to the weed-free control.

Growth Responses of Green and Yellow Foxtail (Setaria viridisand S.lutescens) to Shade

Weed Science ◽  
1984 ◽  
Vol 32 (6) ◽  
pp. 774-780 ◽  
Author(s):  
Carol J. Bubar ◽  
Ian N. Morrison
Keyword(s):  
Dry Matter ◽  
Field Experiments ◽  
Dry Weight ◽  
Tiller Number ◽  
The Other ◽  
Dry Matter Accumulation ◽  
Setaria Viridis ◽  
Growth Responses ◽  
Full Sunlight ◽  
Green Foxtail

The growth of green foxtail (Setaria viridisL. Beauv. ♯3SETVI) and yellow foxtail [S. lutescens(Weigel.) Hubb. ♯ SETLU] in full sunlight, under 55 and 73% shade and within a wheat (Triticum aestivumL. ‘Neepawa’) stand, was compared in field experiments conducted over 3 yr. Shade resulted in a proportionately greater reduction in tiller number of yellow foxtail than of green foxtail. Plants growing in full sunlight produced up to five times more tillers than those growing in the crop. Averaged over the 3 yr, the two shade treatments reduced dry-matter accumulation of both species by 40% or more. The dry weight of plants within the crop was only about one-eighth of that of plants grown in full sunlight. Under both shade treatments and in the crop, yellow foxtail was consistently taller than green foxtail. Nevertheless, no differences in dry weight occurred between species under either shade treatment or in the crop. The results indicate that neither of the two species is distinctly more shade tolerant than the other, nor better adapted to compete with wheat.

scholarly journals Control of volunteer soybean plants in sunflower crop1

2015 ◽  
Vol 45 (3) ◽  
pp. 274-281 ◽  
Author(s):  
Alexandre Magno Brighenti
Keyword(s):  
Glycine Max ◽  
Helianthus Annuus ◽  
Crop Yield ◽  
Dry Weight ◽  
The Other ◽  
Yield Losses ◽  
Glufosinate Ammonium ◽  
Total Death ◽  
Sunflower Crop ◽  
Soybean Plants

ABSTRACTSunflower (Helianthus annuus) sown offseason, after soybean crop (Glycine max), is affected by the competition imposed by volunteer plants. Two experiments were carried out to evaluate the control of volunteer soybean plants in sunflower crops. The sulfentrazone herbicide (75 g ha-1, 100 g ha-1 and 250 g ha-1) causes phytotoxicity to sunflower immediately after application, however, plants recover, with no yield losses. These doses do not cause the total death of volunteer soybean plants, but temporarily paralyzes their growth, avoiding the competition with the sunflower crop. The glufosinate ammonium and ametryn herbicides are effective in controlling volunteer soybean plants, however, symptoms of phytotoxicity in the sunflower crop are high, reflecting in losses of dry weight biomass and crop yield. The other treatments do not provide satisfactory control of volunteer soybean plants and even reduce the sunflower dry weight biomass and yield.

Canopy Measurements as Predictors of Weed-Crop Competition

Weed Science ◽  
1996 ◽  
Vol 44 (3) ◽  
pp. 511-516 ◽  
Author(s):  
J. I. Vitta ◽  
C. Fernandez Quintanilla
Keyword(s):  
Leaf Area ◽  
Crop Yield ◽  
Weed Management ◽  
Yield Losses ◽  
Weed Density ◽  
Damage Coefficient ◽  
Relative Damage ◽  
Weed Cover ◽  
Better Than ◽  
Crop Competition

The development of weed management systems requires accurate prediction of weed-crop competition. In this paper, simple regression models of crop yield losses based on weed density and weed leaf area are compared. In weed leaf area models, variations in the relative damage coefficient (q) were also analyzed. Finally, three simple methods to assess weed cover were compared: visual, photographic, and optic device assessment. Leaf area models were at least as accurate as weed density models. However, the generality of the leaf area models was restricted by changes in q, according to the date of leaf area evaluation and the year. Although all methods to assess weed cover correlated adequately with weed leaf area, visual estimates were the best to predict crop yield losses perhaps because very low levels of weed leaf area could be distinguished visually better than by other methods.

Efficiency of an Optically Controlled Sprayer for Controlling Weeds in Fallow

1998 ◽  
Vol 12 (4) ◽  
pp. 638-645 ◽  
Author(s):  
Gail A. Wicks ◽  
Warwick L. Felton ◽  
Robert D. Murison ◽  
Gordon E. Hanson ◽  
Paul G. Nash
Keyword(s):  
Winter Wheat ◽  
Growth Pattern ◽  
Field Experiments ◽  
Growth Patterns ◽  
The Other ◽  
Field Of View ◽  
Controlled System ◽  
Weed Density ◽  
Redroot Pigweed ◽  
Green Foxtail

Field experiments were conducted to compare performance of glyphosate with three different boom arrangements in a winter wheat-fallow rotation near North Platte, NE, in 1994 and 1995. One boom was optically controlled, and the other boom was for broadcast herbicide applications. Spraying with both booms at the same time was called “dual boom.” The sprayers were tested during May, June, and July on two weed density levels established by applying glyphosate at 0.42 kg ae/ha with and without atrazine at 0.84 kg ai/ha in October following wheat harvest. The dual-boom and the broadcast herbicide applications were more efficient in controlling weeds than the optically controlled system. The dual boom reduced weed density 4.5-fold compared with the optically controlled sprayer used alone. Horseweed < 8 cm tall was more difficult to control with the optically controlled sprayer than redroot pigweed and kochia because of its cylindrical-shaped growth patterns. Barnyardgrass and green foxtail seedlings with an erect growth pattern were also difficult for the sensors to detect. Poorer control with the optically controlled sprayer was associated with failure to identify small weeds, chlorotic plants, inconsistency among sensors, and too wide a field of view (FOV), as sensors were spaced farther apart than presently recommended. The number of sensors on a boom needs to be increased to improve the performance of the optically controlled sprayer.

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