scholarly journals Weed seedbank dynamics in maize under different herbicide regimes

2001 ◽  
Vol 54 ◽  
pp. 168-173
Author(s):  
A. Rahman ◽  
T.K. James ◽  
J. Mellsop ◽  
N. Grbavac
Keyword(s):  
Weed Control ◽  
Sharp Increase ◽  
Chenopodium Album ◽  
Seedling Emergence ◽  
Soil Samples ◽  
Strong Positive Correlation ◽  
Herbicide Treatments ◽  
Soil Seedbank ◽  
Seed Extraction ◽  
Low Levels

The influence of different herbicide regimes on the size and composition of the soil weed seedbank in maize was studied over three years Preemergence atrazine alachlor atrazine alachlor or no herbicide treatments were imposed on the same plots each year Soil samples to 100 mm depth were collected each autumn and spring and the seedbank was estimated by seed extraction and seedling emergence Data showed strong positive correlation between the two methods Soil seedbank increased dramatically by each autumn but declined by spring The total seedbank increased over three years in the no herbicide treatment Good weed control by atrazine alachlor kept seedbank density at low levels However seed numbers increased particularly in the first two years with only partial weed control using atrazine or alachlor singly A sharp increase of fathen (Chenopodium album) seeds illustrated the danger of building seedbanks of weeds which become tolerant to the strategies used

scholarly journals Predicting broadleaf weed populations in maize from the soil seedbank

2004 ◽  
Vol 57 ◽  
pp. 281-285 ◽  
Author(s):  
A. Rahman ◽  
T.K. James ◽  
J.M. Mellsop ◽  
N. Grbavac
Keyword(s):  
White Clover ◽  
Chenopodium Album ◽  
Seedling Emergence ◽  
Soil Samples ◽  
Weed Species ◽  
Linear Relationships ◽  
Weed Seeds ◽  
Soil Seedbank ◽  
The Relationship ◽  
Field Plots

Investigations over three years studied the relationship between weed seeds in the soil seedbank and the resultant populations of broadleaf weeds in maize fields Plots were protected from preemergence herbicide after which soil samples (100 mm) were collected and weed seeds therein enumerated Emerged weed seedlings in field plots were counted over the following 8 weeks Up to 67 broadleaf weed species were identified although not all were found at every site and some were specific to a region or soil type On average 2182 of the seed in the soil seedbank emerged For most weeds strong linear relationships were noted between seedling numbers and the seed numbers in the soil although for some like white clover (Trifolium repens) only a weak relationship was observed In the case of fathen (Chenopodium album) which had the largest seedbank there was evidence of asymptotic behaviour with seedling emergence levelling off at high seed numbers

A Comparison of Methods to Predict Weed Seedling Populations from the Soil Seedbank

Weed Science ◽  
1996 ◽  
Vol 44 (1) ◽  
pp. 46-51 ◽  
Author(s):  
John Cardina ◽  
Denise H. Sparrow
Keyword(s):  
Seedling Emergence ◽  
Rank Correlation ◽  
Control Measures ◽  
No Tillage ◽  
Common Lambsquarters ◽  
Annual Grasses ◽  
Soil Seedbank ◽  
Seed Extraction ◽  
Corn Seedling ◽  
Preemergence Herbicides

Accurate prediction of potential weed seedling density would allow growers to implement control measures more effectively and could help avoid inappropriate and over application of preemergence herbicides. We compared three methods for handling soil samples to predict potential weed seedling emergence in plow-disk and no-tillage corn: seedling emergence from greenhouse trays, emergence from intact cores, and seed extraction following sieving. Seedbank numbers were highest for common lambsquarters followed by annual grasses and redroot pigweed, and seed numbers were higher in no-tillage than plow-disk plots. Coefficients of variation typically exceeded 60%. Density of seedling emergence from cores was more similar to field density than was emergence from trays. The percent of seeds in the seedbank that emerged was commonly more than 90% for annual grasses and usually less than 20% for common lambsquarters. All methods gave equivalent and relatively poor predictions of field population density. Spearman rank correlation between predicted and actual populations ranged from low negative values for common lambsquarters in no-tillage to 0.60 for annual grass emergence from trays in 1991. No method consistently gave highest correlations in both years and both tillage systems. Seedling emergence from intact cores, evaluated for 4 yr in plow-disk and no-tillage soybean fields, was significantly correlated (rs= 0.15 to 0.68) with emergence in the field. Pooling data from three to five neighboring sample sites increased the correlation between core and field emergence densities.

Interaction of Rice Residue and PRE Herbicides on Emergence and Biomass of Four Weed Species

2012 ◽  
Vol 26 (4) ◽  
pp. 627-632 ◽  
Author(s):  
Bhagirath S. Chauhan ◽  
Seth B. Abugho
Keyword(s):  
Weed Control ◽  
Seedling Emergence ◽  
Conservation Agriculture ◽  
Bare Soil ◽  
Weed Species ◽  
Herbicide Treatments ◽  
Agriculture Systems

Studies were conducted in a screenhouse to determine the interaction of rice residue as mulch (0, 3, and 6 t ha−1) and herbicides (nontreated, oxadiazon at 0.5 and 1.0 kg ai ha−1, and pendimethalin at 1.0 and 2.0 kg ai ha−1) on seedling emergence and biomass of barnyardgrass, crowfootgrass, junglerice, and rice flatsedge. Regardless of the residue amount, crowfootgrass and junglerice were effectively controlled by all herbicide treatments. No seedlings of these weed species escaped the herbicides when applied in the presence of residue cover. There was no survival of barnyardgrass seedlings when both herbicides were applied on bare soil (without residue cover); however, some seedlings survived oxadiazon and pendimethalin when applied in the presence of residue cover. For rice flatsedge, the herbicide applications in the presence of residue cover resulted in lower weed control than in the absence of residue. These results suggest that some weed species can escape the application of PRE herbicides in conservation agriculture systems in which residue can bind soil-applied herbicides and result in lower efficacy.

scholarly journals Early Season Broadleaf Weed Control in Onion

HortScience ◽  
2006 ◽  
Vol 41 (4) ◽  
pp. 971D-972
Author(s):  
Harlene M. Hatterman-Valenti ◽  
Carrie E. Schumacher ◽  
Collin P. Auwarter ◽  
Paul E. Hendrickson
Keyword(s):  
Weed Control ◽  
Chenopodium Album ◽  
Field Studies ◽  
Amaranthus Retroflexus ◽  
High Rate ◽  
Early Season ◽  
Common Lambsquarters ◽  
Redroot Pigweed ◽  
Herbicide Treatments ◽  
Residual Control

Field studies were conducted at Absaraka, Carrington, and Oakes, N.D., in 2005 to evaluate early season broadleaf weed control and onion (Allium cepa L.) injury with herbicides applied preemergence to the crop. DCPA is a common preemergence herbicide used in onion. However, DCPA can be uneconomical in most high-weed situations, or the usage may be restricted due to possible groundwater contamination. Potential substitutes evaluated were bromoxynil, dimethenamid-P, and pendimethalin. Main broadleaf weeds were redroot pigweed (Amaranthus retroflexus L.) and common lambsquarters (Chenopodium album L.). In general, all herbicides, except bromoxynil, provided acceptable broadleaf weed control 4 weeks after treatment. The highest herbicide rate provided greater weed control compared with the lowest rate for each herbicide. However, onion height was also reduced with the highest herbicide rate. In addition, the two highest rates of dimethenamid-P reduced the onion stand compared with the untreated. A postemergence application of bromoxynil + oxyfluorfen + pendimethalin to onion at the four- to five-leaf stage controlled the few broadleaf weeds that escaped the preemergence treatments and provided residual control of mid- and late-season germinating broadleaf weeds at two of the three locations. Intense germination of redroot pigweed during July at the Oakes location reduced onion yield with all treatments compared with the hand-weeded check. In contrast, total onion yields with all herbicide treatments except the high rate of dimethenamid-P were similar to the hand-weeded check at Absaraka and Carrington.

Weed Control by Alachlor and Residues in Sweet Potato (Ipomoea batatas) and Soil

Weed Science ◽  
1983 ◽  
Vol 31 (4) ◽  
pp. 567-571 ◽  
Author(s):  
Nancy D. Herman ◽  
Thomas J. Monaco ◽  
T. Jack Sheets
Keyword(s):  
North Carolina ◽  
Weed Control ◽  
Sweet Potato ◽  
Ipomoea Batatas ◽  
Soil Samples ◽  
Potato Root ◽  
Sweet Potatoes ◽  
Early Season ◽  
Herbicide Treatments ◽  
Residue Levels

Alachlor [2-chloro-2′,6′-diethyl-N-(methoxymethyl)acetanilide] at 3.4 and 6.7 kg/ha controlled weeds present in sweet potatoes (Ipomoea batatasL. ‘Jewel’, ‘Centennial’, ‘Caromex’) at two locations in North Carolina. Yield was not reduced from slight early season injury observed with the herbicide treatments. Most sweet potato root samples contained less than the detectable limit of 0.05 ppmw of alachlor. At one location, samples of the cultivars Jewel and Centennial that received 6.7 kg/ha contained 0.06 and 0.05 ppmw, respectively. Averaged over locations, residue levels in soil samples from plots treated at 6.7 kg/ha decreased from 1.55 ppmw initially to less than 0.05 ppmw by 16 weeks after application.

scholarly journals Replace of the EPOST glyphosate with pre herbicides and application of different LPOST glyphosate rates for weed control in established vineyard

2020 ◽  
Vol 116 (2) ◽  
pp. 299
Author(s):  
Zvonko PACANOSKI ◽  
Krum BOŠKOV ◽  
Arben Beni MEHMETI
Keyword(s):  
Weed Control ◽  
Cynodon Dactylon ◽  
Lolium Multiflorum ◽  
Chenopodium Album ◽  
Field Trials ◽  
Early Summer ◽  
Xanthium Strumarium ◽  
Summer Period ◽  
Herbicide Treatments ◽  
Annual Weeds

<p>Two-year field trials were conducted at two winegrowing districts (Kavadarci and Skopje in 2016 and 2017) to evaluate wheather oxyfluorfen, pendimethalin and flazasulfuron can replace early post-emergence (EPOST) application of glyphosate in established vineyard until its application in early summer period. The weed vegetation in vineyards in both years was consisted mainly of <em>Chenopodium album </em>L.<em>, Setaria viridis </em>(L). Beauv.,<em> Papaver rhoeas </em>L.<em>, Xanthium strumarium </em>L.<em>, Lolium multiflorum</em> Lam., <em>Sorghum halepense </em>(L.) Pers.<em> </em>and<em> Cynodon dactylon</em> (L.) Pers. Pendimethalin, oxyfluorfen and flazasulfuron efficiently reduced predominant annual weeds and <em>S. halepense</em> seedlings in 2017, but not in 2016. PRE herbicides, regardless year, had no significant effect on <em>C. dactylon</em>. Opposite, the efficacy of EPOST applied glyphosate was significantly lower in 2017 compared to 2016. LPOST glyphosate applied at 2.0 l ha<sup>-1</sup> provided at least 94 % control of dominant annual broadleaf and grass weeds. LPOST application of glyphosate at 2.0 l ha<sup>-1</sup> and glyphosate at 2.0 and 4.0 l ha<sup>-1</sup> resulted in unsatisfactory weed control of predominant perennial <em>S. halepense, </em>and<em> C. dactylon</em>, respectively. LPOST glyphosate applied at 4.0 l ha<sup>-1</sup> provided control of <em>S. halepense</em> by 84 % or more. LPOST glyphosate applied at 8.0 l ha<sup>-1</sup> reduced the amount of <em>S. halepense </em>and<em> C. dactylon</em> at least 97 %. Grapevine yield of both varieties was not lower in all herbicide treatments in 2016 compared with 2017. However, yield in the PRE herbicide treatments fb 2.0 and 4.0 l ha<sup>-1</sup> glyphosate was collectively 15-19 % and 17-19 % lower compare to PRE herbicide treatments fb 8.0 l ha<sup>-1</sup> glyphosate and standard two applications of glyphosate, respectively for both years and districts. No impacts to grapevine growth were observed from PRE herbicide treatments at either district</p>

scholarly journals Quinoa (Chenopodium quinoa) reaction to herbicide residue in a Brazilian Savannah soil

2003 ◽  
Vol 38 (6) ◽  
pp. 771-776 ◽  
Author(s):  
Roberto Lorena de Barros Santos ◽  
Carlos Roberto Spehar ◽  
Lucio Vivaldi
Keyword(s):  
Weed Control ◽  
Chenopodium Quinoa ◽  
Residual Effect ◽  
Soil Samples ◽  
Brazilian Savannah ◽  
Double Cropping ◽  
Herbicide Residue ◽  
Herbicide Treatments ◽  
Red Latosol ◽  
And Control

The quinoa (Chenopodium quinoa Willd.) cultivation, one of the most promising in double cropping with soybeans or maize, depends on weed control. The objective of this work was to evaluate quinoa reaction to herbicide residue in a savannah soil. Six herbicide treatments, trifluralin, pendimethalin, clomazone, imazaquin, trifluralin + imazaquin and control, were applied, prior to summer cultivation of soybean, in a Dark-Red Latosol (typic Haplustox). Soybean cultivar BR 9 Savana was grown and soil samples were collected at 15, 38, 100, 145 and 206 days after treatment and stored at -5ºC. Bioassays were conducted in greenhouse, using quinoa, cultivar Q18. Imazaquin was the most harmful to quinoa seedlings, up to 206 days after application, followed by clomazone 15-38 days after application; trifluralin and pendimethalin had no residual effect. These results suggest that a broad-base screening should be conducted.

Effects of Weed Control in Established Alfalfa (Medicago sativa) on Forage Yield and Quality

Weed Science ◽  
1987 ◽  
Vol 35 (4) ◽  
pp. 564-567 ◽  
Author(s):  
Dennis R. Cosgrove ◽  
Michael Barrett
Keyword(s):  
Medicago Sativa ◽  
Weed Control ◽  
Stand Density ◽  
Forage Yield ◽  
Control Measures ◽  
Acid Detergent Fiber ◽  
Yield And Quality ◽  
Herbicide Treatments ◽  
Forage Yields

The effects of weed control measures in established alfalfa (Medicago sativaL.) on forage yield and quality were investigated at three sites with varying alfalfa densities and weed populations. Herbicide treatments were 0.56 and 1.12 kg/ha metribuzin [4-amino-6-(1,1-dimethylethyl)-3-(methylthio)-1,2,4-triazin-5(4H)-one] applied in fall or spring, respectively, 1.68 kg/ha pronamide [3,5-dichloro (N-1,1-dimethyl-2-propynyl)benzamide] applied in fall, and combinations of these treatments. First-harvest forage yields (weeds plus alfalfa) were either reduced or unchanged by herbicide treatments. Total forage yield was not altered by the herbicide treatments, but first-harvest and total alfalfa yield as well as first-harvest forage protein content were increased by several treatments, depending on stand density and weed pressure. Little effect was observed on in vitro digestible dry matter or acid detergent fiber content.

Evaluation of weed control in acetyl coA carboxylase-resistant rice with mixtures of quizalofop and auxinic herbicides

2019 ◽  
Vol 34 (4) ◽  
pp. 498-505
Author(s):  
Tameka L. Sanders ◽  
Jason A. Bond ◽  
Benjamin H. Lawrence ◽  
Bobby R. Golden ◽  
Thomas W. Allen ◽  
...  
Keyword(s):  
Weed Control ◽  
Rice Yield ◽  
Field Studies ◽  
Growth Stages ◽  
Acetyl Coa Carboxylase ◽  
Acetyl Coa ◽  
Herbicide Treatments ◽  
Herbicide Mixture ◽  
Sequential Treatments ◽  
And Control

AbstractRice with enhanced tolerance to herbicides that inhibit acetyl coA carboxylase (ACCase) allows POST application of quizalofop, an ACCase-inhibiting herbicide. Two concurrent field studies were conducted in 2017 and 2018 near Stoneville, MS, to evaluate control of grass (Grass Study) and broadleaf (Broadleaf Study) weeds with sequential applications of quizalofop alone and in mixtures with auxinic herbicides applied in the first or second application. Sequential treatments of quizalofop were applied at 119 g ai ha−1 alone and in mixtures with labeled rates of auxinic herbicides to rice at the two- to three-leaf (EPOST) or four-leaf to one-tiller (LPOST) growth stages. In the Grass Study, no differences in rice injury or control of volunteer rice (‘CL151’ and ‘Rex’) were detected 14 and 28 d after last application (DA-LPOST). Barnyardgrass control at 14 and 28 DA-LPOST with quizalofop applied alone or with auxinic herbicides EPOST was ≥93% for all auxinic herbicide treatments except penoxsulam plus triclopyr. Barnyardgrass control was ≥96% with quizalofop applied alone and with auxinic herbicides LPOST. In the Broadleaf Study, quizalofop plus florpyrauxifen-benzyl controlled more Palmer amaranth 14 DA-LPOST than other mixtures with auxinic herbicides, and control with this treatment was greater EPOST compared with LPOST. Hemp sesbania control 14 DA-LPOST was ≤90% with quizalofop plus quinclorac LPOST, orthosulfamuron plus quinclorac LPOST, and triclopyr EPOST or LPOST. All mixtures except quinclorac and orthosulfamuron plus quinclorac LPOST controlled ivyleaf morningglory ≥91% 14 DA-LPOST. Florpyrauxifen-benzyl or triclopyr were required for volunteer soybean control >63% 14 DA-LPOST. To optimize barnyardgrass control and rice yield, penoxsulam plus triclopyr and orthosulfamuron plus quinclorac should not be mixed with quizalofop. Quizalofop mixtures with auxinic herbicides are safe and effective for controlling barnyardgrass, volunteer rice, and broadleaf weeds in ACCase-resistant rice, and the choice of herbicide mixture could be adjusted based on weed spectrum in the treated field.

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