scholarly journals Weed Control in Spring and Summer After Fall Application of Sulfometuron

1999 ◽  
Vol 14 (2) ◽  
pp. 80-85
Author(s):  
J. Scott Ketchum ◽  
Robin Rose ◽  
Bruce Kelpsas
Keyword(s):  
Weed Control ◽  
Vegetation Cover ◽  
Forest Regeneration ◽  
Coastal Forests ◽  
Late Fall ◽  
Silvicultural Treatment ◽  
Herbicide Treatments ◽  
Fall Application

Abstract This study tested the residual spring and summer efficacy of sulfometuron after fall applications in forest regeneration settings in coastal forests of Oregon. This is the first reporting of results from what is becoming a more widely used silvicultural treatment. Sulfometuron alone (S) and sulfometuron plus imazapyr and glyphosate (SIG) were applied to vegetation on mechanically scarified sites and unscarified sites. The applications were replicated each month through fall 1994. Vegetation cover was assessed in mid-June and mid-August 1995. The SIG treatment controlled the vegetation more than the S treatment did, although cover was significantly lower for both herbicide treatments (9% to 54% for summed cover) compared to the control (64% to 104% for summed cover). On scarified sites, the month of application, early or late fall, did not significantly influence the efficacy of S or SIG treatments. On unscarified sites, however, later applications of the SIG treatment were less effective than earlier treatments were. These results suggest that fall applications of sulfometuron are still effective in spring and may eliminate the need to retreat sites in the spring to achieve effective weed control. West. J. Appl. For. 14(2):80-85.

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.

MON-37500 for Weed Control and Alfalfa Seed Production

2004 ◽  
Vol 18 (3) ◽  
pp. 810-815 ◽  
Author(s):  
Clayton D. Myhre ◽  
Heather A. Loeppky ◽  
F. Craig Stevenson
Keyword(s):  
Weed Control ◽  
Seed Yield ◽  
Organic Matter Content ◽  
Residual Activity ◽  
Matter Content ◽  
Management Tool ◽  
Early Season ◽  
Perennial Weed ◽  
Herbicide Treatments ◽  
Alfalfa Seed

Alfalfa seed producers have a limited number of herbicide options to manage weed problems. MON-37500 (proposed name sulfosulfuron) is a sulfonylurea herbicide that controls dandelion and quackgrass, two common weeds in alfalfa fields. A study was conducted in two alfalfa fields at Valparaiso and Carrot River, Saskatchewan, Canada, from 1999 to 2001 to evaluate perennial weed control and alfalfa production responses with 0.5×, 1×, and 1.5× label-recommended rates of MON-37500 and also 2,4-DB and hexazinone. MON-37500 applied at the 1× and 1.5× rates at both locations reduced mid-May alfalfa vigor from 100% to between 80 and 90% and increased early-season control of dandelion and quackgrass by about 10 to 40 percentage units, when compared with other herbicide treatments. Improved weed control with 1× and 1.5× MON-37500 rates was sustained into mid-June only at Carrot River and was completely eliminated (100% vigor and 0% weed control), or almost so, by mid-July. MON-37500 did not control Canada thistle. Improved early-season weed control with the 1× MON-37500 rate apparently compensated for the loss of alfalfa vigor at Valparaiso, thus resulting in 27% (57 kg/ha) greater seed yield than with the other herbicide treatments. At Carrot River, hexazinone generally provided levels of weed control similar to MON-37500 but did not injure alfalfa. Consequently, alfalfa yields were highest and the proportion of dead (decaying) seed was least with this treatment. The 0.5× MON-37500 rate often resulted in inferior weed control relative to the 1× and 1.5× rates and never was among the herbicide treatments providing the greatest seed yield. Managing the residual activity of MON-37500 and its negative effect on alfalfa growth, especially at locations with soils having coarse texture and low organic matter content, represents the greatest challenge in making MON-37500 a reliable weed management tool for alfalfa seed producers.

The Influence of Weed Management in Wheat (Triticum aestivum) Stubble on Weed Control in Corn (Zea mays)

1998 ◽  
Vol 12 (3) ◽  
pp. 522-526 ◽  
Author(s):  
Theodore M. Webster ◽  
John Cardina ◽  
Mark M. Loux
Keyword(s):  
Weed Control ◽  
Weed Management ◽  
Management Practices ◽  
Field Studies ◽  
Giant Foxtail ◽  
Giant Ragweed ◽  
Herbicide Treatments ◽  
Postharvest Treatment ◽  
Full Rate ◽  
Wheat Stubble

The objectives of this study were to determine how the timing of weed management treatments in winter wheat stubble affects weed control the following season and to determine if spring herbicide rates in corn can be reduced with appropriately timed stubble management practices. Field studies were conducted at two sites in Ohio between 1993 and 1995. Wheat stubble treatments consisted of glyphosate (0.84 kg ae/ha) plus 2,4-D (0.48 kg ae/ha) applied in July, August, or September, or at all three timings, and a nontreated control. In the following season, spring herbicide treatments consisted of a full rate of atrazine (1.7 kg ai/ha) plus alachlor (2.8 kg ai/ha) preemergence, a half rate of these herbicides, or no spring herbicide treatment. Across all locations, a postharvest treatment of glyphosate plus 2,4-D followed by alachlor plus atrazine at half or full rates in the spring controlled all broadleaf weeds, except giant ragweed, at least 88%. Giant foxtail control at three locations was at least 83% when a postharvest glyphosate plus 2,4-D treatment was followed by spring applications of alachlor plus atrazine at half or full rates. Weed control in treatments without alachlor plus atrazine was variable, although broadleaf control from July and August glyphosate plus 2,4-D applications was greater than from September applications. Where alachlor and atrazine were not applied, August was generally the best timing of herbicide applications to wheat stubble for reducing weed populations the following season.

scholarly journals Residual Activity of ACCase-Inhibiting Herbicides on Monocot Crops and Weeds

2018 ◽  
Vol 32 (4) ◽  
pp. 364-370 ◽  
Author(s):  
Zachary D. Lancaster ◽  
Jason K. Norsworthy ◽  
Robert C. Scott
Keyword(s):  
Weed Control ◽  
Field Experiments ◽  
Residual Activity ◽  
Sprinkler Irrigation ◽  
Grain Sorghum ◽  
Rainfall Event ◽  
Rice Grain ◽  
Acetyl Coa Carboxylase ◽  
Herbicide Treatments ◽  
Residual Control

AbstractField experiments were conducted in 2014 and 2015 in Fayetteville, Arkansas, to evaluate the residual activity of acetyl-CoA carboxylase (ACCase)–inhibiting herbicides for monocot crop injury and weed control. Conventional rice, quizalofop-resistant rice, grain sorghum, and corn crops were evaluated for tolerance to soil applications of six herbicides (quizalofop at 80 and 160 g ai ha–1, clethodim at 68 and 136 g ai ha–1, fenoxaprop at 122 g ai ha–1, cyhalofop at 313 g ai ha–1, fluazifop at 210 and 420 g ai ha–1, and sethoxydim at 140 and 280 g ai ha–1). Overhead sprinkler irrigation of 1.3 cm was applied immediately after treatment to half of the plots, and the crops planted into the treated plots at 0, 7, and 14 d after herbicide treatment. In 2014, injury from herbicide treatments increased with activation for all crops evaluated, except for quizalofop-resistant rice. At 14 d after treatment (DAT) in 2014, corn and grain sorghum were injured 19% and 20%, respectively, from the higher rate of sethoxydim with irrigation activation averaged over plant-back dates. Conventional rice was injured 13% by the higher rate of fluazifop in 2014. Quizalofop-resistant rice was injured no more than 4% by any of the graminicides evaluated in either year. In 2015, a rainfall event occurred within 24 h of initiating the experiment; thus, there were no differences between activation via irrigation or by rainfall. However, as in 2014, grain sorghum and corn were injured 16% and 13%, respectively, by the higher rate of sethoxydim, averaged over plant-back dates. All herbicides provided little residual control of grass weeds, mainly broadleaf signalgrass and barnyardgrass. These findings indicate the need to continue allowing a plant-back interval to rice following a graminicide application, unless quizalofop-resistant rice is to be planted. The plant-back interval will vary by graminicide and the amount of moisture received following the application.

scholarly journals Herbicide Evaluation for Sweet Potatoes

1969 ◽  
Vol 66 (4) ◽  
pp. 254-260 ◽  
Author(s):  
Lii-Chyuan Liu ◽  
Edwin Acevedo-Borrero ◽  
F. H. Ortiz
Keyword(s):  
Weed Control ◽  
Sweet Potato ◽  
Tuber Yield ◽  
Potato Cultivar ◽  
Weed Competition ◽  
Sweet Potatoes ◽  
Minimum Rate ◽  
Potato Plants ◽  
Herbicide Treatments ◽  
Rate Controlled

Two herbicide experiments were carried out in 1980 to evaluate Alachor and Metribuzin alone or combined for weed control in sweet potato cultivar Miguela at the Isabela and Fortuna Substations, Metribuzin at 1.12 kg ai/ha rate controlled effectively both broadleaf weeds and grasses. A minimum rate of 6.73 kg ai/ha of Alachor was needed for acceptable weed control. Metribuzin at the 1.12 kg al/ha rate in combination with Alachor at the 3.36 kg ai/ha rate provided the best weed control. There was no visible herbicide injury to sweet potato plants at the Isabela Substation. Moderate crop injury as a consequence of Metribuzin application at 2.24 kg ai/ha was apparent at the Fortuna Substation. The highest tuber yield was obtained with Metribuzin at 1.12 kg ai/ha in combination with Alachor at 3.36 kg ai/ha at both Substations. Metribuzin at 1.12 kg ai/ha rate alone or in combination with any other herbicide also produced good tuber yield. Sweet potatoes with standard herbicide treatments, Diphenamid and Chloramben, yielded poorly because of weed competition.

scholarly journals HPPD-Inhibiting Herbicides Alone or in Tank-Mix with Atrazine in Elephant Grass

2017 ◽  
Vol 9 (11) ◽  
pp. 234
Author(s):  
Alexandre M. Brighenti ◽  
Juarez C. Machado ◽  
Francisco J. S. Ledo ◽  
Leonardo H. F. Calsavara ◽  
Yago V. Guerra Varotto
Keyword(s):  
Weed Control ◽  
Rio De Janeiro ◽  
Mineral Oil ◽  
Minas Gerais ◽  
Forage Yield ◽  
Elephant Grass ◽  
Application Rates ◽  
Minas Gerais State ◽  
Herbicide Treatments ◽  
Janeiro State

The interference imposed by weeds is one of the most important factors limiting elephant grass forage yield. Two experiments were carried out in 2015/2016 and 2017 to evaluate the selectivity and weed control of 4-hydroxyphenylpyruvate dioxygenase (HPPD)-inhibiting herbicides applied alone or in combination with atrazine in elephant grass. The treatments applied in the experiment conducted in Valença, Rio de Janeiro State, Brazil, were as follows: two rates of mesotrione (0.072 and 0.144 kg ha-1 + 0.5% v/v mineral oil - Assist®), two rates of tembotrione (0.075 and 0.100 kg ha-1 + 0.5% v/v mineral oil - Aureo®), atrazine + mesotrione (1.25 + 0.072 kg ha-1 + 0.5% v/v mineral oil - Assist®), atrazine + tembotrione (1.25 + 0.100 kg ha-1 + 0.5% v/v mineral oil - Aureo®), atrazine + mesotrione (1.25 + 0.072 kg ha-1), atrazine + tembotrione (1.25 + 0.100 kg ha-1) and two checks (weed-free check and weedy check). The same herbicide treatments and a check without application were applied in an experiment conducted in Coronel Pacheco, Minas Gerais State, Brazil. Two application rates of mesotrione with the addition of mineral oil or the tank mixture of atrazine plus mesotrione, with or without the addition of mineral oil, did not provide injuries capable to reduce elephant grass forage yield. Tembotrione was phytotoxic to elephant grass when applied with mineral oil. Atrazine plus tembotrione in a tank-mix, with or without mineral oil, were also phytotoxic to elephant grass. All treatments provided satisfactory weed control.

Fall-Applied Glyphosate for Canada Thistle (Cirsium arvense) Control in Spring Wheat (Triticum aestivum)

1988 ◽  
Vol 2 (4) ◽  
pp. 445-455 ◽  
Author(s):  
Steven J. Carlson ◽  
William W. Donald
Keyword(s):  
Triticum Aestivum ◽  
Spring Wheat ◽  
Shoot Density ◽  
Cirsium Arvense ◽  
Fresh Weight ◽  
Canada Thistle ◽  
Hard Red Spring Wheat ◽  
Late Fall ◽  
Fall Application ◽  
Root Buds

Effects of repeated late-fall applications of the isopropylamine salt of glyphosate at 1.7 kg ae/ha plus 0.5% (v/v) surfactant on adventitious root buds, thickened propagative roots (> 1.3 mm diam), and shoot density of Canada thistle were studied in continuous hard red spring wheat over a 4-yr period. Glyphosate suppressed Canada thistle shoot density more quickly and to a greater extent than thickened root fresh weight or root bud number. A single fall application of glyphosate drastically decreased Canada thistle shoot density for 1 yr after treatment. However, shoot density was the same as the untreated control by 2 yr after a single fall treatment. Two consecutive late-fall applications of glyphosate in 2 yr decreased Canada thistle shoot density 94% in the fall 1 yr after the last treatment. Glyphosate reduced Canada thistle thickened root fresh weight 70% in the first fall 1 yr after a single fall treatment. However, 2 yr after a single fall application of glyphosate, root fresh weight equalled the controls. Two consecutive fall applications of glyphosate reduced thickened root fresh weight 77% 1 yr after the second treatment.

scholarly journals Multiple resistance of Conyza sumatrensis to Chlorimuronethyl and to Glyphosate

2014 ◽  
Vol 32 (2) ◽  
pp. 409-416 ◽  
Author(s):  
G. Santos ◽  
R.S. Oliveira Jr. ◽  
J. Constantin ◽  
A. C. Francischini ◽  
J. B. Osipe
Keyword(s):  
Weed Control ◽  
Shoot Biomass ◽  
Multiple Resistance ◽  
Response Curves ◽  
No Till ◽  
Herbicide Treatments ◽  
Grain Crop ◽  
Chlorimuron Ethyl ◽  
Resistance To Herbicides ◽  
Weed Resistance

Weed resistance to herbicides has been a major issue in Brazil, mainly due to the inefficiency of the herbicides used in no-till areas and to the high cost of these herbicide treatments. Failures in controlling the weed Conyza have been reported in Western and Northern grain crop areas in Paraná (Brazil). This work aimed to evaluate the potential occurrence of C. sumatrensis biotypes resistant to the herbicides chlorimuron-ethyl and glyphosate. Experiments were carried out under greenhouse conditions with four biotypes (Cascavel-2, Toledo-4, Tupãssi-6, and Assis Chateaubriand-7) possibly resistant to, as well as a population considered susceptible to chlorimuron-ethyl and glyphosate. To obtain dose-response curves, eight herbicide doses of chlorimuron-ethyl (0, 2.5, 5, 10, 20, 40, 80 and 160 g ha-1) and glyphosate (0, 90, 180, 360, 720, 1,440, 2,880 and 5,760 g e.a. ha-1) were applied and weed control and shoot biomass evaluations were made. Results provided evidence that two biotypes (Cascavel-2 and Tupãssi-6) were resistant to glyphosate and four biotypes (Cascavel-2, Toledo-4, Tupãssi-6 and Assis Chateaubriand-7) were resistant to chlorimuronethyl. Multiple resistance to glyphosate and chlorimuron was confirmed for biotypes Cascavel2 and Tupãssi 6. This is the first report on multiple resistance in Conyza sumatrensis, worldwide.

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