Tropical Signalgrass (Urochloa subquadripara) Control with Preemergence- and Postemergence-Applied Herbicides

2004 ◽  
Vol 18 (2) ◽  
pp. 419-425 ◽  
Author(s):  
Travis C. Teuton ◽  
J. Bryan Unruh ◽  
Barry J. Brecke ◽  
Greg E. Macdonald ◽  
Grady L. Miller ◽  
...  
Keyword(s):  
Field Trials ◽  
Production Costs ◽  
Leaf Stage ◽  
Greenhouse Experiments ◽  
Herbicide Treatments ◽  
Turfgrass Quality ◽  
Postemergence Herbicides ◽  
Sod Production

Tropical signalgrass is one of the most serious weed problems in the St. Augustinegrass sod production in Florida, and its presence increases production costs and lowers turfgrass quality. The objectives of our research were to: (1) evaluate herbicides preemergence and postemergence for control of tropical signalgrass and (2) compare control of tropical signalgrass and other problem weeds (torpedograss, blanket crabgrass, and India crabgrass) with postemergence herbicides. In preemergence herbicide field trials, only benefin + oryzalin, imazapic, imazapic + 2,4-D, and oryzalin provided ≥75% tropical signalgrass control 8 wk after application (WAA). By 11 WAA, only benefin + oryzalin and imazapic + 2,4-D provided ≥75% tropical signalgrass control. In greenhouse experiments, eight herbicide treatments were applied postemergence to tropical signalgrass seedlings at the two-, four-, six-, and eight-leaf stages. Asulam and CGA 362622 provided ≥89% tropical signalgrass control at all application timings. Imazaquin controlled tropical signalgrass ≥98% when applied before the eight-leaf stage. However, in field trials with mature tropical signalgrass (>20 cm stolons), none of the 20 herbicide treatments applied postemergence provided acceptable control.

scholarly journals CROP COMPETITION AIDS EFFICACY OF WILD OAT HERBICIDES

1983 ◽  
Vol 63 (2) ◽  
pp. 503-507 ◽  
Author(s):  
M. P. SHARMA ◽  
W. H. VANDEN BORN
Keyword(s):  
Field Experiments ◽  
Wheat Yield ◽  
Dry Weight ◽  
Crop Plants ◽  
Wild Oat ◽  
Leaf Stage ◽  
Wild Oats ◽  
Herbicide Treatments ◽  
Postemergence Herbicides ◽  
Crop Competition

Field experiments were conducted over a 2-yr period to evaluate the need for competition by crop plants along with the application of postemergence herbicides for wild oat (Avena fatua L.) control in barley and wheat. Barban, difenzoquat, and barban plus difenzoquat were used in barley and barban, benzoylprop ethyl, diclofop methyl, flamprop methyl, and barban plus benzoylprop ethyl were used in wheat, at the two-leaf stage and the four-leaf stage of wild oats seeded alone or in a crop. Barban and diclofop methyl were effective for wild oat control at both the two-leaf and four-leaf stage of wild oats. Benzoylprop ethyl, difenzoquat and flamprop methyl alone or in combination with barban were more effective at the four-leaf than at the two-leaf stage of wild oats. Herbicide treatments increased barley yield up to 84% and wheat yield up to 177%. In the absence of herbicide treatments, crop competition from barley or wheat reduced the wild oat dry weight by about 50%. Competition by crop plants was essential for effective wild oat control with all foliage-applied wild oat herbicides included in this study.Key words: Competition, crop, wild oat, herbicides, wheat, barley

scholarly journals Response of 17 Species of Container-Grown Woody Landscape and Foliage Plants to Four Postemergence Herbicides

1986 ◽  
Vol 4 (2) ◽  
pp. 52-55
Author(s):  
P.R. Gilreath ◽  
J.P. Gilreath
Keyword(s):  
Propanoic Acid ◽  
Digitaria Sanguinalis ◽  
Leaf Stage ◽  
Full Sunlight ◽  
Foliage Plants ◽  
Herbicide Treatments ◽  
Excellent Control ◽  
And Control ◽  
Postemergence Herbicides ◽  
Quizalofop Ethyl

Postemergence applications of 2 rates of Whip [fenoxaprop-ethyl) (ethyl 2-[4-[(6 chloro-2-benzoxazolyl) oxy]-phenoxy] propanoic acid), Assure (quizalofop-ethyl) (2-[4-[6-chloro-2-quinoxalinyl) oxy]-phenoxy]-propanolc acid, Fusilade 2000 (fluazifop-p-butyl) (R-butyl 2-[4-(5) trifluoromethyl-2-pyridyloxy)-phenoxy] propanoic acid), and Poast (sethoxydim) (2-[1-(ethoxyamino) butyl]-5-[2-(ethylthio) propyl 1]-3-hydroxy-2 cyclohexene-l-one) were evaluated for phytotoxicity to 17 species of container-grown woody landscape and foliage plants and control of large crabgrass (Digitaria sanguinalis L.). Crabgrass plants were treated at the 2 to 4 and 8 to 10 leaf stages and were grown under both full sun and 40% shade. Each herbicide injured at least one species. Fusilade 2000 injured the fewest species, while Poast injured the most. Under 40% shade, control of crabgrass with 2-4 leaves was acceptable with all herbicides except 0.28 kg/ha (0.25 lb/A) Whip. All herbicides were effective when applied in the 8-10 leaf stage of growth. In full sunlight, excellent control of crabgrass at the 2-4 leaf stage was obtained with all herbicide treatments except Poast. Two weeks after application to the 8-10 leaf stage, the best control was obtained with Whip; however, by the end of 8 weeks, all treatments, except Poast, provided excellent control.

Influence of Stage of Growth and Adjuvants on Fall Panicum Control in Corn with Cyanazine

Weed Science ◽  
1975 ◽  
Vol 23 (3) ◽  
pp. 241-245
Author(s):  
A. D. Kern ◽  
W. F. Meggitt ◽  
Donald Penner
Keyword(s):  
Zea Mays ◽  
Grain Yield ◽  
Vegetable Oil ◽  
Field Trials ◽  
Corn Yield ◽  
Leaf Stage ◽  
Greenhouse Experiments ◽  
Stages Of Growth ◽  
Three Stages ◽  
Panicum Dichotomiflorum

The response of corn (Zea maysL.) and fall panicum (Panicum dichotomiflorumMichx.) to postemergence herbicide applications at three stages of growth was examined. Early postemergence application of cyanazine 2-[[4-chloro-6-(ethylamino)-s-triazine-2-yl] amino]-2- methylpropionitrile at 3.4 kg/ha provided the best control with minimum crop injury and greatest corn yield. A reduction of 25% in corn yield resulted when fall panicum was removed by hand at the seven to eight-leaf stage as compared to removal of plants with two leaves. Various adjuvants increased cyanazine action on both fall panicum and corn in field and greenhouse experiments; however, field trials showed no differences in grain yield at harvest. In the greenhouse, less corn injury was observed with a vegetable oil additive than with other adjuvants.

scholarly journals Immediate Irrigation Improves Turfgrass Safety to Postemergence Herbicides

HortScience ◽  
2019 ◽  
Vol 54 (2) ◽  
pp. 353-356 ◽  
Author(s):  
Robert Andrew Kerr ◽  
Lambert B. McCarty ◽  
Philip J. Brown ◽  
James Harris ◽  
J. Scott McElroy
Keyword(s):  
Propionic Acid ◽  
Cynodon Dactylon ◽  
Warm Season ◽  
Eleusine Indica ◽  
Herbicide Treatments ◽  
Turfgrass Quality ◽  
Cynodon Transvaalensis ◽  
Vegetative Indices ◽  
Postemergence Herbicides ◽  
Control Irrigation

Summer annual grassy weeds such as goosegrass (Eleusine indica L. Gaertn.) continue to be problematic to control selectively with postemergence (POST) herbicides within turfgrass stands. In recent years, reduced performance by certain herbicides (e.g., foramsulfuron), cancellation of goosegrass-specific herbicides (e.g., diclofop-methyl), and cancellation and/or severe use reductions of other herbicides [e.g., monosodium methanearsonate (MSMA)] have limited the options for satisfactory control and maintenance of an acceptable (≤30% visual turfgrass injury) turfgrass quality. Currently available herbicides (e.g., topramezone and metribuzin) with goosegrass activity typically injure warm-season turfgrass species. The objectives of this research were to evaluate both ‘Tifway 419’ bermudagrass [Cynodon dactylon (L.) Pers. ×Cynodon transvaalensis Burtt-Davy] injury after treatment with POST herbicides, and to determine whether irrigating immediately after application reduces turfgrass injury. Treatments were control (± irrigation); topramezone (Pylex 2.8C; ± irrigation); carfentrazone + 2,4-D + dicamba + 2-(2-methyl-4-chlorophenoxy) propionic acid (MCPP) (Speedzone 2.2L; ± irrigation); carfentrazone + 2,4-D + dicamba + MCPP in combination with topramezone (± irrigation); metribuzin (Sencor 75DF; ± irrigation); mesotrione (Tenacity 4L; ± irrigation); simazine 4L (±irrigation); and mesotrione + simazine (± irrigation). Irrigated treatments were applied immediately with a hand hose precalibrated to apply 0.6 cm or 0.25 inch (≈6.3 L). Visual turfgrass injury for combined herbicide treatments for the irrigated plots was 6% 4 days after treatment (DAT), 12% 1 week after treatment (WAT), 17% 2 WAT, and 6% 4 WAT, whereas nonirrigated plots had turfgrass injury of 14% at 4 DAT, 31% 1 WAT, 35% 2 WAT, and 12% 4 WAT. Irrigated pots had normalized differences vegetative indices (NDVI) ratings of 0.769 at 4 DAT, 0.644 at 1 WAT, 0.612 at 2 WAT, and 0.621 at 4 WAT, whereas nonirrigated plots had the lowest (least green) turfgrass NDVI ratings of 0.734 at 4 DAT, 0.599 at 1 WAT, 0.528 at 2 WAT, and 0.596 at 4 WAT. These experiments suggest turfgrass injury could be alleviated by immediately incorporating herbicides through irrigation.

scholarly journals Sensitivity and Recovery of Grain Sorghum to Simulated Drift Rates of Glyphosate, Glufosinate, and Paraquat

Agriculture ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 70 ◽  
Author(s):  
Ralph Hale ◽  
Taghi Bararpour ◽  
Gurpreet Kaur ◽  
John Seale ◽  
Bhupinder Singh ◽  
...  
Keyword(s):  
Growth Stage ◽  
Leaf Growth ◽  
Flag Leaf ◽  
Grain Sorghum ◽  
Yield Reduction ◽  
Leaf Stage ◽  
Herbicide Treatments ◽  
Significant Yield ◽  
Glyphosate Drift ◽  
Herbicide Drift

A field experiment was conducted in 2017 and 2018 to evaluate the sensitivity and recovery of grain sorghum to the simulated drift of glufosinate, glyphosate, and paraquat at two application timings (V6 and flag leaf growth stage). Paraquat drift caused maximum injury to sorghum plants in both years, whereas the lowest injury was caused by glyphosate in 2017. Averaged over all herbicide treatments, injury to grain sorghum from the simulated herbicide drift was 5% greater when herbicides were applied at flag leaf stage, as compared to herbicide applications at the six-leaf stage in 2017. In 2018, injury from glyphosate drift was higher when applied at the six-leaf stage than at the flag leaf stage. Paraquat and glufosinate drift caused more injury when applied at flag leaf stage than at six-leaf stage at 14 days after application in 2018. About 21% to 29% of injury from the simulated drift of paraquat led to a 31% reduction in grain sorghum yield, as compared to a nontreated check in 2017. The simulated drift of glyphosate and glufosinate did not result in any significant yield reduction compared to the nontreated check in 2017, possibly due to the recovery of sorghum plants after herbicides’ drift application.

scholarly journals Integrated Control of Rhizoctonia Crown and Root Rot of Sugar Beet with Fungicides and Antagonistic Bacteria

Plant Disease ◽  
2001 ◽  
Vol 85 (7) ◽  
pp. 718-722 ◽  
Author(s):  
Sebastian Kiewnick ◽  
Barry J. Jacobsen ◽  
Andrea Braun-Kiewnick ◽  
Joyce L. A. Eckhoff ◽  
Jerry W. Bergman
Keyword(s):  
Sugar Beet ◽  
Root Rot ◽  
Integrated Control ◽  
The United States ◽  
Field Trials ◽  
Sugar Yield ◽  
Economic Losses ◽  
Yield Increase ◽  
Leaf Stage ◽  
Crown And Root Rot

Rhizoctonia crown and root rot, caused by the fungus Rhizoctonia solani AG 2-2, is one of the most damaging sugar beet diseases worldwide and causes significant economic losses in more than 25% of the sugar beet production area in the United States. We report on field trials in the years 1996 to 1999 testing both experimental fungicides and antagonistic Bacillus sp. for their potential to reduce disease severity and increase sugar yield in trials inoculated with R. solani AG 2-2. Fungicides were applied as in-furrow sprays at planting or as band sprays directed at the crown at the four-leaf stage, or four- plus eight-leaf stage, while bacteria were applied at the four-leaf stage only. The fungicides azoxystrobin and tebuconazole reduced crown and root rot disease by 50 to 90% over 3 years when used at rates of 76 to 304 g a.i./ha and 250 g a.i./ha, respectively. The disease index at harvest was reduced and the root and sugar yield increased with azoxystrobin compared with tebuconazole. The combination of azoxystrobin applied at 76 g a.i./ha and the Bacillus isolate MSU-127 resulted in best disease reduction and greatest root and sucrose yield increase.

Influence of 2,4-D, dicamba, and glyphosate on clethodim efficacy of volunteer glyphosate-resistant corn

2019 ◽  
Vol 34 (3) ◽  
pp. 394-401
Author(s):  
Nick T. Harre ◽  
Julie M. Young ◽  
Bryan G. Young
Keyword(s):  
Field Trials ◽  
Negligible Effect ◽  
Greenhouse Experiments

AbstractManagement of volunteer glyphosate-resistant (GR) corn may be problematic in soybean resistant to glyphosate and 2,4-D or dicamba, as auxinic herbicides often antagonize graminicide efficacy. Field and greenhouse trials were conducted using mixtures of 2,4-D or dicamba in combination with glyphosate and clethodim-A (formulated without an adjuvant) or clethodim-SM (adjuvant-inclusive formulation) to determine the effect on volunteer GR corn control. Neither auxinic herbicide reduced clethodim efficacy, regardless of clethodim rate or formulation in field trials. However, the addition of glyphosate to these mixtures at the 35 g ai ha−1 clethodim dose reduced control from clethodim-A and clethodim-SM by 62% to 75% and 27% to 47%, respectively. Increasing the clethodim dose to 105 g ha−1 or greater in combination with glyphosate and either auxinic herbicide generally restored clethodim efficacy (74% to 98% control); in one site-year, the addition of glyphosate plus dicamba to clethodim-A at 140 g ha−1 still reduced control by 34%. In greenhouse experiments, clethodim-A efficacy was reduced by 17% and 28% when applied with glyphosate plus 420 and 1,680 g ae ha−1 2,4-D, respectively, in the absence of crop oil concentrate (COC). Increasing the dose of dicamba in a similar mixture had a negligible effect. Irrespective of auxinic herbicide dose, the inclusion of COC to clethodim-A mixtures with glyphosate plus 2,4-D or dicamba resulted in ≥ 90% control. These results specify an enhanced risk of reduced clethodim efficacy on volunteer GR corn when glyphosate is added to mixtures containing 2,4-D or dicamba. To optimize control from these mixtures, clethodim should be applied at ≥ 105 g ha−1 and should include an activator adjuvant in the form of COC and/or an adjuvant-inclusive clethodim formulation. This recommendation contrasts with several labels of clethodim that do not require COC when applied with adjuvant-loaded glyphosate products.

Control of common cocklebur (Xanthium strumarium L.) in corn

2010 ◽  
Vol 90 (6) ◽  
pp. 933-938 ◽  
Author(s):  
N. Soltani ◽  
C. Shropshire ◽  
P.H. Sikkema
Keyword(s):  
Environmental Conditions ◽  
Dry Weight ◽  
Field Trials ◽  
Xanthium Strumarium ◽  
Corn Yield ◽  
Shoot Dry Weight ◽  
Herbicide Treatments ◽  
Excellent Control

Nine field trials (five with PRE and four with POST herbicides) were conducted in 2006 to 2009 on various Ontario farms with heavy common cocklebur infestations to determine the effectiveness of PRE and POST herbicides for the control of common cocklebur in corn. There was no commercially significant corn injury from the PRE herbicides evaluated. Saflufenacil, saflufenacil/dimethenamid-p, isoxaflutole + atrazine, mesotrione + atrazine and dicamba/atrazine, applied PRE provided 85, 85, 76, 73 and 67% control of common cocklebur in corn 8 wk after emergence (WAE), respectively. Common cocklebur shoot dry weight was reduced 84, 80, 79, 75 and 68% with saflufenacil/dimethenamid-p, isoxaflutole + atrazine, mesotrione + atrazine, saflufenacil and dicamba/atrazine, respectively. There was no effect on corn yield compared with the weedy control with the PRE herbicides evaluated. The application of 2,4-D/atrazine POST resulted in unacceptable injury (28%) in corn. Dicamba/atrazine, dicamba/diflufenzopyr, dicamba and mesotrione + atrazine provided up to 98, 95, 90 and 90% control of common cocklebur 8 wk after application (WAA), respectively. All POST herbicide treatments increased corn yield compared with the non-treated control. Saflufenacil and saflufenacil/dimethenamid-p applied PRE and dicamba, dicamba/diflufenzopyr, dicamba/atrazine or mesotrione + atrazine applied POST have potential to provide good to excellent control of common cocklebur in corn under Ontario environmental conditions.

Tolerance of 12 Sugarbeet Varieties to Applications ofs-Metolachlor and Dimethenamid-P

2008 ◽  
Vol 22 (4) ◽  
pp. 699-706 ◽  
Author(s):  
Scott L. Bollman ◽  
Christy L. Sprague
Keyword(s):  
Disease Resistance ◽  
Weed Control ◽  
Herbicide Tolerance ◽  
Field Trials ◽  
Sugar Yield ◽  
Varietal Differences ◽  
Leaf Stage ◽  
Variety Selection

Sugarbeet varieties vary in their response to herbicides.s-Metolachlor and dimethenamid-P were recently registered for use in sugarbeet. Field trials were conducted in Michigan in 2004, 2005, and 2006 to evaluate the response of 12 sugarbeet varieties tos-metolachlor and dimethenamid-P applied PRE and POST to two-leaf and four-leaf stage sugarbeet.s-Metolachlor and dimethenamid-P reduced sugarbeet density when rainfall occurred within 7 d of the PRE applications. Dimethenamid-P PRE caused the most injury across all varieties followed bys-metolachlor PRE. Applying dimethenamid-P POST to two-leaf sugarbeet injured plants more thans-metolachlor applied POST to two- and four-leaf stage sugarbeet. The least amount of sugarbeet injury from dimethenamid-P was from POST applications at the four-leaf stage. Sugarbeet varietal differences were most pronounced from PRE applications of both herbicides and from the POST two-leaf application of dimethenamid-P. Of the 12 sugarbeet varieties evaluated, Hilleshog 2771RZ and Beta 5833R were the most tolerant, whereas Hilleshog 7172RZ was typically the most sensitive variety to these herbicides. Growers will probably not choose varieties based on herbicide tolerance alone, but instead base variety selection on sugar yield and disease resistance. However, if a grower has chosen a particular variety, this information could assist in assessing the risk of usings-metolachlor or dimethenamid-P for weed control.

Tolerance of Kenaf to Selected Postemergence Herbicides

1992 ◽  
Vol 6 (1) ◽  
pp. 125-128 ◽  
Author(s):  
Mark E. Kurtz ◽  
Samuel W. Neill
Keyword(s):  
Field Trials ◽  
Postemergence Herbicides ◽  
Significant Injury ◽  
Cotyledonary Stage

In field trials conducted in 1989 and 1990, fifteen postemergence herbicides were tested for phytotoxicity to kenaf. Clethodim (110 g ai ha–1), fluazifop (220 g ai ha–1), quizalofop (70 g ai ha–1), and sethoxydim (210 g ai ha–1) were not phytotoxic to kenaf in the cotyledonary stage. MSMA (2.2 kg ha–1) was not phytotoxic to kenaf at the cotyledonary or 35-cm stage. All other herbicides applied postemergence to kenaf caused significant injury.

Sign in / Sign up

Export Citation Format

Share Document