Application Time of Day Influences Glyphosate Efficacy

2007 ◽  
Vol 21 (1) ◽  
pp. 7-13 ◽  
Author(s):  
Keith Mohr ◽  
Brent A. Sellers ◽  
Reid J. Smeda
Keyword(s):  
Weed Control ◽  
Field Trials ◽  
Time Of Day ◽  
Leaf Angle ◽  
Diurnal Changes ◽  
Leaf Movement ◽  
Application Time ◽  
Soybean Yield ◽  
Time Of Application ◽  
Greenhouse Study

Variability in glyphosate efficacy has been observed following late day field applications, but the influence of this “time-of-day effect” on weed control and soybean yield is unknown. Additionally, the basis for differences in weed control due to application time of day has not been fully elucidated. In field trials, broadleaf weed biomass was ≥5-fold greater when glyphosate was applied at 6:00 A.M. compared to 6:00 P.M. in three of four site–years. No consistent time-of-day effect was observed on treated grass weeds. Soybean yield was unaffected by treatments, and was similar to the weed-free control. In a greenhouse study, both barnyardgrass and velvetleaf biomass were as much as 25 to 80% greater when glyphosate was applied at 8:00 P.M. vs. 2:00 P.M. Examination of individual components of the time-of-day effect for velvetleaf indicated that leaf angle and time of application accounted for 82 and 18%, respectively, of the biomass change. This research suggests that diurnal changes in leaf movement of velvetleaf account for much of the time-of-day effect, with the remainder likely due to an unknown physiological component.

The Effect of Time of Day on the Activity of Postemergence Soybean Herbicides

2013 ◽  
Vol 27 (4) ◽  
pp. 690-695 ◽  
Author(s):  
Gregory J. Stopps ◽  
Robert E. Nurse ◽  
Peter H. Sikkema
Keyword(s):  
Weed Control ◽  
Yield Loss ◽  
Early Morning ◽  
Field Trials ◽  
Time Of Day ◽  
Weed Species ◽  
Time Of Application ◽  
Late Evening ◽  
Chlorimuron Ethyl ◽  
Herbicide Activity

The effect of time of day (TOD) on the activity of six common POST herbicides was investigated in field trials from 2007 to 2009 at two locations in southwestern Ontario. Percentage weed control was assessed following application of bentazon, chlorimuron-ethyl, fomesafen, glyphosate, imazethapyr, or quizalofop-p-ethyl applied at 3-h intervals from 6:00 A.M. to midnight, when weeds averaged 15 cm tall. The effect of time of day varied with weed species, but weed control was generally reduced when herbicides were applied at 6:00 A.M., 9:00 P.M., and midnight. Herbicide activity on velvetleaf was most frequently reduced, especially for chlorimuron-ethyl, glyphosate, and imazethapyr. Control of common ragweed with glyphosate and imazethapyr was also affected by the timing of application, and pigweed species only showed an effect with glyphosate. Variation in temperature, relative humidity, and dew presence/absence at different times of the day, as well as morphological/physiological characteristics such as weed size at time of application and diurnal leaf movement in response to light intensity, may account for the variation in weed control at different times of the day. Significant soybean yield loss was not observed in this study, but may occur if herbicide efficacy is severely reduced by application at inappropriate times of day. These results provide valuable information for growers, and suggest that POST herbicides are most effective when applied midday, rather than in the early morning or late evening.

scholarly journals FLUAZIFOP-P-BUTYL EFFICACY AS A FUNCTION OF APPLICATION TIME AND HERBICIDE DOSE

2017 ◽  
Vol 35 (0) ◽  
Author(s):  
L.F. CIESLIK ◽  
R.A. VIDAL ◽  
A.B. MACHADO ◽  
M.M. TREZZI
Keyword(s):  
Relative Humidity ◽  
Common Bean ◽  
Weed Control ◽  
Air Temperature ◽  
Field Experiments ◽  
Time Of Day ◽  
Leaf Angle ◽  
Herbicide Application ◽  
The Common ◽  
Bean Crop

ABSTRACT Grass weeds are common in summer crops and strongly decreases the grain yield of the common bean crop. The time of herbicide application influences the variability of environmental conditions and affects the product performance. The objectives of this work were to identify the time of fluazifop-p-butyl (fluazifop) application which gives best grass weed control in the common bean crop and to elucidate the environmental variables most important for the efficacy of this herbicide. Field experiments were conducted involving five application times (2 a.m., 6 a.m., 11 a.m., 4 p.m. and 9 p.m.) and five doses of fluazifop (80, 110, 140, 170 and 200 g ha-1), with additional no-herbicide control. At the time of the herbicide application it was determined the air temperature, relative humidity, the photosynthetically active radiation (PAR) and the leaf angle, whereas the weed control and the dry mass of the weed Urochloa plantaginea was assessed at 20 days after treatment (DAT). Efficacy on grass control with fluazifop was dependent on the herbicide dose and on the time of day that the product was applied. Spray at early morning hours (6 a.m.) showed better efficacy on weed control in relation to periods during warmer conditions of the day (11 a.m. and 4 p.m.). Nocturnal fluazifop application had better weed control when compared to herbicide sprayed in the afternoon. The air temperature, relative humidity and PAR were correlated to weed leaf angle, which correlated the most with fluazifop performance.

Time of Day Impacts Postemergence Weed Control in Corn

2009 ◽  
Vol 23 (3) ◽  
pp. 346-355 ◽  
Author(s):  
Christie L. Stewart ◽  
Robert E. Nurse ◽  
Peter H. Sikkema
Keyword(s):  
Light Intensity ◽  
Weed Control ◽  
Air Temperature ◽  
Ambient Air ◽  
Field Trials ◽  
Time Of Day ◽  
Weed Species ◽  
Application Timing ◽  
Reducing Costs ◽  
Species Specific

Field trials were conducted from 2005 to 2007 at two locations in southwestern Ontario to investigate how weed control in corn was affected by the time of day that herbicides were applied. Weed control following the application of six POST herbicides (atrazine, bromoxynil, dicamba/diflufenzopyr, glyphosate, glufosinate, and nicosulfuron) at 06:00, 09:00, 12:00, 15:00, 18:00, 21:00, and 24:00 h was assessed. For many weed species herbicide efficacy was reduced when applications were made at 06:00, 21:00, and 24:00 h. Velvetleaf was the most sensitive to the time of day effect, followed by common ragweed, common lambsquarters, and redroot pigweed. Annual grasses were not as sensitive to application timing; however, control of barnyardgrass and green foxtail was reduced in some environments at 06:00 h and after 21:00 h. Only in the most severe cases was the grain yield of corn reduced due to decreased weed control. Daily changes in air temperature, relative humidity, and light intensity that cause species-specific physiological changes may account for the variation in weed control throughout the day. The results of this research suggest that there is a strong species-specific influence of ambient air temperature, light intensity, and leaf orientation on the efficacy of POST herbicides. These results should aid growers in applying herbicides when they are most efficacious, thus reducing costs associated with reduced efficacy.

scholarly journals Response of Soil Applied Herbicides at Different Application Timings on The Weed Control Efficacy and Phytotoxicity to Rice In Dry-seeded Condition

2020 ◽  
Vol 22 (1) ◽  
pp. 15-25
Author(s):  
Sharif Ahmed ◽  
Akbar Hossain ◽  
Abu Abdullah Miajy ◽  
Tahir H Awan
Keyword(s):  
Weed Control ◽  
Rice Plant ◽  
Plant Density ◽  
Control Measure ◽  
Effective Control ◽  
Application Time ◽  
Control Efficacy ◽  
Time Of Application ◽  
Significant Difference ◽  
Weeds Control

Dry-seeded rice (DSR) is a labor and water saving emerging production system. The use of pre-emergence herbicides was found to be the most effective weeds control measure under the DSR system. Although several herbicides are now available in market, the selection of right herbicides with a time of application is crucial for effective control of weeds as well as to reduce the phyto toxicity of crops. A field study in a split-plot design with three replications was conducted  to evaluate the effect of application time of soil applied herbicides (viz., 3 times - before crop sowing, after crop sowing but before the first irrigation, and after sowing and first irrigation) and four weeding regimes (viz., weed free, partial-weedy, herbicide oxadiargyl 80 g ai ha-1, and pendimethalin 1000 g ai ha-1) on weed control efficacy, crop performance as well as phytotoxicity of applied herbicides under DSR system. Rice plant stand establishment was highly influenced by application time of herbicides and weeding regimes. Application of pendimethalin at 1000 g ai ha-1 significantly reduced the density of rice plant, more so as sowing was advanced. Compared with the non-treated (partial-weedy) treatment (190 to 195 rice plants m-2), pendimethalin application before sowing, after sowing but before irrigation, and after sowing and irrigation reduced rice plant density by 48, 25 and 12%, respectively. While no significant difference was observed on plant density due to the application of oxadiargyl 80 g ai ha-1, regardless of application time. In case of weed control efficacy for individual herbicides, pendimethalin effectively controlled weeds even spraying before sowing and irrigation; but comparatively less effective than spraying after irrigation. In controlling weeds, oxadiargyl was only effective when spraying after sowing and irrigation, but not before irrigation. Grain yield was significantly increased as the time of herbicide was delayed from before sowing (2.2-2.4 t ha-1), after sowing but before irrigation (2.5-2.6 t ha-1), and after sowing and irrigation (4.0-4.1 tha-1). The results suggest that pre-emergence herbicides should be applied after sowing and irrigation for controlling weeds effectively and also reduce crop toxicity under the DSR system. Bangladesh Agron. J. 2019, 22(1): 15-25

Time of Application Influences Translocation of Auxinic Herbicides in Palmer Amaranth (Amaranthus palmeri)

Weed Science ◽  
2017 ◽  
Vol 66 (1) ◽  
pp. 4-14 ◽  
Author(s):  
Christopher R. Johnston ◽  
Peter M. Eure ◽  
Timothy L. Grey ◽  
A. Stanley Culpepper ◽  
William K. Vencill
Keyword(s):  
Mechanism Of Action ◽  
Resistance Management ◽  
Time Of Day ◽  
Palmer Amaranth ◽  
Effective Control ◽  
Application Time ◽  
Time Of Application ◽  
Group 4 ◽  
Treated Leaf ◽  
Root Treatment

The efficacy of WSSA Group 4 herbicides has been reported to vary with dependence on the time of day the application is made, which may affect the value of this mechanism of action as a control option and resistance management tool for Palmer amaranth. The objectives of this research were to evaluate the effect of time of day for application on 2,4-D and dicamba translocation and whether or not altering translocation affected any existing variation in phytotoxicity seen across application time of day. Maximum translocation (Tmax) of [14C]2,4-D and [14C]dicamba out of the treated leaf was significantly increased 52% and 29% to 34% in one of two repeated experiments for each herbicide, respectively, with application at 7:00 AM compared with applications at 2:00 PM and/or 12:00 AM. Applications at 7:00 AM increased [14C]2,4-D distribution to roots and increased [14C]dicamba distribution above the treated leaf compared with other application timings. In phytotoxicity experiments, dicamba application at 8 h after exposure to darkness (HAED) resulted in significantly lower dry root biomass than dicamba application at 8 h after exposure to light (HAEL). Contrasts indicated that injury resulting from dicamba application at 8 HAEL, corresponding to midday, was significantly reduced with a root treatment of 5-[N-(3,4-dimethoxyphenylethyl)methylamino]-2-(3,4-dimethoxyphenyl)-2-isopropylvaleronitrile hydrochloride (verapamil) compared with injury observed with dicamba application and a root treatment of verapamil at 8 HAED, which corresponded to dawn. Overall, time of application appears to potentially influence translocation of 2,4-D and dicamba. Furthermore, inhibition of translocation appears to somewhat influence variation in phytotoxicity across times of application. Therefore, translocation may be involved in the varying efficacy of WSSA Group 4 herbicides due to application time of day, which has implications for the use of this mechanism of action for effective control and resistance management of Palmer amaranth.

Biologically effective dose of glyphosate as influenced by weed size in corn

2016 ◽  
Vol 96 (3) ◽  
pp. 455-460 ◽  
Author(s):  
Nader Soltani ◽  
Robert E. Nurse ◽  
Peter H. Sikkema
Keyword(s):  
Effective Dose ◽  
Weed Control ◽  
Field Trials ◽  
Biologically Effective Dose ◽  
Limited Information ◽  
Weed Species ◽  
Common Ragweed ◽  
Time Of Application ◽  
Green Foxtail ◽  
Lamb’S Quarters

There is limited information on the effect of weed size at the time of application on glyphosate efficacy in Ontario. Eleven field trials were conducted over a 3 yr period (2010–2012) in Ontario to determine the biologically effective dose of glyphosate applied postemergence (POST) in corn at doses of 112.5–1350 g acid equivalent (a.e.) ha−1 for the control of various grass and broadleaved weed species when the weeds were 10, 20 or 30 cm in height. The GR90 for redroot pigweed, common ragweed, common lamb’s-quarters, barnyardgrass, and green foxtail were 353, 630, 621, 763, and <112.5 g a.e. ha−1 when applied at 10 cm weed height, 235, 201, 906, 868, and 296 g a.e. ha−1 when applied at 20 cm weed height, and 792, >1350, >1350, 912, and 675 g a.e. ha−1 when applied at 30 cm weed height, respectively. Corn yields were maximized when glyphosate was applied to weeds that were up to 10 cm in height, but was reduced with later glyphosate application timings. The results of this study reinforce the importance of early POST weed control in corn.

Influence of Preplant Applications of 2,4-D, Dicamba, Tribenuron, and Tribenuron Plus Thifensulfuron on Peanut

2003 ◽  
Vol 30 (1) ◽  
pp. 18-22 ◽  
Author(s):  
E. P. Prostko ◽  
T. L. Grey ◽  
W. C. Johnson ◽  
D. L. Jordan ◽  
W. J. Grichar ◽  
...  
Keyword(s):  
North Carolina ◽  
Weed Control ◽  
Production Systems ◽  
Field Trials ◽  
Tillage Systems ◽  
Time Of Application ◽  
Conventional Production ◽  
Strip Tillage

Abstract Field trials were conducted in Georgia, North Carolina, and Texas to evaluate the effects of preplant applications of 2,4-D, dicamba, tribenuron, and tribenuron plus thifensulfuron on peanut yield. Herbicides were applied 30, 15, 7, or 0 d before planting (DBP) in conventional production systems in Georgia and Texas, and 28, 21, 14, 7, and 0 DBP in no- and strip-tillage systems in North Carolina. Amine and ester formulations of 2,4-D did not affect peanut yield at any time of application in any state. Dicamba reduced peanut yield when applied at 0 DBP in two of seven trials. Tribenuron did not affect peanut yield regardless of preplant interval. However, tribenuron plus thifensulfuron reduced yields when applied at 7 DBP in one of five trials. These data suggest that 2,4-D, tribenuron, and tribenuron plus thifensulfuron can be safely used for preplant weed control in peanut when applied 7 DBP. Dicamba should be applied a minimum of 15 DBP.

Evaluation of Weed Control and Crop Tolerance with Co-application of Glyphosate and Pyraflufen-ethyl in Glyphosate-resistant Soybean (Glycine Max)

2006 ◽  
Vol 20 (4) ◽  
pp. 1035-1039 ◽  
Author(s):  
Derek M. Scroggs ◽  
Donnie K. Miller ◽  
Paul R. Vidrine ◽  
Robert G. Downer
Keyword(s):  
Glycine Max ◽  
Weed Control ◽  
Reduction Potential ◽  
Control Program ◽  
Field Trials ◽  
Yield Reduction ◽  
Soybean Yield ◽  
Crop Tolerance ◽  
Affect Control ◽  
Pitted Morningglory

Field trials were conducted to evaluate weed control and soybean tolerance with co-application of pyraflufen-ethyl and glyphosate. Pyraflufen-ethyl applied at 11, 23, or 45 g ai/ha in combination with glyphosate did not affect control of barnyardgrass, browntop millet, redroot pigweed, sicklepod, or smellmelon compared to glyphosate alone or co-applied with chlorimuron. Initial benefit (7 DAT) to pitted morningglory control with pyraflufen-ethyl plus glyphosate compared to glyphosate alone or co-applied with chlorimuron was not observed 28 DAT. Hemp sesbania control was increased by pyraflufen-ethyl at 45 g/ha plus glyphosate and glyphosate plus chlorimuron relative to glyphosate applied alone. Pyraflufen-ethyl plus glyphosate resulted in significant visual soybean injury, and a reduction in soybean yield was observed with pyraflufen-ethyl at 45 g/ha relative to glyphosate applied alone or in combination with chlorimuron. Results from a weed-free study confirmed crop injury and yield reduction potential with pyraflufen-ethyl plus glyphosate. Overall results suggest no benefit with respect to weed control or crop tolerance to pyraflufen-ethyl inclusion in a glyphosate-resistant soybean weed control program over that observed with currently registered co-application of glyphosate and chlorimuron.

scholarly journals Optimising time of planting and herbicide aplication for control of problem weeds in maize

2007 ◽  
Vol 60 ◽  
pp. 183-188
Author(s):  
T.K. James ◽  
A. Rahman ◽  
M. Trolove
Keyword(s):  
Weed Control ◽  
Residual Activity ◽  
Good Control ◽  
Field Trials ◽  
Application Time ◽  
Annual Grass ◽  
Weed Species ◽  
Long Period ◽  
Preemergence Herbicides ◽  
Postemergence Herbicides

Field trials in Waikato Bay of Plenty and Manawatu investigated the efficacy of pre and postemergence herbicides for weed control in maize crops planted early mid or late season with prior cultivation or into a stale seedbed Achieving good control of broadleaf weeds was easier than for annual grass weeds Some weed species germinated over a long period from spring to summer months The residual activity of preemergence herbicides was not sufficient for seasonlong control of such weeds in the early and mid planted crops and a postemergence herbicide was essential to control them and to maintain grain yields When grass weeds were dominant the pre and postemergence combination still did not provide season long control in the early plantings In late planted crops weed control was also poor in the absence of a postemergence herbicide even though few weeds were present at the postemergence application time The weed seedbank was reduced where good weed control was achieved

scholarly journals Seaside Petunia Susceptibility to Herbicides Used in Dry Bulb Onion

2021 ◽  
pp. 1-9
Author(s):  
Brian J. Schutte ◽  
Abdur Rashid ◽  
Israel Marquez ◽  
Erik A. Lehnhoff ◽  
Leslie L. Beck
Keyword(s):  
United States ◽  
Weed Control ◽  
Plant Species ◽  
Seedling Emergence ◽  
Plant Size ◽  
Field Trials ◽  
Stem Length ◽  
Greenhouse Study ◽  
Chamber Study ◽  
Herbicide Programs

Seaside petunia (Calibrachoa parviflora) is a mat-forming plant species that was recently reported in fall-seeded onion (Allium cepa) in the southwestern United States. To initiate development of herbicide recommendations for seaside petunia in onion, we conducted a study to determine seaside petunia susceptibility to commonly used herbicides for broadleaf weed control after onion emergence. Our study included herbicides applied at below-label rates, which provided insights on seaside petunia responses to reductions in the amount of herbicide available for plant absorption. For herbicides with preemergence activity, our growth chamber study indicated that soil applications of flumioxazin or oxyfluorfen (0.06 and 0.25 lb/acre, respectively) prevented seaside petunia seedling emergence when applied at 0.125×, 0.25×, 0.5×, and 1.0× the labeled rates for onion. Labeled rate treatments of dimethenamid-P (0.84 lb/acre) and S-metolachlor (0.64 lb/acre) inhibited seedling emergence similar to labeled rate treatments of flumioxazin and oxyfluorfen; however, below-label rate treatments of dimethenamid-P and S-metolachlor resulted in diminished control of seaside petunia compared with the labeled rate treatments. Following labeled rate applications of dimethyl tetrachloroterephthalate [DCPA (6 lb/acre)] and pendimethalin (0.71 lb/acre), more than 50% of seaside petunia seedlings emerged compared with the nontreated control. For herbicides with postemergence activity on weeds, our greenhouse study indicated that bromoxynil at 0.37 lb/acre, flumioxazin at 0.06 lb/acre, and oxyfluorfen at 0.25 lb/acre equally reduced growth of seaside petunia plants that were small at the time of spraying (stem length, 1–2 cm). Postemergence control of seaside petunia with oxyfluorfen and flumioxazin decreased as plant size at spraying increased; however, bromoxynil effects on seaside petunia remained high as stem length at spraying increased from 5 to 12 cm. Based on the results of this study, we conclude that promising herbicide programs for seaside petunia in onion include oxyfluorfen or flumioxazin for preemergence control and bromoxynil for postemergence control. These herbicides, alone and in combination, should be evaluated for seaside petunia control and onion phytotoxicity in future field trials.

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