Influence of Application Timing on the Efficacy of Reduced Rate Postemergence Herbicides for Wild Oat (Avena fatua) Control in Spring Barley (Hordeum vulgare)

1997 ◽  
Vol 11 (2) ◽  
pp. 283-289 ◽  
Author(s):  
Robert N. Stougaard ◽  
Bruce D. Maxwell ◽  
Jerry D. Harris
Keyword(s):  
Growth Stage ◽  
Field Experiments ◽  
Spring Barley ◽  
Avena Fatua ◽  
Wild Oat ◽  
Minimal Effect ◽  
Application Timing ◽  
Environmental Considerations ◽  
Reduced Rate ◽  
Postemergence Herbicides

Field experiments were conducted during 1992 and 1993 at Kalispell and Moccasin, MT, to determine the influence of application timing on the efficacy of reduced rate postemergence applications of imazamethabenz and diclofop in spring barley. Herbicides were applied at their respective 1 × and ½ × use rates at either 1, 2, or 3 weeks after crop emergence (WAE). While excellent wild oat control was sometimes achieved with reduced rates, there was no consistent relationship between wild oat growth stage and the level of control at either site regardless of the herbicide or rate applied. This response suggests that efficacy is governed not only by wild oat growth stage, but also by weed demographics and environmental considerations. Barley yield and adjusted gross return values were highest at Kalispell when imazamethabenz treatments were applied at 1 WAE, regardless of the level of wild oat control. Adjusted gross return values were similar for the 1 × and ½ × imazamethabenz treatments. Yields and adjusted gross returns with diclofop treatments were more related to the level of wild oat control at Kalispell, with the 1 × diclofop treatments providing the greatest yields and adjusted gross return values. The level of wild oat control at Moccasin had minimal effect on barley yield and adjusted gross returns, with both values being comparable to the nontreated check.

Effect of imazamethabenz on green foxtail, tartary buckwheat and wild oat at different growth stages

1991 ◽  
Vol 71 (3) ◽  
pp. 821-829 ◽  
Author(s):  
K. N. Harker ◽  
P. A. O'Sullivan
Keyword(s):  
Growth Stage ◽  
Field Experiments ◽  
Avena Fatua ◽  
Tartary Buckwheat ◽  
Growth Stages ◽  
Research Station ◽  
Regression Equations ◽  
Wild Oat ◽  
Setaria Viridis ◽  
Green Foxtail

Field experiments were conducted at the Lacombe Research Station to determine the influence of growth stage on the control of wild oat (Avena fatua L.) and Tartary buckwheat (Fagopyrum tartaricum (L.) Gaertn.) with imazamethabenz in wheat (Triticum aestivum L.). In greenhouse experiments, the effct of imazamethabenz on canola (Brassica campestris L.) or green foxtail (Setaria viridis L. Beauv.) at two growth stages was also studied. Canola and wild oat were highly susceptible, Tartary buckwheat was somewhat less susceptible, and green foxtail was rather tolerant to imazamethabenz. Imazamethabenz was much more effective on early growth stages of wild oat (2 leaf) and Tartary buckwheat (1–2 leaf), whereas the control of canola and the suppression of green foxtail was much less dependent on growth stage. Linear regression equations were developed to describe the response of the above species to the imazamethabenz treatments. Key words: AC 222, 293; phenology; regression; Setaria viridis; Fagopyrum tartaricum; Avena fatua

Integrating Reduced Rates of Postemergence Herbicides and Cultivation for Broadleaf Weed Control in Soybeans (Glycine max)

Weed Science ◽  
1990 ◽  
Vol 38 (6) ◽  
pp. 541-545 ◽  
Author(s):  
Lawrence E. Steckel ◽  
Michael S. Defelice ◽  
Barry D. Sims
Keyword(s):  
Glycine Max ◽  
Weed Control ◽  
Seed Production ◽  
Field Experiments ◽  
Soybean Yield ◽  
Application Timing ◽  
Late Season ◽  
Full Rate ◽  
Reduced Rate ◽  
Postemergence Herbicides

The interaction of reduced rates of bentazon, chlorimuron, imazaquin, and imazethapyr with cultivation for broadleaf weed control in soybeans was investigated in field experiments conducted at three sites in Missouri in 1987 and 1988. Single reduced-rate herbicide applications provided soybean yields equal to full rates although visual weed control was slightly lower. Sequential applications of all four herbicides at reduced rates provided weed control and soybean yields equal to full-rate applications. The number of velvetleaf plants m−2and seeds plant−1were not influenced by herbicide, herbicide rate, or application timing. Cultivation improved weed control and soybean yield and decreased late-season weed populations and seed production.

Factors of Wild Oat (Avena fatua) Interference on Spring Barley (Hordeum vulgare) Growth and Yield

Weed Science ◽  
1988 ◽  
Vol 36 (1) ◽  
pp. 37-42 ◽  
Author(s):  
Don W. Morishita ◽  
Donald C. Thill
Keyword(s):  
Hordeum Vulgare ◽  
Grain Yield ◽  
Field Experiments ◽  
Plant Density ◽  
Spring Barley ◽  
Avena Fatua ◽  
Growth And Yield ◽  
Critical Duration ◽  
Wild Oat ◽  
Boot Stage

Field experiments were conducted in 1983 and 1984 to measure the interference of wild oat (Avena fatuaL. # AVEFA) removed at various stages of development (two to three leaves, two to three tillers, two nodes, and heading), plus treatments with wild oat not removed, and wild oat-free stands on the growth and yield of spring barley (Hordeum vulgareL. ‘Advance’). The final plant density of barley and wild oat was 160 and 170 plants/m2, respectively. Based on aboveground barley biomass and yield, the critical duration of wild oat interference began about the two-node stage and continued until maturity of the barley. Wild oat interference reduced barley biomass, the number of tiller heads/plant, tiller heads/unit area, and tiller grain yield, but not the number or grain yield of the main-stem heads. Wild oat did not affect the soil matric potential or the barley total plant and soil nitrogen contents. However, wild oat did reduce total water and turgor potential in barley at the boot stage of growth, which may have affected tiller head formation.

Carrier Volume Adjustments Improve Imazamethabenz Efficacy

1999 ◽  
Vol 13 (2) ◽  
pp. 227-232 ◽  
Author(s):  
Robert N. Stougaard
Keyword(s):  
Growth Stage ◽  
Field Experiments ◽  
Wild Oat ◽  
Reduced Rate ◽  
Carrier Volume ◽  
Positive Effect

Reduced-rate herbicide strategies, which rely on treatment of small weed seedlings, are not effective under all situations. The consistency of reduced-rate treatments may be improved by adjustments in application variables. Field experiments were conducted at Kalispell, MT, during 1994 and 1995 to determine the effects of carrier volume on the efficacy of reduced-rate imazamethabenz applications for wild oat control in barley. Imazamethabenz was applied to two- and four-leaf wild oat plants at 0.26 and 0.52 kg ai/ha in carrier volumes of 75, 150, and 225 L/ha. Wild oat control generally increased as carrier volume increased, regardless of imazamethabenz rate or wild oat growth stage. However, increasing carrier volumes had a greater positive effect on wild oat control when imazamethabenz was applied to two-leaf vs. four-leaf wild oat seedlings. Barley yield was most affected by the duration of wild oat interference, with the greatest yield being observed with the earliest application. Barley yield tended to increase as carrier volume increased in 1 of 2 yr. These results indicate that wild oat control with imazamethabenz can be enhanced by increasing carrier volume, providing more consistent wild oat control from reduced imazamethabenz rates.

WILD OAT INTERFERENCE IN SUNFLOWER

1985 ◽  
Vol 65 (1) ◽  
pp. 219-222 ◽  
Author(s):  
W. O. CHUBB ◽  
G. H. FRIESEN
Keyword(s):  
Helianthus Annuus ◽  
Seed Yield ◽  
Critical Period ◽  
Oil Content ◽  
Field Experiments ◽  
Avena Fatua ◽  
Wild Oat ◽  
Helianthus Annuus L ◽  
Wild Oats ◽  
Postemergence Herbicides

In field experiments, sunflower (Helianthus annuus L. ’Hybrid 894’) recovered from initial effects of wild oat (Avena fatua L.) interference and yielded normally if the weed was removed within 4 wk after crop emergence and the crop was kept relatively free of wild oats thereafter until harvest. In widely spaced plantings, wild oats growing between-the-rows competed just as vigorously as in-the-row infestations. Selective postemergence herbicides did not always provide sufficient control of wild oats to prevent significant losses in sunflower yield.Key words: Competition, interference, seed yield, oil content, herbicides, critical period

Integrated Wild Oat (Avena fatua) Management Affects Spring Barley (Hordeum vulgare) Yield and Economics

1992 ◽  
Vol 6 (1) ◽  
pp. 129-135 ◽  
Author(s):  
David L. Barton ◽  
Donald C. Thill ◽  
Bahman Shafii
Keyword(s):  
Grain Yield ◽  
Field Experiments ◽  
Control Strategies ◽  
Integrated Control ◽  
Spring Barley ◽  
Barley Grain ◽  
Row Spacing ◽  
Wild Oat ◽  
Seeding Rate ◽  
Net Return

The effect of barley seeding rate and row spacing, and triallate, diclofop, and difenzoquat herbicide rate on barley grain yield and quality, and wild oat control were evaluated in field experiments near Bonners Ferry, Idaho, in 1989 and 1990. The purpose of the study was to develop integrated control strategies for wild oat in spring barley. Barley row spacing (9 and 18 cm) did not affect barley grain yield. Barley grain yield was greatest when barley was seeded at 134 or 201 kg ha–1compared to 67 kg ha–1. Wild oat control increased as wild oat herbicide rate increased and barley grain yield was greatest when wild oat herbicides were applied. However, barley grain yield was similar when wild oat biomass was reduced by either 65 or 85% by applications of half and full herbicide rates, respectively. Net return was greatest when the half rate of herbicide was applied to 100 wild oat plants per m2and was greatest when half or full herbicide rates were applied to 290 wild oat plants per m2. Net return increased when the seeding rate was increased to 134 or 201 kg ha–1when no herbicide was applied and when 290 wild oat plants per m2were present.

Effects of Herbicide Application Timing on Johnsongrass (Sorghum halepense) and Pitted Morningglory (Ipomoea lacunosa) Control

1990 ◽  
Vol 4 (4) ◽  
pp. 900-903 ◽  
Author(s):  
David R. Shaw ◽  
Sunil Ratnayake ◽  
Clyde A. Smith
Keyword(s):  
Growth Stage ◽  
Field Experiments ◽  
Sorghum Halepense ◽  
Herbicide Application ◽  
Ipomoea Lacunosa ◽  
Application Timing ◽  
Final Treatment ◽  
Pitted Morningglory

Field experiments were conducted to evaluate the influence of application timing of imazethapyr and fluazifop-P on rhizome johnsongrass and pitted morningglory control in soybean. Herbicides were applied at three timings keyed to johnsongrass heights of 15, 30, and 60 cm and 3-, 6-, and 9-leaf pitted morningglory. Evaluations 6 wk after the final treatment indicated imazethapyr controlled both species best when applied at the 15-cm johnsongrass growth stage. Increasing imazethapyr rate did not increase control of pitted morningglory, but did increase johnsongrass control at the 15-cm application timing. However, at the 30-cm johnsongrass application timing, increasing the rate from 0.07 to 0.10 kg ha-1improved control of both species. Johnsongrass control with imazethapyr was no more than 64% when applications were delayed to 30-cm or larger johnsongrass. Fluazifop-P controlled johnsongrass well at all timings.

Wild Oat (Avena fatua) Control in Spring Wheat (Triticum aestivum) and Barley (Hordeum vulgare) with Reduced Rates of Postemergence Herbicides

1997 ◽  
Vol 11 (3) ◽  
pp. 591-597 ◽  
Author(s):  
Eric Spandl ◽  
Beverly R. Durgan ◽  
Douglas W. Miller
Keyword(s):  
Triticum Aestivum ◽  
Hordeum Vulgare ◽  
Spring Wheat ◽  
Avena Fatua ◽  
Wild Oat ◽  
Economic Return ◽  
Grain Yields ◽  
Oat Biomass ◽  
Postemergence Herbicides

Rates and application timings of postemergence herbicides for wild oat control in spring wheat and barley were evaluated at Crookston, MN, from 1994 to 1996. Diclofop, imazamethabenz, and fenoxaprop plus MCPA plus thifensulfuron plus tribenuron were applied to one- to three-leaf wild oat; and difenzoquat, imazamethabenz, fenoxaprop plus MCPA plus thifensulfuron plus tribenuron, and fenoxaprop plus 2,4-D plus MCPA were applied to four- to five-leaf wild oat at 1/2 ×, 3/4 ×, and 1 × rates. Wild oat response to herbicide rate and timing was similar in wheat and barley. Wild oat control with 1/2 × rates generally was less than that with 3/4 × rates, which was lower than or similar to that with 1 × rates. Wild oat biomass was often reduced less with 1/2 × rates than 1 × rates. However, reducing herbicide rates generally did not influence grain yields or net economic return. Grain yields and net economic return were generally greater in herbicide-treated plots than in the nontreated control.

Effect of Application Factors on Efficacy of Fluazifop-P-Butyl in Flax

1991 ◽  
Vol 5 (3) ◽  
pp. 504-508 ◽  
Author(s):  
George H. Friesen ◽  
David A. Wall
Keyword(s):  
Growth Stage ◽  
Field Experiments ◽  
Time Of Day ◽  
Wild Oat ◽  
Spray Nozzle ◽  
Green Foxtail ◽  
Drought Conditions ◽  
Orientation Time ◽  
Moisture Conditions ◽  
Nozzle Orientation

Field experiments were conducted to determine the efficacy of fluazifop-P-butyl for the control of green foxtail, wild oat, barley, and wheat in flax as influenced by spray nozzle orientation, time of day, and growth stage. Under drought conditions in 1988, control of wild oat, wheat, and barley with fluazifop-P-butyl was enhanced 75%, 53% and 78%, respectively, when nozzles were oriented to spray forward 45°. Under adequate soil moisture conditions enhancement of control was minimal. Green foxtail control improved when fluazifop-P-butyl was applied from 1700 to 2100 h, but time of day had no effect on control of wild oat, barley, or wheat. Fluazifop-P-butyl effectiveness was reduced when applied 4 d after flax emergence due to late emerging grass seedlings. Green foxtail was the most tolerant to fluazifop-P-butyl, whereas wild oat, wheat, and barley were the most susceptible.

Wild Oat (Avena fatua L.) Control With Reduced Rates Of Postemergence Herbicides

2007 ◽  
Vol 6 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Krishona B. Martinson ◽  
Beverly R. Durgan ◽  
Jochum J. Wiersma
Keyword(s):  
Avena Fatua ◽  
Wild Oat ◽  
Postemergence Herbicides
Sign in / Sign up

Export Citation Format

Share Document